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  • How to code a 'Next in Results' within search results in PHP

    - by thebluefox
    Right, bit of a head scratcher, although I've got a feeling there's an obvious answer and I'm just not seeing the wood for the trees. Baiscally, using Solr as a search engine for my site, bringing back 15 results per page. When you click on a result, you get a detail page, that has a "Next in Results" link on it, which obviously forwards you on to the next result. Whats the best way of doing this? I've come up with a few solutions but they're either too inpractical or just don't work. I could store all the ids in a session array, then grab the one after the current one and put that in the link. But with possibly hundreds/thousands of results, the memory that array would need, and the performance hit of dealing with it isn't practical. I could take the same approach and put it into the db, but I'll still have to deal with a potentially huge array when I grab them out of the db. Or; I could do the search again, only returning the id's, and grab the one after the one we're currently looking at. I think this could be the best option? Although it does seem kind of messy, namely because of when I have to select the id thats on a different 'page' (ie the 16th, 31st etc result). Unless I pass through where it was in the results, and select from there, but that still doesn't seem like the right way to do it. I'm really sorry if this is just complete nonsense, any help is massively appreciated as always, Cheers guys!

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  • NHibernate listener/event to replace object before insert/update

    - by vIceBerg
    Hi! I have a Company class which have a collection of Address. Here's my Address class:(written top of my head): public class Address { public string Civic; public string Street; public City City; } This is the City class: public class City { public int Id; public string Name; public string SearchableName{ get { //code } } } Address is persisted in his own table and have a reference to the city's ID. City are also persisted in is own table. The City's SearchableName is used to prevent some mistakes in the city the user type. For example, if the city name is "Montréal", the searchable name will be "montreal". If the city name is "St. John", the searchable name will be "stjohn", etc. It's used mainly to to search and to prevent having multiple cities with a typo in it. When I save an address, I want an listener/event to check if the city is already in the database. If so, cancel the insert and replace the user's city with the database one. I would like the same behavior with updates. I tried this: public bool OnPreInsert(PreInsertEvent @event) { City entity = (@event.Entity as City); if (entity != null) { if (entity.Id == 0) { var city = (from c in @event.Session.Linq<City>() where c.SearchableName == entity.SearchableName select c).SingleOrDefault(); if (city != null) { //don't know what to do here return true; } } } return false; } But if there's already a City in the database, I don't know what to do. @event.Entity is readonly, if I set @event.Entity.Id, I get an "null identifier" exception. I tried to trap insert/update on Address and on Company, but the City if the first one to get inserted (it's logic...) Any thoughts? Thanks

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  • Can a page opt out of IIS 7 compression?

    - by Glen Little
    My pages are automatically being compressed by IIS7 with GZIP. That is great... but, for one particular page, I need to stream it to the user, using Response.Flush() when needed. But when the output is being compressed, the IIS server seems to collect all my output until the page is done before compressing and sending it to the client. That nullifies my attempt to Flush the content out to the user. Is there a way that I can have this one page opt out of the compression? One possible option I've determined that if I manually set the content type to one that does not match the IIS configuration at c:\windows\system32\inetsrv\config\applicationhost.config, then IIS will not compress it. Eg. Response.ContentType = "x-text/html". This works okay with IE8, as it falls back to display the HTML. But Firefox will ask the user what to do with the unknown file type. This could work, if there was another Mime Type I could use that browsers would accept as HTML, that is not matched in the applicationhost.config. For reference, these are the mime types that will be compressed: <add mimeType="text/*" enabled="true" /> <add mimeType="message/*" enabled="true" /> <add mimeType="application/x-javascript" enabled="true" /> <add mimeType="application/atom+xml" enabled="true" /> <add mimeType="application/xaml+xml" enabled="true" /> Others options? Are there other options to opt out of compression?

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  • Why do Scala maps have poor performance relative to Java?

    - by Mike Hanafey
    I am working on a Scala app that consumes large amounts of CPU time, so performance matters. The prototype of the system was written in Python, and performance was unacceptable. The application does a lot with inserting and manipulating data in maps. Rex Kerr's Thyme was used to look at the performance of updating and retrieving data from maps. Basically "n" random Ints were stored in maps, and retrieved from the maps, with the time relative to java.util.HashMap used as a reference. The full results for a range of "n" are here. Sample (n=100,000) performance relative to java, smaller is worse: Update Read Mutable 16.06% 76.51% Immutable 31.30% 20.68% I do not understand why the scala immutable map beats the scala mutable map in update performance. Using the sizeHint on the mutable map does not help (it appears to be ignored in the tested implementation, 2.10.3). Even more surprisingly the immutable read performance is worse than the mutable read performance, more significantly so with larger maps. The update performance of the scala mutable map is surprisingly bad, relative to both scala immutable and plain Java. What is the explanation?

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  • Dangers when deploying Flash/Flex UI test automation hooks to production?

    - by Merlyn Morgan-Graham
    I am interested in doing automated testing against a Flex based UI. I have found out that my best options for UI automation (due to being C# controllable, good licensing conditions, etc) all seem to require that I compile test hooks into my application. Because of this, I am thinking of recommending that these hooks be compiled into our build. I have found a few places on the net that recommend not deploying bits with this instrumentation enabled, and I'd like to know why. Is it a performance drain, or a security risk? If it is a security risk, can you explain how the attack surface is increased? I am not a Flash or Flex developer, though I have some experience with threat modeling. For reference, here's the tools I'm specifically considering: QTP Selenium-Flex API I am having problems finding all the warnings/suggestions I found last night, but here's an example that I can find: http://www.riatest.com/products/getting-started.html Warning! Automation enabled applications expose all properties of all GUI components. This makes them vulnerable to malicious use. Never make automation enabled application publicly available. Always restrict access to such applications and to RIATest Loader to trusted users only. Related question (how to do conditional compilation to insert/remove those hooks): Conditionally including Flex libraries (SWCs) in mxmlc/compc ant tasks

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  • MVC View Model Intellesense / Compile error

    - by Marty Trenouth
    I have one Library with my ORM and am working with a MVC Application. I have a problem where the pages won't compile because the Views can't see the Model's properties (which are inherited from lower level base classes). They system throws a compile error saying that 'object' does not contain a definition for 'ID' and no extension method 'ID' accepting a first argument of type 'object' could be found (are you missing a using directive or an assembly reference?) implying that the View is not seeing the model. In the Controller I have full access to the Model and have check the Inherits from portion of the view to validate the correct type is being passed. Controller: return View(new TeraViral_Blog()); View: <%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<com.models.TeraViral_Blog>" %> <asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server"> Index2 </asp:Content> <asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> <h2>Index2</h2> <fieldset> <legend>Fields</legend> <p> ID: <%= Html.Encode(Model.ID) %> </p> </fieldset> </asp:Content>

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  • OpenAL not playing on Max OS X 10.6

    - by Grimless
    I've been working on getting a basic audio engine running on my Mac using OpenAL. It seems relatively straightforward after working with OpenGL for a while. However, despite the fact that I believe I have everything in place, my sound will not play. Here is the order of things I am doing: //Creating a new device ALCdevice* device = alcOpenDevice(NULL); //Create a new context with the device ALCcontext* context = alcCreateContext(device, NULL); //Make that context current alcMakeContextCurrent(context); //Do lots of loading stuff to bring in an AIFF... voodooAIFF = myAIFFLoader("name"); //Then use that data ALuint buf; alGenBuffers(1, &buf); //Check for errors, but none happen... //Bind buffer data. alBufferData(buf, voodooAIFF.format, voodooAIFF.data, voodooAIFF.sizeInBytes, voodooAIFF.frequency); //Check for errors, none here either... //Create Source ALuint src; alGenSources(1, &src); //Error check again, no errors. //Bind source to buffer alSourcei(src, AL_BUFFER, buf); //Set reference distance alSourcei(sourceID, AL_REFERENCE_DISTANCE, 1); //Set source attributes including gain and pitch to 1 (direction set to 0,0,0) //Check for errors, nothing... //Set up listener attributes. //Check for errors, no errors. //Begin playing. alSourcePlay(src); Observe silence... Any insight, what steps am I missing here?

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  • How can I generate a FindBugs report that shows me the bugs removed between two revisions in the bug

    - by David Deschenes
    I am attempting to execute a combination of the FindBugs commands filterBugs and convertXmlToText, against a bug database that I created, to generate a report that shows me the all of the bugs removed between two revisions of the system that I am working on. Unfortunately, the resulting report does not show any bug details. It appears that the convertXmlToText throws away all bugs that are dead (aka inactive)... the exact set of bugs that I'd like to see. Below is what I see when I pass the results of the filterBugs command to the mineBugHistory command: build/findbugs/bin> ./filterBugs -before r39921 -absent r41558 -active:false ../../../mmfg/bugDB-2.xml | ./mineBugHistory seq version time classes NCSS added newCode fixed removed retained dead active 0 r39764 1271169398000 438 74069 0 64 0 0 0 0 64 1 r39921 1271186932000 441 74333 0 0 22 0 42 0 42 2 r40149 1271185876000 449 74636 0 0 3 0 39 22 39 3 r40344 1271180332000 452 74789 0 0 7 0 32 25 32 4 r40558 1271179612000 452 74806 0 0 1 0 31 32 31 5 r40793 1271178818000 464 75610 0 0 20 0 11 33 11 6 r41016 1271176154000 467 75712 0 0 4 0 7 53 7 7 r41303 1271175616000 481 76931 0 0 7 0 0 57 0 8 r41558 1271175026000 486 77793 0 0 0 0 0 64 0 What I'd like to see in the HTML report is the list of the 64 bugs that are shown as active in version r39764 (sequence # 0). Below is the command line that I am using to generate the HTML report: build/findbugs/bin> ./filterBugs -before r39921 -absent r41558 -active:false ../../../mmfg/bugDB-2.xml | ./convertXmlToText -html:fancy-hist.xsl > ../../../mmfg/bugDB-removed.html

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  • Windows Azure: Creating a subdirectories inside the blob

    - by veda
    I wanted to create some subdirectories inside my blob. But it is not working out well Here is my code protected void ButUpload_click(object sender, EventArgs e) { // store upladed file as a blob storage if (uplFileUpload.HasFile) { name = uplFileUpload.FileName; // get refernce to the cloud blob container CloudBlobContainer blobContainer = cloudBlobClient.GetContainerReference("documents"); if (textbox.Text != "") { name = textbox.Text + "/" + name; } // set the name for the uploading files string UploadDocName = name; // get the blob reference and set the metadata properties CloudBlockBlob blob = blobContainer.GetBlockBlobReference(UploadDocName); blob.Metadata["FILETYPE"] = "text"; blob.Properties.ContentType = uplFileUpload.PostedFile.ContentType; // upload the blob to the storage blob.UploadFromStream(uplFileUpload.FileContent); } } What I did is that, If I have to create a sub directory, I will enter the name of the sub directory in the textbox. for example, if I need to create a file named "test.txt" inside the sub directory "files" Then, my textbox.text = files and uplFileUpload.FileName = test.txt Now I will concatenate them and upload to the blob.. But it is not working well.. I am getting just https://test.core.windows.net/documents/files/ I am not getting the entire thing I was expecting https://test.core.windows.net/documents/files/test.txt What am I doing wrong... How to create sub directories inside the blob.

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  • structDelete doesn't affect the shallow copy?

    - by Travis
    I was playing around onError so I tried to create an error using a large xml document object. <cfset XMLByRef = variables.parsedXML.XMLRootElement.XMLChildElement> <cfset structDelete(variables.parsedXML, "XMLRootElement")> <cfset startXMLShortLoop = getTickCount()> <cfloop from = "1" to = "#arrayLen(variables.XMLByRef)#" index = "variables.i"> <cfoutput>#variables.XMLByRef[variables.i].id.xmltext#</cfoutput><br /> </cfloop> <cfset stopXMLShortLoop = getTickCount()> I expected to get an error because I deleted the structure I was referencing. From LiveDocs: Variable Assignment - Creates an additional reference, or alias, to the structure. Any change to the data using one variable name changes the structure that you access using the other variable name. This technique is useful when you want to add a local variable to another scope or otherwise change a variable's scope without deleting the variable from the original scope. instead I got 580df1de-3362-ca9b-b287-47795b6cdc17 25a00498-0f68-6f04-a981-56853c0844ed ... ... ... db49ed8a-0ba6-8644-124a-6d6ebda3aa52 57e57e28-e044-6119-afe2-aebffb549342 Looped 12805 times in 297 milliseconds <cfdump var = "#variables#"> Shows there's nothing in the structure, just parsedXML.xmlRoot.xmlName with the value of XMLRootElement. I also tried <cfset structDelete(variables.parsedXML.XMLRootElement, "XMLChildElement")> as well as structClear for both. More information on deleting from the xml document object. http://help.adobe.com/en_US/ColdFusion/9.0/Developing/WSc3ff6d0ea77859461172e0811cbec22c24-78e3.html Can someone please explain my faulty logic? Thanks.

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  • Is a call to the following method considered late binding?

    - by AspOnMyNet
    1) Assume: • B1 defines methods virtualM() and nonvirtualM(), where former method is virtual while the latter is non-virtual • B2 derives from B1 • B2 overrides virtualM() • B2 is defined inside assembly A • Application app doesn’t have a reference to assembly A In the following code application app dynamically loads an assembly A, creates an instance of a type B2 and calls methods virtualM() and nonvirtualM(): Assembly a=Assembly.Load(“A”); Type t= a.GetType(“B2”); B1 a = ( B1 ) Activator.CreateInstance ( “t” ); a.virtualM(); a.nonvirtualM(); a) Is call to a.virtualM() considered early binding or late binding? b) I assume a call to a.nonvirtualM() is resolved during compilation time? 2) Does the term late binding refer only to looking up the target method at run time or does it also refer to creating an instance of given type at runtime? thanx EDIT: 1) A a=new A(); a.M(); As far as I know, it is not known at compile time where on the heap (thus at which memory address ) will instance a be created during runtime. Now, with early binding the function calls are replaced with memory addresses during compilation process. But how can compiler replace function call with memory address, if it doesn’t know where on the heap will object a be created during runtime ( here I’m assuming the address of method a.M will also be at same memory location as a )? 2) The method slot is determined at compile time I assume that by method slot you’re referring to the entry point in V-table?

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  • Passing params in rails... Breakthrough in understanding params, aka, the "aha" moment

    - by Brian McDonough
    I have a simple has_many belongs_to relationship and I want to include the parent object for the view of the belongs_to model and I have had some success, but I want it to work better. class Submission < ActiveRecord::Base belongs_to :user belongs_to :contest end class Contest < ActiveRecord::Base belongs_to :user has_many :submissions, :dependent => :destroy end In the case that works, I pass contest_id to submissions by placing it in the url: <%= link_to 'Submit Contest Entry', new_submission_path(:contest_id => @contest.id), :class => 'btn btn-primary btn-large mleft10' %> So that, combined with a hidden_field: <%= f.hidden_field :contest_id %> And a find_contest method in the controller (called with a before_filter): def find_contest #the next line is giving the error (line 76) @contest = Contest.find(params[:submission][:contest_id]) end Makes it work for submissions/new, but how do I add a find to the controller that just works across more than that one page, like if I want to access in show and index. Right now, I get an error: Started GET "/submissions?contest_id=5" for 127.0.0.1 at 2012-12-01 16:01:45 -0800 Processing by SubmissionsController#index as HTML Parameters: {"contest_id"=>"5"} User Load (0.3ms) SELECT "users".* FROM "users" WHERE "users"."id" = 2 ORDER BY users.created_at DESC LIMIT 1 Completed 500 Internal Server Error in 37ms NoMethodError (undefined method `[]' for nil:NilClass): app/controllers/submissions_controller.rb:76:in `find_contest' [edited] Adding show action for submissions: before_filter :find_contest, :except => [:index, :show, :edit, :update, :destroy] def find_contest @contest = Contest.find(params[:submission][:contest_id]) end def show contest_id = @submission.contest_id @submission = @commentable = Submission.find(params[:id]) @comments = @commentable.comments.order(:created_at).reverse respond_to do |format| format.html # show.html.erb format.json { render :json => @submission } end end

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  • Seeding many to many tables with Entity Framework

    - by Doozer1979
    I have a meeting entity and a users entity which have a many to many relationship. I'm using Autopoco to create seed data for the Users and meetings How do i seed the UserMeetings linking table that is created by EntityFramework with seed data? The linking table has two fields in it; User_Id, and Meeting_ID. I'm looping through the list of users that autopoco creates and attaching a random number of meetings Here's what i've got so far. foreach (var user in userList) { var rand = new Random(); var amountOfMeetingsToAdd = rand.Next(1, 300); for (var i = 0; i <= amountOfMeetingsToAdd; i++) { var randomMeeting = rand.Next(1, MeetingRecords); //Error occurs on This line user.Meetings.Add(_meetings[randomMeeting]); } } I got an 'Object reference not set to an instance of an object.' even though the meeting record that i'm trying to attach does exist. For info all this is happening prior to me saving the context to the DB.

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  • How to find which file is open in eclipse editor without using IEditorPart?

    - by Destructor
    I want to know which file (or even project is enough) is opened in eclipse editor? I know we can do this once we get IEditorPart from doSetInput method, IFile file = ((IFileEditorInput) iEditorPart).getFile(); But I want the name of file without using IEditorPart, how can I do the same? Checking which is the selected file in project explorer is not of much help because, user can select multiple files at once and open all simultaneously and I did not way to distinguish which file opened at what time. Adding more info: I have an editor specified for a particular type of file, now every time it opens, during intializing editor I have some operation to do based on project properties. While initializing editor, I need the file handle (of the one which user opened/double clicked) or the corresponding project handle. I have my editor something this way: public class MyEditor extends TextEditor{ @Override protected void initializeEditor() { setSourceViewerConfiguration(new MySourceViewerConfiguration( CDTUITools.getColorManager(), store, "MyPartitions", this)); } //other required methods @Override protected void doSetInput(IEditorInput input) throws CoreException { if(input instanceof IFileEditorInput) { IFile file = ((IFileEditorInput) input).getFile(); } } } as I have done in the doSetInput() method , I want the file handle(even project handle is sufficient). But the problem is in initializeEditor() function there is no reference to editorInput, hence I am unable to get the file handle. In the source viewer configuration file, I set the code scanners and this needs some project specific information that will set the corresponding rules.

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  • How to vertically align text in a button with a background drawable?

    - by neutrino
    I had a simple button set up with a background image defined like android:background="?attr/button" where ?attr/button was a reference to a simple 9-patch png. Everything worked fine, text in the button was aligned correctly. Then I needed to have a different background for a pressed state of the button. So I changed that to android:background="@drawable/state_button" where @drawable/state_button is an xml with the following states <?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:state_pressed="true" android:drawable="@drawable/button_pressed" /> <!-- pressed --> <item android:state_focused="true" android:drawable="@drawable/button_pressed" /> <!-- focused --> <item android:drawable="@drawable/button" /> <!-- default --> </selector> And after that I can't align the text properly. If I put android:gravity="center_vertical" the text is drawn about 1/4 of the button height from the top. I double-checked my 9-patch images, everything seems fine with them. And I also tried having regular pngs for the background, it also doesn't change anything.

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  • Pattern for UI configuration

    - by TERACytE
    I have a Win32 C++ program that validates user input and updates the UI with status information and options. Currently it is written like this: void ShowError() { SetIcon(kError); SetMessageString("There was an error"); HideButton(kButton1); HideButton(kButton2); ShowButton(kButton3); } void ShowSuccess() { SetIcon(kError); std::String statusText (GetStatusText()); SetMessageString(statusText); HideButton(kButton1); HideButton(kButton2); ShowButton(kButton3); } // plus several more methods to update the UI using similar mechanisms I do not likes this because it duplicates code and causes me to update several methods if something changes in the UI. I am wondering if there is a design pattern or best practice to remove the duplication and make the functionality easier to understand and update. I could consolidate the code inside a config function and pass in flags to enable/disable UI items, but I am not convinced this is the best approach. Any suggestions and ideas?

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  • Issues with intellisense, references, and builds in Visual Studio 2008

    - by goober
    Hoping you can help me -- the strangest thing seems to have happened with my VS install. System config: Windows 7 Pro x64, Visual Studio 2008 SP1, C#, ASP.NET 3.5. I have two web site projects in a solution. I am referencing NUnit / NHibernate (did this by right-clicking on the project and selecting "Add Reference". I've done this for several projects in the past). Things were working fine but recently stopped working and I can't figure out why. Intellisense completely disappears for any files in my App_Code directory, and none of the references are recognized (they are recognized by any file in the root directory of the web site project. Additionally, pretty simple commands like the following (in Page_Load) fail (assume TextBox1 is definitely an element on the page): if (Page.IsPostBack) { str test1; test1 = TextBox1.Text; } It says that all the page elements are null or that it can't access them. At first I thought it was me, but due to the combination of issues, it seems to be Visual Studio itself. I've tried clearing the temp directories & rebuilding the solution. I've also tried tools -- options -- text editor settings to ensure intellisense is turned on. I'd appreciate any help you can give!

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  • C# - default parameter values from previous parameter

    - by Sagar R. Kothari
    namespace HelloConsole { public class BOX { double height, length, breadth; public BOX() { } // here, I wish to pass 'h' to remaining parameters if not passed // FOLLOWING Gives compilation error. public BOX (double h, double l = h, double b = h) { Console.WriteLine ("Constructor with default parameters"); height = h; length = l; breadth = b; } } } // // BOX a = new BOX(); // default constructor. all okay here. // BOX b = new BOX(10,20,30); // all parameter passed. all okay here. // BOX c = new BOX(10); // Here, I want = length=10, breadth=10,height=10; // BOX d = new BOX(10,20); // Here, I want = length=10, breadth=20,height=10; Question is : 'To achieve above, Is 'constructor overloading' (as follows) is the only option? public BOX(double h) { height = length = breadth = h; } public BOX(double h, double l) { height = breadth = h; length = l; }

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  • WCF with SSL- not finding localhost

    - by SteveCav
    Hi guys, I'm trying to get WCF to use SSL with ANYTHING for FIVE DAYS now. I've gone through countless walkthroughs, generated more certificates than a mail order diploma company, even tried hot fixes. After working with MS dev tools since VB1, I am now considering flipping burgers as a career option. WCF, as far as I can see, is a complete lemon. Anyway, to get to my actual question: If I run through this walkthrough: http://msdn.microsoft.com/en-us/library/ff648840.aspx I get to step 11 (adding the service reference) and get "There was an error downloading metadata from the address. Please verify that you have entered a valid address". Details of the error gives: There was an error downloading 'https://localhost/SSL6/Service.svc'. Unable to connect to the remote server No connection could be made because the target machine actively refused it 127.0.0.1:443 I'm using VS2008 on Windows 7 with IIS7. I followed the walkthrough exactly (apart from step 5 which was different on IIS7- I went into "SSL Settings" for the VD), so it shows my config (yes I've used httpsGetEnabled and mexHttpsBinding). Anyone care to save my sanity and job?

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  • Is there a pattern for initializing objects created wth a DI container

    - by Igor Zevaka
    I am trying to get Unity to manage the creation of my objects and I want to have some initialization parameters that are not known until run-time: At the moment the only way I could think of the way to do it is to have an Init method on the interface. interface IMyIntf { void Initialize(string runTimeParam); string RunTimeParam { get; } } Then to use it (in Unity) I would do this: var IMyIntf = unityContainer.Resolve<IMyIntf>(); IMyIntf.Initialize("somevalue"); In this scenario runTimeParam param is determined at run-time based on user input. The trivial case here simply returns the value of runTimeParam but in reality the parameter will be something like file name and initialize method will do something with the file. This creates a number of issues, namely that the Initialize method is available on the interface and can be called multiple times. Setting a flag in the implementation and throwing exception on repeated call to Initialize seems way clunky. At the point where I resolve my interface I don't want to know anything about the implementation of IMyIntf. What I do want, though, is the knowledge that this interface needs certain one time initialization parameters. Is there a way to somehow annotate(attributes?) the interface with this information and pass those to framework when the object is created? Edit: Described the interface a bit more.

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  • Creation of Objects: Constructors or Static Factory Methods

    - by Rachel
    I am going through Effective Java and some of my things which I consider as standard are not suggested by the book, for instance creation of object, I was under the impression that constructors are the best way of doing it and books says we should make use of static factory methods, I am not able to few some advantages and so disadvantages and so am asking this question, here are the benefits of using it. Advantages: One advantage of static factory methods is that, unlike constructors, they have names. A second advantage of static factory methods is that, unlike constructors, they are not required to create a new object each time they’re invoked. A third advantage of static factory methods is that, unlike constructors, they can return an object of any subtype of their return type. A fourth advantage of static factory methods is that they reduce the verbosity of creating parameterized type instances. I am not able to understand this advantage and would appreciate if someone can explain this point Disadvantages: The main disadvantage of providing only static factory methods is that classes without public or protected constructors cannot be subclassed. A second disadvantage of static factory methods is that they are not readily distinguishable from other static methods.I am not getting this point and so would really appreciate some explanation. Reference: Effective Java, Joshua Bloch, Edition 2, pg: 5-10 Also, How to decide to use whether to go for Constructor or Static Factory Method for Object Creation ?

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  • TypeError when using v 0.8.1 of FLOT library, but no error with v. 0.7

    - by DanielAttard
    I need some help to figure out why I am getting an error when trying to create a simple graph using the jQuery FLOT library. When I reference version 0.7 of the FLOT library, the page renders correctly: http://attardpropertytax.ca/flot07.html But when I switch to version 0.8.1 of the FLOT library, the page returns an error saying: Uncaught TypeError: Cannot read property 'left' of null http://attardpropertytax.ca/flot81.html The HTML is the same for both pages, so I cannot figure out why the new version 0.8.1 of FLOT returns an error, but the old version 0.7 does not. Any ideas? I somehow stumbled across a work-around that managed to fix my problem. I'm nut sure why, but I had to comment-out the following two sections of code from the v. 0.8.1 FLOT library: This was the first spot: // If the grid is visible, add its border width to the offset for (var a in plotOffset) { if(typeof(options.grid.borderWidth) == "object") { plotOffset[a] += showGrid ? options.grid.borderWidth[a] : 0; } else { plotOffset[a] += showGrid ? options.grid.borderWidth : 0; } } And this was the second spot: if (isNaN(v) || v < axis.min || v > axis.max // skip those lying on the axes if we got a border || (t == "full" && ((typeof bw == "object" && bw[axis.position] > 0) || bw > 0) && (v == axis.min || v == axis.max))) continue; I'm sure eventually @DNS will be taking a look at this question and maybe he will be able to help me understand what is going wrong with my code. Thanks.

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  • Dynamic Method Creation

    - by TJMonk15
    So, I have been trying to research this all morning, and have had no luck. I am trying to find a way to dynamically create a method/delegate/lambda that returns a new instance of a certain class (not known until runtime) that inherits from a certain base class. I can guarantee the following about the unknown/dynamic class It will always inherit from one known Class (Row) It will have atleast 2 constructors (one accepting a long, and one accepting an IDataRecord) I plan on doign the following: Finding all classes that have a certain attribute on them Creating a delegate/method/lambda/whatever that creates a new instance of the class Storing the delegate/whatever along with some properties in a struct/class Insert the struct into a hashtable When needed, pull the info out of the hashtable and calling the delegate/whatever to get a new instance of the class and returning it/adding it to a list/etc. I need help only with #2 above!!! I have no idea where to start. I really just need some reference material to get me started, or some keywords to throw into google. This is for a compact/simple to use ORM for our office here. I understand the above is not simple, but once working, should make maintaining the code incredibly simple. Please let me know if you need any more info! And thanks in advance! :)

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  • Why do I get an error while trying to set the content of a tabspec in android?

    - by rushinge
    I have an android activity in which I'm using tabs. public class UnitActivity extends TabActivity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.unit_view); TabHost tabHost = getTabHost(); TabSpec spec; spec = tabHost.newTabSpec("controls"); spec.setIndicator("Control"); spec.setContent(R.layout.unit_control); tabHost.addTab(spec); spec = tabHost.newTabSpec("data"); spec.setIndicator("Data"); spec.setContent(R.layout.unit_data); tabHost.addTab(spec); } } However when I run the program it crashes with the error: "Could not create tab content because could not find view with id 2130903042". I don't understand what the problem is because R.layout.unit_data refers to a layout file in my resource directory (res/layout/unit_data.xml) as far as I can tell unit_data.xml is well formed and I've even referenced it successfully in another activity class UnitData extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.unit_data); Toast.makeText(this, "Hi from UnitData.onCreate", 5); } } which does not give an error and renders the layout just fine. What's going on? Why can't I reference this layout when creating a tab?

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  • Generic callbacks

    - by bobobobo
    Extends So, I'm trying to learn template metaprogramming better and I figure this is a good exercise for it. I'm trying to write code that can callback a function with any number of arguments I like passed to it. // First function to call int add( int x, int y ) ; // Second function to call double square( double x ) ; // Third func to call void go() ; The callback creation code should look like: // Write a callback object that // will be executed after 42ms for "add" Callback<int, int, int> c1 ; c1.func = add ; c1.args.push_back( 2 ); // these are the 2 args c1.args.push_back( 5 ); // to pass to the "add" function // when it is called Callback<double, double> c2 ; c2.func = square ; c2.args.push_back( 52.2 ) ; What I'm thinking is, using template metaprogramming I want to be able to declare callbacks like, write a struct like this (please keep in mind this is VERY PSEUDOcode) <TEMPLATING ACTION <<ANY NUMBER OF TYPES GO HERE>> > struct Callback { double execTime ; // when to execute TYPE1 (*func)( TYPE2 a, TYPE3 b ) ; void* argList ; // a stored list of arguments // to plug in when it is time to call __func__ } ; So for when called with Callback<int, int, int> c1 ; You would automatically get constructed for you by < HARDCORE TEMPLATING ACTION > a struct like struct Callback { double execTime ; // when to execute int (*func)( int a, int b ) ; void* argList ; // this would still be void*, // but I somehow need to remember // the types of the args.. } ; Any pointers in the right direction to get started on writing this?

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