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What is wrong with my XSLT for the XML File?

- by atrueguy

Actually my XML file has SVG info, and my Project lead wants me to develop an XSLT for the XMl file to convert it in to a PDF file. But when I try to do so I am failing to convert the XML file to PDF, can anyone help me out in this....... My Sample XML file <?xml version="1.0" encoding="ISO-8859-1"?>   <svg width="100%" height="100%" viewBox="0 0 214.819 278.002"> <g id="Standard_x0020_layer"/> <g id="Catalog"> <line stroke-width="0.353" stroke-linecap="butt" x1="5.839" y1="262.185" x2="209.039" y2="262.185"/> <text transform="matrix(0.984 0 0 0.93 183.515 265.271)" stroke="none" fill="#000000" font-family="'Helvetica'" font-size="3.174">© 2009 k Co.</text> <text transform="matrix(0.994 0 0 0.93 7.235 265.3)" stroke="none" fill="#000000" font-family="'Helvetica'" font-size="3.174">087156-8-</text> <text transform="matrix(0.995 0 0 0.93 21.708 265.357)" stroke="none" fill="#000000" font-family="'Helvetica'" font-size="3.174" font-weight="bold">AB</text> <text x="103.292" y="265.298" stroke="none" fill="#000000" font-family="'Helvetica'" font-size="3.174">P. 1/1</text> <g id="IC_TextBlock.1"> <g> <text transform="matrix(0.994 0 0 0.93 192.812 8.076)" stroke="none" fill="#000000" font-family="'Helvetica'" font-size="4.586" font-weight="bold">Fittings</text> <text transform="matrix(0.994 0 0 0.93 188.492 13.323)" stroke="none" fill="#000000" font-family="'Helvetica'" font-size="4.586" font-weight="bold">Raccords</text> <text transform="matrix(0.994 0 0 0.93 183.431 18.571)" stroke="none" fill="#000000" font-family="'Helvetica'" font-size="4.586" font-weight="bold">Conexiones</text> </g> </g> <g> <path stroke="none" fill="#000000" d="M26.507 12.628L26.507 4.977 28.599 4.977 28.599 10.673 30.946 10.673 30.946 12.628 26.507 12.628z"/> <path stroke="none" fill="#000000" d="M19.693 12.628L19.693 4.977 21.785 4.977 21.785 7.66 23.893 7.66 23.893 4.977 25.986 4.977 25.986 12.628 23.893 12.628 23.893 9.782 21.785 9.782 21.785 12.628 19.693 12.628z"/> <path stroke="none" fill="#000000" d="M12.587 4.977L9.566 8.621 13.019 12.631 10.25 12.63 7.905 9.9 7.9 9.9 7.9 12.628 5.81 12.628 5.81 4.977 7.9 4.977 7.9 7.267 7.884 7.27 9.875 4.977 12.587 4.977z"/> <path stroke="none" fill="#000000" d="M11.455 8.739C11.455 6.538 13.221 4.753 15.4 4.753L15.4 6.775C14.419 6.775 13.625 7.653 13.625 8.737 13.625 9.821 14.419 10.699 15.4 10.699 16.382 10.699 17.176 9.821 17.176 8.737 17.176 7.653 16.382 6.775 15.4 6.775L15.4 4.753C17.579 4.753 19.346 6.538 19.346 8.739 19.346 10.941 17.579 12.724 15.4 12.724 13.221 12.724 11.455 10.941 11.455 8.739z"/> <path stroke="none" fill="#000000" d="M33.472 4.977L35.621 4.977 35.621 6.74 33.521 6.743 33.515 7.952 35.454 7.952 35.454 9.664 33.518 9.664 33.518 10.833 35.64 10.833 35.64 12.628 33.491 12.628 31.376 12.628 31.376 4.977 33.472 4.977z"/> <path stroke="none" fill="#000000" d="M39.97 9.57L42.146 12.631 39.862 12.628 38.156 10.279 38.156 12.622 36.107 12.622 36.107 4.974 38.728 4.974 38.741 6.75 38.149 6.75 38.149 8.221 38.741 8.223C39.149 8.223 39.478 7.894 39.478 7.487 39.478 7.08 39.149 6.75 38.741 6.75L38.728 4.974C41.036 4.974 42.5 7.867 39.97 9.57z"/> <path stroke="none" fill="#000000" d="M42.415 12.205C42.415 11.82 42.72 11.512 43.106 11.512 43.49 11.512 43.796 11.82 43.796 12.205 43.796 12.586 43.49 12.894 43.106 12.894L43.106 12.73C43.402 12.73 43.631 12.51 43.631 12.205 43.631 11.894 43.402 11.676 43.106 11.676L43.179 11.837C43.344 11.837 43.457 11.868 43.457 12.057 43.457 12.189 43.39 12.243 43.262 12.252L43.436 12.554 43.262 12.554 43.103 12.252 42.99 12.252 42.99 12.143 43.182 12.143C43.262 12.143 43.308 12.127 43.308 12.035 43.308 11.962 43.216 11.962 43.146 11.962L42.99 11.962 42.99 12.143 42.99 12.252 42.99 12.554 42.832 12.554 42.832 11.837 43.179 11.837 43.106 11.676C42.804 11.676 42.579 11.894 42.579 12.205 42.579 12.51 42.804 12.73 43.106 12.73L43.106 12.894C42.72 12.894 42.415 12.586 42.415 12.205z"/> <g> <path stroke="none" fill="#000000" d="M8.837 17.466L8.599 17.466 8.554 16.832 8.544 16.832C8.31 17.329 7.843 17.539 7.339 17.539 6.243 17.539 5.697 16.675 5.697 15.724 5.697 14.774 6.243 13.91 7.339 13.91 8.071 13.91 8.666 14.305 8.794 15.067L8.461 15.067C8.417 14.666 8.003 14.194 7.339 14.194 6.418 14.194 6.027 14.964 6.027 15.724 6.027 16.486 6.418 17.257 7.339 17.257 8.111 17.257 8.56 16.716 8.544 15.978L7.36 15.978 7.36 15.695 8.837 15.695 8.837 17.466z"/> <path stroke="none" fill="#000000" d="M9.477 13.984L11.881 13.984 11.881 14.266 9.807 14.266 9.807 15.525 11.749 15.525 11.749 15.807 9.807 15.807 9.807 17.182 11.906 17.182 11.906 17.466 9.477 17.466 9.477 13.984z"/> <path stroke="none" fill="#000000" d="M12.364 13.984L12.734 13.984 14.763 16.929 14.772 16.929 14.772 13.984 15.105 13.984 15.105 17.466 14.734 17.466 12.705 14.521 12.695 14.521 12.695 17.466 12.364 17.466 12.364 13.984z"/> <path stroke="none" fill="#000000" d="M15.768 13.984L16.1 13.984 16.1 16.14C16.094 16.949 16.48 17.257 17.118 17.257 17.763 17.257 18.147 16.949 18.143 16.14L18.143 13.984 18.475 13.984 18.475 16.213C18.475 16.929 18.089 17.539 17.118 17.539 16.153 17.539 15.768 16.929 15.768 16.213L15.768 13.984z"/> <path stroke="none" fill="#000000" d="M19.167 13.984L19.498 13.984 19.498 17.466 19.167 17.466 19.167 13.984z"/> <path stroke="none" fill="#000000" d="M20.221 13.984L20.591 13.984 22.62 16.929 22.629 16.929 22.629 13.984 22.961 13.984 22.961 17.466 22.591 17.466 20.562 14.521 20.553 14.521 20.553 17.466 20.221 17.466 20.221 13.984z"/> <path stroke="none" fill="#000000" d="M23.658 13.984L26.064 13.984 26.064 14.266 23.99 14.266 23.99 15.525 25.931 15.525 25.931 15.807 23.99 15.807 23.99 17.182 26.088 17.182 26.088 17.466 23.658 17.466 23.658 13.984z"/> <path stroke="none" fill="#000000" d="M27.908 13.984L29.452 13.984C30.077 13.984 30.487 14.349 30.487 14.978 30.487 15.608 30.077 15.974 29.452 15.974L28.239 15.974 28.239 15.691 29.379 15.691C29.838 15.691 30.155 15.457 30.155 14.978 30.155 14.5 29.838 14.266 29.379 14.266L28.239 14.266 28.239 15.691 28.239 15.974 28.239 17.466 27.908 17.466 27.908 13.984z"/> <path stroke="none" fill="#000000" d="M31.643 13.984L32.014 13.984 33.38 17.466 33.024 17.466 32.598 16.384 31.013 16.384 31.117 16.1 32.487 16.1 31.814 14.314 31.117 16.1 31.013 16.384 30.594 17.466 30.239 17.466 31.643 13.984z"/> <path stroke="none" fill="#000000" d="M33.695 13.984L35.292 13.984C35.866 13.984 36.35 14.262 36.35 14.891 36.35 15.33 36.121 15.691 35.671 15.778L35.671 15.788C36.125 15.846 36.256 16.16 36.28 16.574 36.296 16.812 36.296 17.291 36.442 17.466L36.076 17.466C35.993 17.329 35.993 17.071 35.984 16.925 35.954 16.437 35.915 15.896 35.286 15.919L34.029 15.919 34.029 15.637 35.267 15.637C35.671 15.637 36.018 15.384 36.018 14.96 36.018 14.535 35.765 14.266 35.267 14.266L34.029 14.266 34.029 15.637 34.029 15.919 34.029 17.466 33.695 17.466 33.695 13.984z"/> <path stroke="none" fill="#000000" d="M36.603 13.984L39.363 13.984 39.363 14.266 38.149 14.266 38.149 17.466 37.817 17.466 37.817 14.266 36.603 14.266 36.603 13.984z"/> <path stroke="none" fill="#000000" d="M39.847 16.32C39.832 17.038 40.348 17.257 40.982 17.257 41.348 17.257 41.905 17.056 41.905 16.548 41.905 16.155 41.509 15.997 41.188 15.919L40.411 15.73C40.003 15.628 39.627 15.432 39.627 14.891 39.627 14.55 39.847 13.91 40.826 13.91 41.515 13.91 42.118 14.281 42.115 14.993L41.783 14.993C41.762 14.461 41.325 14.194 40.832 14.194 40.378 14.194 39.959 14.368 39.959 14.885 39.959 15.212 40.203 15.349 40.485 15.417L41.335 15.628C41.826 15.759 42.237 15.974 42.237 16.545 42.237 16.783 42.139 17.539 40.905 17.539 40.081 17.539 39.475 17.169 39.515 16.32L39.847 16.32z"/> </g> </g> </g> </svg> My Sample XSLT File <?xml version="1.0" encoding="ISO-8859-1"?> <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:svg="http://www.w3.org/2000/svg"> <xsl:template match="/"> <fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"> <fo:layout-master-set> <fo:simple-page-master master-name="simple" page-height="11in" page-width="8.5in"> <fo:region-body margin="0.7in" margin-top="1.15in" margin-left=".8in"/> <fo:region-before extent="1.5in"/> <fo:region-after extent="1.5in"/> <fo:region-start extent="1.5in"/> <fo:region-end extent="1.5in"/> </fo:simple-page-master> </fo:layout-master-set> <fo:page-sequence master-reference="simple"> <fo:flow flow-name="xsl-region-body"> <fo:block> <fo:instream-foreign-object xmlns:svg="http://www.w3.org/2000/svg"> <svg:svg height="100%" width="100%" viewBox="0 0 214.819 278.002"> <xsl:for-each select="svg/g/path"> <svg:g style="stroke:none;fill:#000000;stroke:black;"> <svg:path> <xsl:variable name="s"> <xsl:value-of select="translate(@d,' ','')"/> </xsl:variable> <xsl:attribute name="d"><xsl:value-of select="translate($s,',',' ')"/></xsl:attribute> </svg:path> </svg:g> </xsl:for-each> <xsl:for-each select="svg/g/text()"> <xsl:value-of select="."/> </xsl:for-each> <xsl:for-each select="svg/g/g/path"> <svg:g style="stroke:none;fill:#000000;stroke:black;"> <svg:path> <xsl:variable name="s"> <xsl:value-of select="translate(@d,' ','')"/> </xsl:variable> <xsl:attribute name="d"><xsl:value-of select="translate($s,',',' ')"/></xsl:attribute> </svg:path> </svg:g> </xsl:for-each> <xsl:for-each select="svg/g/g/g/path"> <svg:g style="stroke:none;fill:#000000;"> <svg:path> <xsl:variable name="s1"> <xsl:value-of select="translate(@d,' ','')"/> </xsl:variable> <xsl:attribute name="d"><xsl:value-of select="translate($s1,',',' ')"/></xsl:attribute> </svg:path> </svg:g> </xsl:for-each> <xsl:for-each select="svg/g/line"> <svg:g style="stroke-linecap:butt;"> <xsl:variable name="x1"> <xsl:value-of select="@x1"/> </xsl:variable> <xsl:variable name="y1"> <xsl:value-of select="@y1"/> </xsl:variable> <xsl:variable name="x2"> <xsl:value-of select="@x2"/> </xsl:variable> <xsl:variable name="y2"> <xsl:value-of select="@y2"/> </xsl:variable> <xsl:variable name="stroke-width"> <xsl:value-of select="@stroke-width"/> </xsl:variable> <svg:line x1="$x1" y1="$y1" x2="$x2" y2="$y2" stroke-width="$stroke-width" stroke="black" /> </svg:g> </xsl:for-each> </svg:svg> </fo:instream-foreign-object> </fo:block> </fo:flow> </fo:page-sequence> </fo:root> </xsl:template> </xsl:stylesheet> My Question I have developed the XSLT file for the XML, and I need to produce a pdf output after processing the xslt file. but I am not able to get the xml data in to my pdf. Please ask me if the information what I have provided is not sufficient, as I am bit new to Stackoverflow...

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Sampler referencing in HLSL - Sampler parameter must come from a literal expression

- by user1423893

The following method works fine when referencing a sampler in HLSL float3 P = lightScreenPos; sampler ShadowSampler = DPFrontShadowSampler; float depth; if (alpha >= 0.5f) { // Reference the correct sampler ShadowSampler = DPFrontShadowSampler; // Front hemisphere 'P0' P.z = P.z + 1.0; P.x = P.x / P.z; P.y = P.y / P.z; P.z = lightLength / LightAttenuation.z; // Rescale viewport to be [0, 1] (texture coordinate space) P.x = 0.5f * P.x + 0.5f; P.y = -0.5f * P.y + 0.5f; depth = tex2D(ShadowSampler, P.xy).x; depth = 1.0 - depth; } else { // Reference the correct sampler ShadowSampler = DPBackShadowSampler; // Back hemisphere 'P1' P.z = 1.0 - P.z; P.x = P.x / P.z; P.y = P.y / P.z; P.z = lightLength / LightAttenuation.z; // Rescale viewport to be [0, 1] (texture coordinate space) P.x = 0.5f * P.x + 0.5f; P.y = -0.5f * P.y + 0.5f; depth = tex2D(ShadowSampler, P.xy).x; depth = 1.0 - depth; } // [Standard Depth Calculation] float mydepth = P.z; shadow = depth + Bias.x < mydepth ? 0.0f : 1.0f; If I try and do anything with the sampler reference outside the if statement then I get the following error: Sampler parameter must come from a literal expression This code demonstrates that float3 P = lightScreenPos; sampler ShadowSampler = DPFrontShadowSampler; if (alpha >= 0.5f) { // Reference the correct sampler ShadowSampler = DPFrontShadowSampler; // Front hemisphere 'P0' P.z = P.z + 1.0; P.x = P.x / P.z; P.y = P.y / P.z; P.z = lightLength / LightAttenuation.z; } else { // Reference the correct sampler ShadowSampler = DPBackShadowSampler; // Back hemisphere 'P1' P.z = 1.0 - P.z; P.x = P.x / P.z; P.y = P.y / P.z; P.z = lightLength / LightAttenuation.z; } // Rescale viewport to be [0, 1] (texture coordinate space) P.x = 0.5f * P.x + 0.5f; P.y = -0.5f * P.y + 0.5f; // [Standard Depth Calculation] float depth = tex2D(ShadowSampler, P.xy).x; depth = 1.0 - depth; float mydepth = P.z; shadow = depth + Bias.x < mydepth ? 0.0f : 1.0f; How can I reference the sampler in this manner without triggering the error?

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SQLAuthority News – Microsoft SQL Server Protocol Documentation Download

- by pinaldave

The Microsoft SQL Server protocol documentation provides detailed technical specifications for Microsoft proprietary protocols (including extensions to industry-standard or other published protocols) that are implemented and used in Microsoft SQL Server to interoperate or communicate with Microsoft products. The documentation includes a set of companion overview and reference documents that supplement the technical specifications with conceptual background, overviews of inter-protocol relationships and interactions, and technical reference information. Microsoft SQL Server Protocol Documentation Reference : Pinal Dave (http://blog.SQLAuthority.com) Filed under: SQL, SQL Authority, SQL Documentation, SQL Download, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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Back to Basics: When does a .NET Assembly Dependency get loaded

- by Rick Strahl

When we work on typical day to day applications, it's easy to forget some of the core features of the .NET framework. For me personally it's been a long time since I've learned about some of the underlying CLR system level services even though I rely on them on a daily basis. I often think only about high level application constructs and/or high level framework functionality, but the low level stuff is often just taken for granted. Over the last week at DevConnections I had all sorts of low level discussions with other developers about the inner workings of this or that technology (especially in light of my Low Level ASP.NET Architecture talk and the Razor Hosting talk). One topic that came up a couple of times and ended up a point of confusion even amongst some seasoned developers (including some folks from Microsoft <snicker>) is when assemblies actually load into a .NET process. There are a number of different ways that assemblies are loaded in .NET. When you create a typical project assemblies usually come from: The Assembly reference list of the top level 'executable' project The Assembly references of referenced projects Dynamically loaded at runtime via AppDomain/Reflection loading In addition .NET automatically loads mscorlib (most of the System namespace) the boot process that hosts the .NET runtime in EXE apps, or some other kind of runtime hosting environment (runtime hosting in servers like IIS, SQL Server or COM Interop). In hosting environments the runtime host may also pre-load a bunch of assemblies on its own (for example the ASP.NET host requires all sorts of assemblies just to run itself, before ever routing into your user specific code). Assembly Loading The most obvious source of loaded assemblies is the top level application's assembly reference list. You can add assembly references to a top level application and those assembly references are then available to the application. In a nutshell, referenced assemblies are not immediately loaded - they are loaded on the fly as needed. So regardless of whether you have an assembly reference in a top level project, or a dependent assembly assemblies typically load on an as needed basis, unless explicitly loaded by user code. The same is true of dependent assemblies. To check this out I ran a simple test: I have a utility assembly Westwind.Utilities which is a general purpose library that can work in any type of project. Due to a couple of small requirements for encoding and a logging piece that allows logging Web content (dependency on HttpContext.Current) this utility library has a dependency on System.Web. Now System.Web is a pretty large assembly and generally you'd want to avoid adding it to a non-Web project if it can be helped. So I created a Console Application that loads my utility library: You can see that the top level Console app a reference to Westwind.Utilities and System.Data (beyond the core .NET libs). The Westwind.Utilities project on the other hand has quite a few dependencies including System.Web. I then add a main program that accesses only a simple utillity method in the Westwind.Utilities library that doesn't require any of the classes that access System.Web: static void Main(string[] args) { Console.WriteLine(StringUtils.NewStringId()); Console.ReadLine(); } StringUtils.NewStringId() calls into Westwind.Utilities, but it doesn't rely on System.Web. Any guesses what the assembly list looks like when I stop the code on the ReadLine() command? I'll wait here while you think about it… … … So, when I stop on ReadLine() and then fire up Process Explorer and check the assembly list I get: We can see here that .NET has not actually loaded any of the dependencies of the Westwind.Utilities assembly. Also not loaded is the top level System.Data reference even though it's in the dependent assembly list of the top level project. Since this particular function I called only uses core System functionality (contained in mscorlib) there's in fact nothing else loaded beyond the main application and my Westwind.Utilities assembly that contains the method accessed. None of the dependencies of Westwind.Utilities loaded. If you were to open the assembly in a disassembler like Reflector or ILSpy, you would however see all the compiled in dependencies. The referenced assemblies are in the dependency list and they are loadable, but they are not immediately loaded by the application. In other words the C# compiler and .NET linker are smart enough to figure out the dependencies based on the code that actually is referenced from your application and any dependencies cascading down into the dependencies from your top level application into the referenced assemblies. In the example above the usage requirement is pretty obvious since I'm only calling a single static method and then exiting the app, but in more complex applications these dependency relationships become very complicated - however it's all taken care of by the compiler and linker figuring out what types and members are actually referenced and including only those assemblies that are in fact referenced in your code or required by any of your dependencies. The good news here is: That if you are referencing an assembly that has a dependency on something like System.Web in a few places that are not actually accessed by any of your code or any dependent assembly code that you are calling, that assembly is never loaded into memory! Some Hosting Environments pre-load Assemblies The load behavior can vary however. In Console and desktop applications we have full control over assembly loading so we see the core CLR behavior. However other environments like ASP.NET for example will preload referenced assemblies explicitly as part of the startup process - primarily to minimize load conflicts. Specifically ASP.NET pre-loads all assemblies referenced in the assembly list and the /bin folder. So in Web applications it definitely pays to minimize your top level assemblies if they are not used. Understanding when Assemblies Load To clarify and see it actually happen what I described in the first example , let's look at a couple of other scenarios. To see assemblies loading at runtime in real time lets create a utility function to print out loaded assemblies to the console: public static void PrintAssemblies() { var assemblies = AppDomain.CurrentDomain.GetAssemblies(); foreach (var assembly in assemblies) { Console.WriteLine(assembly.GetName()); } } Now let's look at the first scenario where I have class method that references internally uses System.Web. In the first scenario lets add a method to my main program like this: static void Main(string[] args) { Console.WriteLine(StringUtils.NewStringId()); Console.ReadLine(); PrintAssemblies(); } public static void WebLogEntry() { var entry = new WebLogEntry(); entry.UpdateFromRequest(); Console.WriteLine(entry.QueryString); } UpdateFromWebRequest() internally accesses HttpContext.Current to read some information of the ASP.NET Request object so it clearly needs a reference System.Web to work. In this first example, the method that holds the calling code is never called, but exists as a static method that can potentially be called externally at some point. What do you think will happen here with the assembly loading? Will System.Web load in this example? No - it doesn't. Because the WebLogEntry() method is never called by the mainline application (or anywhere else) System.Web is not loaded. .NET dynamically loads assemblies as code that needs it is called. No code references the WebLogEntry() method and so System.Web is never loaded. Next, let's add the call to this method, which should trigger System.Web to be loaded because a dependency exists. Let's change the code to: static void Main(string[] args) { Console.WriteLine(StringUtils.NewStringId()); Console.WriteLine("--- Before:"); PrintAssemblies(); WebLogEntry(); Console.WriteLine("--- After:"); PrintAssemblies(); Console.ReadLine(); } public static void WebLogEntry() { var entry = new WebLogEntry(); entry.UpdateFromRequest(); Console.WriteLine(entry.QueryString); } Looking at the code now, when do you think System.Web will be loaded? Will the before list include it? Yup System.Web gets loaded, but only after it's actually referenced. In fact, just until before the call to UpdateFromRequest() System.Web is not loaded - it only loads when the method is actually called and requires the reference in the executing code. Moral of the Story So what have we learned - or maybe remembered again? Dependent Assembly References are not pre-loaded when an application starts (by default) Dependent Assemblies that are not referenced by executing code are never loaded Dependent Assemblies are just in time loaded when first referenced in code All of this is nothing new - .NET has always worked like this. But it's good to have a refresher now and then and go through the exercise of seeing it work in action. It's not one of those things we think about everyday, and as I found out last week, I couldn't remember exactly how it worked since it's been so long since I've learned about this. And apparently I'm not the only one as several other people I had discussions with in relation to loaded assemblies also didn't recall exactly what should happen or assumed incorrectly that just having a reference automatically loads the assembly. The moral of the story for me is: Trying at all costs to eliminate an assembly reference from a component is not quite as important as it's often made out to be. For example, the Westwind.Utilities module described above has a logging component, including a Web specific logging entry that supports pulling information from the active HTTP Context. Adding that feature requires a reference to System.Web. Should I worry about this in the scope of this library? Probably not, because if I don't use that one class of nearly a hundred, System.Web never gets pulled into the parent process. IOW, System.Web only loads when I use that specific feature and if I am, well I clearly have to be running in a Web environment anyway to use it realistically. The alternative would be considerably uglier: Pulling out the WebLogEntry class and sticking it into another assembly and breaking up the logging code. In this case - definitely not worth it. So, .NET definitely goes through some pretty nifty optimizations to ensure that it loads only what it needs and in most cases you can just rely on .NET to do the right thing. Sometimes though assembly loading can go wrong (especially when signed and versioned local assemblies are involved), but that's subject for a whole other post…© Rick Strahl, West Wind Technologies, 2005-2012Posted in .NET CSharp Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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ASP.NET and HTML5 Local Storage

- by Stephen Walther

My favorite feature of HTML5, hands-down, is HTML5 local storage (aka DOM storage). By taking advantage of HTML5 local storage, you can dramatically improve the performance of your data-driven ASP.NET applications by caching data in the browser persistently. Think of HTML5 local storage like browser cookies, but much better. Like cookies, local storage is persistent. When you add something to browser local storage, it remains there when the user returns to the website (possibly days or months later). Importantly, unlike the cookie storage limitation of 4KB, you can store up to 10 megabytes in HTML5 local storage. Because HTML5 local storage works with the latest versions of all modern browsers (IE, Firefox, Chrome, Safari), you can start taking advantage of this HTML5 feature in your applications right now. Why use HTML5 Local Storage? I use HTML5 Local Storage in the JavaScript Reference application: http://Superexpert.com/JavaScriptReference The JavaScript Reference application is an HTML5 app that provides an interactive reference for all of the syntax elements of JavaScript (You can read more about the application and download the source code for the application here). When you open the application for the first time, all of the entries are transferred from the server to the browser (all 300+ entries). All of the entries are stored in local storage. When you open the application in the future, only changes are transferred from the server to the browser. The benefit of this approach is that the application performs extremely fast. When you click the details link to view details on a particular entry, the entry details appear instantly because all of the entries are stored on the client machine. When you perform key-up searches, by typing in the filter textbox, matching entries are displayed very quickly because the entries are being filtered on the local machine. This approach can have a dramatic effect on the performance of any interactive data-driven web application. Interacting with data on the client is almost always faster than interacting with the same data on the server. Retrieving Data from the Server In the JavaScript Reference application, I use Microsoft WCF Data Services to expose data to the browser. WCF Data Services generates a REST interface for your data automatically. Here are the steps: Create your database tables in Microsoft SQL Server. For example, I created a database named ReferenceDB and a database table named Entities. Use the Entity Framework to generate your data model. For example, I used the Entity Framework to generate a class named ReferenceDBEntities and a class named Entities. Expose your data through WCF Data Services. I added a WCF Data Service to my project and modified the data service class to look like this: using System.Data.Services; using System.Data.Services.Common; using System.Web; using JavaScriptReference.Models; namespace JavaScriptReference.Services { [System.ServiceModel.ServiceBehavior(IncludeExceptionDetailInFaults = true)] public class EntryService : DataService<ReferenceDBEntities> { // This method is called only once to initialize service-wide policies. public static void InitializeService(DataServiceConfiguration config) { config.UseVerboseErrors = true; config.SetEntitySetAccessRule("*", EntitySetRights.All); config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2; } // Define a change interceptor for the Products entity set. [ChangeInterceptor("Entries")] public void OnChangeEntries(Entry entry, UpdateOperations operations) { if (!HttpContext.Current.Request.IsAuthenticated) { throw new DataServiceException("Cannot update reference unless authenticated."); } } } } The WCF data service is named EntryService. Notice that it derives from DataService<ReferenceEntitites>. Because it derives from DataService<ReferenceEntities>, the data service exposes the contents of the ReferenceEntitiesDB database. In the code above, I defined a ChangeInterceptor to prevent un-authenticated users from making changes to the database. Anyone can retrieve data through the service, but only authenticated users are allowed to make changes. After you expose data through a WCF Data Service, you can use jQuery to retrieve the data by performing an Ajax call. For example, I am using an Ajax call that looks something like this to retrieve the JavaScript entries from the EntryService.svc data service: $.ajax({ dataType: "json", url: “/Services/EntryService.svc/Entries”, success: function (result) { var data = callback(result["d"]); } }); Notice that you must unwrap the data using result[“d”]. After you unwrap the data, you have a JavaScript array of the entries. I’m transferring all 300+ entries from the server to the client when the application is opened for the first time. In other words, I transfer the entire database from the server to the client, once and only once, when the application is opened for the first time. The data is transferred using JSON. Here is a fragment: { "d" : [ { "__metadata": { "uri": "http://superexpert.com/javascriptreference/Services/EntryService.svc/Entries(1)", "type": "ReferenceDBModel.Entry" }, "Id": 1, "Name": "Global", "Browsers": "ff3_6,ie8,ie9,c8,sf5,es3,es5", "Syntax": "object", "ShortDescription": "Contains global variables and functions", "FullDescription": "<p>\nThe Global object is determined by the host environment. In web browsers, the Global object is the same as the windows object.\n</p>\n<p>\nYou can use the keyword <code>this</code> to refer to the Global object when in the global context (outside of any function).\n</p>\n<p>\nThe Global object holds all global variables and functions. For example, the following code demonstrates that the global <code>movieTitle</code> variable refers to the same thing as <code>window.movieTitle</code> and <code>this.movieTitle</code>.\n</p>\n<pre>\nvar movieTitle = \"Star Wars\";\nconsole.log(movieTitle === this.movieTitle); // true\nconsole.log(movieTitle === window.movieTitle); // true\n</pre>\n", "LastUpdated": "634298578273756641", "IsDeleted": false, "OwnerId": null }, { "__metadata": { "uri": "http://superexpert.com/javascriptreference/Services/EntryService.svc/Entries(2)", "type": "ReferenceDBModel.Entry" }, "Id": 2, "Name": "eval(string)", "Browsers": "ff3_6,ie8,ie9,c8,sf5,es3,es5", "Syntax": "function", "ShortDescription": "Evaluates and executes JavaScript code dynamically", "FullDescription": "<p>\nThe following code evaluates and executes the string \"3+5\" at runtime.\n</p>\n<pre>\nvar result = eval(\"3+5\");\nconsole.log(result); // returns 8\n</pre>\n<p>\nYou can rewrite the code above like this:\n</p>\n<pre>\nvar result;\neval(\"result = 3+5\");\nconsole.log(result);\n</pre>", "LastUpdated": "634298580913817644", "IsDeleted": false, "OwnerId": 1 } … ]} I worried about the amount of time that it would take to transfer the records. According to Google Chome, it takes about 5 seconds to retrieve all 300+ records on a broadband connection over the Internet. 5 seconds is a small price to pay to avoid performing any server fetches of the data in the future. And here are the estimated times using different types of connections using Fiddler: Notice that using a modem, it takes 33 seconds to download the database. 33 seconds is a significant chunk of time. So, I would not use the approach of transferring the entire database up front if you expect a significant portion of your website audience to connect to your website with a modem. Adding Data to HTML5 Local Storage After the JavaScript entries are retrieved from the server, the entries are stored in HTML5 local storage. Here’s the reference documentation for HTML5 storage for Internet Explorer: http://msdn.microsoft.com/en-us/library/cc197062(VS.85).aspx You access local storage by accessing the windows.localStorage object in JavaScript. This object contains key/value pairs. For example, you can use the following JavaScript code to add a new item to local storage: <script type="text/javascript"> window.localStorage.setItem("message", "Hello World!"); </script> You can use the Google Chrome Storage tab in the Developer Tools (hit CTRL-SHIFT I in Chrome) to view items added to local storage: After you add an item to local storage, you can read it at any time in the future by using the window.localStorage.getItem() method: <script type="text/javascript"> window.localStorage.setItem("message", "Hello World!"); </script> You only can add strings to local storage and not JavaScript objects such as arrays. Therefore, before adding a JavaScript object to local storage, you need to convert it into a JSON string. In the JavaScript Reference application, I use a wrapper around local storage that looks something like this: function Storage() { this.get = function (name) { return JSON.parse(window.localStorage.getItem(name)); }; this.set = function (name, value) { window.localStorage.setItem(name, JSON.stringify(value)); }; this.clear = function () { window.localStorage.clear(); }; } If you use the wrapper above, then you can add arbitrary JavaScript objects to local storage like this: var store = new Storage(); // Add array to storage var products = [ {name:"Fish", price:2.33}, {name:"Bacon", price:1.33} ]; store.set("products", products); // Retrieve items from storage var products = store.get("products"); Modern browsers support the JSON object natively. If you need the script above to work with older browsers then you should download the JSON2.js library from: https://github.com/douglascrockford/JSON-js The JSON2 library will use the native JSON object if a browser already supports JSON. Merging Server Changes with Browser Local Storage When you first open the JavaScript Reference application, the entire database of JavaScript entries is transferred from the server to the browser. Two items are added to local storage: entries and entriesLastUpdated. The first item contains the entire entries database (a big JSON string of entries). The second item, a timestamp, represents the version of the entries. Whenever you open the JavaScript Reference in the future, the entriesLastUpdated timestamp is passed to the server. Only records that have been deleted, updated, or added since entriesLastUpdated are transferred to the browser. The OData query to get the latest updates looks like this: http://superexpert.com/javascriptreference/Services/EntryService.svc/Entries?$filter=(LastUpdated%20gt%20634301199890494792L) If you remove URL encoding, the query looks like this: http://superexpert.com/javascriptreference/Services/EntryService.svc/Entries?$filter=(LastUpdated gt 634301199890494792L) This query returns only those entries where the value of LastUpdated > 634301199890494792 (the version timestamp). The changes – new JavaScript entries, deleted entries, and updated entries – are merged with the existing entries in local storage. The JavaScript code for performing the merge is contained in the EntriesHelper.js file. The merge() method looks like this: merge: function (oldEntries, newEntries) { // concat (this performs the add) oldEntries = oldEntries || []; var mergedEntries = oldEntries.concat(newEntries); // sort this.sortByIdThenLastUpdated(mergedEntries); // prune duplicates (this performs the update) mergedEntries = this.pruneDuplicates(mergedEntries); // delete mergedEntries = this.removeIsDeleted(mergedEntries); // Sort this.sortByName(mergedEntries); return mergedEntries; }, The contents of local storage are then updated with the merged entries. I spent several hours writing the merge() method (much longer than I expected). I found two resources to be extremely useful. First, I wrote extensive unit tests for the merge() method. I wrote the unit tests using server-side JavaScript. I describe this approach to writing unit tests in this blog entry. The unit tests are included in the JavaScript Reference source code. Second, I found the following blog entry to be super useful (thanks Nick!): http://nicksnettravels.builttoroam.com/post/2010/08/03/OData-Synchronization-with-WCF-Data-Services.aspx One big challenge that I encountered involved timestamps. I originally tried to store an actual UTC time as the value of the entriesLastUpdated item. I quickly discovered that trying to work with dates in JSON turned out to be a big can of worms that I did not want to open. Next, I tried to use a SQL timestamp column. However, I learned that OData cannot handle the timestamp data type when doing a filter query. Therefore, I ended up using a bigint column in SQL and manually creating the value when a record is updated. I overrode the SaveChanges() method to look something like this: public override int SaveChanges(SaveOptions options) { var changes = this.ObjectStateManager.GetObjectStateEntries( EntityState.Modified | EntityState.Added | EntityState.Deleted); foreach (var change in changes) { var entity = change.Entity as IEntityTracking; if (entity != null) { entity.LastUpdated = DateTime.Now.Ticks; } } return base.SaveChanges(options); } Notice that I assign Date.Now.Ticks to the entity.LastUpdated property whenever an entry is modified, added, or deleted. Summary After building the JavaScript Reference application, I am convinced that HTML5 local storage can have a dramatic impact on the performance of any data-driven web application. If you are building a web application that involves extensive interaction with data then I recommend that you take advantage of this new feature included in the HTML5 standard.

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Integrate BING API for Search inside ASP.Net web application

- by sreejukg

As you might already know, Bing is the Microsoft Search engine and is getting popular day by day. Bing offers APIs that can be integrated into your website to increase your website functionality. At this moment, there are two important APIs available. They are Bing Search API Bing Maps The Search API enables you to build applications that utilize Bing’s technology. The API allows you to search multiple source types such as web; images, video etc. and supports various output prototypes such as JSON, XML, and SOAP. Also you will be able to customize the search results as you wish for your public facing website. Bing Maps API allows you to build robust applications that use Bing Maps. In this article I am going to describe, how you can integrate Bing search into your website. In order to start using Bing, First you need to sign in to http://www.bing.com/toolbox/bingdeveloper/ using your windows live credentials. Click on the Sign in button, you will be asked to enter your windows live credentials. Once signed in you will be redirected to the Developer page. Here you can create applications and get AppID for each application. Since I am a first time user, I don’t have any applications added. Click on the Add button to add a new application. You will be asked to enter certain details about your application. The fields are straight forward, only thing you need to note is the website field, here you need to enter the website address from where you are going to use this application, and this field is optional too. Of course you need to agree on the terms and conditions and then click Save. Once you click on save, the application will be created and application ID will be available for your use. Now we got the APP Id. Basically Bing supports three protocols. They are JSON, XML and SOAP. JSON is useful if you want to call the search requests directly from the browser and use JavaScript to parse the results, thus JSON is the favorite choice for AJAX application. XML is the alternative for applications that does not support SOAP, e.g. flash/ Silverlight etc. SOAP is ideal for strongly typed languages and gives a request/response object model. In this article I am going to demonstrate how to search BING API using SOAP protocol from an ASP.Net application. For the purpose of this demonstration, I am going to create an ASP.Net project and implement the search functionality in an aspx page. Open Visual Studio, navigate to File-> New Project, select ASP.Net empty web application, I named the project as “BingSearchSample”. Add a Search.aspx page to the project, once added the solution explorer will looks similar to the following. Now you need to add a web reference to the SOAP service available from Bing. To do this, from the solution explorer, right click your project, select Add Service Reference. Now the new service reference dialog will appear. In the left bottom of the dialog, you can find advanced button, click on it. Now the service reference settings dialog will appear. In the bottom left, you can find Add Web Reference button, click on it. The add web reference dialog will appear now. Enter the URL as http://api.bing.net/search.wsdl?AppID=<YourAppIDHere>&version=2.2 (replace <yourAppIDHere> with the appID you have generated previously) and click on the button next to it. This will find the web service methods available. You can change the namespace suggested by Bing, but for the purpose of this demonstration I have accepted all the default settings. Click on the Add reference button once you are done. Now the web reference to Search service will be added your project. You can find this under solution explorer of your project. Now in the Search.aspx, that you previously created, place one textbox, button and a grid view. For the purpose of this demonstration, I have given the identifiers (ID) as txtSearch, btnSearch, gvSearch respectively. The idea is to search the text entered in the text box using Bing service and show the results in the grid view. In the design view, the search.aspx looks as follows. In the search.aspx.cs page, add a using statement that points to net.bing.api. I have added the following code for button click event handler. The code is very straight forward. It just calls the service with your AppID, a query to search and a source for searching. Let us run this page and see the output when I enter Microsoft in my textbox. If you want to search a specific site, you can include the site name in the query parameter. For e.g. the following query will search the word Microsoft from www.microsoft.com website. searchRequest.Query = “site:www.microsoft.com Microsoft”; The output of this query is as follows. Integrating BING search API to your website is easy and there is no limit on the customization of the interface you can do. There is no Bing branding required so I believe this is a great option for web developers when they plan for site search.

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How to reproject a shapefile from WGS 84 to Spherical/Web Mercator projection.

- by samkea

Definitions: You will need to know the meaning of these terms below. I have given a small description to the acronyms but you can google and know more about them. #1:WGS-84- World Geodetic Systems (1984)- is a standard reference coordinate system used for Cartography, Geodesy and Navigation. #2: EPGS-European Petroleum Survey Group-was a scientific organization with ties to the European petroleum industry consisting of specialists working in applied geodesy, surveying, and cartography related to oil exploration. EPSG::4326 is a common coordinate reference system that refers to WGS84 as (latitude, longitude) pair coordinates in degrees with Greenwich as the central meridian. Any degree representation (e.g., decimal or DMSH: degrees minutes seconds hemisphere) may be used. Which degree representation is used must be declared for the user by the supplier of data. So, the Spherical/Web Mercator projection is referred to as EPGS::3785 which is renamed to EPSG:900913 by google for use in googlemaps. The associated CRS(Coordinate Reference System) for this is the "Popular Visualisation CRS / Mercator ". This is the kind of projection that is used by GoogleMaps, BingMaps,OSM,Virtual Earth, Deep Earth excetra...to show interactive maps over the web with thier nearly precise coordinates. Reprojection: After reading alot about reprojecting my coordinates from the deepearth project on Codeplex, i still could not do it. After some help from a colleague, i got my ball rolling.This is how i did it. #1 You need to download and open your shapefile using Q-GIS; its the one with the biggest number of coordinate reference systems/ projections. #2 Use the plugins menu, and enable ftools and the WFS plugin. #3 Use the Vector menu--> Data Management Tools and choose define current projection. Enable, use predefined reference system and choose WGS 84 coodinate system. I am personally in zone 36, so i chose WGS84-UTM Zone 36N under ( Projected Coordinate Systems--> Universal Transverse Mercator) and click ok. #4 Now use the Vector menu--> Data Management Tools and choose export to new projection. The same dialog will pop-up. Now choose WGS 84 EPGS::4326 under Geodetic Coordinate Systems. My Input user Defined Spatial Reference System should looks like this: +proj=tmerc +lat_0=0 +lon_0=33 +k=0.9996 +x_0=500000 +y_0=200000 +ellps=WGS84 +datum=WGS84 +units=m +no_defs Your Output user Defined Spatial Reference System should look like this: +proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs Browse for the place where the shapefile is going to be and give the shapefile a name(like origna_reprojected). If it prompts you to add the projected layer to the TOC, accept. There, you have your re-projected map with latitude and longitude pair of coordinates. #5 Now, this is not the actual Spherical/Web Mercator projection, but dont worry, this is where you have to stop. All the other custom web-mapping portals will pick this projection and transform it into EPGS::3785 or EPSG:900913 but the coordinates will still remain as the LatLon pair of the projected shapefile. If you want to test, a particular know point, Q-GIS has a lot of room for that. Go ahead and test it.

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Inside the Concurrent Collections: ConcurrentBag

- by Simon Cooper

Unlike the other concurrent collections, ConcurrentBag does not really have a non-concurrent analogy. As stated in the MSDN documentation, ConcurrentBag is optimised for the situation where the same thread is both producing and consuming items from the collection. We'll see how this is the case as we take a closer look. Again, I recommend you have ConcurrentBag open in a decompiler for reference. Thread Statics ConcurrentBag makes heavy use of thread statics - static variables marked with ThreadStaticAttribute. This is a special attribute that instructs the CLR to scope any values assigned to or read from the variable to the executing thread, not globally within the AppDomain. This means that if two different threads assign two different values to the same thread static variable, one value will not overwrite the other, and each thread will see the value they assigned to the variable, separately to any other thread. This is a very useful function that allows for ConcurrentBag's concurrency properties. You can think of a thread static variable: [ThreadStatic] private static int m_Value; as doing the same as: private static Dictionary<Thread, int> m_Values; where the executing thread's identity is used to automatically set and retrieve the corresponding value in the dictionary. In .NET 4, this usage of ThreadStaticAttribute is encapsulated in the ThreadLocal class. Lists of lists ConcurrentBag, at its core, operates as a linked list of linked lists: Each outer list node is an instance of ThreadLocalList, and each inner list node is an instance of Node. Each outer ThreadLocalList is owned by a particular thread, accessible through the thread local m_locals variable: private ThreadLocal<ThreadLocalList<T>> m_locals It is important to note that, although the m_locals variable is thread-local, that only applies to accesses through that variable. The objects referenced by the thread (each instance of the ThreadLocalList object) are normal heap objects that are not specific to any thread. Thinking back to the Dictionary analogy above, if each value stored in the dictionary could be accessed by other means, then any thread could access the value belonging to other threads using that mechanism. Only reads and writes to the variable defined as thread-local are re-routed by the CLR according to the executing thread's identity. So, although m_locals is defined as thread-local, the m_headList, m_nextList and m_tailList variables aren't. This means that any thread can access all the thread local lists in the collection by doing a linear search through the outer linked list defined by these variables. Adding items So, onto the collection operations. First, adding items. This one's pretty simple. If the current thread doesn't already own an instance of ThreadLocalList, then one is created (or, if there are lists owned by threads that have stopped, it takes control of one of those). Then the item is added to the head of that thread's list. That's it. Don't worry, it'll get more complicated when we account for the other operations on the list! Taking & Peeking items This is where it gets tricky. If the current thread's list has items in it, then it peeks or removes the head item (not the tail item) from the local list and returns that. However, if the local list is empty, it has to go and steal another item from another list, belonging to a different thread. It iterates through all the thread local lists in the collection using the m_headList and m_nextList variables until it finds one that has items in it, and it steals one item from that list. Up to this point, the two threads had been operating completely independently. To steal an item from another thread's list, the stealing thread has to do it in such a way as to not step on the owning thread's toes. Recall how adding and removing items both operate on the head of the thread's linked list? That gives us an easy way out - a thread trying to steal items from another thread can pop in round the back of another thread's list using the m_tail variable, and steal an item from the back without the owning thread knowing anything about it. The owning thread can carry on completely independently, unaware that one of its items has been nicked. However, this only works when there are at least 3 items in the list, as that guarantees there will be at least one node between the owning thread performing operations on the list head and the thread stealing items from the tail - there's no chance of the two threads operating on the same node at the same time and causing a race condition. If there's less than three items in the list, then there does need to be some synchronization between the two threads. In this case, the lock on the ThreadLocalList object is used to mediate access to a thread's list when there's the possibility of contention. Thread synchronization In ConcurrentBag, this is done using several mechanisms: Operations performed by the owner thread only take out the lock when there are less than three items in the collection. With three or greater items, there won't be any conflict with a stealing thread operating on the tail of the list. If a lock isn't taken out, the owning thread sets the list's m_currentOp variable to a non-zero value for the duration of the operation. This indicates to all other threads that there is a non-locked operation currently occuring on that list. The stealing thread always takes out the lock, to prevent two threads trying to steal from the same list at the same time. After taking out the lock, the stealing thread spinwaits until m_currentOp has been set to zero before actually performing the steal. This ensures there won't be a conflict with the owning thread when the number of items in the list is on the 2-3 item borderline. If any add or remove operations are started in the meantime, and the list is below 3 items, those operations try to take out the list's lock and are blocked until the stealing thread has finished. This allows a thread to steal an item from another thread's list without corrupting it. What about synchronization in the collection as a whole? Collection synchronization Any thread that operates on the collection's global structure (accessing anything outside the thread local lists) has to take out the collection's global lock - m_globalListsLock. This single lock is sufficient when adding a new thread local list, as the items inside each thread's list are unaffected. However, what about operations (such as Count or ToArray) that need to access every item in the collection? In order to ensure a consistent view, all operations on the collection are stopped while the count or ToArray is performed. This is done by freezing the bag at the start, performing the global operation, and unfreezing at the end: The global lock is taken out, to prevent structural alterations to the collection. m_needSync is set to true. This notifies all the threads that they need to take out their list's lock irregardless of what operation they're doing. All the list locks are taken out in order. This blocks all locking operations on the lists. The freezing thread waits for all current lockless operations to finish by spinwaiting on each m_currentOp field. The global operation can then be performed while the bag is frozen, but no other operations can take place at the same time, as all other threads are blocked on a list's lock. Then, once the global operation has finished, the locks are released, m_needSync is unset, and normal concurrent operation resumes. Concurrent principles That's the essence of how ConcurrentBag operates. Each thread operates independently on its own local list, except when they have to steal items from another list. When stealing, only the stealing thread is forced to take out the lock; the owning thread only has to when there is the possibility of contention. And a global lock controls accesses to the structure of the collection outside the thread lists. Operations affecting the entire collection take out all locks in the collection to freeze the contents at a single point in time. So, what principles can we extract here? Threads operate independently Thread-static variables and ThreadLocal makes this easy. Threads operate entirely concurrently on their own structures; only when they need to grab data from another thread is there any thread contention. Minimised lock-taking Even when two threads need to operate on the same data structures (one thread stealing from another), they do so in such a way such that the probability of actually blocking on a lock is minimised; the owning thread always operates on the head of the list, and the stealing thread always operates on the tail. Management of lockless operations Any operations that don't take out a lock still have a 'hook' to force them to lock when necessary. This allows all operations on the collection to be stopped temporarily while a global snapshot is taken. Hopefully, such operations will be short-lived and infrequent. That's all the concurrent collections covered. I hope you've found it as informative and interesting as I have. Next, I'll be taking a closer look at ThreadLocal, which I came across while analyzing ConcurrentBag. As you'll see, the operation of this class deserves a much closer look.

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Type Casting variables in PHP: Is there a practical example?

- by Stephen

PHP, as most of us know, has weak typing. For those who don't, PHP.net says: PHP does not require (or support) explicit type definition in variable declaration; a variable's type is determined by the context in which the variable is used. Love it or hate it, PHP re-casts variables on-the-fly. So, the following code is valid: $var = "10"; $value = 10 + $var; var_dump($value); // int(20) PHP also alows you to explicitly cast a variable, like so: $var = "10"; $value = 10 + $var; $value = (string)$value; var_dump($value); // string(2) "20" That's all cool... but, for the life of me, I cannot conceive of a practical reason for doing this. I don't have a problem with strong typing in languages that support it, like Java. That's fine, and I completely understand it. Also, I'm aware of—and fully understand the usefulness of—type hinting in function parameters. The problem I have with type casting is explained by the above quote. If PHP can swap types at-will, it can do so even after you force cast a type; and it can do so on-the-fly when you need a certain type in an operation. That makes the following valid: $var = "10"; $value = (int)$var; $value = $value . ' TaDa!'; var_dump($value); // string(8) "10 TaDa!" So what's the point? Can anyone show me a practical application or example of type casting—one that would fail if type casting were not involved? I ask this here instead of SO because I figure practicality is too subjective. Edit in response to Chris' comment Take this theoretical example of a world where user-defined type casting makes sense in PHP: You force cast variable $foo as int -- (int)$foo. You attempt to store a string value in the variable $foo. PHP throws an exception!! <--- That would make sense. Suddenly the reason for user defined type casting exists! The fact that PHP will switch things around as needed makes the point of user defined type casting vague. For example, the following two code samples are equivalent: // example 1 $foo = 0; $foo = (string)$foo; $foo = '# of Reasons for the programmer to type cast $foo as a string: ' . $foo; // example 2 $foo = 0; $foo = (int)$foo; $foo = '# of Reasons for the programmer to type cast $foo as a string: ' . $foo; UPDATE Guess who found himself using typecasting in a practical environment? Yours Truly. The requirement was to display money values on a website for a restaurant menu. The design of the site required that trailing zeros be trimmed, so that the display looked something like the following: Menu Item 1 .............. $ 4 Menu Item 2 .............. $ 7.5 Menu Item 3 .............. $ 3 The best way I found to do that wast to cast the variable as a float: $price = '7.50'; // a string from the database layer. echo 'Menu Item 2 .............. $ ' . (float)$price; PHP trims the float's trailing zeros, and then recasts the float as a string for concatenation.

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URL Rewrite – Protocol (http/https) in the Action

- by OWScott

IIS URL Rewrite supports server variables for pretty much every part of the URL and http header. However, there is one commonly used server variable that isn’t readily available. That’s the protocol—HTTP or HTTPS. You can easily check if a page request uses HTTP or HTTPS, but that only works in the conditions part of the rule. There isn’t a variable available to dynamically set the protocol in the action part of the rule. What I wish is that there would be a variable like {HTTP_PROTOCOL} which would have a value of ‘HTTP’ or ‘HTTPS’. There is a server variable called {HTTPS}, but the values of ‘on’ and ‘off’ aren’t practical in the action. You can also use {SERVER_PORT} or {SERVER_PORT_SECURE}, but again, they aren’t useful in the action. Let me illustrate. The following rule will redirect traffic for http(s)://localtest.me/ to http://www.localtest.me/. <rule name="Redirect to www"> <match url="(.*)" /> <conditions> <add input="{HTTP_HOST}" pattern="^localtest\.me$" /> </conditions> <action type="Redirect" url="http://www.localtest.me/{R:1}" /> </rule> The problem is that it forces the request to HTTP even if the original request was for HTTPS. Interestingly enough, I planned to blog about this topic this week when I noticed in my twitter feed yesterday that Jeff Graves, a former colleague of mine, just wrote an excellent blog post about this very topic. He beat me to the punch by just a couple days. However, I figured I would still write my blog post on this topic. While his solution is a excellent one, I personally handle this another way most of the time. Plus, it’s a commonly asked question that isn’t documented well enough on the web yet, so having another article on the web won’t hurt. I can think of four different ways to handle this, and depending on your situation you may lean towards any of the four. Don’t let the choices overwhelm you though. Let’s keep it simple, Option 1 is what I use most of the time, Option 2 is what Jeff proposed and is the safest option, and Option 3 and Option 4 need only be considered if you have a more unique situation. All four options will work for most situations. Option 1 – CACHE_URL, single rule There is a server variable that has the protocol in it; {CACHE_URL}. This server variable contains the entire URL string (e.g. http://www.localtest.me:80/info.aspx?id=5) All we need to do is extract the HTTP or HTTPS and we’ll be set. This tends to be my preferred way to handle this situation. Indeed, Jeff did briefly mention this in his blog post: … you could use a condition on the CACHE_URL variable and a back reference in the rewritten URL. The problem there is that you then need to match all of the conditions which could be a problem if your rule depends on a logical “or” match for conditions. Thus the problem. If you have multiple conditions set to “Match Any” rather than “Match All” then this option won’t work. However, I find that 95% of all rules that I write use “Match All” and therefore, being the lazy administrator that I am I like this simple solution that only requires adding a single condition to a rule. The caveat is that if you use “Match Any” then you must consider one of the next two options. Enough with the preamble. Here’s how it works. Add a condition that checks for {CACHE_URL} with a pattern of “^(.+)://” like so: How you have a back-reference to the part before the ://, which is our treasured HTTP or HTTPS. In URL Rewrite 2.0 or greater you can check the “Track capture groups across conditions”, make that condition the first condition, and you have yourself a back-reference of {C:1}. The “Redirect to www” example with support for maintaining the protocol, will become: <rule name="Redirect to www" stopProcessing="true"> <match url="(.*)" /> <conditions trackAllCaptures="true"> <add input="{CACHE_URL}" pattern="^(.+)://" /> <add input="{HTTP_HOST}" pattern="^localtest\.me$" /> </conditions> <action type="Redirect" url="{C:1}://www.localtest.me/{R:1}" /> </rule> It’s not as easy as it would be if Microsoft gave us a built-in {HTTP_PROTOCOL} variable, but it’s pretty close. I also like this option since I often create rule examples for other people and this type of rule is portable since it’s self-contained within a single rule. Option 2 – Using a Rewrite Map For a safer rule that works for both “Match Any” and “Match All” situations, you can use the Rewrite Map solution that Jeff proposed. It’s a perfectly good solution with the only drawback being the ever so slight extra effort to set it up since you need to create a rewrite map before you create the rule. In other words, if you choose to use this as your sole method of handling the protocol, you’ll be safe. After you create a Rewrite Map called MapProtocol, you can use “{MapProtocol:{HTTPS}}” for the protocol within any rule action. Following is an example using a Rewrite Map. <rewrite> <rules> <rule name="Redirect to www" stopProcessing="true"> <match url="(.*)" /> <conditions trackAllCaptures="false"> <add input="{HTTP_HOST}" pattern="^localtest\.me$" /> </conditions> <action type="Redirect" url="{MapProtocol:{HTTPS}}://www.localtest.me/{R:1}" /> </rule> </rules> <rewriteMaps> <rewriteMap name="MapProtocol"> <add key="on" value="https" /> <add key="off" value="http" /> </rewriteMap> </rewriteMaps> </rewrite> Option 3 – CACHE_URL, Multi-rule If you have many rules that will use the protocol, you can create your own server variable which can be used in subsequent rules. This option is no easier to set up than Option 2 above, but you can use it if you prefer the easier to remember syntax of {HTTP_PROTOCOL} vs. {MapProtocol:{HTTPS}}. The potential issue with this rule is that if you don’t have access to the server level (e.g. in a shared environment) then you cannot set server variables without permission. First, create a rule and place it at the top of the set of rules. You can create this at the server, site or subfolder level. However, if you create it at the site or subfolder level then the HTTP_PROTOCOL server variable needs to be approved at the server level. This can be achieved in IIS Manager by navigating to URL Rewrite at the server level, clicking on “View Server Variables” from the Actions pane, and added HTTP_PROTOCOL. If you create the rule at the server level then this step is not necessary. Following is an example of the first rule to create the HTTP_PROTOCOL and then a rule that uses it. The Create HTTP_PROTOCOL rule only needs to be created once on the server. <rule name="Create HTTP_PROTOCOL"> <match url=".*" /> <conditions logicalGrouping="MatchAll" trackAllCaptures="false"> <add input="{CACHE_URL}" pattern="^(.+)://" /> </conditions> <serverVariables> <set name="HTTP_PROTOCOL" value="{C:1}" /> </serverVariables> <action type="None" /> </rule> <rule name="Redirect to www" stopProcessing="true"> <match url="(.*)" /> <conditions logicalGrouping="MatchAll" trackAllCaptures="false"> <add input="{HTTP_HOST}" pattern="^localtest\.me$" /> </conditions> <action type="Redirect" url="{HTTP_PROTOCOL}://www.localtest.me/{R:1}" /> </rule> Option 4 – Multi-rule Just to be complete I’ll include an example of how to achieve the same thing with multiple rules. I don’t see any reason to use it over the previous examples, but I’ll include an example anyway. Note that it will only work with the “Match All” setting for the conditions. <rule name="Redirect to www - http" stopProcessing="true"> <match url="(.*)" /> <conditions logicalGrouping="MatchAll" trackAllCaptures="false"> <add input="{HTTP_HOST}" pattern="^localtest\.me$" /> <add input="{HTTPS}" pattern="off" /> </conditions> <action type="Redirect" url="http://www.localtest.me/{R:1}" /> </rule> <rule name="Redirect to www - https" stopProcessing="true"> <match url="(.*)" /> <conditions logicalGrouping="MatchAll" trackAllCaptures="false"> <add input="{HTTP_HOST}" pattern="^localtest\.me$" /> <add input="{HTTPS}" pattern="on" /> </conditions> <action type="Redirect" url="https://www.localtest.me/{R:1}" /> </rule> Conclusion Above are four working examples of methods to call the protocol (HTTP or HTTPS) from the action of a URL Rewrite rule. You can use whichever method you most prefer. I’ve listed them in the order that I favor them, although I could see some people preferring Option 2 as their first choice. In any of the cases, hopefully you can use this as a reference for when you need to use the protocol in the rule’s action when writing your URL Rewrite rules. Further information: Viewing all Server Variable for a site. URL Parts available to URL Rewrite Rules Further URL Rewrite articles

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Upgraded Linux, now CMS Made Simple is spewing errors

- by Paul Tomblin

I upgraded my host from Debian Lenny to Debian Squeeze, and now my CMS Made Simple site is spewing PHP errors all over the screen. I thought I'd upgrade the CMS because I haven't done so in a while, but Google Chrome tells me that the CMS Made Simple site is infested with malware. What are my options now? Example errors: Deprecated: Assigning the return value of new by reference is deprecated in /www/danmurn/cms/include.php on line 73 Deprecated: Assigning the return value of new by reference is deprecated in /www/danmurn/cms/include.php on line 162 Deprecated: Assigning the return value of new by reference is deprecated in /www/danmurn/cms/include.php on line 240 Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at /www/danmurn/cms/include.php:73) in /www/danmurn/cms/include.php on line 34 Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /www/danmurn/cms/include.php:73) in /www/danmurn/cms/include.php on line 34 Deprecated: Function set_magic_quotes_runtime() is deprecated in /www/danmurn/cms/include.php on line 62 Deprecated: Assigning the return value of new by reference is deprecated in /www/danmurn/cms/lib/classes/class.global.inc.php on line 184 Deprecated: Assigning the return value of new by reference is deprecated in /www/danmurn/cms/lib/classes/class.global.inc.php on line 196

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Recent ALM Rangers Summary Posts

- by Enrique Lima

Willy-Peter Schaub has been a machine producing and posting content. It is such a gem of information that you can find in the content being posted. He has created some Summary Posts on the specific topics the ALM Rangers are working on. Here is the list of quick access TOC Posts. TOC: “Tags” a la acronyms … what do they all mean? TOC: TFS Integration Tools Blog Posts and Reference Sites TOC: TFS Iteration Automation Blog Posts and Reference Sites TOC: Virtual Machine (VM) Factory TOC: Build Customization Guide Blog Posts and Reference Sites TOC: Lab Management Guide Blog Posts and Reference Sites

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Type Casting variables in PHP: Is there a practical example?

- by Stephen

PHP, as most of us know, has weak typing. For those who don't, PHP.net says: PHP does not require (or support) explicit type definition in variable declaration; a variable's type is determined by the context in which the variable is used. Love it or hate it, PHP re-casts variables on-the-fly. So, the following code is valid: $var = "10"; $value = 10 + $var; var_dump($value); // int(20) PHP also alows you to explicitly cast a variable, like so: $var = "10"; $value = 10 + $var; $value = (string)$value; var_dump($value); // string(2) "20" That's all cool... but, for the life of me, I cannot conceive of a practical reason for doing this. I don't have a problem with strong typing in languages that support it, like Java. That's fine, and I completely understand it. Also, I'm aware of—and fully understand the usefulness of—type hinting in function parameters. The problem I have with type casting is explained by the above quote. If PHP can swap types at-will, it can do so even after you force cast a type; and it can do so on-the-fly when you need a certain type in an operation. That makes the following valid: $var = "10"; $value = (int)$var; $value = $value . ' TaDa!'; var_dump($value); // string(8) "10 TaDa!" So what's the point? Can anyone show me a practical application or example of type casting—one that would fail if type casting were not involved? I ask this here instead of SO because I figure practicality is too subjective. Edit in response to Chris' comment Take this theoretical example of a world where user-defined type casting makes sense in PHP: You force cast variable $foo as int -- (int)$foo. You attempt to store a string value in the variable $foo. PHP throws an exception!! <--- That would make sense. Suddenly the reason for user defined type casting exists! The fact that PHP will switch things around as needed makes the point of user defined type casting vague. For example, the following two code samples are equivalent: // example 1 $foo = 0; $foo = (string)$foo; $foo = '# of Reasons for the programmer to type cast $foo as a string: ' . $foo; // example 2 $foo = 0; $foo = (int)$foo; $foo = '# of Reasons for the programmer to type cast $foo as a string: ' . $foo;

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Handling HumanTask attachments in Oracle BPM 11g PS4FP+ (I)

- by ccasares

Adding attachments to a HumanTask is a feature that exists in Oracle HWF (Human Workflow) since 10g. However, in 11g there have been many improvements on this feature and this entry will try to summarize them. Oracle BPM 11g 11.1.1.5.1 (aka PS4 Feature Pack or PS4FP) introduced two great features: Ability to link attachments at a Task scope or at a Process scope: "Task" attachments are only visible within the scope (lifetime) of a task. This means that, initially, any member of the assignment pattern of the Human Task will be able to handle (add, review or remove) attachments. However, once the task is completed, subsequent human tasks will not have access to them. This does not mean those attachments got lost. Once the human task is completed, attachments can be retrieved in order to, i.e., check them in to a Content Server or to inject them to a new and different human task. Aside note: a "re-initiated" human task will inherit comments and attachments, along with history and -optionally- payload. See here for more info. "Process" attachments are visible within the scope of the process. This means that subsequent human tasks in the same process instance will have access to them. Ability to use Oracle WebCenter Content (previously known as "Oracle UCM") as the backend for the attachments instead of using HWF database backend. This feature adds all content server document lifecycle capabilities to HWF attachments (versioning, RBAC, metadata management, etc). As of today, only Oracle WCC is supported. However, Oracle BPM Suite does include a license of Oracle WCC for the solely usage of document management within BPM scope. Here are some code samples that leverage the above features. Retrieving uploaded attachments -Non UCM- Non UCM attachments (default ones or those that have existed from 10g, and are stored "as-is" in HWK database backend) can be retrieved after the completion of the Human Task. Firstly, we need to know whether any attachment has been effectively uploaded to the human task. There are two ways to find it out: Through an XPath function: Checking the execData/attachment[] structure. For example: Once we are sure one ore more attachments were uploaded to the Human Task, we want to get them. In this example, by "get" I mean to get the attachment name and the payload of the file. Aside note: Oracle HWF lets you to upload two kind of [non-UCM] attachments: a desktop document and a Web URL. This example focuses just on the desktop document one. In order to "retrieve" an uploaded Web URL, you can get it directly from the execData/attachment[] structure. Attachment content (payload) is retrieved through the getTaskAttachmentContents() XPath function: This example shows how to retrieve as many attachments as those had been uploaded to the Human Task and write them to the server using the File Adapter service. The sample process excerpt is as follows: A dummy UserTask using "HumanTask1" Human Task followed by a Embedded Subprocess that will retrieve the attachments (we're assuming at least one attachment is uploaded): and once retrieved, we will write each of them back to a file in the server using a File Adapter service: In detail: We've defined an XSD structure that will hold the attachments (both name and payload): Then, we can create a BusinessObject based on such element (attachmentCollection) and create a variable (named attachmentBPM) of such BusinessObject type. We will also need to keep a copy of the HumanTask output's execData structure. Therefore we need to create a variable of type TaskExecutionData... ...and copy the HumanTask output execData to it: Now we get into the embedded subprocess that will retrieve the attachments' payload. First, and using an XSLT transformation, we feed the attachmentBPM variable with the name of each attachment and setting an empty value to the payload: Please note that we're using the XSLT for-each node to create as many target structures as necessary. Also note that we're setting an Empty text to the payload variable. The reason for this is to make sure the <payload></payload> tag gets created. This is needed when we map the payload to the XML variable later. Aside note: We are assuming that we're retrieving non-UCM attachments. However in real life you might want to check the type of attachment you're handling. The execData/attachment[]/storageType contains the values "UCM" for UCM type attachments, "TASK" for non-UCM ones or "URL" for Web URL ones. Those values are part of the "Ext.Com.Oracle.Xmlns.Bpel.Workflow.Task.StorageTypeEnum" enumeration. Once we have fed the attachmentsBPM structure and so it now contains the name of each of the attachments, it is time to iterate through it and get the payload. Therefore we will use a new embedded subprocess of type MultiInstance, that will iterate over the attachmentsBPM/attachment[] element: In every iteration we will use a Script activity to map the corresponding payload element with the result of the XPath function getTaskAttachmentContents(). Please, note how the target array element is indexed with the loopCounter predefined variable, so that we make sure we're feeding the right element during the array iteration: The XPath function used looks as follows: hwf:getTaskAttachmentContents(bpmn:getDataObject('UserTask1LocalExecData')/ns1:systemAttributes/ns1:taskId, bpmn:getDataObject('attachmentsBPM')/ns:attachment[bpmn:getActivityInstanceAttribute('SUBPROCESS3067107484296', 'loopCounter')]/ns:fileName) where the input parameters are: taskId of the just completed Human Task attachment name we're retrieving the payload from array index (loopCounter predefined variable) Aside note: The reason whereby we're iterating the execData/attachment[] structure through embedded subprocess and not, i.e., using XSLT and for-each nodes, is mostly because the getTaskAttachmentContents() XPath function is currently not available in XSLT mappings. So all this example might be considered as a workaround until this gets fixed/enhanced in future releases. Once this embedded subprocess ends, we will have all attachments (name + payload) in the attachmentsBPM variable, which is the main goal of this sample. But in order to test everything runs fine, we finish the sample writing each attachment to a file. To that end we include a final embedded subprocess to concurrently iterate through each attachmentsBPM/attachment[] element: On each iteration we will use a Service activity that invokes a File Adapter write service. In here we have two important parameters to set. First, the payload itself. The file adapter awaits binary data in base64 format (string). We have to map it using XPath (Simple mapping doesn't recognize a String as a base64-binary valid target): Second, we must set the target filename using the Service Properties dialog box: Again, note how we're making use of the loopCounter index variable to get the right element within the embedded subprocess iteration. Handling UCM attachments will be part of a different and upcoming blog entry. Once I finish will all posts on this matter, I will upload the whole sample project to java.net.

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Dynamically loading Assemblies to reduce Runtime Depencies

- by Rick Strahl

I've been working on a request to the West Wind Application Configuration library to add JSON support. The config library is a very easy to use code-first approach to configuration: You create a class that holds the configuration data that inherits from a base configuration class, and then assign a persistence provider at runtime that determines where and how the configuration data is store. Currently the library supports .NET Configuration stores (web.config/app.config), XML files, SQL records and string storage.About once a week somebody asks me about JSON support and I've deflected this question for the longest time because frankly I think that JSON as a configuration store doesn't really buy a heck of a lot over XML. Both formats require the user to perform some fixup of the plain configuration data - in XML into XML tags, with JSON using JSON delimiters for properties and property formatting rules. Sure JSON is a little less verbose and maybe a little easier to read if you have hierarchical data, but overall the differences are pretty minor in my opinion. And yet - the requests keep rolling in.Hard Link Issues in a Component LibraryAnother reason I've been hesitant is that I really didn't want to pull in a dependency on an external JSON library - in this case JSON.NET - into the core library. If you're not using JSON.NET elsewhere I don't want a user to have to require a hard dependency on JSON.NET unless they want to use the JSON feature. JSON.NET is also sensitive to versions and doesn't play nice with multiple versions when hard linked. For example, when you have a reference to V4.4 in your project but the host application has a reference to version 4.5 you can run into assembly load problems. NuGet's Update-Package can solve some of this *if* you can recompile, but that's not ideal for a component that's supposed to be just plug and play. This is no criticism of JSON.NET - this really applies to any dependency that might change. So hard linking the DLL can be problematic for a number reasons, but the primary reason is to not force loading of JSON.NET unless you actually need it when you use the JSON configuration features of the library.Enter Dynamic LoadingSo rather than adding an assembly reference to the project, I decided that it would be better to dynamically load the DLL at runtime and then use dynamic typing to access various classes. This allows me to run without a hard assembly reference and allows more flexibility with version number differences now and in the future.But there are also a couple of downsides:No assembly reference means only dynamic access - no compiler type checking or IntellisenseRequirement for the host application to have reference to JSON.NET or else get runtime errorsThe former is minor, but the latter can be problematic. Runtime errors are always painful, but in this case I'm willing to live with this. If you want to use JSON configuration settings JSON.NET needs to be loaded in the project. If this is a Web project, it'll likely be there already.So there are a few things that are needed to make this work:Dynamically create an instance and optionally attempt to load an Assembly (if not loaded)Load types into dynamic variablesUse Reflection for a few tasks like statics/enumsThe dynamic keyword in C# makes the formerly most difficult Reflection part - method calls and property assignments - fairly painless. But as cool as dynamic is it doesn't handle all aspects of Reflection. Specifically it doesn't deal with object activation, truly dynamic (string based) member activation or accessing of non instance members, so there's still a little bit of work left to do with Reflection.Dynamic Object InstantiationThe first step in getting the process rolling is to instantiate the type you need to work with. This might be a two step process - loading the instance from a string value, since we don't have a hard type reference and potentially having to load the assembly. Although the host project might have a reference to JSON.NET, that instance might have not been loaded yet since it hasn't been accessed yet. In ASP.NET this won't be a problem, since ASP.NET preloads all referenced assemblies on AppDomain startup, but in other executable project, assemblies are just in time loaded only when they are accessed.Instantiating a type is a two step process: Finding the type reference and then activating it. Here's the generic code out of my ReflectionUtils library I use for this:/// <summary> /// Creates an instance of a type based on a string. Assumes that the type's /// </summary> /// <param name="typeName">Common name of the type</param> /// <param name="args">Any constructor parameters</param> /// <returns></returns> public static object CreateInstanceFromString(string typeName, params object[] args) { object instance = null; Type type = null; try { type = GetTypeFromName(typeName); if (type == null) return null; instance = Activator.CreateInstance(type, args); } catch { return null; } return instance; } /// <summary> /// Helper routine that looks up a type name and tries to retrieve the /// full type reference in the actively executing assemblies. /// </summary> /// <param name="typeName"></param> /// <returns></returns> public static Type GetTypeFromName(string typeName) { Type type = null; // Let default name binding find it type = Type.GetType(typeName, false); if (type != null) return type; // look through assembly list var assemblies = AppDomain.CurrentDomain.GetAssemblies(); // try to find manually foreach (Assembly asm in assemblies) { type = asm.GetType(typeName, false); if (type != null) break; } return type; } To use this for loading JSON.NET I have a small factory function that instantiates JSON.NET and sets a bunch of configuration settings on the generated object. The startup code also looks for failure and tries loading up the assembly when it fails since that's the main reason the load would fail. Finally it also caches the loaded instance for reuse (according to James the JSON.NET instance is thread safe and quite a bit faster when cached). Here's what the factory function looks like in JsonSerializationUtils:/// <summary> /// Dynamically creates an instance of JSON.NET /// </summary> /// <param name="throwExceptions">If true throws exceptions otherwise returns null</param> /// <returns>Dynamic JsonSerializer instance</returns> public static dynamic CreateJsonNet(bool throwExceptions = true) { if (JsonNet != null) return JsonNet; lock (SyncLock) { if (JsonNet != null) return JsonNet; // Try to create instance dynamic json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); if (json == null) { try { var ass = AppDomain.CurrentDomain.Load("Newtonsoft.Json"); json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); } catch (Exception ex) { if (throwExceptions) throw; return null; } } if (json == null) return null; json.ReferenceLoopHandling = (dynamic) ReflectionUtils.GetStaticProperty("Newtonsoft.Json.ReferenceLoopHandling", "Ignore"); // Enums as strings in JSON dynamic enumConverter = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.Converters.StringEnumConverter"); json.Converters.Add(enumConverter); JsonNet = json; } return JsonNet; }This code's purpose is to return a fully configured JsonSerializer instance. As you can see the code tries to create an instance and when it fails tries to load the assembly, and then re-tries loading.Once the instance is loaded some configuration occurs on it. Specifically I set the ReferenceLoopHandling option to not blow up immediately when circular references are encountered. There are a host of other small config setting that might be useful to set, but the default seem to be good enough in recent versions. Note that I'm setting ReferenceLoopHandling which requires an Enum value to be set. There's no real easy way (short of using the cardinal numeric value) to set a property or pass parameters from static values or enums. This means I still need to use Reflection to make this work. I'm using the same ReflectionUtils class I previously used to handle this for me. The function looks up the type and then uses Type.InvokeMember() to read the static property.Another feature I need is have Enum values serialized as strings rather than numeric values which is the default. To do this I can use the StringEnumConverter to convert enums to strings by adding it to the Converters collection.As you can see there's still a bit of Reflection to be done even in C# 4+ with dynamic, but with a few helpers this process is relatively painless.Doing the actual JSON ConversionFinally I need to actually do my JSON conversions. For the Utility class I need serialization that works for both strings and files so I created four methods that handle these tasks two each for serialization and deserialization for string and file.Here's what the File Serialization looks like:/// <summary> /// Serializes an object instance to a JSON file. /// </summary> /// <param name="value">the value to serialize</param> /// <param name="fileName">Full path to the file to write out with JSON.</param> /// <param name="throwExceptions">Determines whether exceptions are thrown or false is returned</param> /// <param name="formatJsonOutput">if true pretty-formats the JSON with line breaks</param> /// <returns>true or false</returns> public static bool SerializeToFile(object value, string fileName, bool throwExceptions = false, bool formatJsonOutput = false) { dynamic writer = null; FileStream fs = null; try { Type type = value.GetType(); var json = CreateJsonNet(throwExceptions); if (json == null) return false; fs = new FileStream(fileName, FileMode.Create); var sw = new StreamWriter(fs, Encoding.UTF8); writer = Activator.CreateInstance(JsonTextWriterType, sw); if (formatJsonOutput) writer.Formatting = (dynamic)Enum.Parse(FormattingType, "Indented"); writer.QuoteChar = '"'; json.Serialize(writer, value); } catch (Exception ex) { Debug.WriteLine("JsonSerializer Serialize error: " + ex.Message); if (throwExceptions) throw; return false; } finally { if (writer != null) writer.Close(); if (fs != null) fs.Close(); } return true; }You can see more of the dynamic invocation in this code. First I grab the dynamic JsonSerializer instance using the CreateJsonNet() method shown earlier which returns a dynamic. I then create a JsonTextWriter and configure a couple of enum settings on it, and then call Serialize() on the serializer instance with the JsonTextWriter that writes the output to disk. Although this code is dynamic it's still fairly short and readable.For full circle operation here's the DeserializeFromFile() version:/// <summary> /// Deserializes an object from file and returns a reference. /// </summary> /// <param name="fileName">name of the file to serialize to</param> /// <param name="objectType">The Type of the object. Use typeof(yourobject class)</param> /// <param name="binarySerialization">determines whether we use Xml or Binary serialization</param> /// <param name="throwExceptions">determines whether failure will throw rather than return null on failure</param> /// <returns>Instance of the deserialized object or null. Must be cast to your object type</returns> public static object DeserializeFromFile(string fileName, Type objectType, bool throwExceptions = false) { dynamic json = CreateJsonNet(throwExceptions); if (json == null) return null; object result = null; dynamic reader = null; FileStream fs = null; try { fs = new FileStream(fileName, FileMode.Open, FileAccess.Read); var sr = new StreamReader(fs, Encoding.UTF8); reader = Activator.CreateInstance(JsonTextReaderType, sr); result = json.Deserialize(reader, objectType); reader.Close(); } catch (Exception ex) { Debug.WriteLine("JsonNetSerialization Deserialization Error: " + ex.Message); if (throwExceptions) throw; return null; } finally { if (reader != null) reader.Close(); if (fs != null) fs.Close(); } return result; }This code is a little more compact since there are no prettifying options to set. Here JsonTextReader is created dynamically and it receives the output from the Deserialize() operation on the serializer.You can take a look at the full JsonSerializationUtils.cs file on GitHub to see the rest of the operations, but the string operations are very similar - the code is fairly repetitive.These generic serialization utilities isolate the dynamic serialization logic that has to deal with the dynamic nature of JSON.NET, and any code that uses these functions is none the wiser that JSON.NET is dynamically loaded.Using the JsonSerializationUtils WrapperThe final consumer of the SerializationUtils wrapper is an actual ConfigurationProvider, that is responsible for handling reading and writing JSON values to and from files. The provider is simple a small wrapper around the SerializationUtils component and there's very little code to make this work now:The whole provider looks like this:/// <summary> /// Reads and Writes configuration settings in .NET config files and /// sections. Allows reading and writing to default or external files /// and specification of the configuration section that settings are /// applied to. /// </summary> public class JsonFileConfigurationProvider<TAppConfiguration> : ConfigurationProviderBase<TAppConfiguration> where TAppConfiguration: AppConfiguration, new() { /// <summary> /// Optional - the Configuration file where configuration settings are /// stored in. If not specified uses the default Configuration Manager /// and its default store. /// </summary> public string JsonConfigurationFile { get { return _JsonConfigurationFile; } set { _JsonConfigurationFile = value; } } private string _JsonConfigurationFile = string.Empty; public override bool Read(AppConfiguration config) { var newConfig = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfiguration)) as TAppConfiguration; if (newConfig == null) { if(Write(config)) return true; return false; } DecryptFields(newConfig); DataUtils.CopyObjectData(newConfig, config, "Provider,ErrorMessage"); return true; } /// <summary> /// Return /// </summary> /// <typeparam name="TAppConfig"></typeparam> /// <returns></returns> public override TAppConfig Read<TAppConfig>() { var result = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfig)) as TAppConfig; if (result != null) DecryptFields(result); return result; } /// <summary> /// Write configuration to XmlConfigurationFile location /// </summary> /// <param name="config"></param> /// <returns></returns> public override bool Write(AppConfiguration config) { EncryptFields(config); bool result = JsonSerializationUtils.SerializeToFile(config, JsonConfigurationFile,false,true); // Have to decrypt again to make sure the properties are readable afterwards DecryptFields(config); return result; } }This incidentally demonstrates how easy it is to create a new provider for the West Wind Application Configuration component. Simply implementing 3 methods will do in most cases.Note this code doesn't have any dynamic dependencies - all that's abstracted away in the JsonSerializationUtils(). From here on, serializing JSON is just a matter of calling the static methods on the SerializationUtils class.Already, there are several other places in some other tools where I use JSON serialization this is coming in very handy. With a couple of lines of code I was able to add JSON.NET support to an older AJAX library that I use replacing quite a bit of code that was previously in use. And for any other manual JSON operations (in a couple of apps I use JSON Serialization for 'blob' like document storage) this is also going to be handy.Performance?Some of you might be thinking that using dynamic and Reflection can't be good for performance. And you'd be right… In performing some informal testing it looks like the performance of the native code is nearly twice as fast as the dynamic code. Most of the slowness is attributable to type lookups. To test I created a native class that uses an actual reference to JSON.NET and performance was consistently around 85-90% faster with the referenced code. That being said though - I serialized 10,000 objects in 80ms vs. 45ms so this isn't hardly slouchy. For the configuration component speed is not that important because both read and write operations typically happen once on first access and then every once in a while. But for other operations - say a serializer trying to handle AJAX requests on a Web Server one would be well served to create a hard dependency.Dynamic Loading - Worth it?On occasion dynamic loading makes sense. But there's a price to be paid in added code complexity and a performance hit. But for some operations that are not pivotal to a component or application and only used under certain circumstances dynamic loading can be beneficial to avoid having to ship extra files and loading down distributions. These days when you create new projects in Visual Studio with 30 assemblies before you even add your own code, trying to keep file counts under control seems a good idea. It's not the kind of thing you do on a regular basis, but when needed it can be a useful tool. Hopefully some of you find this information useful…© Rick Strahl, West Wind Technologies, 2005-2013Posted in .NET C# Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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SOA & Application Grid Specialization step 2 of 6 – References & Marketing Kits

- by Jürgen Kress

In our fist step to become SOA Specialized & Application Grid Specialized we highlighted our OMM to register your opportunities. We continue our path to specialization with our marketing offerings to create your reference cases and run joint marketing campaigns. References: Be Recognized Through Partner Success Stories Oracle delivers a wide variety of services and solutions through our partners and we believe that those successes should be recognized and promoted. References are also required to become specialized. We showcase our partners’ capabilities in Oracle products and industries through partner success stories that are published on Oracle.com. For significant implementations, we may invite partners to participate in a press release or be interviewed in a podcast. To participate and take a further step to become specialized, please take a minute to complete the form and tell us about the successful project you have implemented. If your story is selected, we will contact you for an interview. Create your references The partner reference program Enables partners to be recognized by both Oracle and our customers Provides an opportunity for partners to showcase successes with their customers on Oracle solutions Helps raise awareness of our partners’ capabilities, elevating them above their competition Time to submit a SOA and Application Grid reference request today To learn more about partner references, check out the following resources: Judson Althoff’s YouTube Video: Be Recognized with OPN Specialized Reference Program OPN PartnerCast: Be Recognized…Your Reference Matters!!! (MP3) Partner/Customer Reference Brochure (PDF) Marketing Kits We have created OFM 11g marketing kit http://tinyurl.com/soamarketing (OPN account required) The marketing kit includes all the ppts and demos from our launch event. Oracle package includes: • Event templates like invitation, agenda ,confirmation follow up templates • OFM 11g presentations • Free usage of the Oracle Customer Visit Center • Condition: mandatory lead registration in the Oracle Open Market Model (OMM) To download the material, please make sure that you select the campaign “Enterprise: Fusion Middleware 11g”: OFM 11g Oracle Marketing 4 Partners Package http://tinyurl.com/soamarketing (OPN account required) For more information on Specialization please visit our OPN Specialized Webcast Series And become a member in our SOA Partner Community for registration please visit www.oracle.com/goto/ema/soa Jürgen Kress, SOA Partner Adoption EMEA SOA Specialized Application Grid Specialized Proof 2 transactions with OMM Proof 2 transactions with OMM Create your 2 references Create your 2 references SOA Sales assessment 3, Oracle Application Grid Sales Specialist SOA Pre-Sales assessment 3 Oracle Application Grid PreSales Specialist Support assessment 1 Support assessment 2 SOA Implementation assessment 4 Application Gridplementation assessment 4

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Dynamically loading Assemblies to reduce Runtime Dependencies

- by Rick Strahl

I've been working on a request to the West Wind Application Configuration library to add JSON support. The config library is a very easy to use code-first approach to configuration: You create a class that holds the configuration data that inherits from a base configuration class, and then assign a persistence provider at runtime that determines where and how the configuration data is store. Currently the library supports .NET Configuration stores (web.config/app.config), XML files, SQL records and string storage.About once a week somebody asks me about JSON support and I've deflected this question for the longest time because frankly I think that JSON as a configuration store doesn't really buy a heck of a lot over XML. Both formats require the user to perform some fixup of the plain configuration data - in XML into XML tags, with JSON using JSON delimiters for properties and property formatting rules. Sure JSON is a little less verbose and maybe a little easier to read if you have hierarchical data, but overall the differences are pretty minor in my opinion. And yet - the requests keep rolling in.Hard Link Issues in a Component LibraryAnother reason I've been hesitant is that I really didn't want to pull in a dependency on an external JSON library - in this case JSON.NET - into the core library. If you're not using JSON.NET elsewhere I don't want a user to have to require a hard dependency on JSON.NET unless they want to use the JSON feature. JSON.NET is also sensitive to versions and doesn't play nice with multiple versions when hard linked. For example, when you have a reference to V4.4 in your project but the host application has a reference to version 4.5 you can run into assembly load problems. NuGet's Update-Package can solve some of this *if* you can recompile, but that's not ideal for a component that's supposed to be just plug and play. This is no criticism of JSON.NET - this really applies to any dependency that might change. So hard linking the DLL can be problematic for a number reasons, but the primary reason is to not force loading of JSON.NET unless you actually need it when you use the JSON configuration features of the library.Enter Dynamic LoadingSo rather than adding an assembly reference to the project, I decided that it would be better to dynamically load the DLL at runtime and then use dynamic typing to access various classes. This allows me to run without a hard assembly reference and allows more flexibility with version number differences now and in the future.But there are also a couple of downsides:No assembly reference means only dynamic access - no compiler type checking or IntellisenseRequirement for the host application to have reference to JSON.NET or else get runtime errorsThe former is minor, but the latter can be problematic. Runtime errors are always painful, but in this case I'm willing to live with this. If you want to use JSON configuration settings JSON.NET needs to be loaded in the project. If this is a Web project, it'll likely be there already.So there are a few things that are needed to make this work:Dynamically create an instance and optionally attempt to load an Assembly (if not loaded)Load types into dynamic variablesUse Reflection for a few tasks like statics/enumsThe dynamic keyword in C# makes the formerly most difficult Reflection part - method calls and property assignments - fairly painless. But as cool as dynamic is it doesn't handle all aspects of Reflection. Specifically it doesn't deal with object activation, truly dynamic (string based) member activation or accessing of non instance members, so there's still a little bit of work left to do with Reflection.Dynamic Object InstantiationThe first step in getting the process rolling is to instantiate the type you need to work with. This might be a two step process - loading the instance from a string value, since we don't have a hard type reference and potentially having to load the assembly. Although the host project might have a reference to JSON.NET, that instance might have not been loaded yet since it hasn't been accessed yet. In ASP.NET this won't be a problem, since ASP.NET preloads all referenced assemblies on AppDomain startup, but in other executable project, assemblies are just in time loaded only when they are accessed.Instantiating a type is a two step process: Finding the type reference and then activating it. Here's the generic code out of my ReflectionUtils library I use for this:/// <summary> /// Creates an instance of a type based on a string. Assumes that the type's /// </summary> /// <param name="typeName">Common name of the type</param> /// <param name="args">Any constructor parameters</param> /// <returns></returns> public static object CreateInstanceFromString(string typeName, params object[] args) { object instance = null; Type type = null; try { type = GetTypeFromName(typeName); if (type == null) return null; instance = Activator.CreateInstance(type, args); } catch { return null; } return instance; } /// <summary> /// Helper routine that looks up a type name and tries to retrieve the /// full type reference in the actively executing assemblies. /// </summary> /// <param name="typeName"></param> /// <returns></returns> public static Type GetTypeFromName(string typeName) { Type type = null; // Let default name binding find it type = Type.GetType(typeName, false); if (type != null) return type; // look through assembly list var assemblies = AppDomain.CurrentDomain.GetAssemblies(); // try to find manually foreach (Assembly asm in assemblies) { type = asm.GetType(typeName, false); if (type != null) break; } return type; } To use this for loading JSON.NET I have a small factory function that instantiates JSON.NET and sets a bunch of configuration settings on the generated object. The startup code also looks for failure and tries loading up the assembly when it fails since that's the main reason the load would fail. Finally it also caches the loaded instance for reuse (according to James the JSON.NET instance is thread safe and quite a bit faster when cached). Here's what the factory function looks like in JsonSerializationUtils:/// <summary> /// Dynamically creates an instance of JSON.NET /// </summary> /// <param name="throwExceptions">If true throws exceptions otherwise returns null</param> /// <returns>Dynamic JsonSerializer instance</returns> public static dynamic CreateJsonNet(bool throwExceptions = true) { if (JsonNet != null) return JsonNet; lock (SyncLock) { if (JsonNet != null) return JsonNet; // Try to create instance dynamic json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); if (json == null) { try { var ass = AppDomain.CurrentDomain.Load("Newtonsoft.Json"); json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); } catch (Exception ex) { if (throwExceptions) throw; return null; } } if (json == null) return null; json.ReferenceLoopHandling = (dynamic) ReflectionUtils.GetStaticProperty("Newtonsoft.Json.ReferenceLoopHandling", "Ignore"); // Enums as strings in JSON dynamic enumConverter = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.Converters.StringEnumConverter"); json.Converters.Add(enumConverter); JsonNet = json; } return JsonNet; }This code's purpose is to return a fully configured JsonSerializer instance. As you can see the code tries to create an instance and when it fails tries to load the assembly, and then re-tries loading.Once the instance is loaded some configuration occurs on it. Specifically I set the ReferenceLoopHandling option to not blow up immediately when circular references are encountered. There are a host of other small config setting that might be useful to set, but the default seem to be good enough in recent versions. Note that I'm setting ReferenceLoopHandling which requires an Enum value to be set. There's no real easy way (short of using the cardinal numeric value) to set a property or pass parameters from static values or enums. This means I still need to use Reflection to make this work. I'm using the same ReflectionUtils class I previously used to handle this for me. The function looks up the type and then uses Type.InvokeMember() to read the static property.Another feature I need is have Enum values serialized as strings rather than numeric values which is the default. To do this I can use the StringEnumConverter to convert enums to strings by adding it to the Converters collection.As you can see there's still a bit of Reflection to be done even in C# 4+ with dynamic, but with a few helpers this process is relatively painless.Doing the actual JSON ConversionFinally I need to actually do my JSON conversions. For the Utility class I need serialization that works for both strings and files so I created four methods that handle these tasks two each for serialization and deserialization for string and file.Here's what the File Serialization looks like:/// <summary> /// Serializes an object instance to a JSON file. /// </summary> /// <param name="value">the value to serialize</param> /// <param name="fileName">Full path to the file to write out with JSON.</param> /// <param name="throwExceptions">Determines whether exceptions are thrown or false is returned</param> /// <param name="formatJsonOutput">if true pretty-formats the JSON with line breaks</param> /// <returns>true or false</returns> public static bool SerializeToFile(object value, string fileName, bool throwExceptions = false, bool formatJsonOutput = false) { dynamic writer = null; FileStream fs = null; try { Type type = value.GetType(); var json = CreateJsonNet(throwExceptions); if (json == null) return false; fs = new FileStream(fileName, FileMode.Create); var sw = new StreamWriter(fs, Encoding.UTF8); writer = Activator.CreateInstance(JsonTextWriterType, sw); if (formatJsonOutput) writer.Formatting = (dynamic)Enum.Parse(FormattingType, "Indented"); writer.QuoteChar = '"'; json.Serialize(writer, value); } catch (Exception ex) { Debug.WriteLine("JsonSerializer Serialize error: " + ex.Message); if (throwExceptions) throw; return false; } finally { if (writer != null) writer.Close(); if (fs != null) fs.Close(); } return true; }You can see more of the dynamic invocation in this code. First I grab the dynamic JsonSerializer instance using the CreateJsonNet() method shown earlier which returns a dynamic. I then create a JsonTextWriter and configure a couple of enum settings on it, and then call Serialize() on the serializer instance with the JsonTextWriter that writes the output to disk. Although this code is dynamic it's still fairly short and readable.For full circle operation here's the DeserializeFromFile() version:/// <summary> /// Deserializes an object from file and returns a reference. /// </summary> /// <param name="fileName">name of the file to serialize to</param> /// <param name="objectType">The Type of the object. Use typeof(yourobject class)</param> /// <param name="binarySerialization">determines whether we use Xml or Binary serialization</param> /// <param name="throwExceptions">determines whether failure will throw rather than return null on failure</param> /// <returns>Instance of the deserialized object or null. Must be cast to your object type</returns> public static object DeserializeFromFile(string fileName, Type objectType, bool throwExceptions = false) { dynamic json = CreateJsonNet(throwExceptions); if (json == null) return null; object result = null; dynamic reader = null; FileStream fs = null; try { fs = new FileStream(fileName, FileMode.Open, FileAccess.Read); var sr = new StreamReader(fs, Encoding.UTF8); reader = Activator.CreateInstance(JsonTextReaderType, sr); result = json.Deserialize(reader, objectType); reader.Close(); } catch (Exception ex) { Debug.WriteLine("JsonNetSerialization Deserialization Error: " + ex.Message); if (throwExceptions) throw; return null; } finally { if (reader != null) reader.Close(); if (fs != null) fs.Close(); } return result; }This code is a little more compact since there are no prettifying options to set. Here JsonTextReader is created dynamically and it receives the output from the Deserialize() operation on the serializer.You can take a look at the full JsonSerializationUtils.cs file on GitHub to see the rest of the operations, but the string operations are very similar - the code is fairly repetitive.These generic serialization utilities isolate the dynamic serialization logic that has to deal with the dynamic nature of JSON.NET, and any code that uses these functions is none the wiser that JSON.NET is dynamically loaded.Using the JsonSerializationUtils WrapperThe final consumer of the SerializationUtils wrapper is an actual ConfigurationProvider, that is responsible for handling reading and writing JSON values to and from files. The provider is simple a small wrapper around the SerializationUtils component and there's very little code to make this work now:The whole provider looks like this:/// <summary> /// Reads and Writes configuration settings in .NET config files and /// sections. Allows reading and writing to default or external files /// and specification of the configuration section that settings are /// applied to. /// </summary> public class JsonFileConfigurationProvider<TAppConfiguration> : ConfigurationProviderBase<TAppConfiguration> where TAppConfiguration: AppConfiguration, new() { /// <summary> /// Optional - the Configuration file where configuration settings are /// stored in. If not specified uses the default Configuration Manager /// and its default store. /// </summary> public string JsonConfigurationFile { get { return _JsonConfigurationFile; } set { _JsonConfigurationFile = value; } } private string _JsonConfigurationFile = string.Empty; public override bool Read(AppConfiguration config) { var newConfig = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfiguration)) as TAppConfiguration; if (newConfig == null) { if(Write(config)) return true; return false; } DecryptFields(newConfig); DataUtils.CopyObjectData(newConfig, config, "Provider,ErrorMessage"); return true; } /// <summary> /// Return /// </summary> /// <typeparam name="TAppConfig"></typeparam> /// <returns></returns> public override TAppConfig Read<TAppConfig>() { var result = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfig)) as TAppConfig; if (result != null) DecryptFields(result); return result; } /// <summary> /// Write configuration to XmlConfigurationFile location /// </summary> /// <param name="config"></param> /// <returns></returns> public override bool Write(AppConfiguration config) { EncryptFields(config); bool result = JsonSerializationUtils.SerializeToFile(config, JsonConfigurationFile,false,true); // Have to decrypt again to make sure the properties are readable afterwards DecryptFields(config); return result; } }This incidentally demonstrates how easy it is to create a new provider for the West Wind Application Configuration component. Simply implementing 3 methods will do in most cases.Note this code doesn't have any dynamic dependencies - all that's abstracted away in the JsonSerializationUtils(). From here on, serializing JSON is just a matter of calling the static methods on the SerializationUtils class.Already, there are several other places in some other tools where I use JSON serialization this is coming in very handy. With a couple of lines of code I was able to add JSON.NET support to an older AJAX library that I use replacing quite a bit of code that was previously in use. And for any other manual JSON operations (in a couple of apps I use JSON Serialization for 'blob' like document storage) this is also going to be handy.Performance?Some of you might be thinking that using dynamic and Reflection can't be good for performance. And you'd be right… In performing some informal testing it looks like the performance of the native code is nearly twice as fast as the dynamic code. Most of the slowness is attributable to type lookups. To test I created a native class that uses an actual reference to JSON.NET and performance was consistently around 85-90% faster with the referenced code. This will change though depending on the size of objects serialized - the larger the object the more processing time is spent inside the actual dynamically activated components and the less difference there will be. Dynamic code is always slower, but how much it really affects your application primarily depends on how frequently the dynamic code is called in relation to the non-dynamic code executing. In most situations where dynamic code is used 'to get the process rolling' as I do here the overhead is small enough to not matter.All that being said though - I serialized 10,000 objects in 80ms vs. 45ms so this is hardly slouchy performance. For the configuration component speed is not that important because both read and write operations typically happen once on first access and then every once in a while. But for other operations - say a serializer trying to handle AJAX requests on a Web Server one would be well served to create a hard dependency.Dynamic Loading - Worth it?Dynamic loading is not something you need to worry about but on occasion dynamic loading makes sense. But there's a price to be paid in added code and a performance hit which depends on how frequently the dynamic code is accessed. But for some operations that are not pivotal to a component or application and are only used under certain circumstances dynamic loading can be beneficial to avoid having to ship extra files adding dependencies and loading down distributions. These days when you create new projects in Visual Studio with 30 assemblies before you even add your own code, trying to keep file counts under control seems like a good idea. It's not the kind of thing you do on a regular basis, but when needed it can be a useful option in your toolset… © Rick Strahl, West Wind Technologies, 2005-2013Posted in .NET C# Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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Is there a constant for "end of time"?

- by Nick Rosencrantz

For some systems, the time value 9999-12-31 is used as the "end of time" as the end of the time that the computer can calculate. But what if it changes? Wouldn't it be better to define this time as a builtin variable? In C and other programming languages there usually is a variable such as MAX_INT or similar to get the largest value an integer could have. Why is there not a similar function for MAX_TIME i.e. set the variable to the "end of time" which for many systems usually is 9999-12-31. To avoid the problem of hardcoding to a wrong year (9999) could these systems introduce a variable for the "end of time"?

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A Gentle Introduction to NuGet

- by Joe Mayo

Not too long ago, Microsoft released, NuGet, an automated package manager for Visual Studio. NuGet makes it easy to download and install assemblies, and their references, into a Visual Studio project. These assemblies, which I loosely refer to as packages, are often open source, and include projects such as LINQ to Twitter. In this post, I'll explain how to get started in using NuGet with your projects to include: installng NuGet, installing/uninstalling LINQ to Twitter via console command, and installing/uninstalling LINQ to Twitter via graphical reference menu. Installing NuGet The first step you'll need to take is to install NuGet. Visit the NuGet site, at http://nuget.org/, click on the Install NuGet button, and download the NuGet.Tools.vsix installation file, shown below. Each browser is different (i.e. FireFox, Chrome, IE, etc), so you might see options to run right away, save to a location, or access to the file through the browser's download manager. Regardless of how you receive the NuGet installer, execute the downloaded NuGet.Tools.vsix to install Nuget into visual Studio. The NuGet Footprint When you open visual Studio, observe that there is a new menu option on the Tools menu, titled Library Package Manager; This is where you use NuGet. There are two menu options, from the Library Package Manager Menu that you can use: Package Manager Console and Package Manager Settings. I won't discuss Package Manager Settings in this post, except to give you a general idea that, as one of a set of capabilities, it manages the path to the NuGet server, which is already set for you. Another menu, added by the NuGet installer, is Add Library Package Reference, found by opening the context menu for either a Solution Explorer project or a project's References folder or via the Project menu. I'll discuss how to use this later in the post. The following discussion is concerned with the other menu option, Package Manager Console, which allows you to manage NuGet packages. Gettng a NuGet Package Selecting Tools -> Library Package Manager -> Package Manager Console opens the Package Manager Console. As you can see, below, the Package Manager Console is text-based and you'll need to type in commands to work with packages. In this post, I'll explain how to use the Package Manager Console to install LINQ to Twitter, but there are many more commands, explained in the NuGet Package Manager Console Commands documentation. To install LINQ to Twitter, open your current project where you want LINQ to Twitter installed, and type the following at the PM> prompt: Install-Package linqtotwitter If all works well, you'll receive a confirmation message, similar to the following, after a brief pause: Successfully installed 'linqtotwitter 2.0.20'. Successfully added 'linqtotwitter 2.0.20' to NuGetInstall. Also, observe that a reference to the LinqToTwitter.dll assembly was added to your current project. Uninstalling a NuGet Package I won't be so bold as to assume that you would only want to use LINQ to Twitter because there are other Twitter libraries available; I recommend Twitterizer if you don't care for LINQ to Twitter. So, you might want to use the following command at the PM> prompt to remove LINQ to Twitter from your project: Uninstall-Package linqtotwitter After a brief pause, you'll see a confirmation message similar to the following: Successfully removed 'linqtotwitter 2.0.20' from NuGetInstall. Also, observe that the LinqToTwitter.dll assembly no longer appears in your project references list. Sometimes using the Package Manager Console is required for more sophisticated scenarios. However, LINQ to Twitter doesn't have any dependencies and is a very simple install, so you can use another method of installing graphically, which I'll show you next. Graphical Installations As explained earlier, clicking Add Library Package Reference, from the context menu for either a Solution Explorer project or a project's References folder or via the Project menu opens the Add Library Package Reference window. This window will allow you to add a reference a NuGet package in your project. To the left of the window are a few accordian folders to help you find packages that are either on-line or already installed. Just like the previous section, I'll assume you are installing LINQ to Twitter for the first time, so you would select the Online folder and click All. After waiting for package descriptions to download, you'll notice that there are too many to scroll through in a short period of time, over 900 as I write this. Therefore, use the search box located at the top right corner of the window and type LINQ to Twitter as I've done in the previous figure. You'll see LINQ to Twitter appear in the list. Click the Install button on the LINQ to Twitter entry. If the installation was successful, you'll see a message box display and disappear quickly (or maybe not if your machine is very fast or you blink at that moment). Then you'll see a reference to the LinqToTwitter.dll assembly in your project's references list. Note: While running this demo, I ran into an issue where VS had created a file lock on an installation folder without releasing it, causing an error with "packagename already exists. Skipping..." and then an error describing that it couldn't write to a destination folder. I resolved the problem by closing and reopening VS. If you open the Add a Library Package Reference window again, you'll see LINQ to Twitter listed in the Recent packages folder. Summary You can install NuGet via the on-line home page with a click of a button. Nuget provides two ways to work with packages, via console or graphical window. While the graphical window is easiest, the console window is more powerful. You can now quickly add project references to many available packages via the NuGet service. Joe

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Creating New Scripts Dynamically in Lua

- by bazola

Right now this is just a crazy idea that I had, but I was able to implement the code and get it working properly. I am not entirely sure of what the use cases would be just yet. What this code does is create a new Lua script file in the project directory. The ScriptWriter takes as arguments the file name, a table containing any arguments that the script should take when created, and a table containing any instance variables to create by default. My plan is to extend this code to create new functions based on inputs sent in during its creation as well. What makes this cool is that the new file is both generated and loaded dynamically on the fly. Theoretically you could get this code to generate and load any script imaginable. One use case I can think of is an AI that creates scripts to map out it's functions, and creates new scripts for new situations or environments. At this point, this is all theoretical, though. Here is the test code that is creating the new script and then immediately loading it and calling functions from it: function Card:doScriptWriterThing() local scriptName = "ScriptIAmMaking" local scripter = scriptWriter:new(scriptName, {"argumentName"}, {name = "'test'", one = 1}) scripter:makeFileForLoadedSettings() local loadedScript = require (scriptName) local scriptInstance = loadedScript:new("sayThis") print(scriptInstance:get_name()) --will print test print(scriptInstance:get_one()) -- will print 1 scriptInstance:set_one(10000) print(scriptInstance:get_one()) -- will print 10000 print(scriptInstance:get_argumentName()) -- will print sayThis scriptInstance:set_argumentName("saySomethingElse") print(scriptInstance:get_argumentName()) --will print saySomethingElse end Here is ScriptWriter.lua local ScriptWriter = {} local twoSpaceIndent = " " local equalsWithSpaces = " = " local newLine = "\n" --scriptNameToCreate must be a string --argumentsForNew and instanceVariablesToCreate must be tables and not nil function ScriptWriter:new(scriptNameToCreate, argumentsForNew, instanceVariablesToCreate) local instance = setmetatable({}, { __index = self }) instance.name = scriptNameToCreate instance.newArguments = argumentsForNew instance.instanceVariables = instanceVariablesToCreate instance.stringList = {} return instance end function ScriptWriter:makeFileForLoadedSettings() self:buildInstanceMetatable() self:buildInstanceCreationMethod() self:buildSettersAndGetters() self:buildReturn() self:writeStringsToFile() end --very first line of any script that will have instances function ScriptWriter:buildInstanceMetatable() table.insert(self.stringList, "local " .. self.name .. " = {}" .. newLine) table.insert(self.stringList, newLine) end --every script made this way needs a new method to create its instances function ScriptWriter:buildInstanceCreationMethod() --new() function declaration table.insert(self.stringList, ("function " .. self.name .. ":new(")) self:buildNewArguments() table.insert(self.stringList, ")" .. newLine) --first line inside :new() function table.insert(self.stringList, twoSpaceIndent .. "local instance = setmetatable({}, { __index = self })" .. newLine) --add designated arguments inside :new() self:buildNewArgumentVariables() --create the instance variables with the loaded values for key,value in pairs(self.instanceVariables) do table.insert(self.stringList, twoSpaceIndent .. "instance." .. key .. equalsWithSpaces .. value .. newLine) end --close the :new() function table.insert(self.stringList, twoSpaceIndent .. "return instance" .. newLine) table.insert(self.stringList, "end" .. newLine) table.insert(self.stringList, newLine) end function ScriptWriter:buildNewArguments() --if there are arguments for :new(), add them for key,value in ipairs(self.newArguments) do table.insert(self.stringList, value) table.insert(self.stringList, ", ") end if next(self.newArguments) ~= nil then --makes sure the table is not empty first table.remove(self.stringList) --remove the very last element, which will be the extra ", " end end function ScriptWriter:buildNewArgumentVariables() --add the designated arguments to :new() for key, value in ipairs(self.newArguments) do table.insert(self.stringList, twoSpaceIndent .. "instance." .. value .. equalsWithSpaces .. value .. newLine) end end --the instance variables need separate code because their names have to be the key and not the argument name function ScriptWriter:buildSettersAndGetters() for key,value in ipairs(self.newArguments) do self:buildArgumentSetter(value) self:buildArgumentGetter(value) table.insert(self.stringList, newLine) end for key,value in pairs(self.instanceVariables) do self:buildInstanceVariableSetter(key, value) self:buildInstanceVariableGetter(key, value) table.insert(self.stringList, newLine) end end --code for arguments passed in function ScriptWriter:buildArgumentSetter(variable) table.insert(self.stringList, "function " .. self.name .. ":set_" .. variable .. "(newValue)" .. newLine) table.insert(self.stringList, twoSpaceIndent .. "self." .. variable .. equalsWithSpaces .. "newValue" .. newLine) table.insert(self.stringList, "end" .. newLine) end function ScriptWriter:buildArgumentGetter(variable) table.insert(self.stringList, "function " .. self.name .. ":get_" .. variable .. "()" .. newLine) table.insert(self.stringList, twoSpaceIndent .. "return " .. "self." .. variable .. newLine) table.insert(self.stringList, "end" .. newLine) end --code for instance variable values passed in function ScriptWriter:buildInstanceVariableSetter(key, variable) table.insert(self.stringList, "function " .. self.name .. ":set_" .. key .. "(newValue)" .. newLine) table.insert(self.stringList, twoSpaceIndent .. "self." .. key .. equalsWithSpaces .. "newValue" .. newLine) table.insert(self.stringList, "end" .. newLine) end function ScriptWriter:buildInstanceVariableGetter(key, variable) table.insert(self.stringList, "function " .. self.name .. ":get_" .. key .. "()" .. newLine) table.insert(self.stringList, twoSpaceIndent .. "return " .. "self." .. key .. newLine) table.insert(self.stringList, "end" .. newLine) end --last line of any script that will have instances function ScriptWriter:buildReturn() table.insert(self.stringList, "return " .. self.name) end function ScriptWriter:writeStringsToFile() local fileName = (self.name .. ".lua") file = io.open(fileName, 'w') for key,value in ipairs(self.stringList) do file:write(value) end file:close() end return ScriptWriter And here is what the code provided will generate: local ScriptIAmMaking = {} function ScriptIAmMaking:new(argumentName) local instance = setmetatable({}, { __index = self }) instance.argumentName = argumentName instance.name = 'test' instance.one = 1 return instance end function ScriptIAmMaking:set_argumentName(newValue) self.argumentName = newValue end function ScriptIAmMaking:get_argumentName() return self.argumentName end function ScriptIAmMaking:set_name(newValue) self.name = newValue end function ScriptIAmMaking:get_name() return self.name end function ScriptIAmMaking:set_one(newValue) self.one = newValue end function ScriptIAmMaking:get_one() return self.one end return ScriptIAmMaking All of this is generated with these calls: local scripter = scriptWriter:new(scriptName, {"argumentName"}, {name = "'test'", one = 1}) scripter:makeFileForLoadedSettings() I am not sure if I am correct that this could be useful in certain situations. What I am looking for is feedback on the readability of the code, and following Lua best practices. I would also love to hear whether this approach is a valid one, and whether the way that I have done things will be extensible.

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Converting Encrypted Values

- by Johnm

Your database has been protecting sensitive data at rest using the cell-level encryption features of SQL Server for quite sometime. The employees in the auditing department have been inviting you to their after-work gatherings and buying you drinks. Thousands of customers implicitly include you in their prayers of thanks giving as their identities remain safe in your company's database. The cipher text resting snuggly in a column of the varbinary data type is great for security; but it can create some interesting challenges when interacting with other data types such as the XML data type. The XML data type is one that is often used as a message type for the Service Broker feature of SQL Server. It also can be an interesting data type to capture for auditing or integrating with external systems. The challenge that cipher text presents is that the need for decryption remains even after it has experienced its XML metamorphosis. Quite an interesting challenge nonetheless; but fear not. There is a solution. To simulate this scenario, we first will want to create a plain text value for us to encrypt. We will do this by creating a variable to store our plain text value: -- set plain text value DECLARE @PlainText NVARCHAR(255); SET @PlainText = 'This is plain text to encrypt'; The next step will be to create a variable that will store the cipher text that is generated from the encryption process. We will populate this variable by using a pre-defined symmetric key and certificate combination: -- encrypt plain text value DECLARE @CipherText VARBINARY(MAX); OPEN SYMMETRIC KEY SymKey DECRYPTION BY CERTIFICATE SymCert WITH PASSWORD='mypassword2010'; SET @CipherText = EncryptByKey ( Key_GUID('SymKey'), @PlainText ); CLOSE ALL SYMMETRIC KEYS; The value of our newly generated cipher text is 0x006E12933CBFB0469F79ABCC79A583--. This will be important as we reference our cipher text later in this post. Our final step in preparing our scenario is to create a table variable to simulate the existence of a table that contains a column used to hold encrypted values. Once this table variable has been created, populate the table variable with the newly generated cipher text: -- capture value in table variable DECLARE @tbl TABLE (EncVal varbinary(MAX)); INSERT INTO @tbl (EncVal) VALUES (@CipherText); We are now ready to experience the challenge of capturing our encrypted column in an XML data type using the FOR XML clause: -- capture set in xml DECLARE @xml XML; SET @xml = (SELECT EncVal FROM @tbl AS MYTABLE FOR XML AUTO, BINARY BASE64, ROOT('root')); If you add the SELECT @XML statement at the end of this portion of the code you will see the contents of the XML data in its raw format: <root> <MYTABLE EncVal="AG4Skzy/sEafeavMeaWDBwEAAACE--" /> </root> Strangely, the value that is captured appears nothing like the value that was created through the encryption process. The result being that when this XML is converted into a readable data set the encrypted value will not be able to be decrypted, even with access to the symmetric key and certificate used to perform the decryption. An immediate thought might be to convert the varbinary data type to either a varchar or nvarchar before creating the XML data. This approach makes good sense. The code for this might look something like the following: -- capture set in xml DECLARE @xml XML; SET @xml = (SELECT CONVERT(NVARCHAR(MAX),EncVal) AS EncVal FROM @tbl AS MYTABLE FOR XML AUTO, BINARY BASE64, ROOT('root')); However, this results in the following error: Msg 9420, Level 16, State 1, Line 26 XML parsing: line 1, character 37, illegal xml character A quick query that returns CONVERT(NVARCHAR(MAX),EncVal) reveals that the value that is causing the error looks like something off of a genuine Chinese menu. While this situation does present us with one of those spine-tingling, expletive-generating challenges, rest assured that this approach is on the right track. With the addition of the "style" argument to the CONVERT method, our solution is at hand. When dealing with converting varbinary data types we have three styles available to us: - The first is to not include the style parameter, or use the value of "0". As we see, this style will not work for us. - The second option is to use the value of "1" will keep our varbinary value including the "0x" prefix. In our case, the value will be 0x006E12933CBFB0469F79ABCC79A583-- - The third option is to use the value of "2" which will chop the "0x" prefix off of our varbinary value. In our case, the value will be 006E12933CBFB0469F79ABCC79A583-- Since we will want to convert this back to varbinary when reading this value from the XML data we will want the "0x" prefix, so we will want to change our code as follows: -- capture set in xml DECLARE @xml XML; SET @xml = (SELECT CONVERT(NVARCHAR(MAX),EncVal,1) AS EncVal FROM @tbl AS MYTABLE FOR XML AUTO, BINARY BASE64, ROOT('root')); Once again, with the inclusion of the SELECT @XML statement at the end of this portion of the code you will see the contents of the XML data in its raw format: <root> <MYTABLE EncVal="0x006E12933CBFB0469F79ABCC79A583--" /> </root> Nice! We are now cooking with gas. To continue our scenario, we will want to parse the XML data into a data set so that we can glean our freshly captured cipher text. Once we have our cipher text snagged we will capture it into a variable so that it can be used during decryption: -- read back xml DECLARE @hdoc INT; DECLARE @EncVal NVARCHAR(MAX); EXEC sp_xml_preparedocument @hDoc OUTPUT, @xml; SELECT @EncVal = EncVal FROM OPENXML (@hdoc, '/root/MYTABLE') WITH ([EncVal] VARBINARY(MAX) '@EncVal'); EXEC sp_xml_removedocument @hDoc; Finally, the decryption of our cipher text using the DECRYPTBYKEYAUTOCERT method and the certificate utilized to perform the encryption earlier in our exercise: SELECT CONVERT(NVARCHAR(MAX), DecryptByKeyAutoCert ( CERT_ID('AuditLogCert'), N'mypassword2010', @EncVal ) ) EncVal; Ah yes, another hurdle presents itself! The decryption produced the value of NULL which in cryptography means that either you don't have permissions to decrypt the cipher text or something went wrong during the decryption process (ok, sometimes the value is actually NULL; but not in this case). As we see, the @EncVal variable is an nvarchar data type. The third parameter of the DECRYPTBYKEYAUTOCERT method requires a varbinary value. Therefore we will need to utilize our handy-dandy CONVERT method: SELECT CONVERT(NVARCHAR(MAX), DecryptByKeyAutoCert ( CERT_ID('AuditLogCert'), N'mypassword2010', CONVERT(VARBINARY(MAX),@EncVal) ) ) EncVal; Oh, almost. The result remains NULL despite our conversion to the varbinary data type. This is due to the creation of an varbinary value that does not reflect the actual value of our @EncVal variable; but rather a varbinary conversion of the variable itself. In this case, something like 0x3000780030003000360045003--. Considering the "style" parameter got us past XML challenge, we will want to consider its power for this challenge as well. Knowing that the value of "1" will provide us with the actual value including the "0x", we will opt to utilize that value in this case: SELECT CONVERT(NVARCHAR(MAX), DecryptByKeyAutoCert ( CERT_ID('SymCert'), N'mypassword2010', CONVERT(VARBINARY(MAX),@EncVal,1) ) ) EncVal; Bingo, we have success! We have discovered what happens with varbinary data when captured as XML data. We have figured out how to make this data useful post-XML-ification. Best of all we now have a choice in after-work parties now that our very happy client who depends on our XML based interface invites us for dinner in celebration. All thanks to the effective use of the style parameter.

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I see no LOBs!

- by Paul White

Is it possible to see LOB (large object) logical reads from STATISTICS IO output on a table with no LOB columns? I was asked this question today by someone who had spent a good fraction of their afternoon trying to work out why this was occurring – even going so far as to re-run DBCC CHECKDB to see if any corruption had taken place. The table in question wasn’t particularly pretty – it had grown somewhat organically over time, with new columns being added every so often as the need arose. Nevertheless, it remained a simple structure with no LOB columns – no TEXT or IMAGE, no XML, no MAX types – nothing aside from ordinary INT, MONEY, VARCHAR, and DATETIME types. To add to the air of mystery, not every query that ran against the table would report LOB logical reads – just sometimes – but when it did, the query often took much longer to execute. Ok, enough of the pre-amble. I can’t reproduce the exact structure here, but the following script creates a table that will serve to demonstrate the effect: IF OBJECT_ID(N'dbo.Test', N'U') IS NOT NULL DROP TABLE dbo.Test GO CREATE TABLE dbo.Test ( row_id NUMERIC IDENTITY NOT NULL, col01 NVARCHAR(450) NOT NULL, col02 NVARCHAR(450) NOT NULL, col03 NVARCHAR(450) NOT NULL, col04 NVARCHAR(450) NOT NULL, col05 NVARCHAR(450) NOT NULL, col06 NVARCHAR(450) NOT NULL, col07 NVARCHAR(450) NOT NULL, col08 NVARCHAR(450) NOT NULL, col09 NVARCHAR(450) NOT NULL, col10 NVARCHAR(450) NOT NULL, CONSTRAINT [PK dbo.Test row_id] PRIMARY KEY CLUSTERED (row_id) ) ; The next script loads the ten variable-length character columns with one-character strings in the first row, two-character strings in the second row, and so on down to the 450th row: WITH Numbers AS ( -- Generates numbers 1 - 450 inclusive SELECT TOP (450) n = ROW_NUMBER() OVER (ORDER BY (SELECT 0)) FROM master.sys.columns C1, master.sys.columns C2, master.sys.columns C3 ORDER BY n ASC ) INSERT dbo.Test WITH (TABLOCKX) SELECT REPLICATE(N'A', N.n), REPLICATE(N'B', N.n), REPLICATE(N'C', N.n), REPLICATE(N'D', N.n), REPLICATE(N'E', N.n), REPLICATE(N'F', N.n), REPLICATE(N'G', N.n), REPLICATE(N'H', N.n), REPLICATE(N'I', N.n), REPLICATE(N'J', N.n) FROM Numbers AS N ORDER BY N.n ASC ; Once those two scripts have run, the table contains 450 rows and 10 columns of data like this: Most of the time, when we query data from this table, we don’t see any LOB logical reads, for example: -- Find the maximum length of the data in -- column 5 for a range of rows SELECT result = MAX(DATALENGTH(T.col05)) FROM dbo.Test AS T WHERE row_id BETWEEN 50 AND 100 ; But with a different query… -- Read all the data in column 1 SELECT result = MAX(DATALENGTH(T.col01)) FROM dbo.Test AS T ; …suddenly we have 49 LOB logical reads, as well as the ‘normal’ logical reads we would expect. The Explanation If we had tried to create this table in SQL Server 2000, we would have received a warning message to say that future INSERT or UPDATE operations on the table might fail if the resulting row exceeded the in-row storage limit of 8060 bytes. If we needed to store more data than would fit in an 8060 byte row (including internal overhead) we had to use a LOB column – TEXT, NTEXT, or IMAGE. These special data types store the large data values in a separate structure, with just a small pointer left in the original row. Row Overflow SQL Server 2005 introduced a feature called row overflow, which allows one or more variable-length columns in a row to move to off-row storage if the data in a particular row would otherwise exceed 8060 bytes. You no longer receive a warning when creating (or altering) a table that might need more than 8060 bytes of in-row storage; if SQL Server finds that it can no longer fit a variable-length column in a particular row, it will silently move one or more of these columns off the row into a separate allocation unit. Only variable-length columns can be moved in this way (for example the (N)VARCHAR, VARBINARY, and SQL_VARIANT types). Fixed-length columns (like INTEGER and DATETIME for example) never move into ‘row overflow’ storage. The decision to move a column off-row is done on a row-by-row basis – so data in a particular column might be stored in-row for some table records, and off-row for others. In general, if SQL Server finds that it needs to move a column into row-overflow storage, it moves the largest variable-length column record for that row. Note that in the case of an UPDATE statement that results in the 8060 byte limit being exceeded, it might not be the column that grew that is moved! Sneaky LOBs Anyway, that’s all very interesting but I don’t want to get too carried away with the intricacies of row-overflow storage internals. The point is that it is now possible to define a table with non-LOB columns that will silently exceed the old row-size limit and result in ordinary variable-length columns being moved to off-row storage. Adding new columns to a table, expanding an existing column definition, or simply storing more data in a column than you used to – all these things can result in one or more variable-length columns being moved off the row. Note that row-overflow storage is logically quite different from old-style LOB and new-style MAX data type storage – individual variable-length columns are still limited to 8000 bytes each – you can just have more of them now. Having said that, the physical mechanisms involved are very similar to full LOB storage – a column moved to row-overflow leaves a 24-byte pointer record in the row, and the ‘separate storage’ I have been talking about is structured very similarly to both old-style LOBs and new-style MAX types. The disadvantages are also the same: when SQL Server needs a row-overflow column value it needs to follow the in-row pointer a navigate another chain of pages, just like retrieving a traditional LOB. And Finally… In the example script presented above, the rows with row_id values from 402 to 450 inclusive all exceed the total in-row storage limit of 8060 bytes. A SELECT that references a column in one of those rows that has moved to off-row storage will incur one or more lob logical reads as the storage engine locates the data. The results on your system might vary slightly depending on your settings, of course; but in my tests only column 1 in rows 402-450 moved off-row. You might like to play around with the script – updating columns, changing data type lengths, and so on – to see the effect on lob logical reads and which columns get moved when. You might even see row-overflow columns moving back in-row if they are updated to be smaller (hint: reduce the size of a column entry by at least 1000 bytes if you hope to see this). Be aware that SQL Server will not warn you when it moves ‘ordinary’ variable-length columns into overflow storage, and it can have dramatic effects on performance. It makes more sense than ever to choose column data types sensibly. If you make every column a VARCHAR(8000) or NVARCHAR(4000), and someone stores data that results in a row needing more than 8060 bytes, SQL Server might turn some of your column data into pseudo-LOBs – all without saying a word. Finally, some people make a distinction between ordinary LOBs (those that can hold up to 2GB of data) and the LOB-like structures created by row-overflow (where columns are still limited to 8000 bytes) by referring to row-overflow LOBs as SLOBs. I find that quite appealing, but the ‘S’ stands for ‘small’, which makes expanding the whole acronym a little daft-sounding…small large objects anyone? © Paul White 2011 email: [email protected] twitter: @SQL_Kiwi

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Approach on Software Development Architecture

- by john ryan

Hi i am planning to standardize our way of creating project for our new projects. Currently we are using 3tier architecture where we have our ClassLibrary Project where it includes our Data Access Layer and Business Layer Something like: Solution ClassLibrary >ClassLibrary Project : >DAL(folder) > DAL Classes >BAL(folder) > BAL Classes And this Class Library dll was reference on our presentation Layer Project which are the Application(web/desktop) Something like: Solution WebUniversitySystem >Libraries(folder) > ClassLibrary.dll >WebUniversitySystem(Project): >Reference ClassLibrary.dll >Pages etc... Now i am planning to do is something like: Solution WebUniversitySystem >DataAccess(Project) >BusinesLayer(Project) >Reference DAL >WebUniversitySystem(Project): >Reference BAL >Pages etc... Is this Ok ? Or there is a good Approach that we can follow? Thanks In Regards

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Virtualized data centre–Part four: The design

- by marc dekeyser

Welcome back to the fourth post in this series! Today we will have a look at what Microsoft recommends as a “private cloud design” and what I will make of it. Whilst my own solution is based of the reference architecture, it is quite different indeed! An important thing to know is that, whilst I am using the private cloud as a reference, I am skipping most of the steps in designing a private cloud. If that is why you are here, please read the links at the end of the article and skim through my own content. A private cloud is much more process driven than just building a virtual infrastructure… The architecture of it all… So imagine for a minute that you have unlimited funds to build this lab of yours… You’d want redundancy on all levels and separation of each network where possible! Unfortunately we don’t have that luxury and, as you saw me hinting at in the previous article, our own design will be more limited but still quite capable! Networking From the networking perspective I will not have a fully redundant network, after all, this is but a lab environment! Thanks to Server 2012 I will be able to use bonding on my NIC’s and use LACP to improve the performance on that part. Storage As I mentioned in the previous article a Synology DS1218+ will be used for iSCSI provisioning. This device has 2 NICs on-board which can be bonded in to one 2 Gbps interface giving me a decent throughput and making the disks the most limiting factor in the storage design. Domain controllers and extra infrastructure Server 2012 completely supports running domain controllers virtualized and has no need to actually have a reachable DC when booting… That being said I need a remote access machine to power on the hosts (I have no need for them running 24/7) and a possible System Center VMM 2012 box (although server 2012 is not supported until SP1 :( ). Undecided on if I am to install those boxes separately or as a virtual machine… Which amounts to… Something like this pretty picture! Sources Microsoft Private Cloud Solutions Repository (en-US) http://social.technet.microsoft.com/wiki/contents/articles/12131.microsoft-private-cloud-solutions-repository-en-us.aspx Reference Architecture: http://social.technet.microsoft.com/wiki/contents/articles/3819.reference-architecture-for-private-cloud.aspx Private Cloud Reference Model: http://social.technet.microsoft.com/wiki/contents/articles/4399.private-cloud-reference-model.aspx

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'0' inserted when cross-referencing numbered equations in MSWord 2007

- by Jyotirmoy Bhattacharya

I am inserting numbered equations using tables and multi-level lists as described in http://blogs.msdn.com/b/microsoft_office_word/archive/2006/10/20/equation-numbering.aspx I want to cross-reference the equations in my text. To do so I go to Insert-Cross reference and among the "Numbered Items" I pick the equation I wish to refer to. The problem is that if I pick the "Insert reference to" as "Paragraph number" a zero is always inserted into my text. The surprising thing is that the hyperlink in the cross-reference points to the correct equation. Also if I choose "Insert reference to" as "Page number" then the correct page numbers are inserted and they are correctly updated too.

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