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• Rails 3 fields_for agressive loading?

  - by Seth

  Hi all, I'm trying to optimize (limit) queries in a view. I am using the fields_for function. I need to reference various properties of the object, such as username for display purposes. However, this is a rel table, so I need to join with my users table. The result is N sub-queries, 1 for each field in fields_for. It's difficult to explain, but I think you'll understand what I'm asking if I paste my code: <%= form_for @election do |f| %> <%= f.fields_for :voters do |voter| %> <%= voter.hidden_field :id %> <%= voter.object.user.preferred_name %> <% end %> <% end %> I have like 10,000 users, and many times each election will include all 10,000 users. That's 10,000 subqueries every time this view is loaded. I want fields_for to JOIN on users. Is this possible? I'd like to do something like: ... <%= f.fields_for :voters, :joins => :users do |voter| %> ... <% end %> ... But that, of course, doesn't work :(

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• What was your "aha moment" in understanding delegates?

  - by CM90

  Considering the use of delegates in C#, does anyone know if there is a performance advantage or if it is a convenience to the programmer? If we are creating an object that holds a method, it sounds as if that object would be a constant in memory to be called on, instead of loading the method every time it is called. For example, if we look at the following Unity3D-based code: public delegate H MixedTypeDelegate<G, H>(G g) public class MainParent : MonoBehaviour // Most Unity classes inherit from M.B. { public static Vector3 getPosition(GameObject g) { /* GameObject is a Unity class, and Vector3 is a struct from M.B. The "position" component of a GameObject is a Vector3. This method takes the GameObject I pass to it & returns its position. */ return g.transform.position; } public static MixedTypeDelegate<GameObject, Vector3> PositionOf; void Awake( ) // Awake is the first method called in Unity, always. { PositionOf = MixedTypeDelegate<GameObject, Vector3>(getPosition); } } public class GameScript : MainParent { GameObject g = new GameObject( ); Vector3 whereAmI; void Update( ) { // Now I can say: whereAmI = PositionOf(g); // Instead of: whereAmI = getPosition(g); } } . . . But that seems like an extra step - unless there's that extra little thing that it helps. I suppose the most succinct way to ask a second question would be to say: When you had your aha moment in understanding delegates, what was the context/scenario/source? Thank you!

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• C++, Ifstream opens local file but not file on HTTP Server

  - by fammi

  Hi, I am using ifstream to open a file and then read from it. My program works fine when i give location of the local file on my system. for eg /root/Desktop/abc.xxx works fine But once the location is on the http server the file fails to open. for eg http://192.168.0.10/abc.xxx fails to open. Is there any alternate for ifstream when using a URL address? thanks. part of the code where having problem: bool readTillEof = (endIndex == -1) ? true : false; // Open the file in binary mode and seek to the end to determine file size ifstream file ( fileName.c_str ( ), ios::in|ios::ate|ios::binary ); if ( file.is_open ( ) ) { long size = (long) file.tellg ( ); long numBytesRead; if ( readTillEof ) { numBytesRead = size - startIndex; } else { numBytesRead = endIndex - startIndex + 1; } // Allocate a new buffer ptr to read in the file data BufferSptr buf (new Buffer ( numBytesRead ) ); mpStreamingClientEngine->SetResponseBuffer ( nextRequest, buf ); // Seek to the start index of the byte range // and read the data file.seekg ( startIndex, ios::beg ); file.read ( (char *)buf->GetData(), numBytesRead ); // Pass on the data to the SCE // and signal completion of request mpStreamingClientEngine->HandleDataReceived( nextRequest, numBytesRead); mpStreamingClientEngine->MarkRequestCompleted( nextRequest ); // Close the file file.close ( ); } else { // Report error to the Streaming Client Engine // as unable to open file AHS_ERROR ( ConnectionManager, " Error while opening file \"%s\"\n", fileName.c_str ( ) ); mpStreamingClientEngine->HandleRequestFailed( nextRequest, CONNECTION_FAILED ); } }

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• How to call shared_ptr<boost::signal> from a vector in a loop?

  - by BTR

  I've got a working callback system that uses boost::signal. I'm extending it into a more flexible and efficient callback manager which uses a vector of shared_ptr's to my signals. I've been able to successfully create and add callbacks to the list, but I'm unclear as to how to actually execute the signals. ... // Signal aliases typedef boost::signal<void (float *, int32_t)> Callback; typedef std::shared_ptr<Callback> CallbackRef; // The callback list std::vector<CallbackRef> mCallbacks; // Adds a callback to the list template<typename T> void addCallback(void (T::* callbackFunction)(float * data, int32_t size), T * callbackObject) { CallbackRef mCallback = CallbackRef(new Callback()); mCallback->connect(boost::function<void (float *, int32_t)>(boost::bind(callbackFunction, callbackObject, _1, _2))); mCallbacks.push_back(mCallback); } // Pass the float array and its size to the callbacks void execute(float * data, int32_t size) { // Iterate through the callback list for (vector<CallbackRef>::iterator i = mCallbacks.begin(); i != mCallbacks.end(); ++i) { // What do I do here? // (* i)(data, size); // <-- Dereferencing doesn't work } } ... All of this code works. I'm just not sure how to run the call from within a shared_ptr from with a vector. Any help would be neat-o. Thanks, in advance.

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• How come the Actionscript 3 ENTER_FRAME event is crazy nuts?

  - by nstory

  So, I've been toying around with Flash, browsing through the documentation, and all that, and noticed that the ENTER_FRAME event seems to defy my expectation of a deterministic universe. Take the following example: (new MovieClip()).addEventListener(Event.ENTER_FRAME, function(ev) {trace("Test");}); Notice this anonymous MovieClip is not added to the display hierarchy, and any reference to it is immediately lost. It will actually print "Test" once a frame until it is garbage collected. How insane is that? The behavior of this is actually determined by when the garbage collector feels like coming around in all its unpredictable insanity! Is there a better way to create intermittent failures? Seriously. My two theories are that either the DisplayObject class stores weak references to all its instances for the purpose of dispatching ENTER_FRAME events, or, and much wilder, the Flash player actually scans the heap each frame looking for ENTER_FRAME listeners to pull on. Can any hardened Actionscript developer clue me in on how this works? (And maybe a why - the - f**k they thought this was a good idea?)

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• Android : start intent in setOnClickListener

  - by Derek

  I have a button, and this button is going to get the values from EditText, then using this value to start a new Intent protected void onCreate(Bundle savedInstanceState) { textDay = (EditText) findViewById(R.id.textDay); textMonth = (EditText) findViewById(R.id.textMonth); textYear = (EditText) findViewById(R.id.textYear); gen = (Button) findViewById(R.id.getGraph); gen.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { getthisIntent(); } public Intent getthisIntent(Context context) { day = textDay.getText(); month = textMonth.getText(); year = textYear.getText(); date = day + "/" + month + "/" + year; . .// Plot graph using AchartEngine, then return an Intent // . } } }); but i get the error "The method getthisIntent(Context) in the type new View.OnClickListener(){} is not applicable for the arguments ()" Can i get some help? or do i have another alternative solution, when i click the button, then the button pass the values to the new intent, and start it without having a new xxx.java file? Edit This is basically what I am doing now, i need to get the things inserted by user, and plot a graph, the only way i know how to plot graph using AchartEngine is create a new activity with define this public Intent getthisIntent(Context context) To be honest, i dont really know what the hell I am doing, please correct me...

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• ASP.NET MVC Inserting object and related object into 2 tables

  - by ile

  I have two tables: Users and UserOwners. Table UserOwners contains list of users that certain user created (list of child-users) - or to be more precise, it contains UserOwnerID and UserID fields. So, now I want to create a new user... in Controller I have something like this: var userOwner = accountRepository.GetUser(User.Identity.Name); var userOwnerID = userOwner.UserID; UserReference userReference = new UserReference(); userReference.UserOwnerID = userOwnerID; if (ModelState.IsValid) { try { //accountRepository.Add(user); //accountRepository.Save(); return View(); } catch { return View(); } } What is the easiest way to add new user to a table Users and matching UserOwner to UserOwners table. Is it suppose to be something like this? public void Add(User user) { db.Users.InsertOnSubmit(user); db.UserReferences.InsertOnSubmit(user.UserReference); } ...or I will have to pass two objects and after adding user I must read it's ID and than assign it to userReference object and add that object to DB? If so, how to read ID of the last object added? Thanks, Ile

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• IE is stops Javascript with an error?

  - by Mahmoud

  hey there, i have complete of creating a javascript that well allow visitors ones the mouse is over the button a menu drops down, at some point on FireFox its working fine and also safari, but when it comes to IE it stops the script from running, where on the IE i debugged my script using IE debugger and i found out the error causing is frag+='<br /><li><form action="' + menuobj.items[i][1] + '" ><input type="submit" value="' + menuobj.items[i][0] + '" style="background-color:#000;border:hidden;color:#FFF"/></form></li><br />\n' for reference below is the full function code getmenuHTML:function(menuobj){ var menucontent=[] var frag="" for (var i=0; i < menuobj.items.length; i++){ frag+='<br /><li><form action="' + menuobj.items[i][1] + '" ><input type="submit" value="' + menuobj.items[i][0] + '" style="background-color:#000;border:hidden;color:#FFF"/></form></li><br />\n' if (menuobj.items[i][2]=="efc" || i==menuobj.items.length-1){ menucontent.push(frag) frag="" } } if (typeof menuobj.cols=="undefined") return '<ul>\n' + menucontent.join('') + '\n</ul>' else{ frag="" for (var i=0; i<menucontent.length; i++){ frag+='<div class="' + menuobj.cols.divclass + '" style="' + menuobj.cols.inlinestyle + '">\n<ul>\n' + menucontent[i] + '</ul>\n</div>\n' } return frag } },

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• sending specific data into a collection partial

  - by mikeglaz

  I have a User class with a has_many :messages and a Message class which belongs_to :user. In the Message controller's show action has the corresponding view: <% if @messages.any? %> <ol class="microposts"> <%= render partial: 'shared/message', collection: @messages %> </ol> <% end %> And the shared/_message.html.erb template looks like this: <li id="<%= message.id %>"> <span class="content"><%= message.body %></span> <% user_id = message.from %> <% user = User.find(user_id) %> From: <%= user.name %> </li> I feel like the following two lines should be done in the Messages controller from what I read in tutorials on Rails: <% user_id = message.from %> <% user = User.find(user_id) %> But how would I pass each message's corresponding from value (which stores user.id) into the partial? thanks, mike

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• StructureMap Configuration Per Thread/Request for the Full Dependency Chain

  - by Phil Sandler

  I've been using Structuremap for a few months now, and it has worked great on some smaller (green field) projects. Most of the configurations I have had to set up involve a single implementation per interface. In the cases where I needed to choose a specific implementation at runtime, I created a factory class that used ObjectFactory.GetNamedInstance<(). In the smaller projects, there were few enough of these cases where I was comfortable with the references to ObjectFactory. My understanding is that you want to limit these references as much as possible, and ideally only reference the ObjectFactory once. I am working to refactor a larger codebase to use IOC/StructureMap, and am finding that I may need many of these factory classes with ObjectFactory references to get what I need. Essentially, I am creating a "root service" with the ObjectFactory, so that everything in the dependency chain is managed by the container. The root service is created by name (i.e. "BuildCar", "BuildTruck"), and the services needed deeper in the dependency chain could also be constructed using the same name--so the "IAttachWheels" service could vary based on whether a car or truck is being built. Since the class that depends on IAttachWheels is the same in both configurations, I don't think I can use ConstructedBy in the registry to choose the implementation. Also, to be clear, the IAttachWheels implementations need to be managed by the container as well, because the dependency chain runs fairly deep. I looked briefly at Profiles as an option, but read (here on StackOverflow) that changing profiles essentially changes implementations for all threads. Is there a feature that is similar to profiles that is thread/request specific? Is the factory class that references ObjectFactory approach the right way to go? Any thoughts would be appreciated.

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• Security strategies for storing password on disk

  - by Mike

  I am building a suite of batch jobs that require regular access to a database, running on a Solaris 10 machine. Because of (unchangable) design constraints, we are required use a certain program to connect to it. Said interface requires us to pass a plain-text password over a command line to connect to the database. This is a terrible security practice, but we are stuck with it. I am trying to make sure things are properly secured on our end. Since the processing is automated (ie, we can't prompt for a password), and I can't store anything outside the disk, I need a strategy for storing our password securely. Here are some basic rules The system has multiple users. We can assume that our permissions are properly enforced (ie, if a file with a is chmod'd to 600, it won't be publically readable) I don't mind anyone with superuser access looking at our stored password Here is what i've got so far Store password in password.txt $chmod 600 password.txt Process reads from password.txt when it's needed Buffer overwritten with zeros when it's no longer needed Although I'm sure there is a better way.

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• custom *arbitrary* TemplateField definitions

  - by end-user

  I'm building a GridView on the fly, and I'd like to pre-define the TemplateFields to be included ondemand. So, what I'd like to do is have a declarative file that defines how the different templates look for a specific column. Like: <asp:TemplateField> <HeaderTemplate> this is a text column </HeaderTemplate> <ItemTemplate> data goes here </ItemTemplate> <EditItemTemplate> <asp:TextBox Text="databindhere" /> </EditItemTemplate> </asp:TemplateField> <asp:TemplateField> <HeaderTemplate> this is a bool column </HeaderTemplate> <ItemTemplate> if(true) "yes" else "no" </ItemTemplate> <EditItemTemplate> <asp:CheckBox Checked="databindme" /> </EditItemTemplate> </asp:TemplateField> So, if my query had a text and two bool fields, I could push the appropriate TemplateFields in the the Columns property as needed. (I hope I'm making sense here) So, how would I go about creating declarative files for the above definitions? And then, how would I reference those definitions programmatically?

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• Keeping user data persistent after validates_presence_of

  - by mathee

  I'm designing a question-and-answer Ruby on Rails application. After a user logs in, you can see a list of questions posed by other users. I have a link next to each of the questions to /answers/new?question_id=someNumber. That links to a page that displays the question (to remind the "answerer") above a standard form for submitting your answer. In order to display the question, I call @question = Question.find_by_id(params[:question_id]) and reference @question in the Haml view file: Question details %h2 #{h @question.title} #{h @question.description} %br/ %br/ %h1 Your answer - form_for(@answer) do |f| = f.error_messages %p = f.label :description, "Enter your response here" %br = f.text_area :description = f.hidden_field "question", :value => @question.id %p = f.submit 'Answer' The problem is that if I check validates_presence_of :description in Answer.rb, then I lose question_id if the user did not input anything into the description field when the page reloads, so I can't re-display the question for which the user is answering. How should I fix this? Is there a better way of storing the question the user is trying to answer so that I can display it above the form for entering a new answer (and perhaps in other views in the future)? If you need to see more code, please let me know.

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• Passing objects across Appdomains

  - by MUSTAQ

  My issue is similar to the one posted in "http://stackoverflow.com/questions/981773/moving-objects-across-appdomains-in-net". In one of my application, I am creating a separate appdomain. I need to create an instance of a class (Note: this class is derived by MarshalByRefObject) in my parent domain and invoke a MethodA in that instance. This instance is created using "CreateInstanceAndUnwrap". The problem is that this MethodA takes objects of type class as an argument. These objects are not created in the MethodB where i created the appdomain. It was passed as an argument to the MethodB where i create the appdomain. So is it necessary to create a new instance of these objects using "CreateInstanceAndUnwrap" before passing it to the created domain. Not doing this gives me an error in the created domain mentioning that "MyClass object has no attribute foo" during some invocation. Please let me know how to pass the objects across appdomains and execute the method. My statements might be confusing, please let me know for any specific details required.

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• Java: refactoring static constants

  - by akf

  We are in the process of refactoring some code. There is a feature that we have developed in one project that we would like to now use in other projects. We are extracting the foundation of this feature and making it a full-fledged project which can then be imported by its current project and others. This effort has been relatively straight-forward but we have one headache. When the framework in question was originally developed, we chose to keep a variety of constant values defined as static fields in a single class. Over time this list of static members grew. The class is used in very many places in our code. In our current refactoring, we will be elevating some of the members of this class to our new framework, but leaving others in place. Our headache is in extracting the foundation members of this class to be used in our new project, and more specifically, how we should address those extracted members in our existing code. We know that we can have our existing Constants class subclass this new project's Constants class and it would inherit all of the parent's static members. This would allow us to effect the change without touching the code that uses these members to change the class name on the static reference. However, the tight coupling inherent in this choice doesn't feel right. before: public class ConstantsA { public static final String CONSTANT1 = "constant.1"; public static final String CONSTANT2 = "constant.2"; public static final String CONSTANT3 = "constant.3"; } after: public class ConstantsA extends ConstantsB { public static final String CONSTANT1 = "constant.1"; } public class ConstantsB { public static final String CONSTANT2 = "constant.2"; public static final String CONSTANT3 = "constant.3"; } In our existing code branch, all of the above would be accessible in this manner: ConstantsA.CONSTANT2 I would like to solicit arguments about whether this is 'acceptable' and/or what the best practices are.

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• Which pattern to use for logging? Dependency Injection or Service Locator?

  - by andlju

  Consider this scenario. I have some business logic that now and then will be required to write to a log. interface ILogger { void Log(string stuff); } interface IDependency { string GetInfo(); } class MyBusinessObject { private IDependency _dependency; public MyBusinessObject(IDependency dependency) { _dependency = dependency; } public string DoSomething(string input) { // Process input var info = _dependency.GetInfo(); var intermediateResult = PerformInterestingStuff(input, info); if (intermediateResult== "SomethingWeNeedToLog") { // How do I get to the ILogger-interface? } var result = PerformSomethingElse(intermediateResult); return result; } } How would you get the ILogger interface? I see two main possibilities; Pass it using Dependency Injection on the constructor. Get it via a singleton Service Locator. Which method would you prefer, and why? Or is there an even better pattern? Update: Note that I don't need to log ALL method calls. I only want to log a few (rare) events that may or may not occur within my method.

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• Setting up a view to draw to in Objective-C (iPhone) ?

  - by Johannes Jensen

  Okay, so, I'm all new to iPhone and stuff, but I'm not even at programming, I have many years of experience with ActionScript 2.0 and 3.0, I want to set up a view, that I can also pass variables to. The view is gonna draw everything with Quartz. I tried to make another game where I tried to add a pointer to a NSMutableArray to the view class, but it didn't work cause I didn't know how to store an actual class. I wanted to do like: [myView setNeedsDisplay]; but I had to do [(View*)self.view setNeedsDisplay]; didn't really work out in the end... Okay, so now I got: - (void) viewDidLoad { [super viewDidLoad]; viewClass = [[View class] retain]; gameView = [[[viewClass alloc] initWithFrame: CGRectZero] retain]; [gameView setNeedsDisplay]; } This is in my drawInContext:context, which is fired by drawRect: Also, my drawRect does [self drawInContext: UIGraphicsGetCurrentContext()]; CGContextSetStrokeColorWithColor(context, [[UIColor blackColor] CGColor]); CGContextSetLineWidth(context, 3.0); CGContextSetLineCap(context, kCGLineCapRound); CGContextSetLineJoin(context, kCGLineJoinRound); CGMutablePathRef aPath = CGPathCreateMutable(); CGPathMoveToPoint(aPath, nil, 5, 5); CGPathAddLineToPoint(aPath, nil, 45, 43); CGContextAddPath(context, aPath); CGContextStrokePath(context); Nothing happens. Help? Oh yeah, I get this error: : invalid context for each time I use those functions. :[ Thanks!

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• passing the parent form on the onclick event to javascript function

  - by user1051505

  Hi I am trying to pass variables on the onclick event to a javascript function. I am trying the following way, I can't get the input value in the javascript function.(I am expecting an alert of 1.) Is it the right way of doing this? Please help. <head> <script> function submit_value(form) { alert(form.ip.value); } </script> </head> <table> <tr> <form> <td> <input id="ip" type="text" value="1"> </td> <td> <a href="javascript:;" onClick="submit_value(this)">Button</a> </td> </form> </tr> </table>

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• How to reliably get size of C-style array?

  - by Frank

  How do I reliably get the size of a C-style array? The method often recommended seems to be to use sizeof, but it doesn't work in the foo function, where x is passed in: #include <iostream> void foo(int x[]) { std::cerr << (sizeof(x) / sizeof(int)); // 2 } int main(){ int x[] = {1,2,3,4,5}; std::cerr << (sizeof(x) / sizeof(int)); // 5 foo(x); return 0; } Answers to this question recommend sizeof but they don't say that it (apparently?) doesn't work if you pass the array around. So, do I have to use a sentinel instead? (I don't think the users of my foo function can always be trusted to put a sentinel at the end. Of course, I could use std::vector, but then I don't get the nice shorthand syntax {1,2,3,4,5}.)

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• Changing the href attribute on hover with jQuery

  - by AverageJoe

  Ok, I have an html page that is loaded into another html page via PHP (ok so its a PHP page, whatever). The page that is loaded is a list of hyperlinks. I need to change the href attribute to make the hyperlinks relative to the location of the stored images they refer too. When i load the page containing the hyperlinks the links are relative to the web host server, not the server that the page is actually hosted from. Somthing like this: <div #screenshots) <p><a href="image1.htm">Image1</a></p> <p><a href="image2.htm">Image2</a></p> <p><a href="image3.htm">Image3</a></p> <p><a href="image4.htm">Image4</a></p> <p><a href="image5.htm">Image5</a></p> </div> When I mouse over the links, the status bar shows the reference as "http://webHostServer.com/image1.htm". If I click it I get a 404 error. I need the href to change to something like this when I mouse over it: "http://www.actualImageHostServerIPaddress/image1.htm" I looked at this for assitance and came out with the following jQuery code, but for some reason none of it works: $(document).ready(function(){ $("button").click(function() { $("#screenshots a").addClass('ss'); }); $(".ss").each(function() { $(this).data("oldHref", $(this).attr("href")); orig = $(this).attr("href"); over = "http://208.167.244.33/208.167.244.33/"; $(this).hover(function() { $(this).attr("href", $(this).attr("href").replace(orig, over+orig)); }, function() { $(this).attr("href", $(this).data("oldHref")); }); }); When I click the button it dosen't add the class to the anchor tags, so when I hover over them nothing changes. Any help here would be great.

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• Can't delete record via the datacontext it was retrieved from

  - by Antilogic

  I just upgraded one of my application's methods to use compiled queries (not sure if this is relevant). Now I'm getting contradicting error messages when I run the code. This is my method: MyClass existing = Queries.MyStaticCompiledQuery(MyRequestScopedDataContext, param1, param2).SingleOrDefault(); if (existing != null) { MyRequestScopedDataContext.MyClasses.DeleteOnSubmit(existing); } When I run it I get this message: Cannot remove an entity that has not been attached. Note that the compiled query and the DeleteOnSubmit reference the same DataContext. Still I figured I'd humor the application and add an attach command before the DeleteOnSubmit, like so: MyClass existing = Queries.MyStaticCompiledQuery(MyRequestScopedDataContext, param1, param2).SingleOrDefault(); if (existing != null) { MyRequestScopedDataContext.MyClasses.Attach(existing); MyRequestScopedDataContext.MyClasses.DeleteOnSubmit(existing); } BUT... When I run this code, I get a completely different contradictory error message: An attempt has been made to Attach or Add an entity that is not new, perhaps having been loaded from another DataContext. This is not supported. I'm at a complete loss... Does anyone else have some insight as to why I can't delete a record via the same DataContext I retrieved it from?

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• Do I lose the benefits of macro recording if I develop Excel apps in Visual Studio?

  - by DanM

  I've written lots of Excel macros in the past using the following development process: Record a macro. Open the VBA editor. Edit the macro. I'm now experimenting with a Visual Studio 2008 "Excel 2007 Add-In" project (C#), and I'm wondering if I will have to give up this development process. Questions: I know I can still record macros using Excel, but is there any way to access the resulting code in Visual Studio? Or do I just have to copy and paste then C#-ize it? What happens with my "Personal Macro Workbook"? Can I use the macros I have stored in there within C#? Or is there some way to convert them to C#? If there is some support for opening and editing VBA macros in Visual Studio, can you provide a very brief summary of how it works or point me to a good reference? Do you have any other tips for transitioning from writing macros in VBA using Excel's built-in editor to writing them in C# with Visual Studio?

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• model.matrix() with na.action=NULL?

  - by Vincent

  I have a formula and a data frame, and I want to extract the model.matrix(). However, I need the resulting matrix to include the NAs that were found in the original dataset. If I were to use model.frame() to do this, I would simply pass it na.action=NULL. However, the output I need is of the model.matrix() format. Specifically, I need only the right-hand side variables, I need the output to be a matrix (not a data frame), and I need factors to be converted to a series of dummy variables. I'm sure I could hack something together using loops or something, but I was wondering if anyone could suggest a cleaner and more efficient workaround. Thanks a lot for your time! And here's an example: dat <- data.frame(matrix(rnorm(20),5,4), gl(5,2)) dat[3,5] <- NA names(dat) <- c(letters[1:4], 'fact') ff <- a ~ b + fact # This omits the row with a missing observation on the factor model.matrix(ff, dat) # This keeps the NA, but it gives me a data frame and does not dichotomize the factor model.frame(ff, dat, na.action=NULL) Here is what I would like to obtain: (Intercept) b fact2 fact3 fact4 fact5 1 1 0.7266086 0 0 0 0 2 1 -0.6088697 0 0 0 0 3 NA 0.4643360 NA NA NA NA 4 1 -1.1666248 1 0 0 0 5 1 -0.7577394 0 1 0 0 6 1 0.7266086 0 1 0 0 7 1 -0.6088697 0 0 1 0 8 1 0.4643360 0 0 1 0 9 1 -1.1666248 0 0 0 1 10 1 -0.7577394 0 0 0 1

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• initWithContentsOfURL seems to have issues with "long" URLs

  - by samsam

  Hi there I'm facing a rather strange Issue when trying to load data from an XML-Webservice. The webservice allows me to pass separated identifiers within the URL-Request. It is therefore possible for the URL to become rather long (240 characters). If I open said URL in firefox the response arrives as planned, if I execute the following code xmlData remains empty. NSString *baseUrl = [[NSString alloc] initWithString:[[[[kSearchDateTimeRequestTV stringByReplacingOccurrencesOfString:@"{LANG}" withString:appLanguageCode] stringByReplacingOccurrencesOfString:@"{IDENTIFIERS}" withString:myIdentifiers] stringByReplacingOccurrencesOfString:@"{STARTTICKS}" withString:[NSString stringWithFormat:@"%@", [[startTime getTicks] descriptionWithLocale:nil]]] stringByReplacingOccurrencesOfString:@"{ENDTICKS}" withString:[NSString stringWithFormat:@"%@", [[endTime getTicks] descriptionWithLocale:nil]]]]; NSLog(baseUrl); //looks good, if openend in browser, returnvalue is ok urlRequest = [NSURL URLWithString:baseUrl]; NSString *xmlData = [NSString stringWithContentsOfURL:urlRequest encoding:NSUTF8StringEncoding error:&err]; //err is nil, therefore i guess everything must be ok... :( NSLog(xmlData); //nothing... is there any sort of URL-Length restriction, does the same problem happened to anyone of you as well? whats a good workaround? thanks for your help sam

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• Display Consistent Value of an Item using MVVM and WPF

  - by Blake Blackwell

  In my list view control (or any other WPF control that will fit the situation), I would like to have one TextBlock that stays consistent for all items while another TextBlock that changes based on the value in the ObservableCollection. Here is how my code is currently laid out: XAML <ListView ItemsSource="{Binding Path=MyItems, Mode=TwoWay}"> <ListView.ItemTemplate> <DataTemplate> <StackPanel Orientation="Horizontal"> <TextBlock x:Name="StrVal" Text="{Binding StrVal}" /> <TextBlock x:Name="ConstVal" Text="{Binding MyVM.ConstVal}" /> </StackPanel> </DataTemplate> </ListView.ItemTemplate> </ListView> Model public class MyItem { public string StrVal { get; set; } } ViewModel public class MyVM { public MyVM() { ObservableCollection<MyItem> myItems = new ObservableCollection<MyItem>(); for (int i = 0 ; i < 10; i++) myItems.Add(new MyItem { StrVal = i.ToString()}); MyItems = myItems; ConstVal = "1"; } public string ConstVal { get; set; } public ObservableCollection<MyItem> MyItems { get; set; } } Code Behind this.DataContext = new MyVM(); The StrVal property repeats correctly in the ListView, but the ConstVal TextBlock does not show the ConstVal that is contained in the VM. I would guess that this is because the ItemsSource of the ListView is MyItems and I can't reference other variables outside of what is contained in the MyItems. My question is: How do I get ConstVal to show the value in the ViewModel for all listviewitems that will be controlled by the Observable Collection of MyItems.

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