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  • Mixed Emotions: Humans React to Natural Language Computer

    - by Applications User Experience
    There was a big event in Silicon Valley on Tuesday, November 15. Watson, the natural language computer developed at IBM Watson Research Center in Yorktown Heights, New York, and its inventor and principal research investigator, David Ferrucci, were guests at the Computer History Museum in Mountain View, California for another round of the television game Jeopardy. You may have read about or watched on YouTube how Watson beat Ken Jennings and Brad Rutter, two top Jeopardy competitors, last February. This time, Watson swept the floor with two Silicon Valley high-achievers, one a venture capitalist with a background  in math, computer engineering, and physics, and the other a technology and finance writer well-versed in all aspects of culture and humanities. Watson is the product of the DeepQA research project, which attempts to create an artificially intelligent computing system through advances in natural language processing (NLP), among other technologies. NLP is a computing strategy that seeks to provide answers by processing large amounts of unstructured data contained in multiple large domains of human knowledge. There are several ways to perform NLP, but one way to start is by recognizing key words, then processing  contextual  cues associated with the keyword concepts so that you get many more “smart” (that is, human-like) deductions,  rather than a series of “dumb” matches.  Jeopardy questions often require more than key word matching to get the correct answer; typically several pieces of information put together, often from vastly different categories, to come up with a satisfactory word string solution that can be rephrased as a question.  Smarter than your average search engine, but is it as smart as a human? Watson was especially fast at descrambling mixed-up state capital names, and recalling and pairing movie titles where one started and the other ended in the same word (e.g., Billion Dollar Baby Boom, where both titles used the word Baby). David said they had basically removed the variable of how fast Watson hit the buzzer compared to human contestants, but frustration frequently appeared on the faces of the contestants beaten to the punch by Watson. David explained that top Jeopardy winners like Jennings achieved their success with a similar strategy, timing their buzz to the end of the reading of the clue,  and “running the board”, being first to respond on about 60% of the clues.  Similar results for Watson. It made sense that Watson would be good at the technical and scientific stuff, so I figured the venture capitalist was toast. But I thought for sure Watson would lose to the writer in categories such as pop culture, wines and foods, and other humanities. Surprisingly, it held its own. I was amazed it could recognize a word definition of a syllogism in the category of philosophy. So what was the audience reaction to all of this? We started out expecting our formidable human contestants to easily run some of their categories; however, they started off on the wrong foot with the state capitals which Watson could unscramble so efficiently. By the end of the first round, contestants and the audience were feeling a little bit, well, …. deflated. Watson was winning by about $13,000, and the humans had gone into negative dollars. The IBM host said he was going to “slow Watson down a bit,” and the humans came back with respectable scores in Double Jeopardy. This was partially thanks to a very sympathetic audience (and host, also a human) providing “group-think” on many questions, especially baseball ‘s most valuable players, which by the way, couldn’t have been hard because even I knew them.  Yes, that’s right, the humans cheated. Since Watson could speak but not hear us (it didn’t have speech recognition capability), it was probably unaware of this. In Final Jeopardy, the single question had to do with law. I was sure Watson would blow this one, but all contestants were able to answer correctly about a copyright law. In a career devoted to making computers more helpful to people, I think I may have seen how a computer can do too much. I’m not sure I’d want to work side-by-side with a Watson doing my job. Certainly listening and empathy are important traits we humans still have over Watson.  While there was great enthusiasm in the packed room of computer scientists and their friends for this standing-room-only show, I think it made several of us uneasy (especially the poor human contestants whose egos were soundly bashed in the first round). This computer system, by the way , only took 4 years to program. David Ferrucci mentioned several practical uses for Watson, including medical diagnoses and legal strategies. Are you “the expert” in your job? Imagine NLP computing on an Oracle database.   This may be the user interface of the future to enable users to better process big data. How do you think you’d like it? Postscript: There were three little boys sitting in front of me in the very first row. They looked, how shall I say it, … unimpressed!

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  • Validation firing in ASP.NET MVC

    - by rkrauter
    I am lost on this MVC project I am working on. I also read Brad Wilsons article. http://bradwilson.typepad.com/blog/2010/01/input-validation-vs-model-validation-in-aspnet-mvc.html I have this: public class Employee { [Required] public int ID { get; set; } [Required] public string FirstName { get; set; } [Required] public string LastName { get; set; } } and these in a controller: public ActionResult Edit(int id) { var emp = GetEmployee(); return View(emp); } [HttpPost] public ActionResult Edit(int id, Employee empBack) { var emp = GetEmployee(); if (TryUpdateModel(emp,new string[] { "LastName"})) { Response.Write("success"); } return View(emp); } public Employee GetEmployee() { return new Employee { FirstName = "Tom", LastName = "Jim", ID = 3 }; } and my view has the following: <% using (Html.BeginForm()) {%> <%= Html.ValidationSummary() %> <fieldset> <legend>Fields</legend> <div class="editor-label"> <%= Html.LabelFor(model => model.FirstName) %> </div> <div class="editor-field"> <%= Html.DisplayFor(model => model.FirstName) %> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.LastName) %> </div> <div class="editor-field"> <%= Html.TextBoxOrLabelFor(model => model.LastName, true)%> <%= Html.ValidationMessageFor(model => model.LastName) %> </div> <p> <input type="submit" value="Save" /> </p> </fieldset> <% } %> Note that the only field editable is the LastName. When I postback, I get back the original employee and try to update it with only the LastName property. But but I see on the page is the following error: •The FirstName field is required. This from what I understand, is because the TryUpdateModel failed. But why? I told it to update only the LastName property. I am using MVC2 RTM Thanks in advance.

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  • Downloading Python 2.5.4 (from official website) in order to install it

    - by brilliant
    I was quite hesitant about whether I should post this question here on "StackOverflow" or on "SuperUser", but finally decided to post it here as Python is more a programming language rather than a piece of software. I've been recently using Python 2.5.4 that is installed on my computer, but at the moment I am not at home (and won't be for about two weeks from now), so I need to install the same version of Python on another computer. This computer has Windows XP installed – just like the one that I have at home. The reason why I need Python 2.5.4 is because I am using “Google App Engine”, and I was told that it only supports Python 2.5 However, when I went to the official Python page for the download, I discovered that certain things have changed, and I don’t quite remember where exactly from that site I had downloaded Python 2.5.4 on my computer at home. I found this page: http://www.python.org/download/releases/2.5.4/ Here is how it looks: (If you can’t see it here, please check it out at this address: http://brad.cwahi.net/some_pictures/python_page.jpg ) A few things here are not clear to me. It says: “For x86 processors: python-2.5.4.msi For Win64-Itanium users: python-2.5.4.ia64.msi For Win64-AMD64 users: python-2.5.4.amd64.msi” First of all, I don’t know what processor I am using – whether mine is “x86” or not; and also, I don’t know whether I am an “Win64-Itanium” or an “Win64-AMD64” user. Are Itanium and AMD64 also processors? Later it says: “Windows XP and later already have MSI; many older machines will already have MSI installed.” I guess, it is my case, but then I am totally puzzled as to which link I should click as it seems now that I don’t need those three previous links (as MSI is already installed on Windows XP), but there is no fourth link provided for those who use “Windows XP” or older machines. Of course, there are these words after that: “Windows users may also be interested in Mark Hammond's win32all package, available from Sourceforge.” but it seems to me that it is something additional rather than the main file. So, my question is simple: Where in the official Python website I can download Python 2.5.4, precisely, which link I should click?

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  • ASP.NET MVC2: Can you get ModelMetadata.ContainerType from within a collection?

    - by CodeSponge
    I'm trying to call DisplayFor and DisplayForModel to iterate an IEnumerable< with various element types from within a view. I have Templates defined for each element/Model type. What I would like to do is check the ViewData.ModelMetadata.ContainerType from within the Template so that Template can determine if it was called as part of a collection. A simple example: Index1.aspx: To render a collection of Foos. <%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<IEnumerable<Foo>>" %> <asp:Content ContentPlaceHolderID="MainPlaceHolder" runat="server"> <ul><%:Html.DisplayForModel()%></ul> </asp:Content> Index2.aspx: To render a Foo. <%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<Foo>" %> <asp:Content ContentPlaceHolderID="MainPlaceHolder" runat="server"> <%:Html.DisplayForModel()%> </asp:Content> Shared\DisplayTemplates\Foo.ascx: A context aware Template for Foo. <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<Foo>" %> <% var tag = typeof(IEnumerable).IsAssignableFrom(ViewData.ModelMetaData.ContainerType) ? "li" : "div"; %> <<%:tag%>><%:Model.Name%></<%:tag%>> The problem with this example is that ViewData.ModelMetaData.ContainerType is null in the Template when resolved though Index1.aspx. From what I've read on Brad Wilson post and others it has to do with the use of IEnumerable and its being an interface. Is there a way to insure that the ContainerType is set? Perhaps by creating a ModelMetadataProviders? I looked into that breifly but it appears the ContainerType value is determined before and then passed to the Provider. Any suggestions would be appreciated.

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  • .NET: Avoidance of custom exceptions by utilising existing types, but which?

    - by Mr. Disappointment
    Consider the following code (ASP.NET/C#): private void Application_Start(object sender, EventArgs e) { if (!SetupHelper.SetUp()) { throw new ShitHitFanException(); } } I've never been too hesitant to simply roll my own exception type, basically because I have found (bad practice, or not) that mostly a reasonable descriptive type name gives us enough as developers to go by in order to know what happened and why something might have happened. Sometimes the existing .NET exception types even accommodate these needs - regardless of the message. In this particular scenario, for demonstration purposes only, the application should die a horrible, disgraceful death should SetUp not complete properly (as dictated by its return value), but I can't find an already existing exception type in .NET which would seem to suffice; though, I'm sure one will be there and I simply don't know about it. Brad Abrams posted this article that lists some of the available exception types. I say some because the article is from 2005, and, although I try to keep up to date, it's a more than plausible assumption that more have been added to future framework versions that I am still unaware of. Of course, Visual Studio gives you a nicely formatted, scrollable list of exceptions via Intellisense - but even on analysing those, I find none which would seem to suffice for this situation... ApplicationException: ...when a non-fatal application error occurs The name seems reasonable, but the error is very definitely fatal - the app is dead. ExecutionEngineException: ...when there is an internal error in the execution engine of the CLR Again, sounds reasonable, superficially; but this has a very definite purpose and to help me out here certainly isn't it. HttpApplicationException: ...when there is an error processing an HTTP request Well, we're running an ASP.NET application! But we're also just pulling at straws here. InvalidOperationException: ...when a call is invalid for the current state of an instance This isn't right but I'm adding it to the list of 'possible should you put a gun to my head, yes'. OperationCanceledException: ...upon cancellation of an operation the thread was executing Maybe I wouldn't feel so bad using this one, but I'd still be hijacking the damn thing with little right. You might even ask why on earth I would want to raise an exception here but the idea is to find out that if I were to do so then do you know of an appropriate exception for such a scenario? And basically, to what extent can we piggy-back on .NET while keeping in line with rationality?

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  • Get data from aspx.cs page to aspx page.

    - by Brad8118
    So I am using a jquery plug in that allows me to change the order of things in a list by dragging and dropping them. So my goal is to be able to grab a list of my objects (AlertInfo) and using it in a javascript function. I was able to use a json webservice call in a test project to pass the data to the page. But we don't have a webservice page now so I tried to grab it from a aspx.cs page and it hasn't worked. ///Aspx page: $.ajax({ type: "POST", url: "~/Alerts/GetAlerts", data: "{}", contentType: "application/json; charset=utf-8", dataType: "json", success: function (msg) { var data = eval("(" + msg.d + ")"); jQuery.each(data, function (rec) { AlertList[AlertList.length] = new objAlert(this.id, this.title, this.details, JSONDateSerializationFix(this.startdate), JSONDateSerializationFix(this.enddate)); UpdateDisplayList(); }) }, error: function (msg) { alert("BRAD" + msg); } The issue is that the Alerts page in "URL /Alerts/GetAlerts" is Alerts.aspx.cs. I can't figure out if I can use this ajax command to call a method in a aspx.cs page. //Code behind page aspx.cs [WebMethod] //[ScriptMethod(ResponseFormat = ResponseFormat.Json)] public string GetAlerts() { List list = AlertInfo.GetTestAlerts(); return new JavaScriptSerializer().Serialize(list); } public List GetAlertsList() { List list = AlertInfo.GetTestAlerts(); return list; ; } So I was hoping that I could load data into an asp control (dataList) and then grab the data //code behind page protected void Page_Load(object sender, EventArgs e) { dataListAlertList.DataSource = GetAlertsList(); dataListAlertList.DataBind(); } public static List<AlertInfo> GetTestAlerts() { List<AlertInfo> list = new List<AlertInfo>(); list.Add(new AlertInfo("0", "Alert 1 Title", "Alert 1 Detail", "10/10/2010", "10/10/2011")); list.Add(new AlertInfo("1", "Alert 2 Title", "Alert 2 Detail", "10/10/2010", "10/10/2011")); return list; } //.aspx page $(document).ready(function () { var a1 = $("#dataListAlertList").val(); // do fun stuff now. } But I keep getting undefined....

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  • TechEd 2010 Day One – How I Travel

    - by BuckWoody
    Normally when I blog on the first day of a conference, well, there hasn’t been a first day yet. So I talk about the value of a conference or some other facet. And normally in my (non-conference) blogs, I show you how I have learned to be a data professional – things I’ve learned how to do over the years. But in all that time, I don’t think I’ve ever talked about a big part of my job – traveling. I’ve traveled a lot throughout the years, when I’ve taught, gone to conferences, consulted and in my current role assisting Microsoft customers with large-scale database system designs.  So I’ll share a few thoughts about what I do. Keep in mind that I travel for short durations, just a day or so, and sometimes I travel internationally. For those I prepare differently – what I’m talking about here is what I do for a multi-day, same-country trip. Hopefully you find it useful. I’ll tag a few other travelers I know to add their thoughts.  Preparing for Travel   When I’m notified of a trip, I begin researching the location. I find the flights, hotel and (if I have to) a car to use while I’m away. We have an in-house system we use to book the travel, but when I travel not-for-Microsoft I use Expedia and Kayak to find what I need.  Traveling on Sunday and Friday is the worst. I have to do it sometimes (like this week) and it’s always a bad idea. But you can blunt the impact by booking as early as you can stand it. That means I have to be up super-early, but the flights are normally on time. I stay flexible, and always have a backup plan in case the flights are delayed or canceled.  For the hotel, I tend to go on the cheaper side, and I look for older hotels that have been renovated, or quirky ones. For instance, in Boise, ID recently I stayed at a 60’s-themed (think Mad-Men) hotel that was very cool. Always I go on the less expensive side – I find the “luxury” hotels nail me for Internet, food, everything. The cheaper places include all kinds of things, and even have breakfasts, shuttles and all kinds of things that start to add up. I even call ahead to make sure there’s an iron and ironing board available, since I’ll need those when I get there.  I find any way I can not to get a car. I use mass-transit wherever possible, and try to make friends and pay their gas to take me places. In a pinch, I’ll use a taxi. It ends up being cheaper, faster, and less stressful all around.  Packing  Over the years I’ve learned never to check luggage whenever I can. To do that, I lay out everything I want to take with me on the bed, and then try and make sure I’m really going to use it. I wear a dark wool set of pants, which I can clean and wear in hot and cold climates. I bring undies and socks of course, and for most places I have to wear “dress up” shirts. I bring at least two print T-Shirts in case I want to dress down for something while I’m gone, but I only bring one set of shoes. All the  clothes are rolled as tightly as possible as I learned in the military. Then I use those to cushion the electronics I take.  For toiletries I bring a shaver, toothpaste and toothbrush, D/O and a small brush. Everything else the hotel will provide.  For entertainment, I take a small Zune, a full PC-Headset (so I can make IP calls on the road) and my laptop. I don’t take books or anything else – everything is electronic. I use E-books (downloaded from our Library), Audio-Books (on the Zune) and I also bring along a Kaossilator (more here) to play music in the hotel room or even on the plane without being heard.  If I can, I pack into one roll-on bag. There’s not a lot better than this one, but I also have a Bag I was given as a prize for something or other here at Microsoft. Either way, I like something with less pockets and more big, open compartments. Everything gets rolled up and packed in, with all of the wires and charges in small bags my wife made for me. The laptop (and anything I don’t want gate-checked) goes on top or in an outside pouch so I can grab it quickly if I have to gate-check the bag. As much as I can, I try to go in one bag. When I can’t (like this week) I use this bag since it can expand, roll up, crush and even be put away later. It’s super-heavy canvas and worth the price. This allows me to not check a bag.  Journey Logistics The day of the trip, I have everything ready since I’m getting up early. I pack a few small snacks inside a plastic large-mouth water bottle, which protects the snacks and lets me get water in the terminal. I bring along those little powdered drink mixes to add to the water.  At the airport, I make a beeline for the power-outlets. I charge up my laptop and phone, and download all my e-mails so I can work on them off-line in the air. I don’t travel as often as I used to – just every month or so now, so I don’t have a membership to an airline club. If I travel much more, I’ll invest in one again – they are WELL worth the money, for the wifi, food and quiet if for nothing else.  I print out my logistics on paper and put that in my pocket – flight numbers, hotel addresses and phones for everything. That way if I have to make a change, I don’t have to boot up anything or even have power to be able to roll with the punches if things change.  Working While Away  While I’m away I realize I’m going to be swamped with things at the conference or with my clients. So I turn on Out-Of-Office notifications to let people know I won’t be as responsive, and I keep my Outlook calendar up to date so my co-workers know what I’m up to. I even update it with hotel and phone info in case they really need to reach me. I share my calendar with my wife so my family knows what I’m doing as well.  I check my e-mail during breaks, but I only respond to them in the evening or early morning at the hotel. I tweet during conferences. The point is to be as present as possible during the event or when I’m at the clients. Both deserve it.  So those are my initial thoughts. I’ll tag Brent Ozar, Brad McGeHee and Paul Randal, and they can tag whomever they wish. Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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  • Rotate rectangle around center

    - by ESoft
    I am playing with Brad Larsen's adaption of the trackball app. I have two views at a 60 degree angle to each other and was wondering how I get the rotation to be in the center of this (non-closed) rectangle? In the images below I would have liked the rotation to take place all within the blue lines. Code (modified to only rotate around x axis): #import "MyView.h" //===================================================== // Defines //===================================================== #define DEGREES_TO_RADIANS(degrees) \ (degrees * (M_PI / 180.0f)) //===================================================== // Public Interface //===================================================== @implementation MyView - (void)awakeFromNib { transformed = [CALayer layer]; transformed.anchorPoint = CGPointMake(0.5f, 0.5f); transformed.frame = self.bounds; [self.layer addSublayer:transformed]; CALayer *imageLayer = [CALayer layer]; imageLayer.frame = CGRectMake(10.0f, 4.0f, self.bounds.size.width / 2.0f, self.bounds.size.height / 2.0f); imageLayer.transform = CATransform3DMakeRotation(DEGREES_TO_RADIANS(60.0f), 1.0f, 0.0f, 0.0f); imageLayer.contents = (id)[[UIImage imageNamed:@"IMG_0051.png"] CGImage]; imageLayer.borderColor = [UIColor yellowColor].CGColor; imageLayer.borderWidth = 2.0f; [transformed addSublayer:imageLayer]; imageLayer = [CALayer layer]; imageLayer.frame = CGRectMake(10.0f, 120.0f, self.bounds.size.width / 2.0f, self.bounds.size.height / 2.0f); imageLayer.transform = CATransform3DMakeRotation(DEGREES_TO_RADIANS(-60.0f), 1.0f, 0.0f, 0.0f); imageLayer.contents = (id)[[UIImage imageNamed:@"IMG_0089.png"] CGImage]; imageLayer.borderColor = [UIColor greenColor].CGColor; imageLayer.borderWidth = 2.0f; transformed.borderColor = [UIColor whiteColor].CGColor; transformed.borderWidth = 2.0f; [transformed addSublayer:imageLayer]; UIView *line = [[UIView alloc] initWithFrame:CGRectMake(0, self.bounds.size.height / 2.0f, self.bounds.size.width, 2)]; [line setBackgroundColor:[UIColor redColor]]; [self addSubview:line]; line = [[UIView alloc] initWithFrame:CGRectMake(0, self.bounds.size.height * (1.0f / 4.0f), self.bounds.size.width, 2)]; [line setBackgroundColor:[UIColor blueColor]]; [self addSubview:line]; line = [[UIView alloc] initWithFrame:CGRectMake(0, self.bounds.size.height * (3.0f / 4.0f), self.bounds.size.width, 2)]; [line setBackgroundColor:[UIColor blueColor]]; [self addSubview:line]; } - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { previousLocation = [[touches anyObject] locationInView:self]; } - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { CGPoint location = [[touches anyObject] locationInView:self]; //location = CGPointMake(previousLocation.x, location.y); CATransform3D currentTransform = transformed.sublayerTransform; //CGFloat displacementInX = location.x - previousLocation.x; CGFloat displacementInX = previousLocation.x - location.x; CGFloat displacementInY = previousLocation.y - location.y; CGFloat totalRotation = sqrt((displacementInX * displacementInX) + (displacementInY * displacementInY)); CGFloat angle = DEGREES_TO_RADIANS(totalRotation); CGFloat x = ((displacementInX / totalRotation) * currentTransform.m12 + (displacementInY/totalRotation) * currentTransform.m11); CATransform3D rotationalTransform = CATransform3DRotate(currentTransform, angle, x, 0, 0); previousLocation = location; transformed.sublayerTransform = rotationalTransform; } - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { } - (void)dealloc { [super dealloc]; } @end

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  • ASP.NET MVC ‘Extendable-hooks’ – ControllerActionInvoker class

    - by nmarun
    There’s a class ControllerActionInvoker in ASP.NET MVC. This can be used as one of an hook-points to allow customization of your application. Watching Brad Wilsons’ Advanced MP3 from MVC Conf inspired me to write about this class. What MSDN says: “Represents a class that is responsible for invoking the action methods of a controller.” Well if MSDN says it, I think I can instill a fair amount of confidence into what the class does. But just to get to the details, I also looked into the source code for MVC. Seems like the base class Controller is where an IActionInvoker is initialized: 1: protected virtual IActionInvoker CreateActionInvoker() { 2: return new ControllerActionInvoker(); 3: } In the ControllerActionInvoker (the O-O-B behavior), there are different ‘versions’ of InvokeActionMethod() method that actually call the action method in question and return an instance of type ActionResult. 1: protected virtual ActionResult InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary<string, object> parameters) { 2: object returnValue = actionDescriptor.Execute(controllerContext, parameters); 3: ActionResult result = CreateActionResult(controllerContext, actionDescriptor, returnValue); 4: return result; 5: } I guess that’s enough on the ‘behind-the-screens’ of this class. Let’s see how we can use this class to hook-up extensions. Say I have a requirement that the user should be able to get different renderings of the same output, like html, xml, json, csv and so on. The user will type-in the output format in the url and should the get result accordingly. For example: http://site.com/RenderAs/ – renders the default way (the razor view) http://site.com/RenderAs/xml http://site.com/RenderAs/csv … and so on where RenderAs is my controller. There are many ways of doing this and I’m using a custom ControllerActionInvoker class (even though this might not be the best way to accomplish this). For this, my one and only route in the Global.asax.cs is: 1: routes.MapRoute("RenderAsRoute", "RenderAs/{outputType}", 2: new {controller = "RenderAs", action = "Index", outputType = ""}); Here the controller name is ‘RenderAsController’ and the action that’ll get called (always) is the Index action. The outputType parameter will map to the type of output requested by the user (xml, csv…). I intend to display a list of food items for this example. 1: public class Item 2: { 3: public int Id { get; set; } 4: public string Name { get; set; } 5: public Cuisine Cuisine { get; set; } 6: } 7:  8: public class Cuisine 9: { 10: public int CuisineId { get; set; } 11: public string Name { get; set; } 12: } Coming to my ‘RenderAsController’ class. I generate an IList<Item> to represent my model. 1: private static IList<Item> GetItems() 2: { 3: Cuisine cuisine = new Cuisine { CuisineId = 1, Name = "Italian" }; 4: Item item = new Item { Id = 1, Name = "Lasagna", Cuisine = cuisine }; 5: IList<Item> items = new List<Item> { item }; 6: item = new Item {Id = 2, Name = "Pasta", Cuisine = cuisine}; 7: items.Add(item); 8: //... 9: return items; 10: } My action method looks like 1: public IList<Item> Index(string outputType) 2: { 3: return GetItems(); 4: } There are two things that stand out in this action method. The first and the most obvious one being that the return type is not of type ActionResult (or one of its derivatives). Instead I’m passing the type of the model itself (IList<Item> in this case). We’ll convert this to some type of an ActionResult in our custom controller action invoker class later. The second thing (a little subtle) is that I’m not doing anything with the outputType value that is passed on to this action method. This value will be in the RouteData dictionary and we’ll use this in our custom invoker class as well. It’s time to hook up our invoker class. First, I’ll override the Initialize() method of my RenderAsController class. 1: protected override void Initialize(RequestContext requestContext) 2: { 3: base.Initialize(requestContext); 4: string outputType = string.Empty; 5:  6: // read the outputType from the RouteData dictionary 7: if (requestContext.RouteData.Values["outputType"] != null) 8: { 9: outputType = requestContext.RouteData.Values["outputType"].ToString(); 10: } 11:  12: // my custom invoker class 13: ActionInvoker = new ContentRendererActionInvoker(outputType); 14: } Coming to the main part of the discussion – the ContentRendererActionInvoker class: 1: public class ContentRendererActionInvoker : ControllerActionInvoker 2: { 3: private readonly string _outputType; 4:  5: public ContentRendererActionInvoker(string outputType) 6: { 7: _outputType = outputType.ToLower(); 8: } 9: //... 10: } So the outputType value that was read from the RouteData, which was passed in from the url, is being set here in  a private field. Moving to the crux of this article, I now override the CreateActionResult method. 1: protected override ActionResult CreateActionResult(ControllerContext controllerContext, ActionDescriptor actionDescriptor, object actionReturnValue) 2: { 3: if (actionReturnValue == null) 4: return new EmptyResult(); 5:  6: ActionResult result = actionReturnValue as ActionResult; 7: if (result != null) 8: return result; 9:  10: // This is where the magic happens 11: // Depending on the value in the _outputType field, 12: // return an appropriate ActionResult 13: switch (_outputType) 14: { 15: case "json": 16: { 17: JavaScriptSerializer serializer = new JavaScriptSerializer(); 18: string json = serializer.Serialize(actionReturnValue); 19: return new ContentResult { Content = json, ContentType = "application/json" }; 20: } 21: case "xml": 22: { 23: XmlSerializer serializer = new XmlSerializer(actionReturnValue.GetType()); 24: using (StringWriter writer = new StringWriter()) 25: { 26: serializer.Serialize(writer, actionReturnValue); 27: return new ContentResult { Content = writer.ToString(), ContentType = "text/xml" }; 28: } 29: } 30: case "csv": 31: controllerContext.HttpContext.Response.AddHeader("Content-Disposition", "attachment; filename=items.csv"); 32: return new ContentResult 33: { 34: Content = ToCsv(actionReturnValue as IList<Item>), 35: ContentType = "application/ms-excel" 36: }; 37: case "pdf": 38: string filePath = controllerContext.HttpContext.Server.MapPath("~/items.pdf"); 39: controllerContext.HttpContext.Response.AddHeader("content-disposition", 40: "attachment; filename=items.pdf"); 41: ToPdf(actionReturnValue as IList<Item>, filePath); 42: return new FileContentResult(StreamFile(filePath), "application/pdf"); 43:  44: default: 45: controllerContext.Controller.ViewData.Model = actionReturnValue; 46: return new ViewResult 47: { 48: TempData = controllerContext.Controller.TempData, 49: ViewData = controllerContext.Controller.ViewData 50: }; 51: } 52: } A big method there! The hook I was talking about kinda above actually is here. This is where different kinds / formats of output get returned based on the output type requested in the url. When the _outputType is not set (string.Empty as set in the Global.asax.cs file), the razor view gets rendered (lines 45-50). This is the default behavior in most MVC applications where-in a view (webform/razor) gets rendered on the browser. As you see here, this gets returned as a ViewResult. But then, for an outputType of json/xml/csv, a ContentResult gets returned, while for pdf, a FileContentResult is returned. Here are how the different kinds of output look like: This is how we can leverage this feature of ASP.NET MVC to developer a better application. I’ve used the iTextSharp library to convert to a pdf format. Mike gives quite a bit of detail regarding this library here. You can download the sample code here. (You’ll get an option to download once you open the link). Verdict: Hot chocolate: $3; Reebok shoes: $50; Your first car: $3000; Being able to extend a web application: Priceless.

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  • ASP.NET MVC Postbacks and HtmlHelper Controls ignoring Model Changes

    - by Rick Strahl
    So here's a binding behavior in ASP.NET MVC that I didn't really get until today: HtmlHelpers controls (like .TextBoxFor() etc.) don't bind to model values on Postback, but rather get their value directly out of the POST buffer from ModelState. Effectively it looks like you can't change the display value of a control via model value updates on a Postback operation. To demonstrate here's an example. I have a small section in a document where I display an editable email address: This is what the form displays on a GET operation and as expected I get the email value displayed in both the textbox and plain value display below, which reflects the value in the mode. I added a plain text value to demonstrate the model value compared to what's rendered in the textbox. The relevant markup is the email address which needs to be manipulated via the model in the Controller code. Here's the Razor markup: <div class="fieldcontainer"> <label> Email: &nbsp; <small>(username and <a href="http://gravatar.com">Gravatar</a> image)</small> </label> <div> @Html.TextBoxFor( mod=> mod.User.Email, new {type="email",@class="inputfield"}) @Model.User.Email </div> </div>   So, I have this form and the user can change their email address. On postback the Post controller code then asks the business layer whether the change is allowed. If it's not I want to reset the email address back to the old value which exists in the database and was previously store. The obvious thing to do would be to modify the model. Here's the Controller logic block that deals with that:// did user change email? if (!string.IsNullOrEmpty(oldEmail) && user.Email != oldEmail) { if (userBus.DoesEmailExist(user.Email)) { userBus.ValidationErrors.Add("New email address exists already. Please…"); user.Email = oldEmail; } else // allow email change but require verification by forcing a login user.IsVerified = false; }… model.user = user; return View(model); The logic is straight forward - if the new email address is not valid because it already exists I don't want to display the new email address the user entered, but rather the old one. To do this I change the value on the model which effectively does this:model.user.Email = oldEmail; return View(model); So when I press the Save button after entering in my new email address ([email protected]) here's what comes back in the rendered view: Notice that the textbox value and the raw displayed model value are different. The TextBox displays the POST value, the raw value displays the actual model value which are different. This means that MVC renders the textbox value from the POST data rather than from the view data when an Http POST is active. Now I don't know about you but this is not the behavior I expected - initially. This behavior effectively means that I cannot modify the contents of the textbox from the Controller code if using HtmlHelpers for binding. Updating the model for display purposes in a POST has in effect - no effect. (Apr. 25, 2012 - edited the post heavily based on comments and more experimentation) What should the behavior be? After getting quite a few comments on this post I quickly realized that the behavior I described above is actually the behavior you'd want in 99% of the binding scenarios. You do want to get the POST values back into your input controls at all times, so that the data displayed on a form for the user matches what they typed. So if an error occurs, the error doesn't mysteriously disappear getting replaced either with a default value or some value that you changed on the model on your own. Makes sense. Still it is a little non-obvious because the way you create the UI elements with MVC, it certainly looks like your are binding to the model value:@Html.TextBoxFor( mod=> mod.User.Email, new {type="email",@class="inputfield",required="required" }) and so unless one understands a little bit about how the model binder works this is easy to trip up. At least it was for me. Even though I'm telling the control which model value to bind to, that model value is only used initially on GET operations. After that ModelState/POST values provide the display value. Workarounds The default behavior should be fine for 99% of binding scenarios. But if you do need fix up values based on your model rather than the default POST values, there are a number of ways that you can work around this. Initially when I ran into this, I couldn't figure out how to set the value using code and so the simplest solution to me was simply to not use the MVC Html Helper for the specific control and explicitly bind the model via HTML markup and @Razor expression: <input type="text" name="User.Email" id="User_Email" value="@Model.User.Email" /> And this produces the right result. This is easy enough to create, but feels a little out of place when using the @Html helpers for everything else. As you can see by the difference in the name and id values, you also are forced to remember the naming conventions that MVC imposes in order for ModelBinding to work properly which is a pain to remember and set manually (name is the same as the property with . syntax, id replaces dots with underlines). Use the ModelState Some of my original confusion came because I didn't understand how the model binder works. The model binder basically maintains ModelState on a postback, which holds a value and binding errors for each of the Post back value submitted on the page that can be mapped to the model. In other words there's one ModelState entry for each bound property of the model. Each ModelState entry contains a value property that holds AttemptedValue and RawValue properties. The AttemptedValue is essentially the POST value retrieved from the form. The RawValue is the value that the model holds. When MVC binds controls like @Html.TextBoxFor() or @Html.TextBox(), it always binds values on a GET operation. On a POST operation however, it'll always used the AttemptedValue to display the control. MVC binds using the ModelState on a POST operation, not the model's value. So, if you want the behavior that I was expecting originally you can actually get it by clearing the ModelState in the controller code:ModelState.Clear(); This clears out all the captured ModelState values, and effectively binds to the model. Note this will produce very similar results - in fact if there are no binding errors you see exactly the same behavior as if binding from ModelState, because the model has been updated from the ModelState already and binding to the updated values most likely produces the same values you would get with POST back values. The big difference though is that any values that couldn't bind - like say putting a string into a numeric field - will now not display back the value the user typed, but the default field value or whatever you changed the model value to. This is the behavior I was actually expecting previously. But - clearing out all values might be a bit heavy handed. You might want to fix up one or two values in a model but rarely would you want the entire model to update from the model. So, you can also clear out individual values on an as needed basis:if (userBus.DoesEmailExist(user.Email)) { userBus.ValidationErrors.Add("New email address exists already. Please…"); user.Email = oldEmail; ModelState.Remove("User.Email"); } This allows you to remove a single value from the ModelState and effectively allows you to replace that value for display from the model. Why? While researching this I came across a post from Microsoft's Brad Wilson who describes the default binding behavior best in a forum post: The reason we use the posted value for editors rather than the model value is that the model may not be able to contain the value that the user typed. Imagine in your "int" editor the user had typed "dog". You want to display an error message which says "dog is not valid", and leave "dog" in the editor field. However, your model is an int: there's no way it can store "dog". So we keep the old value. If you don't want the old values in the editor, clear out the Model State. That's where the old value is stored and pulled from the HTML helpers. There you have it. It's not the most intuitive behavior, but in hindsight this behavior does make some sense even if at first glance it looks like you should be able to update values from the model. The solution of clearing ModelState works and is a reasonable one but you have to know about some of the innards of ModelState and how it actually works to figure that out.© Rick Strahl, West Wind Technologies, 2005-2012Posted in ASP.NET  MVC   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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  • top tweets WebLogic Partner Community – September 2012

    - by JuergenKress
    Send your tweets @wlscommunity #WebLogicCommunity and follow us at http://twitter.com/wlscommunity Oracle Exalogic? VIDEO: Oracle Public Cloud Built on Exalogic!, http://www.youtube.com/watch?v=UGzjDloUw_s&feature=plcp … oracleopenworld #NetBeans Community Day at #JavaOne http://ow.ly/dunFL Oracle Cloud Zone Building an enterprise Cloud? Have Oracle show you the RIGHT way to plan, deploy and monitor enterprise clouds.... http://fb.me/286978S4S OTNArchBeat? Oracle Exalogic X2-2 walk-through with Brad Cameron | @jvzoggel http://pub.vitrue.com/yE7d Oracle Technet? Stash your cash. September OTN Member Offers - discounts on books, more | OTN Blog http://pub.vitrue.com/yTr9 C2B2 Consulting? C2B2 is Speaking at @UKOUG App Server Middleware SIG Meeting 'Real Life #WebLogic Performance Tuning' http://www.c2b2.co.uk/ukoug_application_server_middleware_sig_meeting … @wlscommunity JAXenter.com? From yesterday, @smeyen offers his views on the next generation #Java - do you agree? http://jaxenter.com/next-gen-java-we-don-t-need-another-revolutionary-44334.html … Markus Eisele? Awesome: professor from ITU uploads her programming lectures to #YouTube. Programming classes without having to pay! http://bit.ly/UtkJIW Adam Bien? Real World Java EE 6 Patterns--Rethinking Best Practices Reloaded: A completely rewritten, second, iteration of ... http://bit.ly/Qc3xTH Markus Eisele [blog] #PrimeFaces Push with #Atmosphere on #GlassFish 3.1.2.2 http://goo.gl/fb/jPDzA Lucas Jellema? Forms community event at Oracle Open World - Tuesday, 2nd Oct with the BIG names in Forms - see: http://oracleformsinfo.wordpress.com/2012/08/28/ask-the-product-manager-join-us-at-the-oracle-forms-community-event-at-openworld-2012/ … WebLogic Community WebLogic & Coherence & Cloud presentations for customer meetings http://wp.me/p1LMIb-kw Adam Bien? New Book: Rethinking Best Practices with Java EE 6 is out: http://realworldpatterns.com (fully rewritten, re-edited and reformatted) WebLogic Community? Want to become and WebLogic 12c expert? free WebLogic 12c partner bootcamps &ndash;new locations: Madrid Spain http://wp.me/p1LMIb-kK WebLogic Community? Promote Your WebLogic events at http://oracle.com http://wp.me/p1LMIb-ku OracleBlogs Gartner review Oracle ADF http://ow.ly/1mgkCV Simon Haslam Next #ukoug App Server & MW SIG on 10 Oct: http://www.ukoug.org/events/ukoug-application-server-and-middleware-sig-meeting8/ … Hopefully plenty of good admin stuff! Michel Schildmeijer My book "WebLogic 12c; First look" has been reviewed again..see http://www.amazon.com/review/R28L6E3CC9RPMK/ref=cm_cr_pr_perm?ie=UTF8&ASIN=1849687188&linkCode=&nodeID=&tag= … … Markus Eisele? #Weblogic 11g Interactive Quick Reference Map: http://bit.ly/Ugsq52 #wls #oracle #reference /via @TonyvanEsch Marc? Playing with #syslog server and #weblogic. Is there a simple how-to to configure all the logging from #WLS to #syslog-ng WebLogic Community Java update http://wp.me/p1LMIb-kI WebLogic Community top tweets WebLogic Partner Community &ndash; August 2012 http://wp.me/p1LMIb-kA Andrejus Baranovskis? Oracle University Training: ADF/WebCenter 11g Development in Depth | Andrejus Baranovskis http://fb.me/253ZTS2zp OracleSupport_WLS? How neat is a free tool that allows you to inspect and debug traffic from virtually any application? http://pub.vitrue.com/vXdP WebLogic Community WebLogic Partner Community Newsletter August 2012 http://wp.me/p1LMIb-kn OTNArchBeat Integrating Coherence & Java EE 6 Applications using ActiveCache | Ricardo Ferreira http://pub.vitrue.com/rwGg Adam Bien? Thanks for attending the #javaee #techtalk "Enterprise Java 2.0" I pushed the project and slides to: http://kenai.com/projects/javaee-patterns/sources/hg/show/hacks/techtalk2012?rev=429 … JDeveloper & ADF? How to service-enable Oracle ADF Business Components http://ht.ly/1mcfsZ OracleSupport_WLS? Do you know that #WebLogic 12.1.1.0 is certified for production with JDK 7? @ http://pub.vitrue.com/35Kn Andreas Koop? My latest upload : WebLogic Administration und Deployment mit WLST on @slideshare http://www.slideshare.net/multikoop/weblogic-administration-und-deployment-mit-wlst … OTNArchBeat? Demo for OPN: Oracle Coherence Management with EM Cloud Control 12c http://pub.vitrue.com/reoo Markus Eisele? [blog] Java Champions at #JavaOne 2012 http://goo.gl/fb/Ibb6N #javachampion OracleBlogs Buy This Book!: Oracle Exalogic Elastic Cloud Handbook http://ow.ly/1malM1 WebLogic Community? Coherence Management with EM Cloud Control 12c &ndash;demo for partners http://wp.me/p1LMIb-iE Arun Gupta? Learn how Java can help Internet of Things at Java Embedded at JavaOne: http://bit.ly/POBizh WebLogic Community? Follow WebLogicCommunity on facebook http://www.facebook.com/WebLogicCommunity … #WebLogicCommunity WebLogic Community? Building Java EE in the Cloud–Webcast August 30th 2012 https://weblogiccommunity.wordpress.com/2012/08/27/building-java-ee-in-the-cloudwebcast-august-30th-2012/ … #WebLogicCommunity #Java #oracle #opn WebLogic Community? Call for WebLogic Community newsletter content. Please send @wlscommunity #WebLogicCommunity OracleSupport_WLS? The #weblogic wasp: lots of tips, Q&A and examples http://pub.vitrue.com/v0bw Frank Nimphius? Free ADF Best Practices Webinar by Andrejus Baranovskis for ODTUG (18, 2012 12:00 PM - 1:00 PM EDT) http://bit.ly/OiSWbi ADF Code Corner Webcast- Friday September 14, 8:30 AM - 9.00 AM (CET) - ADF as a basis of Fusion Apps (in English) - with Chris Muir: http://bit.ly/OiQVMb Oracle WebLogic? New blog post: Developing Custom User Principal Object http://pub.vitrue.com/ltam JAX London? Just 4days left to get in on the early bird special, don't miss out!! http://jaxlondon.com/ #JAXLondon #Java WebLogic Community Building Java EE in the Cloud&ndash;Webcast August 30th 2012 http://wp.me/p1LMIb-kE Andrejus Baranovskis? New Record Master-Detail Validation and ADF BC Groovy Use Case http://fb.me/1D2NEIl8g JAX London? Don't miss out!!! Only 6 days left to make use of our early bird offer #JAXLondon #JAVA http://jaxlondon.com/ Michel Schildmeijer Qualogy launches Proof of Concept Center for Oracle Fusion Applications http://www.qualogy.com/qualogy-launches-proof-of-concept-center-for-oracle-fusion-applications/ … via @Qualogy_news OracleSupport_WLS ?Need to troubleshoot redeployment failure in #Weblogic? Check this http://pub.vitrue.com/auhz OracleEnterpriseMgr? Blog : Managing Oracle #Exalogic Elastic #Cloud with Oracle Enterprise Manager Ops Center http://ow.ly/dd40e #em12c ODTUG? Want free advanced technical ADF training?Join @andrejusb for an @odtug webinar! check out his blog for more info http://bit.ly/SvKJDq chriscmuir Oracle Open World 2012 and ADF EMG http://zite.to/QyusZE OTNArchBeat? Boost your infrastructure with Coherence into the Cloud | Nino Guarnacci http://pub.vitrue.com/v3aJ WebLogic Community? Presentations & Training material OFM Summer Camps & Impressions & Feedback http://wp.me/p1LMIb-ks Arun Gupta? Java EE 6 pocket guide by O'Reilly available for pre-order from Amazon: http://amzn.to/O6YyoP and B&N: http://bit.ly/NjWLk1 OTNArchBeat Joining the Existing Cluster in Coherence | A. Fuat Sungur http://pub.vitrue.com/6uLh Andrejus Baranovskis Sample Application for Switching Application Module Data Sources http://fb.me/1PSURUzch OTNArchBeat Oracle WebLogic DevCast: Building Java EE in the Cloud - August 30 - 10am PT/ 1pm ET http://pub.vitrue.com/xXg0 OTNArchBeat? GlassFish Community Event at #javaone - Sept 30 -11am – 1pm -Moscone South. Register Now! http://pub.vitrue.com/p2f5 OracleSupport_WLS? Connecting To HTTPS Site Using Simple Java Program When Using Proxy http://pub.vitrue.com/stVv Michel Schildmeijer? Before you go to #OOW take the sneak preview of WebLogic 12c with you: http://www.qualogy.com/ga-nog-niet-naar-oow-en-neem-mee-weblogic-12c/ … via @Qualogy_news Simon Haslam? Even more great ADF content at #oow2012 this year including a packed ADF EMG day on Sunday: https://blogs.oracle.com/onesizedoesntfitall/entry/the_year_after_the_year … OracleBlogs ExaLogic trainings for partners http://ow.ly/1m6a5D Robin? First presentation on DOAG conference (thanks to @Steffen2042) "Weblogic Server for Dummies". Now I´m pretty excited :) http://www.doag.org/de/events/konferenzen/doag-2012.html … Markus Eisele There is a #facebook page for the upcoming #Java Mission Control (JRockit Mission Control for #Hotspot)! ttp://on.fb.me/Q31oyA Adam Bien? The almost free #javaee workshop in Rapperswil has only 60 registrations so far: http://www.adam-bien.com/roller/abien/entry/enterprise_java_2_0_swiss … What's the problem? :-) WebLogic Community ExaLogic trainings for partners http://wp.me/p1LMIb-iC OracleBlogs How to install Oracle Weblogic Server using Generic Package installer? http://ow.ly/1m5ms7 OracleSupport_WLS #Weblogic Server new blog post - Developing Custom User Principal Object http://pub.vitrue.com/ltam OracleBlogs? Architects and Architecture at JavaOne 2012 http://ow.ly/1m4oS5 WebLogic Community Are you WebLogic or Application Grid Specialized? Do you get Recognized? Get your plaque https://weblogiccommunity.wordpress.com/2012/08/21/plaques-weblogic-application-grid-specialization/ … #WebLogicCommunity #opn WebLogic Community? Plaques WebLogic & Application Grid Specialization http://wp.me/p1LMIb-iA JDeveloper & ADF? First Steps With Oracle Application Testing Suite: Recording a Test With OpenScript http://dlvr.it/222npy WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: twitter,WebLogic,WebLogic Community,Oracle,OPN,Jürgen Kress

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  • When is a SQL function not a function?

    - by Rob Farley
    Should SQL Server even have functions? (Oh yeah – this is a T-SQL Tuesday post, hosted this month by Brad Schulz) Functions serve an important part of programming, in almost any language. A function is a piece of code that is designed to return something, as opposed to a piece of code which isn’t designed to return anything (which is known as a procedure). SQL Server is no different. You can call stored procedures, even from within other stored procedures, and you can call functions and use these in other queries. Stored procedures might query something, and therefore ‘return data’, but a function in SQL is considered to have the type of the thing returned, and can be used accordingly in queries. Consider the internal GETDATE() function. SELECT GETDATE(), SomeDatetimeColumn FROM dbo.SomeTable; There’s no logical difference between the field that is being returned by the function and the field that’s being returned by the table column. Both are the datetime field – if you didn’t have inside knowledge, you wouldn’t necessarily be able to tell which was which. And so as developers, we find ourselves wanting to create functions that return all kinds of things – functions which look up values based on codes, functions which do string manipulation, and so on. But it’s rubbish. Ok, it’s not all rubbish, but it mostly is. And this isn’t even considering the SARGability impact. It’s far more significant than that. (When I say the SARGability aspect, I mean “because you’re unlikely to have an index on the result of some function that’s applied to a column, so try to invert the function and query the column in an unchanged manner”) I’m going to consider the three main types of user-defined functions in SQL Server: Scalar Inline Table-Valued Multi-statement Table-Valued I could also look at user-defined CLR functions, including aggregate functions, but not today. I figure that most people don’t tend to get around to doing CLR functions, and I’m going to focus on the T-SQL-based user-defined functions. Most people split these types of function up into two types. So do I. Except that most people pick them based on ‘scalar or table-valued’. I’d rather go with ‘inline or not’. If it’s not inline, it’s rubbish. It really is. Let’s start by considering the two kinds of table-valued function, and compare them. These functions are going to return the sales for a particular salesperson in a particular year, from the AdventureWorks database. CREATE FUNCTION dbo.FetchSales_inline(@salespersonid int, @orderyear int) RETURNS TABLE AS  RETURN (     SELECT e.LoginID as EmployeeLogin, o.OrderDate, o.SalesOrderID     FROM Sales.SalesOrderHeader AS o     LEFT JOIN HumanResources.Employee AS e     ON e.EmployeeID = o.SalesPersonID     WHERE o.SalesPersonID = @salespersonid     AND o.OrderDate >= DATEADD(year,@orderyear-2000,'20000101')     AND o.OrderDate < DATEADD(year,@orderyear-2000+1,'20000101') ) ; GO CREATE FUNCTION dbo.FetchSales_multi(@salespersonid int, @orderyear int) RETURNS @results TABLE (     EmployeeLogin nvarchar(512),     OrderDate datetime,     SalesOrderID int     ) AS BEGIN     INSERT @results (EmployeeLogin, OrderDate, SalesOrderID)     SELECT e.LoginID, o.OrderDate, o.SalesOrderID     FROM Sales.SalesOrderHeader AS o     LEFT JOIN HumanResources.Employee AS e     ON e.EmployeeID = o.SalesPersonID     WHERE o.SalesPersonID = @salespersonid     AND o.OrderDate >= DATEADD(year,@orderyear-2000,'20000101')     AND o.OrderDate < DATEADD(year,@orderyear-2000+1,'20000101')     ;     RETURN END ; GO You’ll notice that I’m being nice and responsible with the use of the DATEADD function, so that I have SARGability on the OrderDate filter. Regular readers will be hoping I’ll show what’s going on in the execution plans here. Here I’ve run two SELECT * queries with the “Show Actual Execution Plan” option turned on. Notice that the ‘Query cost’ of the multi-statement version is just 2% of the ‘Batch cost’. But also notice there’s trickery going on. And it’s nothing to do with that extra index that I have on the OrderDate column. Trickery. Look at it – clearly, the first plan is showing us what’s going on inside the function, but the second one isn’t. The second one is blindly running the function, and then scanning the results. There’s a Sequence operator which is calling the TVF operator, and then calling a Table Scan to get the results of that function for the SELECT operator. But surely it still has to do all the work that the first one is doing... To see what’s actually going on, let’s look at the Estimated plan. Now, we see the same plans (almost) that we saw in the Actuals, but we have an extra one – the one that was used for the TVF. Here’s where we see the inner workings of it. You’ll probably recognise the right-hand side of the TVF’s plan as looking very similar to the first plan – but it’s now being called by a stack of other operators, including an INSERT statement to be able to populate the table variable that the multi-statement TVF requires. And the cost of the TVF is 57% of the batch! But it gets worse. Let’s consider what happens if we don’t need all the columns. We’ll leave out the EmployeeLogin column. Here, we see that the inline function call has been simplified down. It doesn’t need the Employee table. The join is redundant and has been eliminated from the plan, making it even cheaper. But the multi-statement plan runs the whole thing as before, only removing the extra column when the Table Scan is performed. A multi-statement function is a lot more powerful than an inline one. An inline function can only be the result of a single sub-query. It’s essentially the same as a parameterised view, because views demonstrate this same behaviour of extracting the definition of the view and using it in the outer query. A multi-statement function is clearly more powerful because it can contain far more complex logic. But a multi-statement function isn’t really a function at all. It’s a stored procedure. It’s wrapped up like a function, but behaves like a stored procedure. It would be completely unreasonable to expect that a stored procedure could be simplified down to recognise that not all the columns might be needed, but yet this is part of the pain associated with this procedural function situation. The biggest clue that a multi-statement function is more like a stored procedure than a function is the “BEGIN” and “END” statements that surround the code. If you try to create a multi-statement function without these statements, you’ll get an error – they are very much required. When I used to present on this kind of thing, I even used to call it “The Dangers of BEGIN and END”, and yes, I’ve written about this type of thing before in a similarly-named post over at my old blog. Now how about scalar functions... Suppose we wanted a scalar function to return the count of these. CREATE FUNCTION dbo.FetchSales_scalar(@salespersonid int, @orderyear int) RETURNS int AS BEGIN     RETURN (         SELECT COUNT(*)         FROM Sales.SalesOrderHeader AS o         LEFT JOIN HumanResources.Employee AS e         ON e.EmployeeID = o.SalesPersonID         WHERE o.SalesPersonID = @salespersonid         AND o.OrderDate >= DATEADD(year,@orderyear-2000,'20000101')         AND o.OrderDate < DATEADD(year,@orderyear-2000+1,'20000101')     ); END ; GO Notice the evil words? They’re required. Try to remove them, you just get an error. That’s right – any scalar function is procedural, despite the fact that you wrap up a sub-query inside that RETURN statement. It’s as ugly as anything. Hopefully this will change in future versions. Let’s have a look at how this is reflected in an execution plan. Here’s a query, its Actual plan, and its Estimated plan: SELECT e.LoginID, y.year, dbo.FetchSales_scalar(p.SalesPersonID, y.year) AS NumSales FROM (VALUES (2001),(2002),(2003),(2004)) AS y (year) CROSS JOIN Sales.SalesPerson AS p LEFT JOIN HumanResources.Employee AS e ON e.EmployeeID = p.SalesPersonID; We see here that the cost of the scalar function is about twice that of the outer query. Nicely, the query optimizer has worked out that it doesn’t need the Employee table, but that’s a bit of a red herring here. There’s actually something way more significant going on. If I look at the properties of that UDF operator, it tells me that the Estimated Subtree Cost is 0.337999. If I just run the query SELECT dbo.FetchSales_scalar(281,2003); we see that the UDF cost is still unchanged. You see, this 0.0337999 is the cost of running the scalar function ONCE. But when we ran that query with the CROSS JOIN in it, we returned quite a few rows. 68 in fact. Could’ve been a lot more, if we’d had more salespeople or more years. And so we come to the biggest problem. This procedure (I don’t want to call it a function) is getting called 68 times – each one between twice as expensive as the outer query. And because it’s calling it in a separate context, there is even more overhead that I haven’t considered here. The cheek of it, to say that the Compute Scalar operator here costs 0%! I know a number of IT projects that could’ve used that kind of costing method, but that’s another story that I’m not going to go into here. Let’s look at a better way. Suppose our scalar function had been implemented as an inline one. Then it could have been expanded out like a sub-query. It could’ve run something like this: SELECT e.LoginID, y.year, (SELECT COUNT(*)     FROM Sales.SalesOrderHeader AS o     LEFT JOIN HumanResources.Employee AS e     ON e.EmployeeID = o.SalesPersonID     WHERE o.SalesPersonID = p.SalesPersonID     AND o.OrderDate >= DATEADD(year,y.year-2000,'20000101')     AND o.OrderDate < DATEADD(year,y.year-2000+1,'20000101')     ) AS NumSales FROM (VALUES (2001),(2002),(2003),(2004)) AS y (year) CROSS JOIN Sales.SalesPerson AS p LEFT JOIN HumanResources.Employee AS e ON e.EmployeeID = p.SalesPersonID; Don’t worry too much about the Scan of the SalesOrderHeader underneath a Nested Loop. If you remember from plenty of other posts on the matter, execution plans don’t push the data through. That Scan only runs once. The Index Spool sucks the data out of it and populates a structure that is used to feed the Stream Aggregate. The Index Spool operator gets called 68 times, but the Scan only once (the Number of Executions property demonstrates this). Here, the Query Optimizer has a full picture of what’s being asked, and can make the appropriate decision about how it accesses the data. It can simplify it down properly. To get this kind of behaviour from a function, we need it to be inline. But without inline scalar functions, we need to make our function be table-valued. Luckily, that’s ok. CREATE FUNCTION dbo.FetchSales_inline2(@salespersonid int, @orderyear int) RETURNS table AS RETURN (SELECT COUNT(*) as NumSales     FROM Sales.SalesOrderHeader AS o     LEFT JOIN HumanResources.Employee AS e     ON e.EmployeeID = o.SalesPersonID     WHERE o.SalesPersonID = @salespersonid     AND o.OrderDate >= DATEADD(year,@orderyear-2000,'20000101')     AND o.OrderDate < DATEADD(year,@orderyear-2000+1,'20000101') ); GO But we can’t use this as a scalar. Instead, we need to use it with the APPLY operator. SELECT e.LoginID, y.year, n.NumSales FROM (VALUES (2001),(2002),(2003),(2004)) AS y (year) CROSS JOIN Sales.SalesPerson AS p LEFT JOIN HumanResources.Employee AS e ON e.EmployeeID = p.SalesPersonID OUTER APPLY dbo.FetchSales_inline2(p.SalesPersonID, y.year) AS n; And now, we get the plan that we want for this query. All we’ve done is tell the function that it’s returning a table instead of a single value, and removed the BEGIN and END statements. We’ve had to name the column being returned, but what we’ve gained is an actual inline simplifiable function. And if we wanted it to return multiple columns, it could do that too. I really consider this function to be superior to the scalar function in every way. It does need to be handled differently in the outer query, but in many ways it’s a more elegant method there too. The function calls can be put amongst the FROM clause, where they can then be used in the WHERE or GROUP BY clauses without fear of calling the function multiple times (another horrible side effect of functions). So please. If you see BEGIN and END in a function, remember it’s not really a function, it’s a procedure. And then fix it. @rob_farley

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  • Introducing the Earthquake Locator – A Bing Maps Silverlight Application, part 1

    - by Bobby Diaz
    Update: Live demo and source code now available!  The recent wave of earthquakes (no pun intended) being reported in the news got me wondering about the frequency and severity of earthquakes around the world. Since I’ve been doing a lot of Silverlight development lately, I decided to scratch my curiosity with a nice little Bing Maps application that will show the location and relative strength of recent seismic activity. Here is a list of technologies this application will utilize, so be sure to have everything downloaded and installed if you plan on following along. Silverlight 3 WCF RIA Services Bing Maps Silverlight Control * Managed Extensibility Framework (optional) MVVM Light Toolkit (optional) log4net (optional) * If you are new to Bing Maps or have not signed up for a Developer Account, you will need to visit www.bingmapsportal.com to request a Bing Maps key for your application. Getting Started We start out by creating a new Silverlight Application called EarthquakeLocator and specify that we want to automatically create the Web Application Project with RIA Services enabled. I cleaned up the web app by removing the Default.aspx and EarthquakeLocatorTestPage.html. Then I renamed the EarthquakeLocatorTestPage.aspx to Default.aspx and set it as my start page. I also set the development server to use a specific port, as shown below. RIA Services Next, I created a Services folder in the EarthquakeLocator.Web project and added a new Domain Service Class called EarthquakeService.cs. This is the RIA Services Domain Service that will provide earthquake data for our client application. I am not using LINQ to SQL or Entity Framework, so I will use the <empty domain service class> option. We will be pulling data from an external Atom feed, but this example could just as easily pull data from a database or another web service. This is an important distinction to point out because each scenario I just mentioned could potentially use a different Domain Service base class (i.e. LinqToSqlDomainService<TDataContext>). Now we can start adding Query methods to our EarthquakeService that pull data from the USGS web site. Here is the complete code for our service class: using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.ServiceModel.Syndication; using System.Web.DomainServices; using System.Web.Ria; using System.Xml; using log4net; using EarthquakeLocator.Web.Model;   namespace EarthquakeLocator.Web.Services {     /// <summary>     /// Provides earthquake data to client applications.     /// </summary>     [EnableClientAccess()]     public class EarthquakeService : DomainService     {         private static readonly ILog log = LogManager.GetLogger(typeof(EarthquakeService));           // USGS Data Feeds: http://earthquake.usgs.gov/earthquakes/catalogs/         private const string FeedForPreviousDay =             "http://earthquake.usgs.gov/earthquakes/catalogs/1day-M2.5.xml";         private const string FeedForPreviousWeek =             "http://earthquake.usgs.gov/earthquakes/catalogs/7day-M2.5.xml";           /// <summary>         /// Gets the earthquake data for the previous week.         /// </summary>         /// <returns>A queryable collection of <see cref="Earthquake"/> objects.</returns>         public IQueryable<Earthquake> GetEarthquakes()         {             var feed = GetFeed(FeedForPreviousWeek);             var list = new List<Earthquake>();               if ( feed != null )             {                 foreach ( var entry in feed.Items )                 {                     var quake = CreateEarthquake(entry);                     if ( quake != null )                     {                         list.Add(quake);                     }                 }             }               return list.AsQueryable();         }           /// <summary>         /// Creates an <see cref="Earthquake"/> object for each entry in the Atom feed.         /// </summary>         /// <param name="entry">The Atom entry.</param>         /// <returns></returns>         private Earthquake CreateEarthquake(SyndicationItem entry)         {             Earthquake quake = null;             string title = entry.Title.Text;             string summary = entry.Summary.Text;             string point = GetElementValue<String>(entry, "point");             string depth = GetElementValue<String>(entry, "elev");             string utcTime = null;             string localTime = null;             string depthDesc = null;             double? magnitude = null;             double? latitude = null;             double? longitude = null;             double? depthKm = null;               if ( !String.IsNullOrEmpty(title) && title.StartsWith("M") )             {                 title = title.Substring(2, title.IndexOf(',')-3).Trim();                 magnitude = TryParse(title);             }             if ( !String.IsNullOrEmpty(point) )             {                 var values = point.Split(' ');                 if ( values.Length == 2 )                 {                     latitude = TryParse(values[0]);                     longitude = TryParse(values[1]);                 }             }             if ( !String.IsNullOrEmpty(depth) )             {                 depthKm = TryParse(depth);                 if ( depthKm != null )                 {                     depthKm = Math.Round((-1 * depthKm.Value) / 100, 2);                 }             }             if ( !String.IsNullOrEmpty(summary) )             {                 summary = summary.Replace("</p>", "");                 var values = summary.Split(                     new string[] { "<p>" },                     StringSplitOptions.RemoveEmptyEntries);                   if ( values.Length == 3 )                 {                     var times = values[1].Split(                         new string[] { "<br>" },                         StringSplitOptions.RemoveEmptyEntries);                       if ( times.Length > 0 )                     {                         utcTime = times[0];                     }                     if ( times.Length > 1 )                     {                         localTime = times[1];                     }                       depthDesc = values[2];                     depthDesc = "Depth: " + depthDesc.Substring(depthDesc.IndexOf(":") + 2);                 }             }               if ( latitude != null && longitude != null )             {                 quake = new Earthquake()                 {                     Id = entry.Id,                     Title = entry.Title.Text,                     Summary = entry.Summary.Text,                     Date = entry.LastUpdatedTime.DateTime,                     Url = entry.Links.Select(l => Path.Combine(l.BaseUri.OriginalString,                         l.Uri.OriginalString)).FirstOrDefault(),                     Age = entry.Categories.Where(c => c.Label == "Age")                         .Select(c => c.Name).FirstOrDefault(),                     Magnitude = magnitude.GetValueOrDefault(),                     Latitude = latitude.GetValueOrDefault(),                     Longitude = longitude.GetValueOrDefault(),                     DepthInKm = depthKm.GetValueOrDefault(),                     DepthDesc = depthDesc,                     UtcTime = utcTime,                     LocalTime = localTime                 };             }               return quake;         }           private T GetElementValue<T>(SyndicationItem entry, String name)         {             var el = entry.ElementExtensions.Where(e => e.OuterName == name).FirstOrDefault();             T value = default(T);               if ( el != null )             {                 value = el.GetObject<T>();             }               return value;         }           private double? TryParse(String value)         {             double d;             if ( Double.TryParse(value, out d) )             {                 return d;             }             return null;         }           /// <summary>         /// Gets the feed at the specified URL.         /// </summary>         /// <param name="url">The URL.</param>         /// <returns>A <see cref="SyndicationFeed"/> object.</returns>         public static SyndicationFeed GetFeed(String url)         {             SyndicationFeed feed = null;               try             {                 log.Debug("Loading RSS feed: " + url);                   using ( var reader = XmlReader.Create(url) )                 {                     feed = SyndicationFeed.Load(reader);                 }             }             catch ( Exception ex )             {                 log.Error("Error occurred while loading RSS feed: " + url, ex);             }               return feed;         }     } }   The only method that will be generated in the client side proxy class, EarthquakeContext, will be the GetEarthquakes() method. The reason being that it is the only public instance method and it returns an IQueryable<Earthquake> collection that can be consumed by the client application. GetEarthquakes() calls the static GetFeed(String) method, which utilizes the built in SyndicationFeed API to load the external data feed. You will need to add a reference to the System.ServiceModel.Web library in order to take advantage of the RSS/Atom reader. The API will also allow you to create your own feeds to serve up in your applications. Model I have also created a Model folder and added a new class, Earthquake.cs. The Earthquake object will hold the various properties returned from the Atom feed. Here is a sample of the code for that class. Notice the [Key] attribute on the Id property, which is required by RIA Services to uniquely identify the entity. using System; using System.Collections.Generic; using System.Linq; using System.Runtime.Serialization; using System.ComponentModel.DataAnnotations;   namespace EarthquakeLocator.Web.Model {     /// <summary>     /// Represents an earthquake occurrence and related information.     /// </summary>     [DataContract]     public class Earthquake     {         /// <summary>         /// Gets or sets the id.         /// </summary>         /// <value>The id.</value>         [Key]         [DataMember]         public string Id { get; set; }           /// <summary>         /// Gets or sets the title.         /// </summary>         /// <value>The title.</value>         [DataMember]         public string Title { get; set; }           /// <summary>         /// Gets or sets the summary.         /// </summary>         /// <value>The summary.</value>         [DataMember]         public string Summary { get; set; }           // additional properties omitted     } }   View Model The recent trend to use the MVVM pattern for WPF and Silverlight provides a great way to separate the data and behavior logic out of the user interface layer of your client applications. I have chosen to use the MVVM Light Toolkit for the Earthquake Locator, but there are other options out there if you prefer another library. That said, I went ahead and created a ViewModel folder in the Silverlight project and added a EarthquakeViewModel class that derives from ViewModelBase. Here is the code: using System; using System.Collections.ObjectModel; using System.ComponentModel.Composition; using System.ComponentModel.Composition.Hosting; using Microsoft.Maps.MapControl; using GalaSoft.MvvmLight; using EarthquakeLocator.Web.Model; using EarthquakeLocator.Web.Services;   namespace EarthquakeLocator.ViewModel {     /// <summary>     /// Provides data for views displaying earthquake information.     /// </summary>     public class EarthquakeViewModel : ViewModelBase     {         [Import]         public EarthquakeContext Context;           /// <summary>         /// Initializes a new instance of the <see cref="EarthquakeViewModel"/> class.         /// </summary>         public EarthquakeViewModel()         {             var catalog = new AssemblyCatalog(GetType().Assembly);             var container = new CompositionContainer(catalog);             container.ComposeParts(this);             Initialize();         }           /// <summary>         /// Initializes a new instance of the <see cref="EarthquakeViewModel"/> class.         /// </summary>         /// <param name="context">The context.</param>         public EarthquakeViewModel(EarthquakeContext context)         {             Context = context;             Initialize();         }           private void Initialize()         {             MapCenter = new Location(20, -170);             ZoomLevel = 2;         }           #region Private Methods           private void OnAutoLoadDataChanged()         {             LoadEarthquakes();         }           private void LoadEarthquakes()         {             var query = Context.GetEarthquakesQuery();             Context.Earthquakes.Clear();               Context.Load(query, (op) =>             {                 if ( !op.HasError )                 {                     foreach ( var item in op.Entities )                     {                         Earthquakes.Add(item);                     }                 }             }, null);         }           #endregion Private Methods           #region Properties           private bool autoLoadData;         /// <summary>         /// Gets or sets a value indicating whether to auto load data.         /// </summary>         /// <value><c>true</c> if auto loading data; otherwise, <c>false</c>.</value>         public bool AutoLoadData         {             get { return autoLoadData; }             set             {                 if ( autoLoadData != value )                 {                     autoLoadData = value;                     RaisePropertyChanged("AutoLoadData");                     OnAutoLoadDataChanged();                 }             }         }           private ObservableCollection<Earthquake> earthquakes;         /// <summary>         /// Gets the collection of earthquakes to display.         /// </summary>         /// <value>The collection of earthquakes.</value>         public ObservableCollection<Earthquake> Earthquakes         {             get             {                 if ( earthquakes == null )                 {                     earthquakes = new ObservableCollection<Earthquake>();                 }                   return earthquakes;             }         }           private Location mapCenter;         /// <summary>         /// Gets or sets the map center.         /// </summary>         /// <value>The map center.</value>         public Location MapCenter         {             get { return mapCenter; }             set             {                 if ( mapCenter != value )                 {                     mapCenter = value;                     RaisePropertyChanged("MapCenter");                 }             }         }           private double zoomLevel;         /// <summary>         /// Gets or sets the zoom level.         /// </summary>         /// <value>The zoom level.</value>         public double ZoomLevel         {             get { return zoomLevel; }             set             {                 if ( zoomLevel != value )                 {                     zoomLevel = value;                     RaisePropertyChanged("ZoomLevel");                 }             }         }           #endregion Properties     } }   The EarthquakeViewModel class contains all of the properties that will be bound to by the various controls in our views. Be sure to read through the LoadEarthquakes() method, which handles calling the GetEarthquakes() method in our EarthquakeService via the EarthquakeContext proxy, and also transfers the loaded entities into the view model’s Earthquakes collection. Another thing to notice is what’s going on in the default constructor. I chose to use the Managed Extensibility Framework (MEF) for my composition needs, but you can use any dependency injection library or none at all. To allow the EarthquakeContext class to be discoverable by MEF, I added the following partial class so that I could supply the appropriate [Export] attribute: using System; using System.ComponentModel.Composition;   namespace EarthquakeLocator.Web.Services {     /// <summary>     /// The client side proxy for the EarthquakeService class.     /// </summary>     [Export]     public partial class EarthquakeContext     {     } }   One last piece I wanted to point out before moving on to the user interface, I added a client side partial class for the Earthquake entity that contains helper properties that we will bind to later: using System;   namespace EarthquakeLocator.Web.Model {     /// <summary>     /// Represents an earthquake occurrence and related information.     /// </summary>     public partial class Earthquake     {         /// <summary>         /// Gets the location based on the current Latitude/Longitude.         /// </summary>         /// <value>The location.</value>         public string Location         {             get { return String.Format("{0},{1}", Latitude, Longitude); }         }           /// <summary>         /// Gets the size based on the Magnitude.         /// </summary>         /// <value>The size.</value>         public double Size         {             get { return (Magnitude * 3); }         }     } }   View Now the fun part! Usually, I would create a Views folder to place all of my View controls in, but I took the easy way out and added the following XAML code to the default MainPage.xaml file. Be sure to add the bing prefix associating the Microsoft.Maps.MapControl namespace after adding the assembly reference to your project. The MVVM Light Toolkit project templates come with a ViewModelLocator class that you can use via a static resource, but I am instantiating the EarthquakeViewModel directly in my user control. I am setting the AutoLoadData property to true as a way to trigger the LoadEarthquakes() method call. The MapItemsControl found within the <bing:Map> control binds its ItemsSource property to the Earthquakes collection of the view model, and since it is an ObservableCollection<T>, we get the automatic two way data binding via the INotifyCollectionChanged interface. <UserControl x:Class="EarthquakeLocator.MainPage"     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"     xmlns:bing="clr-namespace:Microsoft.Maps.MapControl;assembly=Microsoft.Maps.MapControl"     xmlns:vm="clr-namespace:EarthquakeLocator.ViewModel"     mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480" >     <UserControl.Resources>         <DataTemplate x:Key="EarthquakeTemplate">             <Ellipse Fill="Red" Stroke="Black" StrokeThickness="1"                      Width="{Binding Size}" Height="{Binding Size}"                      bing:MapLayer.Position="{Binding Location}"                      bing:MapLayer.PositionOrigin="Center">                 <ToolTipService.ToolTip>                     <StackPanel>                         <TextBlock Text="{Binding Title}" FontSize="14" FontWeight="Bold" />                         <TextBlock Text="{Binding UtcTime}" />                         <TextBlock Text="{Binding LocalTime}" />                         <TextBlock Text="{Binding DepthDesc}" />                     </StackPanel>                 </ToolTipService.ToolTip>             </Ellipse>         </DataTemplate>     </UserControl.Resources>       <UserControl.DataContext>         <vm:EarthquakeViewModel AutoLoadData="True" />     </UserControl.DataContext>       <Grid x:Name="LayoutRoot">           <bing:Map x:Name="map" CredentialsProvider="--Your-Bing-Maps-Key--"                   Center="{Binding MapCenter, Mode=TwoWay}"                   ZoomLevel="{Binding ZoomLevel, Mode=TwoWay}">             <bing:MapItemsControl ItemsSource="{Binding Earthquakes}"                                   ItemTemplate="{StaticResource EarthquakeTemplate}" />         </bing:Map>       </Grid> </UserControl>   The EarthquakeTemplate defines the Ellipse that will represent each earthquake, the Width and Height that are determined by the Magnitude, the Position on the map, and also the tooltip that will appear when we mouse over each data point. Running the application will give us the following result (shown with a tooltip example): That concludes this portion of our show but I plan on implementing additional functionality in later blog posts. Be sure to come back soon to see the next installments in this series. Enjoy!   Additional Resources USGS Earthquake Data Feeds Brad Abrams shows how RIA Services and MVVM can work together

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  • Windows Azure: Backup Services Release, Hyper-V Recovery Manager, VM Enhancements, Enhanced Enterprise Management Support

    - by ScottGu
    This morning we released a huge set of updates to Windows Azure.  These new capabilities include: Backup Services: General Availability of Windows Azure Backup Services Hyper-V Recovery Manager: Public preview of Windows Azure Hyper-V Recovery Manager Virtual Machines: Delete Attached Disks, Availability Set Warnings, SQL AlwaysOn Configuration Active Directory: Securely manage hundreds of SaaS applications Enterprise Management: Use Active Directory to Better Manage Windows Azure Windows Azure SDK 2.2: A massive update of our SDK + Visual Studio tooling support All of these improvements are now available to use immediately.  Below are more details about them. Backup Service: General Availability Release of Windows Azure Backup Today we are releasing Windows Azure Backup Service as a general availability service.  This release is now live in production, backed by an enterprise SLA, supported by Microsoft Support, and is ready to use for production scenarios. Windows Azure Backup is a cloud based backup solution for Windows Server which allows files and folders to be backed up and recovered from the cloud, and provides off-site protection against data loss. The service provides IT administrators and developers with the option to back up and protect critical data in an easily recoverable way from any location with no upfront hardware cost. Windows Azure Backup is built on the Windows Azure platform and uses Windows Azure blob storage for storing customer data. Windows Server uses the downloadable Windows Azure Backup Agent to transfer file and folder data securely and efficiently to the Windows Azure Backup Service. Along with providing cloud backup for Windows Server, Windows Azure Backup Service also provides capability to backup data from System Center Data Protection Manager and Windows Server Essentials, to the cloud. All data is encrypted onsite before it is sent to the cloud, and customers retain and manage the encryption key (meaning the data is stored entirely secured and can’t be decrypted by anyone but yourself). Getting Started To get started with the Windows Azure Backup Service, create a new Backup Vault within the Windows Azure Management Portal.  Click New->Data Services->Recovery Services->Backup Vault to do this: Once the backup vault is created you’ll be presented with a simple tutorial that will help guide you on how to register your Windows Servers with it: Once the servers you want to backup are registered, you can use the appropriate local management interface (such as the Microsoft Management Console snap-in, System Center Data Protection Manager Console, or Windows Server Essentials Dashboard) to configure the scheduled backups and to optionally initiate recoveries. You can follow these tutorials to learn more about how to do this: Tutorial: Schedule Backups Using the Windows Azure Backup Agent This tutorial helps you with setting up a backup schedule for your registered Windows Servers. Additionally, it also explains how to use Windows PowerShell cmdlets to set up a custom backup schedule. Tutorial: Recover Files and Folders Using the Windows Azure Backup Agent This tutorial helps you with recovering data from a backup. Additionally, it also explains how to use Windows PowerShell cmdlets to do the same tasks. Below are some of the key benefits the Windows Azure Backup Service provides: Simple configuration and management. Windows Azure Backup Service integrates with the familiar Windows Server Backup utility in Windows Server, the Data Protection Manager component in System Center and Windows Server Essentials, in order to provide a seamless backup and recovery experience to a local disk, or to the cloud. Block level incremental backups. The Windows Azure Backup Agent performs incremental backups by tracking file and block level changes and only transferring the changed blocks, hence reducing the storage and bandwidth utilization. Different point-in-time versions of the backups use storage efficiently by only storing the changes blocks between these versions. Data compression, encryption and throttling. The Windows Azure Backup Agent ensures that data is compressed and encrypted on the server before being sent to the Windows Azure Backup Service over the network. As a result, the Windows Azure Backup Service only stores encrypted data in the cloud storage. The encryption key is not available to the Windows Azure Backup Service, and as a result the data is never decrypted in the service. Also, users can setup throttling and configure how the Windows Azure Backup service utilizes the network bandwidth when backing up or restoring information. Data integrity is verified in the cloud. In addition to the secure backups, the backed up data is also automatically checked for integrity once the backup is done. As a result, any corruptions which may arise due to data transfer can be easily identified and are fixed automatically. Configurable retention policies for storing data in the cloud. The Windows Azure Backup Service accepts and implements retention policies to recycle backups that exceed the desired retention range, thereby meeting business policies and managing backup costs. Hyper-V Recovery Manager: Now Available in Public Preview I’m excited to also announce the public preview of a new Windows Azure Service – the Windows Azure Hyper-V Recovery Manager (HRM). Windows Azure Hyper-V Recovery Manager helps protect your business critical services by coordinating the replication and recovery of System Center Virtual Machine Manager 2012 SP1 and System Center Virtual Machine Manager 2012 R2 private clouds at a secondary location. With automated protection, asynchronous ongoing replication, and orderly recovery, the Hyper-V Recovery Manager service can help you implement Disaster Recovery and restore important services accurately, consistently, and with minimal downtime. Application data in an Hyper-V Recovery Manager scenarios always travels on your on-premise replication channel. Only metadata (such as names of logical clouds, virtual machines, networks etc.) that is needed for orchestration is sent to Azure. All traffic sent to/from Azure is encrypted. You can begin using Windows Azure Hyper-V Recovery today by clicking New->Data Services->Recovery Services->Hyper-V Recovery Manager within the Windows Azure Management Portal.  You can read more about Windows Azure Hyper-V Recovery Manager in Brad Anderson’s 9-part series, Transform the datacenter. To learn more about setting up Hyper-V Recovery Manager follow our detailed step-by-step guide. Virtual Machines: Delete Attached Disks, Availability Set Warnings, SQL AlwaysOn Today’s Windows Azure release includes a number of nice updates to Windows Azure Virtual Machines.  These improvements include: Ability to Delete both VM Instances + Attached Disks in One Operation Prior to today’s release, when you deleted VMs within Windows Azure we would delete the VM instance – but not delete the drives attached to the VM.  You had to manually delete these yourself from the storage account.  With today’s update we’ve added a convenience option that now allows you to either retain or delete the attached disks when you delete the VM:   We’ve also added the ability to delete a cloud service, its deployments, and its role instances with a single action. This can either be a cloud service that has production and staging deployments with web and worker roles, or a cloud service that contains virtual machines.  To do this, simply select the Cloud Service within the Windows Azure Management Portal and click the “Delete” button: Warnings on Availability Sets with Only One Virtual Machine In Them One of the nice features that Windows Azure Virtual Machines supports is the concept of “Availability Sets”.  An “availability set” allows you to define a tier/role (e.g. webfrontends, databaseservers, etc) that you can map Virtual Machines into – and when you do this Windows Azure separates them across fault domains and ensures that at least one of them is always available during servicing operations.  This enables you to deploy applications in a high availability way. One issue we’ve seen some customers run into is where they define an availability set, but then forget to map more than one VM into it (which defeats the purpose of having an availability set).  With today’s release we now display a warning in the Windows Azure Management Portal if you have only one virtual machine deployed in an availability set to help highlight this: You can learn more about configuring the availability of your virtual machines here. Configuring SQL Server Always On SQL Server Always On is a great feature that you can use with Windows Azure to enable high availability and DR scenarios with SQL Server. Today’s Windows Azure release makes it even easier to configure SQL Server Always On by enabling “Direct Server Return” endpoints to be configured and managed within the Windows Azure Management Portal.  Previously, setting this up required using PowerShell to complete the endpoint configuration.  Starting today you can enable this simply by checking the “Direct Server Return” checkbox: You can learn more about how to use direct server return for SQL Server AlwaysOn availability groups here. Active Directory: Application Access Enhancements This summer we released our initial preview of our Application Access Enhancements for Windows Azure Active Directory.  This service enables you to securely implement single-sign-on (SSO) support against SaaS applications (including Office 365, SalesForce, Workday, Box, Google Apps, GitHub, etc) as well as LOB based applications (including ones built with the new Windows Azure AD support we shipped last week with ASP.NET and VS 2013). Since the initial preview we’ve enhanced our SAML federation capabilities, integrated our new password vaulting system, and shipped multi-factor authentication support. We've also turned on our outbound identity provisioning system and have it working with hundreds of additional SaaS Applications: Earlier this month we published an update on dates and pricing for when the service will be released in general availability form.  In this blog post we announced our intention to release the service in general availability form by the end of the year.  We also announced that the below features would be available in a free tier with it: SSO to every SaaS app we integrate with – Users can Single Sign On to any app we are integrated with at no charge. This includes all the top SAAS Apps and every app in our application gallery whether they use federation or password vaulting. Application access assignment and removal – IT Admins can assign access privileges to web applications to the users in their active directory assuring that every employee has access to the SAAS Apps they need. And when a user leaves the company or changes jobs, the admin can just as easily remove their access privileges assuring data security and minimizing IP loss User provisioning (and de-provisioning) – IT admins will be able to automatically provision users in 3rd party SaaS applications like Box, Salesforce.com, GoToMeeting, DropBox and others. We are working with key partners in the ecosystem to establish these connections, meaning you no longer have to continually update user records in multiple systems. Security and auditing reports – Security is a key priority for us. With the free version of these enhancements you'll get access to our standard set of access reports giving you visibility into which users are using which applications, when they were using them and where they are using them from. In addition, we'll alert you to un-usual usage patterns for instance when a user logs in from multiple locations at the same time. Our Application Access Panel – Users are logging in from every type of devices including Windows, iOS, & Android. Not all of these devices handle authentication in the same manner but the user doesn't care. They need to access their apps from the devices they love. Our Application Access Panel will support the ability for users to access access and launch their apps from any device and anywhere. You can learn more about our plans for application management with Windows Azure Active Directory here.  Try out the preview and start using it today. Enterprise Management: Use Active Directory to Better Manage Windows Azure Windows Azure Active Directory provides the ability to manage your organization in a directory which is hosted entirely in the cloud, or alternatively kept in sync with an on-premises Windows Server Active Directory solution (allowing you to seamlessly integrate with the directory you already have).  With today’s Windows Azure release we are integrating Windows Azure Active Directory even more within the core Windows Azure management experience, and enabling an even richer enterprise security offering.  Specifically: 1) All Windows Azure accounts now have a default Windows Azure Active Directory created for them.  You can create and map any users you want into this directory, and grant administrative rights to manage resources in Windows Azure to these users. 2) You can keep this directory entirely hosted in the cloud – or optionally sync it with your on-premises Windows Server Active Directory.  Both options are free.  The later approach is ideal for companies that wish to use their corporate user identities to sign-in and manage Windows Azure resources.  It also ensures that if an employee leaves an organization, his or her access control rights to the company’s Windows Azure resources are immediately revoked. 3) The Windows Azure Service Management APIs have been updated to support using Windows Azure Active Directory credentials to sign-in and perform management operations.  Prior to today’s release customers had to download and use management certificates (which were not scoped to individual users) to perform management operations.  We still support this management certificate approach (don’t worry – nothing will stop working).  But we think the new Windows Azure Active Directory authentication support enables an even easier and more secure way for customers to manage resources going forward.  4) The Windows Azure SDK 2.2 release (which is also shipping today) includes built-in support for the new Service Management APIs that authenticate with Windows Azure Active Directory, and now allow you to create and manage Windows Azure applications and resources directly within Visual Studio using your Active Directory credentials.  This, combined with updated PowerShell scripts that also support Active Directory, enables an end-to-end enterprise authentication story with Windows Azure. Below are some details on how all of this works: Subscriptions within a Directory As part of today’s update, we have associated all existing Window Azure accounts with a Windows Azure Active Directory (and created one for you if you don’t already have one). When you login to the Windows Azure Management Portal you’ll now see the directory name in the URI of the browser.  For example, in the screen-shot below you can see that I have a “scottgu” directory that my subscriptions are hosted within: Note that you can continue to use Microsoft Accounts (formerly known as Microsoft Live IDs) to sign-into Windows Azure.  These map just fine to a Windows Azure Active Directory – so there is no need to create new usernames that are specific to a directory if you don’t want to.  In the scenario above I’m actually logged in using my @hotmail.com based Microsoft ID which is now mapped to a “scottgu” active directory that was created for me.  By default everything will continue to work just like you used to before. Manage your Directory You can manage an Active Directory (including the one we now create for you by default) by clicking the “Active Directory” tab in the left-hand side of the portal.  This will list all of the directories in your account.  Clicking one the first time will display a getting started page that provides documentation and links to perform common tasks with it: You can use the built-in directory management support within the Windows Azure Management Portal to add/remove/manage users within the directory, enable multi-factor authentication, associate a custom domain (e.g. mycompanyname.com) with the directory, and/or rename the directory to whatever friendly name you want (just click the configure tab to do this).  You can also setup the directory to automatically sync with an on-premises Active Directory using the “Directory Integration” tab. Note that users within a directory by default do not have admin rights to login or manage Windows Azure based resources.  You still need to explicitly grant them co-admin permissions on a subscription for them to login or manage resources in Windows Azure.  You can do this by clicking the Settings tab on the left-hand side of the portal and then by clicking the administrators tab within it. Sign-In Integration within Visual Studio If you install the new Windows Azure SDK 2.2 release, you can now connect to Windows Azure from directly inside Visual Studio without having to download any management certificates.  You can now just right-click on the “Windows Azure” icon within the Server Explorer and choose the “Connect to Windows Azure” context menu option to do so: Doing this will prompt you to enter the email address of the username you wish to sign-in with (make sure this account is a user in your directory with co-admin rights on a subscription): You can use either a Microsoft Account (e.g. Windows Live ID) or an Active Directory based Organizational account as the email.  The dialog will update with an appropriate login prompt depending on which type of email address you enter: Once you sign-in you’ll see the Windows Azure resources that you have permissions to manage show up automatically within the Visual Studio server explorer and be available to start using: No downloading of management certificates required.  All of the authentication was handled using your Windows Azure Active Directory! Manage Subscriptions across Multiple Directories If you have already have multiple directories and multiple subscriptions within your Windows Azure account, we have done our best to create a good default mapping of your subscriptions->directories as part of today’s update.  If you don’t like the default subscription-to-directory mapping we have done you can click the Settings tab in the left-hand navigation of the Windows Azure Management Portal and browse to the Subscriptions tab within it: If you want to map a subscription under a different directory in your account, simply select the subscription from the list, and then click the “Edit Directory” button to choose which directory to map it to.  Mapping a subscription to a different directory takes only seconds and will not cause any of the resources within the subscription to recycle or stop working.  We’ve made the directory->subscription mapping process self-service so that you always have complete control and can map things however you want. Filtering By Directory and Subscription Within the Windows Azure Management Portal you can filter resources in the portal by subscription (allowing you to show/hide different subscriptions).  If you have subscriptions mapped to multiple directory tenants, we also now have a filter drop-down that allows you to filter the subscription list by directory tenant.  This filter is only available if you have multiple subscriptions mapped to multiple directories within your Windows Azure Account:   Windows Azure SDK 2.2 Today we are also releasing a major update of our Windows Azure SDK.  The Windows Azure SDK 2.2 release adds some great new features including: Visual Studio 2013 Support Integrated Windows Azure Sign-In support within Visual Studio Remote Debugging Cloud Services with Visual Studio Firewall Management support within Visual Studio for SQL Databases Visual Studio 2013 RTM VM Images for MSDN Subscribers Windows Azure Management Libraries for .NET Updated Windows Azure PowerShell Cmdlets and ScriptCenter I’ll post a follow-up blog shortly with more details about all of the above. Additional Updates In addition to the above enhancements, today’s release also includes a number of additional improvements: AutoScale: Richer time and date based scheduling support (set different rules on different dates) AutoScale: Ability to Scale to Zero Virtual Machines (very useful for Dev/Test scenarios) AutoScale: Support for time-based scheduling of Mobile Service AutoScale rules Operation Logs: Auditing support for Service Bus management operations Today we also shipped a major update to the Windows Azure SDK – Windows Azure SDK 2.2.  It has so much goodness in it that I have a whole second blog post coming shortly on it! :-) Summary Today’s Windows Azure release enables a bunch of great new scenarios, and enables a much richer enterprise authentication offering. If you don’t already have a Windows Azure account, you can sign-up for a free trial and start using all of the above features today.  Then visit the Windows Azure Developer Center to learn more about how to build apps with it. Hope this helps, Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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  • ASP.NET MVC 2 Model Binding for a Collection

    - by nmarun
    Yes, my yet another post on Model Binding (previous one is here), but this one uses features presented in MVC 2. How I got to writing this blog? Well, I’m on a project where we’re doing some MVC things for a shopping cart. Let me show you what I was working with. Below are my model classes: 1: public class Product 2: { 3: public int Id { get; set; } 4: public string Name { get; set; } 5: public int Quantity { get; set; } 6: public decimal UnitPrice { get; set; } 7: } 8:   9: public class Totals 10: { 11: public decimal SubTotal { get; set; } 12: public decimal Tax { get; set; } 13: public decimal Total { get; set; } 14: } 15:   16: public class Basket 17: { 18: public List<Product> Products { get; set; } 19: public Totals Totals { get; set;} 20: } The view looks as below:  1: <h2>Shopping Cart</h2> 2:   3: <% using(Html.BeginForm()) { %> 4: 5: <h3>Products</h3> 6: <% for (int i = 0; i < Model.Products.Count; i++) 7: { %> 8: <div style="width: 100px;float:left;">Id</div> 9: <div style="width: 100px;float:left;"> 10: <%= Html.TextBox("ID", Model.Products[i].Id) %> 11: </div> 12: <div style="clear:both;"></div> 13: <div style="width: 100px;float:left;">Name</div> 14: <div style="width: 100px;float:left;"> 15: <%= Html.TextBox("Name", Model.Products[i].Name) %> 16: </div> 17: <div style="clear:both;"></div> 18: <div style="width: 100px;float:left;">Quantity</div> 19: <div style="width: 100px;float:left;"> 20: <%= Html.TextBox("Quantity", Model.Products[i].Quantity)%> 21: </div> 22: <div style="clear:both;"></div> 23: <div style="width: 100px;float:left;">Unit Price</div> 24: <div style="width: 100px;float:left;"> 25: <%= Html.TextBox("UnitPrice", Model.Products[i].UnitPrice)%> 26: </div> 27: <div style="clear:both;"><hr /></div> 28: <% } %> 29: 30: <h3>Totals</h3> 31: <div style="width: 100px;float:left;">Sub Total</div> 32: <div style="width: 100px;float:left;"> 33: <%= Html.TextBox("SubTotal", Model.Totals.SubTotal)%> 34: </div> 35: <div style="clear:both;"></div> 36: <div style="width: 100px;float:left;">Tax</div> 37: <div style="width: 100px;float:left;"> 38: <%= Html.TextBox("Tax", Model.Totals.Tax)%> 39: </div> 40: <div style="clear:both;"></div> 41: <div style="width: 100px;float:left;">Total</div> 42: <div style="width: 100px;float:left;"> 43: <%= Html.TextBox("Total", Model.Totals.Total)%> 44: </div> 45: <div style="clear:both;"></div> 46: <p /> 47: <input type="submit" name="Submit" value="Submit" /> 48: <% } %> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Nothing fancy, just a bunch of div’s containing textboxes and a submit button. Just make note that the textboxes have the same name as the property they are going to display. Yea, yea, I know. I’m displaying unit price as a textbox instead of a label, but that’s beside the point (and trust me, this will not be how it’ll look on the production site!!). The way my controller works is that initially two dummy products are added to the basked object and the Totals are calculated based on what products were added in what quantities and their respective unit price. So when the page loads in edit mode, where the user can change the quantity and hit the submit button. In the ‘post’ version of the action method, the Totals get recalculated and the new total will be displayed on the screen. Here’s the code: 1: public ActionResult Index() 2: { 3: Product product1 = new Product 4: { 5: Id = 1, 6: Name = "Product 1", 7: Quantity = 2, 8: UnitPrice = 200m 9: }; 10:   11: Product product2 = new Product 12: { 13: Id = 2, 14: Name = "Product 2", 15: Quantity = 1, 16: UnitPrice = 150m 17: }; 18:   19: List<Product> products = new List<Product> { product1, product2 }; 20:   21: Basket basket = new Basket 22: { 23: Products = products, 24: Totals = ComputeTotals(products) 25: }; 26: return View(basket); 27: } 28:   29: [HttpPost] 30: public ActionResult Index(Basket basket) 31: { 32: basket.Totals = ComputeTotals(basket.Products); 33: return View(basket); 34: } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } That’s that. Now I run the app, I see two products with the totals section below them. I look at the view source and I see that the input controls have the right ID, the right name and the right value as well. 1: <input id="ID" name="ID" type="text" value="1" /> 2: <input id="Name" name="Name" type="text" value="Product 1" /> 3: ... 4: <input id="ID" name="ID" type="text" value="2" /> 5: <input id="Name" name="Name" type="text" value="Product 2" /> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } So just as a regular user would do, I change the quantity value of one of the products and hit the submit button. The ‘post’ version of the Index method gets called and I had put a break-point on line 32 in the above snippet. When I hovered my mouse on the ‘basked’ object, happily assuming that the object would be all bound and ready for use, I was surprised to see both basket.Products and basket.Totals were null. Huh? A little research and I found out that the reason the DefaultModelBinder could not do its job is because of a naming mismatch on the input controls. What I mean is that when you have to bind to a custom .net type, you need more than just the property name. You need to pass a qualified name to the name property of the input control. I modified my view and the emitted code looked as below: 1: <input id="Product_Name" name="Product.Name" type="text" value="Product 1" /> 2: ... 3: <input id="Product_Name" name="Product.Name" type="text" value="Product 2" /> 4: ... 5: <input id="Totals_SubTotal" name="Totals.SubTotal" type="text" value="550" /> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Now, I update the quantity and hit the submit button and I see that the Totals object is populated, but the Products list is still null. Once again I went: ‘Hmm.. time for more research’. I found out that the way to do this is to provide the name as: 1: <%= Html.TextBox(string.Format("Products[{0}].ID", i), Model.Products[i].Id) %> 2: <!-- this will be rendered as --> 3: <input id="Products_0__ID" name="Products[0].ID" type="text" value="1" /> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } It was only now that I was able to see both the products and the totals being properly bound in the ‘post’ action method. Somehow, I feel this is kinda ‘clunky’ way of doing things. Seems like people at MS felt in a similar way and offered us a much cleaner way to solve this issue. The simple solution is that instead of using a Textbox, we can either use a TextboxFor or an EditorFor helper method. This one directly spits out the name of the input property as ‘Products[0].ID and so on. Cool right? I totally fell for this and changed my UI to contain EditorFor helper method. At this point, I ran the application, changed the quantity field and pressed the submit button. Of course my basket object parameter in my action method was correctly bound after these changes. I let the app complete the rest of the lines in the action method. When the page finally rendered, I did see that the quantity was changed to what I entered before the post. But, wait a minute, the totals section did not reflect the changes and showed the old values. My status: COMPLETELY PUZZLED! Just to recap, this is what my ‘post’ Index method looked like: 1: [HttpPost] 2: public ActionResult Index(Basket basket) 3: { 4: basket.Totals = ComputeTotals(basket.Products); 5: return View(basket); 6: } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } A careful debug confirmed that the basked.Products[0].Quantity showed the updated value and the ComputeTotals() method also returns the correct totals. But still when I passed this basket object, it ended up showing the old totals values only. I began playing a bit with the code and my first guess was that the input controls got their values from the ModelState object. For those who don’t know, the ModelState is a temporary storage area that ASP.NET MVC uses to retain incoming attempted values plus binding and validation errors. Also, the fact that input controls populate the values using data taken from: Previously attempted values recorded in the ModelState["name"].Value.AttemptedValue Explicitly provided value (<%= Html.TextBox("name", "Some value") %>) ViewData, by calling ViewData.Eval("name") FYI: ViewData dictionary takes precedence over ViewData's Model properties – read more here. These two indicators led to my guess. It took me quite some time, but finally I hit this post where Brad brilliantly explains why this is the preferred behavior. My guess was right and I, accordingly modified my code to reflect the following way: 1: [HttpPost] 2: public ActionResult Index(Basket basket) 3: { 4: // read the following posts to see why the ModelState 5: // needs to be cleared before passing it the view 6: // http://forums.asp.net/t/1535846.aspx 7: // http://forums.asp.net/p/1527149/3687407.aspx 8: if (ModelState.IsValid) 9: { 10: ModelState.Clear(); 11: } 12:   13: basket.Totals = ComputeTotals(basket.Products); 14: return View(basket); 15: } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } What this does is that in the case where your ModelState IS valid, it clears the dictionary. This enables the values to be read from the model directly and not from the ModelState. So the verdict is this: If you need to pass other parameters (like html attributes and the like) to your input control, use 1: <%= Html.TextBox(string.Format("Products[{0}].ID", i), Model.Products[i].Id) %> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Since, in EditorFor, there is no direct and simple way of passing this information to the input control. If you don’t have to pass any such ‘extra’ piece of information to the control, then go the EditorFor way. The code used in the post can be found here.

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  • xslt cookbook example not working

    - by Liza dawson
    Hi I am working on this from xslt cookbook type my.xml <?xml version="1.0" encoding="UTF-8"?> <people> <person name="Al Zehtooney" age="33" sex="m" smoker="no"/> <person name="Brad York" age="38" sex="m" smoker="yes"/> <person name="Charles Xavier" age="32" sex="m" smoker="no"/> <person name="David Williams" age="33" sex="m" smoker="no"/> <person name="Edward Ulster" age="33" sex="m" smoker="yes"/> <person name="Frank Townsend" age="35" sex="m" smoker="no"/> <person name="Greg Sutter" age="40" sex="m" smoker="no"/> <person name="Harry Rogers" age="37" sex="m" smoker="no"/> <person name="John Quincy" age="43" sex="m" smoker="yes"/> <person name="Kent Peterson" age="31" sex="m" smoker="no"/> <person name="Larry Newell" age="23" sex="m" smoker="no"/> <person name="Max Milton" age="22" sex="m" smoker="no"/> <person name="Norman Lamagna" age="30" sex="m" smoker="no"/> <person name="Ollie Kensington" age="44" sex="m" smoker="no"/> <person name="John Frank" age="24" sex="m" smoker="no"/> <person name="Mary Williams" age="33" sex="f" smoker="no"/> <person name="Jane Frank" age="38" sex="f" smoker="yes"/> <person name="Jo Peterson" age="32" sex="f" smoker="no"/> <person name="Angie Frost" age="33" sex="f" smoker="no"/> <person name="Betty Bates" age="33" sex="f" smoker="no"/> <person name="Connie Date" age="35" sex="f" smoker="no"/> <person name="Donna Finster" age="20" sex="f" smoker="no"/> <person name="Esther Gates" age="37" sex="f" smoker="no"/> <person name="Fanny Hill" age="33" sex="f" smoker="yes"/> <person name="Geta Iota" age="27" sex="f" smoker="no"/> <person name="Hillary Johnson" age="22" sex="f" smoker="no"/> <person name="Ingrid Kent" age="21" sex="f" smoker="no"/> <person name="Jill Larson" age="20" sex="f" smoker="no"/> <person name="Kim Mulrooney" age="41" sex="f" smoker="no"/> <person name="Lisa Nevins" age="21" sex="f" smoker="no"/> </people> type generic-attr-to-csv.xslt <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:csv="http://www.ora.com/XSLTCookbook/namespaces/csv"> <xsl:param name="delimiter" select=" ',' "/> <xsl:output method="text" /> <xsl:strip-space elements="*"/> <xsl:template match="/"> <xsl:for-each select="$columns"> <xsl:value-of select="@name"/> <xsl:if test="position( ) != last( )"> <xsl:value-of select="$delimiter/> </xsl:if> </xsl:for-each> <xsl:text>&#xa;</xsl:text> <xsl:apply-templates/> </xsl:template> <xsl:template match="/*/*"> <xsl:variable name="row" select="."/> <xsl:for-each select="$columns"> <xsl:apply-templates select="$row/@*[local-name(.)=current( )/@attr]" mode="csv:map-value"/> <xsl:if test="position( ) != last( )"> <xsl:value-of select="$delimiter"/> </xsl:if> </xsl:for-each> <xsl:text>&#xa;</xsl:text> </xsl:template> <xsl:template match="@*" mode="map-value"> <xsl:value-of select="."/> </xsl:template> </xsl:stylesheet> type my.xsl <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:csv="http://www.ora.com/XSLTCookbook/namespaces/csv"> <xsl:import href="generic-attr-to-csv.xslt"/> <!--Defines the mapping from attributes to columns --> <xsl:variable name="columns" select="document('')/*/csv:column"/> <csv:column name="Name" attr="name"/> <csv:column name="Age" attr="age"/> <csv:column name="Gender" attr="sex"/> <csv:column name="Smoker" attr="smoker"/> <!-- Handle custom attribute mappings --> <xsl:template match="@sex" mode="csv:map-value"> <xsl:choose> <xsl:when test=".='m'">male</xsl:when> <xsl:when test=".='f'">female</xsl:when> <xsl:otherwise>error</xsl:otherwise> </xsl:choose> </xsl:template> </xsl:stylesheet> using the apache xalan parser D:\Test>java org.apache.xalan.xslt.Process -in my.xml -xsl my.xsl -out my.csv [Fatal Error] generic-attr-to-csv.xslt:15:6: The value of attribute "select" associated with an element type "xsl:v alue-of" must not contain the '<' character. file:///D:/Test/generic-attr-to-csv.xslt; Line #15; Column #6; org.xml.sax.SAXParseException: The value of attribut e "select" associated with an element type "xsl:value-of" must not contain the '<' character. java.lang.NullPointerException at org.apache.xalan.transformer.TransformerImpl.createSerializationHandler(TransformerImpl.java:1171) at org.apache.xalan.transformer.TransformerImpl.createSerializationHandler(TransformerImpl.java:1060) at org.apache.xalan.transformer.TransformerImpl.transform(TransformerImpl.java:1268) at org.apache.xalan.transformer.TransformerImpl.transform(TransformerImpl.java:1251) at org.apache.xalan.xslt.Process.main(Process.java:1048) Exception in thread "main" java.lang.RuntimeException at org.apache.xalan.xslt.Process.doExit(Process.java:1155) at org.apache.xalan.xslt.Process.main(Process.java:1128) Any ideas what am i doing wrong

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  • Pure Server-Side Filtering with RadGridView and WCF RIA Services

    Those of you who are familiar with WCF RIA Services know that the DomainDataSource control provides a FilterDescriptors collection that enables you to filter data returned by the query on the server. We have been using this DomainDataSource feature in our RIA Services with DomainDataSource online example for almost an year now. In the example, we are listening for RadGridViews Filtering event in order to intercept any filtering that is performed on the client and translate it to something that the DomainDataSource will understand, in this case a System.Windows.Data.FilterDescriptor being added or removed from its FilterDescriptors collection. Think of RadGridView.FilterDescriptors as client-side filtering and of DomainDataSource.FilterDescriptors as server-side filtering. We no longer need the client-side one. With the introduction of the Custom Filtering Controls feature many new possibilities have opened. With these custom controls we no longer need to do any filtering on the client. I have prepared a very small project that demonstrates how to filter solely on the server by using a custom filtering control. As I have already mentioned filtering on the server is done through the FilterDescriptors collection of the DomainDataSource control. This collection holds instances of type System.Windows.Data.FilterDescriptor. The FilterDescriptor has three important properties: PropertyPath: Specifies the name of the property that we want to filter on (the left operand). Operator: Specifies the type of comparison to use when filtering. An instance of FilterOperator Enumeration. Value: The value to compare with (the right operand). An instance of the Parameter Class. By adding filters, you can specify that only entities which meet the condition in the filter are loaded from the domain context. In case you are not familiar with these concepts you might find Brad Abrams blog interesting. Now, our requirements are to create some kind of UI that will manipulate the DomainDataSource.FilterDescriptors collection. When it comes to collections, my first choice of course would be RadGridView. If you are not familiar with the Custom Filtering Controls concept I would strongly recommend getting acquainted with my step-by-step tutorial Custom Filtering with RadGridView for Silverlight and checking the online example out. I have created a simple custom filtering control that contains a RadGridView and several buttons. This control is aware of the DomainDataSource instance, since it is operating on its FilterDescriptors collection. In fact, the RadGridView that is inside it is bound to this collection. In order to display filters that are relevant for the current column only, I have applied a filter to the grid. This filter is a Telerik.Windows.Data.FilterDescriptor and is used to filter the little grid inside the custom control. It should not be confused with the DomainDataSource.FilterDescriptors collection that RadGridView is actually bound to. These are the RIA filters. Additionally, I have added several other features. For example, if you have specified a DataFormatString on your original column, the Value column inside the custom control will pick it up and format the filter values accordingly. Also, I have transferred the data type of the column that you are filtering to the Value column of the custom control. This will help the little RadGridView determine what kind of editor to show up when you begin edit, for example a date picker for DateTime columns. Finally, I have added four buttons two of them can be used to add or remove filters and the other two will communicate the changes you have made to the server. Here is the full source code of the DomainDataSourceFilteringControl. The XAML: <UserControl x:Class="PureServerSideFiltering.DomainDataSourceFilteringControl"    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"     xmlns:telerikGrid="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls.GridView"     xmlns:telerik="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls"     Width="300">     <Border x:Name="LayoutRoot"             BorderThickness="1"             BorderBrush="#FF8A929E"             Padding="5"             Background="#FFDFE2E5">           <Grid>             <Grid.RowDefinitions>                 <RowDefinition Height="Auto"/>                 <RowDefinition Height="150"/>                 <RowDefinition Height="Auto"/>             </Grid.RowDefinitions>               <StackPanel Grid.Row="0"                         Margin="2"                         Orientation="Horizontal"                         HorizontalAlignment="Center">                 <telerik:RadButton Name="addFilterButton"                                   Click="OnAddFilterButtonClick"                                   Content="Add Filter"                                   Margin="2"                                   Width="96"/>                 <telerik:RadButton Name="removeFilterButton"                                   Click="OnRemoveFilterButtonClick"                                   Content="Remove Filter"                                   Margin="2"                                   Width="96"/>             </StackPanel>               <telerikGrid:RadGridView Name="filtersGrid"                                     Grid.Row="1"                                     Margin="2"                                     ItemsSource="{Binding FilterDescriptors}"                                     AddingNewDataItem="OnFilterGridAddingNewDataItem"                                     ColumnWidth="*"                                     ShowGroupPanel="False"                                     AutoGenerateColumns="False"                                     CanUserResizeColumns="False"                                     CanUserReorderColumns="False"                                     CanUserFreezeColumns="False"                                     RowIndicatorVisibility="Collapsed"                                     IsFilteringAllowed="False"                                     CanUserSortColumns="False">                 <telerikGrid:RadGridView.Columns>                     <telerikGrid:GridViewComboBoxColumn DataMemberBinding="{Binding Operator}"                                                         UniqueName="Operator"/>                     <telerikGrid:GridViewDataColumn Header="Value"                                                     DataMemberBinding="{Binding Value.Value}"                                                     UniqueName="Value"/>                 </telerikGrid:RadGridView.Columns>             </telerikGrid:RadGridView>               <StackPanel Grid.Row="2"                         Margin="2"                         Orientation="Horizontal"                         HorizontalAlignment="Center">                 <telerik:RadButton Name="filterButton"                                   Click="OnApplyFiltersButtonClick"                                   Content="Apply Filters"                                   Margin="2"                                   Width="96"/>                 <telerik:RadButton Name="clearButton"                                   Click="OnClearFiltersButtonClick"                                   Content="Clear Filters"                                   Margin="2"                                   Width="96"/>             </StackPanel>           </Grid>       </Border> </UserControl>   And the code-behind: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Animation; using System.Windows.Shapes; using Telerik.Windows.Controls.GridView; using System.Windows.Data; using Telerik.Windows.Controls; using Telerik.Windows.Data;   namespace PureServerSideFiltering {     /// <summary>     /// A custom filtering control capable of filtering purely server-side.     /// </summary>     public partial class DomainDataSourceFilteringControl : UserControl, IFilteringControl     {         // The main player here.         DomainDataSource domainDataSource;           // This is the name of the property that this column displays.         private string dataMemberName;           // This is the type of the property that this column displays.         private Type dataMemberType;           /// <summary>         /// Identifies the <see cref="IsActive"/> dependency property.         /// </summary>         /// <remarks>         /// The state of the filtering funnel (i.e. full or empty) is bound to this property.         /// </remarks>         public static readonly DependencyProperty IsActiveProperty =             DependencyProperty.Register(                 "IsActive",                 typeof(bool),                 typeof(DomainDataSourceFilteringControl),                 new PropertyMetadata(false));           /// <summary>         /// Gets or sets a value indicating whether the filtering is active.         /// </summary>         /// <remarks>         /// Set this to true if you want to lit-up the filtering funnel.         /// </remarks>         public bool IsActive         {             get { return (bool)GetValue(IsActiveProperty); }             set { SetValue(IsActiveProperty, value); }         }           /// <summary>         /// Gets or sets the domain data source.         /// We need this in order to work on its FilterDescriptors collection.         /// </summary>         /// <value>The domain data source.</value>         public DomainDataSource DomainDataSource         {             get { return this.domainDataSource; }             set { this.domainDataSource = value; }         }           public System.Windows.Data.FilterDescriptorCollection FilterDescriptors         {             get { return this.DomainDataSource.FilterDescriptors; }         }           public DomainDataSourceFilteringControl()         {             InitializeComponent();         }           public void Prepare(GridViewBoundColumnBase column)         {             this.LayoutRoot.DataContext = this;               if (this.DomainDataSource == null)             {                 // Sorry, but we need a DomainDataSource. Can't do anything without it.                 return;             }               // This is the name of the property that this column displays.             this.dataMemberName = column.GetDataMemberName();               // This is the type of the property that this column displays.             // We need this in order to see which FilterOperators to feed to the combo-box column.             this.dataMemberType = column.DataType;               // We will use our magic Type extension method to see which operators are applicable for             // this data type. You can go to the extension method body and see what it does.             ((GridViewComboBoxColumn)this.filtersGrid.Columns["Operator"]).ItemsSource                 = this.dataMemberType.ApplicableFilterOperators();               // This is very nice as well. We will tell the Value column its data type. In this way             // RadGridView will pick up the best editor according to the data type. For example,             // if the data type of the value is DateTime, you will be editing it with a DatePicker.             // Nice!             ((GridViewDataColumn)this.filtersGrid.Columns["Value"]).DataType = this.dataMemberType;               // Yet another nice feature. We will transfer the original DataFormatString (if any) to             // the Value column. In this way if you have specified a DataFormatString for the original             // column, you will see all filter values formatted accordingly.             ((GridViewDataColumn)this.filtersGrid.Columns["Value"]).DataFormatString = column.DataFormatString;               // This is important. Since our little filtersGrid will be bound to the entire collection             // of this.domainDataSource.FilterDescriptors, we need to set a Telerik filter on the             // grid so that it will display FilterDescriptor which are relevane to this column ONLY!             Telerik.Windows.Data.FilterDescriptor columnFilter = new Telerik.Windows.Data.FilterDescriptor("PropertyPath"                 , Telerik.Windows.Data.FilterOperator.IsEqualTo                 , this.dataMemberName);             this.filtersGrid.FilterDescriptors.Add(columnFilter);               // We want to listen for this in order to activate and de-activate the UI funnel.             this.filtersGrid.Items.CollectionChanged += this.OnFilterGridItemsCollectionChanged;         }           /// <summary>         // Since the DomainDataSource is a little bit picky about adding uninitialized FilterDescriptors         // to its collection, we will prepare each new instance with some default values and then         // the user can change them later. Go to the event handler to see how we do this.         /// </summary>         void OnFilterGridAddingNewDataItem(object sender, GridViewAddingNewEventArgs e)         {             // We need to initialize the new instance with some values and let the user go on from here.             System.Windows.Data.FilterDescriptor newFilter = new System.Windows.Data.FilterDescriptor();               // This is a must. It should know what member it is filtering on.             newFilter.PropertyPath = this.dataMemberName;               // Initialize it with one of the allowed operators.             // TypeExtensions.ApplicableFilterOperators method for more info.             newFilter.Operator = this.dataMemberType.ApplicableFilterOperators().First();               if (this.dataMemberType == typeof(DateTime))             {                 newFilter.Value.Value = DateTime.Now;             }             else if (this.dataMemberType == typeof(string))             {                 newFilter.Value.Value = "<enter text>";             }             else if (this.dataMemberType.IsValueType)             {                 // We need something non-null for all value types.                 newFilter.Value.Value = Activator.CreateInstance(this.dataMemberType);             }               // Let the user edit the new filter any way he/she likes.             e.NewObject = newFilter;         }           void OnFilterGridItemsCollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)         {             // We are active only if we have any filters define. In this case the filtering funnel will lit-up.             this.IsActive = this.filtersGrid.Items.Count > 0;         }           private void OnApplyFiltersButtonClick(object sender, RoutedEventArgs e)         {             if (this.DomainDataSource.IsLoadingData)             {                 return;             }               // Comment this if you want the popup to stay open after the button is clicked.             this.ClosePopup();               // Since this.domainDataSource.AutoLoad is false, this will take into             // account all filtering changes that the user has made since the last             // Load() and pull the new data to the client.             this.DomainDataSource.Load();         }           private void OnClearFiltersButtonClick(object sender, RoutedEventArgs e)         {             if (this.DomainDataSource.IsLoadingData)             {                 return;             }               // We want to remove ONLY those filters from the DomainDataSource             // that this control is responsible for.             this.DomainDataSource.FilterDescriptors                 .Where(fd => fd.PropertyPath == this.dataMemberName) // Only "our" filters.                 .ToList()                 .ForEach(fd => this.DomainDataSource.FilterDescriptors.Remove(fd)); // Bye-bye!               // Comment this if you want the popup to stay open after the button is clicked.             this.ClosePopup();               // After we did our housekeeping, get the new data to the client.             this.DomainDataSource.Load();         }           private void OnAddFilterButtonClick(object sender, RoutedEventArgs e)         {             if (this.DomainDataSource.IsLoadingData)             {                 return;             }               // Let the user enter his/or her requirements for a new filter.             this.filtersGrid.BeginInsert();             this.filtersGrid.UpdateLayout();         }           private void OnRemoveFilterButtonClick(object sender, RoutedEventArgs e)         {             if (this.DomainDataSource.IsLoadingData)             {                 return;             }               // Find the currently selected filter and destroy it.             System.Windows.Data.FilterDescriptor filterToRemove = this.filtersGrid.SelectedItem as System.Windows.Data.FilterDescriptor;             if (filterToRemove != null                 && this.DomainDataSource.FilterDescriptors.Contains(filterToRemove))             {                 this.DomainDataSource.FilterDescriptors.Remove(filterToRemove);             }         }           private void ClosePopup()         {             System.Windows.Controls.Primitives.Popup popup = this.ParentOfType<System.Windows.Controls.Primitives.Popup>();             if (popup != null)             {                 popup.IsOpen = false;             }         }     } }   Finally, we need to tell RadGridViews Columns to use this custom control instead of the default one. Here is how to do it: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Animation; using System.Windows.Shapes; using System.Windows.Data; using Telerik.Windows.Data; using Telerik.Windows.Controls; using Telerik.Windows.Controls.GridView;   namespace PureServerSideFiltering {     public partial class MainPage : UserControl     {         public MainPage()         {             InitializeComponent();             this.grid.AutoGeneratingColumn += this.OnGridAutoGeneratingColumn;               // Uncomment this if you want the DomainDataSource to start pre-filtered.             // You will notice how our custom filtering controls will correctly read this information,             // populate their UI with the respective filters and lit-up the funnel to indicate that             // filtering is active. Go ahead and try it.             this.employeesDataSource.FilterDescriptors.Add(new System.Windows.Data.FilterDescriptor("Title", System.Windows.Data.FilterOperator.Contains, "Assistant"));             this.employeesDataSource.FilterDescriptors.Add(new System.Windows.Data.FilterDescriptor("HireDate", System.Windows.Data.FilterOperator.IsGreaterThan, new DateTime(1998, 12, 31)));             this.employeesDataSource.FilterDescriptors.Add(new System.Windows.Data.FilterDescriptor("HireDate", System.Windows.Data.FilterOperator.IsLessThanOrEqualTo, new DateTime(1999, 12, 31)));               this.employeesDataSource.Load();         }           /// <summary>         /// First of all, we will need to replace the default filtering control         /// of each column with out custom filtering control DomainDataSourceFilteringControl         /// </summary>         private void OnGridAutoGeneratingColumn(object sender, GridViewAutoGeneratingColumnEventArgs e)         {             GridViewBoundColumnBase dataColumn = e.Column as GridViewBoundColumnBase;             if (dataColumn != null)             {                 // We do not like ugly dates.                 if (dataColumn.DataType == typeof(DateTime))                 {                     dataColumn.DataFormatString = "{0:d}"; // Short date pattern.                       // Notice how this format will be later transferred to the Value column                     // of the grid that we have inside the DomainDataSourceFilteringControl.                 }                   // Replace the default filtering control with our.                 dataColumn.FilteringControl = new DomainDataSourceFilteringControl()                 {                     // Let the control know about the DDS, after all it will work directly on it.                     DomainDataSource = this.employeesDataSource                 };                   // Finally, lit-up the filtering funnel through the IsActive dependency property                 // in case there are some filters on the DDS that match our column member.                 string dataMemberName = dataColumn.GetDataMemberName();                 dataColumn.FilteringControl.IsActive =                     this.employeesDataSource.FilterDescriptors                     .Where(fd => fd.PropertyPath == dataMemberName)                     .Count() > 0;             }         }     } } The best part is that we are not only writing filters for the DomainDataSource we can read and load them. If the DomainDataSource has some pre-existing filters (like I have created in the code above), our control will read them and will populate its UI accordingly. Even the filtering funnel will light-up! Remember, the funnel is controlled by the IsActive property of our control. While this is just a basic implementation, the source code is absolutely yours and you can take it from here and extend it to match your specific business requirements. Below the main grid there is another debug grid. With its help you can monitor what filter descriptors are added and removed to the domain data source. Download Source Code. (You will have to have the AdventureWorks sample database installed on the default SQLExpress instance in order to run it.) Enjoy!Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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