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  • Issue calling superclass method in subclass constructor

    - by stormin986
    I get a NullPointerException calling a Superclass Method in Subclass Inner Class Constructor... What's the Deal? In my application's main class (subclass of Application), I have a public inner class that simply contains 3 public string objects. In the parent class I declare an object of that inner class. public class MainApplication extends Application { public class Data { public String x; public String y; public String z; } private Data data; MainApplication() { data = new Data() data.x = SuperClassMethod(); } } After I instantiate the object in the constructor, I get a runtime error when I try to assign a value in the inner class with a superclass method. Any idea what's up here?? Can you not call superclass methods in the subclass constructor? ** Edit ** Original question was about inner class member assignment in outer class constructor. Turned out the issue was with calling a superclass method in the class's constructor. It was giving me a null pointer exception. Thus, the question has changed.

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  • two controllers in one layout, rails 3

    - by Grizlord
    Okay, I have two models, a recipe model and a category model. In my layout(application.html.erb) I have a main container div that "yields" the recipes index action. I'm trying to list all the category names as links in a side bar(also a div) by iterating over them in an unordered list. When you click one of the links it will go to the category show page which will then list all the recipes in that category. Here is how I'm trying to list the links in - <div class="container" id="categories"> <% for category in @categories %> <ul> <li><%= link_to category.name, category %></li> </ul> <% end %> </div> The problem is I get a NoMethodError - You have a nil object when you didn't expect it! You might have expected an instance of Array. The error occurred while evaluating nil.each It is not retrieving the records from the model. Any suggestions on how to get this done would be greatly appreciated. I tried to render a partial as some of the other similar posts have said but still get the same error. This is the exact error - NoMethodError in Recipes#index Showing /Users/grizlord/Rails/recipe2/app/views/layouts/application.html.erb where line #39 raised: You have a nil object when you didn't expect it! You might have expected an instance of Array. The error occurred while evaluating nil.each Extracted source (around line #39): 36: </div> 37: <div class="container" id="categories"> 38: Browse by Category 39: <% for category in @categories %> 40: <ul> 41: <li><%= link_to category.name, category %></li> 42: </ul>

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  • handle large Parcelable ArrayList in Android

    - by Gal Ben-Haim
    I'm developing an Android app that is a client to a JSON webservice API. I have classes of resource objects (some are nested) and I pass results from an IntentService that access the webserive using the Parcelable interface for all the resource classes. the webservice returns arrays or results that can be potentially large (because of the nesting, for example, a post object also contains comments array, each comment also contains a user object). currently I'm either inserting the results into a SQlite database or displaying them in a ListView. (my relevant methods are accepting ArrayList<resourceClass> as arguments). (some data need to be persistent stored and some should not). since I don't know what size of lists I can handle this way without reaching the memory limits, is this a good practice ? is it a better idea to save the parsed JSON to a local file immediately and pass the file path to the ResultReceiver, then either insert to database from that file or display the data ? is there a better way to handle this ? btw - I'm parsing the JSON as a stream with Gson's Reader so there shouldn't be memory issues at that stage.

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  • How to use a getter with a nullable?

    - by Desmond Lost
    I am reading a bunch of queries from a database. I had an issue with the queries not closing, so I added a CommandTimeout. Now, the individual queries read from the config file each time they are run. How would I make the code cache the int from the config file only once using a static nullable and getter. I was thinking of doing something along the lines of: static int? var; get{ var = null; if (var.HasValue) ...(i dont know how to complete the rest) My actual code: private object ExecuteQuery(string dbConnStr, bool fixIt) { object result = false; using (SqlConnection connection = new SqlConnection(dbConnStr)) { connection.Open(); using (SqlCommand sqlCmd = new SqlCommand()) { AddSQLParms(sqlCmd); sqlCmd.CommandTimeout = 30; sqlCmd.CommandText = _cmdText; sqlCmd.Connection = connection; sqlCmd.CommandType = System.Data.CommandType.Text; sqlCmd.ExecuteNonQuery(); } connection.Close(); } return result; }}

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  • Postback Removing Styling from Page

    - by Roy
    Hi, Currently I've created a ASP.Net page that has a dropdown control with autopostback set to true. I've also added color backgrounds for individual listitems. Whenever an item is selected in the dropdown control the styling is completely removed from all of the list items. How can I prevent this from happening? I need the postback to pull data based on the dropdown item that is selected. Here is my code. aspx file: <asp:DropDownList ID="EmpDropDown" AutoPostBack="True" OnSelectedIndexChanged="EmpDropDown_SelectedIndexChanged" runat="server"> </asp:DropDownList> <asp:TextBox ID="MessageTextBox" TextMode="MultiLine" Width="550" Height="100px" runat="server"></asp:TextBox> aspx.cs code behind: protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { GetEmpList(); } } protected void EmpDropDown_SelectedIndexChanged(object sender, EventArgs e) { GetEmpDetails(); } private void GetEmpList() { SqlDataReader dr = ToolsLayer.GetEmpList(); int currentIndex = 0; while (dr.Read()) { EmpDropDown.Items.Add(new ListItem(dr["Title"].ToString(), dr["EmpKey"].ToString())); if (dr["Status"].ToString() == "disabled") { EmpDropDown.Items[currentIndex].Attributes.Add("style", "background-color:red;"); } currentIndex++; } dr.Close(); } private void GetEmpDetails() { SqlDataReader dr = ToolsLayer.GetEmpDetails(EmpDropDown.SelectedValue); while (dr.Read()) { MessageTextBox.Text = dr["Message"].ToString(); } dr.Close(); } Thank You

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  • ASP.NET MVC3 - Bug using Javascript

    - by ebb
    Hey there, I'm trying to use Ajax.BeginForm() to POST A Json result from my controller (I'm using MVC3). When the Json result is called it should be sent to a javascript function and extract the object using "var myObject = content.get_response().get_object();", However it just throws a "Microsoft JScript runtime error: Object doesn't support this property or method" when trying to invoke the Ajax POST. My code: Controller: [HttpPost] public ActionResult Index(string message) { return Json(new { Success = true, Message = message }); } View: <!DOCTYPE html> <html> <head> <script src="@Url.Content("~/Scripts/jquery-1.4.4.min.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery.unobtrusive-ajax.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/MicrosoftAjax.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/MicrosoftMvcAjax.js")" type="text/javascript"></script> <script type="text/javascript"> function JsonAdd_OnComplete(mycontext) { var myObject = mycontext.get_response().get_object(); alert(mycontext.Message); } </script> </head> <body> <div> @using(Ajax.BeginForm("Index", "Home", new AjaxOptions() { HttpMethod = "POST", OnComplete = "JsonAdd_OnComplete" })) { @Html.TextBox("message") <input type="submit" value="SUBMIT" /> } </div> </body> </html> The strange thing is that the exactly same code works in MVC2 - Is this a bug, or have I forgot something? Thanks in advance.

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  • How to Create a Folder in the Current Document Library if it's not already present?

    - by Rosh Malai
    All I want to do is to create a folder "MetaFolder" inside a document library. User can be on any document library and I would like to create this folder after item is added (so on itemAdded event handler). I do NOT want workflow so please dont suggest workflow. This code works but I have to hardcode the url but need to get url from current url. also need to verify the folder uHippo does not exists in the current doc library... public override void ItemAdded(SPItemEventProperties properties) { base.ItemAdded(properties); using (SPSite currentSite = new SPSite(properties.WebUrl)) using (SPWeb currentWeb = currentSite.OpenWeb()) { // This code works and creates Folder in the "My TEST Doc library" //SPList docLib = currentWeb.Lists["My TEST Doc Library"]; //SPListItem folder = docLib.Folders.Add(docLib.RootFolder.ServerRelativeUrl, SPFileSystemObjectType.Folder, "My folder"); //folder.Update(); string doclibname = "Not a doclib"; //SPList doclibList = currentWeb.GetList(HttpContext.Current.Request.RawUrl); // NOT WORKING. Tried properties.weburl SPList doclibList = currentWeb.GetListFromUrl("https://mycompanyportal/sites/testsitecol/testwebsite/My%20TEST%20Doc%20Library/Forms/AllItems.aspx"); if (null != doclibList) { doclibname = doclibList.Title; } // this section also not working. // getting Object reference not set to an instance of an object or something like that. //if (currentWeb.GetFolder("uHippo").Exists == false) //{ SPListItem folder = doclibList.Folders.Add(doclibList.RootFolder.ServerRelativeUrl, SPFileSystemObjectType.Folder, "uHippo"); folder.Update(); //} } }

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  • C# async callback on disposed form

    - by Rodney Burton
    Quick question: One of my forms in my winform app (c#) makes an async call to a WCF service to get some data. If the form happens to close before the callback happens, it crashes with an error about accessing a disposed object. What's the correct way to check/handle this situation? The error happens on the Invoke call to the method to update my form, but I can't drill down to the inner exception because it says the code has been optimized. The Code: public void RequestUserPhoto(int userID) { WCF.Service.BeginGetUserPhoto(userID, new AsyncCallback(GetUserPhotoCB), userID); } public void GetUserPhotoCB(IAsyncResult result) { var photo = WCF.Service.EndGetUserPhoto(result); int userID = (int)result.AsyncState; UpdateUserPhoto(userID, photo); } public delegate void UpdateUserPhotoDelegate(int userID, Binary photo); public void UpdateUserPhoto(int userID, Binary photo) { if (InvokeRequired) { var d = new UpdateUserPhotoDelegate(UpdateUserPhoto); Invoke(d, new object[] { userID, photo }); } else { if (photo != null) { var ms = new MemoryStream(photo.ToArray()); var bmp = new System.Drawing.Bitmap(ms); if (userID == theForm.AuthUserID) { pbMyPhoto.BackgroundImage = bmp; } else { pbPhoto.BackgroundImage = bmp; } } } }

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  • Flash won't load, embed error?

    - by Adrian M.
    Hello, I want to know why the flash movie in the header located here: http://www.dolphintemplate.com/demo/dolphin7/index.php?skin=dt_firestarter_red only loads in Firefox but NOT in IE and Chrome.. The flash movie resides in a iframe, this is the code of the iframe: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> <title>header</title> </head> <body bgcolor="#000000" topmargin="0" leftmargin="0" marginwidth="0" marginheight="0"> <object data="header.swf" type="application/x-shockwave-flash" id="myflash" width="988" height="240"> <param name="movie" value="header.swf" /> <param name="bgcolor" value="#000000" /> <param name="height" value="988" /> <param name="width" value="240" /> <param name="quality" value="high" /> <param name="menu" value="false" /> <param name="allowscriptaccess" value="samedomain" /> <p>Adobe <a href="http://get.adobe.com/flashplayer/">Flash Player</a> is required to view this content.</p> </object> </body> </html> Thanks.

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  • How to setup/calculate texturebuffer in glTexCoordPointer when importing from OBJ-file

    - by JohnMurdoch
    Hi all, I'm parsing an OBJ-file in Android and my goal is to render & display the object. Everything works fine except the correct texture mapping (importing the resource/image into opengl etc works fine). I don't know how to populate the texture related data from the obj-file into an texturebuffer-object. In the OBJ-file I've vt-lines: vt 0.495011 0.389417 vt 0.500686 0.561346 and face-lines: f 127/73/62 98/72/62 125/75/62 My draw-routine looks like (only relevant parts): gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); gl.glEnableClientState(GL10.GL_NORMAL_ARRAY); gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY); gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer); gl.glNormalPointer(GL10.GL_FLOAT, 0, normalsBuffer); gl.glTexCoordPointer(2, GL10.GL_SHORT, 0, t.getvtBuffer()); gl.glDrawElements(GL10.GL_TRIANGLES, t.getFacesCount(), GL10.GL_UNSIGNED_SHORT, t.getFaceBuffer()); Output of the counts of the OBJ-file: Vertex-count: 1023 Vns-count: 1752 Vts-count: 524 ///////////////////////// Part 0 Material name:default Number of faces:2037 Number of vnPointers:2037 Number of vtPointers:2037 Any advise is welcome.

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  • Adroid's DateFormat replacement - missing the format() with FieldPosition

    - by user331244
    Hi, I need to split a date string into pieces and I'm doing it using the public final StringBuffer format (Object object, StringBuffer buffer, FieldPosition field) from the java.text.DateFormat class. However, the implementation of this function is really slow, hence Android has an own implementation in android.text.format.DateFormat. BUT, in my case, I want to extract the different pieces of the date string (year, minute and so on). Since I need to be locale independent, I can not use SimpleDateFormat and custom strings. I do it as follows: Calendar c = ... // find out what field to extract int field = getField(); // Create a date string Field calendarField = DateFormat.Field.ofCalendarField(field); FieldPosition fieldPosition = new FieldPosition(calendarField); StringBuffer label = new StringBuffer(); label = getDateFormat().format(c.getTime(), label, fieldPosition); // Find the piece that we are looking for int beginIndex = fieldPosition.getBeginIndex(); int endIndex = fieldPosition.getEndIndex(); String asString = label.substring(beginIndex, endIndex); For some reason, the format() overload with the FieldPosition argument is not included in the android platform. Any ideas of how to do this in another way? Is there any easy way to tokenize the pattern string? Any other ideas?

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  • Silverlight 4 ComboBox - Binding to Nullable data (tried TargetNullValue but not working as expected)

    - by Laurence
    (Please note - I am a Silverlight beginner and am looking for the simplest solution here, e.g. that doesn't involve writing/installing a replacement for the ComboBox control!) This is an issue with a Silverlight 4 application that uses the View Model (MVVM) approach. I have a simple form for editing a "Product" object. Product has a CategoryID property which is nullable (int?). A ComboBox is used to view and set the CategoryID - this is bound to an ObservableCollection of Categories. Product also has number of non-nullable properties bound to TextBoxes. I want the user to see "N/A" in the ComboBox for a product with no category, and to be use this "N/A" option to set CategoryID to null. So, I manually added a Category object with CategoryID=0 and CategoryName="N/A" to the collection; then I set TargetNullValue=0 in the SelectedValue Binding of the ComboBox. My thinking was - when the ComboBox SelectedValue was bound to a null CategoryID it would substitute zero, and therefore select the "N/A" option. When editing a Product with a non-null CategoryID, everything works. However when a null CategoryID is found, two problems occur: No option is selected in the ComboBox (its blank) The ComboBox binding seems broken from this point onwards - any Product I subsequently edit (incl. ones with a non-null CategoryID) have nothing selected in the ComboBox (its still populated with all categories - just no selected item). I've seen reports of problem #2 (here, here) but I was under the impression that #1 should have worked. What am I missing to get the "N/A" option to be selected? XAML for ComboBox: <ComboBox x:Name="cboCategory" ItemsSource="{Binding colCategories, Mode=OneWay}" SelectedValuePath="CategoryID" DisplayMemberPath="CategoryName" SelectedValue="{Binding CurrentProduct.CategoryID, Mode=TwoWay, TargetNullValue=0}" Height="24" Width="344"></ComboBox>

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  • [grails] setting cookies when render type is "contentType: text/json"

    - by Robin Jamieson
    Is it possible to set cookies on response when the return render type is set as json? I can set cookies on the response object when returning with a standard render type and later on, I'm able to get it back on the subsequent request. However, if I were to set the cookies while rendering the return values as json, I can't seem to get back the cookie on the next request object. What's happening here? These two actions work as expected with 'basicForm' performing a regular form post to the action, 'withRegularSubmit', when the user clicks submit. // first action set the cookie and second action yields the originally set cookie def regularAction = { // using cookie plugin response.setCookie("username-regular", "regularCookieUser123",604800); return render(view: "basicForm"); } // called by form post def withRegularSubmit = { def myCookie = request.getCookie("username-regular"); // returns the value 'regularCookieUser123' return render(view: "resultView"); } When I switch to setting the cookie just before returning from the response with json, I don't get the cookie back with the post. The request starts by getting an html document that contains a form and when doc load event is fired, the following request is invoked via javascript with jQuery like this: var someUrl = "http://localhost/jsonAction"; $.get(someUrl, function(jsonData) { // do some work with javascript} The controller work: // this action is called initially and returns an html doc with a form. def loadJsonForm = { return render(view: "jsonForm"); } // called via javascript when the document load event is fired def jsonAction = { response.setCookie("username-json", "jsonCookieUser456",604800); // using cookie plugin return render(contentType:'text/json') { 'pair'('myKey': "someValue") }; } // called by form post def withJsonSubmit = { def myCookie = request.getCookie("username-json"); // got null value, expecting: jsonCookieUser456 return render(view: "resultView"); } The data is returned to the server as a result of the user pressing the 'submit' button and not through a script. Prior to the submit of both 'withRegularSubmit' and 'withJsonSubmit', I see the cookies stored in the browser (Firefox) so I know they reached the client.

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  • Static content not displayed with Zend FW

    - by shin
    I am trying to display a static content with Zend framework. When I go to http://square.localhost/content/services, I get an error message. Could anyone tell me how to fix this please? Thanks in advance. application.ini .... .... resources.layout.layoutPath = APPLICATION_PATH "/layouts" resources.layout.layout = "master" resources.router.routes.home.route = /home resources.router.routes.home.defaults.module = default resources.router.routes.home.defaults.controller = index resources.router.routes.home.defaults.action = index resources.router.routes.static-content.route = /content/:page resources.router.routes.static-content.defaults.module = default resources.router.routes.static-content.defaults.controller = static-content resources.router.routes.static-content.defaults.action = display application/modules/default/controllers/StaticContentController.php class StaticContentController extends Zend_Controller_Action { public function init() { } // display static views public function displayAction() { $page = $this->getRequest()->getParam('page'); if (file_exists($this->view->getScriptPath(null) . "/" . $this->getRequest()->getControllerName() . "/$page." . $this->viewSuffix)) { $this->render($page); } else { throw new Zend_Controller_Action_Exception('Page not found', 404); } } } application/modules/default/views/scripts/static-content/services.phtml some html ... ... Error message An error occurred Page not found Exception information: Message: Page not found Stack trace: #0 /var/www/square/library/Zend/Controller/Action.php(513): StaticContentController->displayAction() #1 /var/www/square/library/Zend/Controller/Dispatcher/Standard.php(295): Zend_Controller_Action->dispatch('displayAction') #2 /var/www/square/library/Zend/Controller/Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http)) #3 /var/www/square/library/Zend/Application/Bootstrap/Bootstrap.php(97): Zend_Controller_Front->dispatch() #4 /var/www/square/library/Zend/Application.php(366): Zend_Application_Bootstrap_Bootstrap->run() #5 /var/www/square/public/index.php(26): Zend_Application->run() #6 {main} Request Parameters: array ( 'page' => 'services', 'module' => 'default', 'controller' => 'static-content', 'action' => 'display', )

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  • Why does resolveBinding() return null even though I setResolveBindings(true) on my ASTParser?

    - by Woody Zenfell III
    I am writing an Eclipse plug-in that uses JDT AST's ASTParser to parse a method. I am looking within that method for the creation of a particular type of object. When I find a ClassInstanceCreation, I call getType() on it to see what type is being instantiated. I want to be sure that the fully-resolved type being dealt with there is the one I think it is, so I tell the resultant Type object to resolveBinding(). I get null back even though there are no compilation errors and even though I called setResolveBindings(true) on my ASTParser. I gave my ASTParser (via setSource()) the ICompilationUnit that contains my method, so the parser has access to the entire workspace context. final IMethod method = ...; final ASTParser parser = ASTParser.newParser(AST.JLS3); parser.setResolveBindings(true); parser.setSource(method.getCompilationUnit()); parser.setSourceRange(method.getSourceRange().getOffset(), method.getSourceRange().getLength()); parser.setKind(ASTParser.K_CLASS_BODY_DECLARATIONS); final TypeDeclaration astRoot = (TypeDeclaration) parser.createAST(null); final ClassInstanceCreation classInstanceCreation = walkAstAndFindMyExpression(astRoot); final Type instantiatedType = classInstanceCreation.getType(); System.out.println("BINDING: " + instantiatedType.resolveBinding()); Why does resolveBinding() return null? How can I get the binding information?

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  • Exception calling remote SOAP call from thread

    - by Duncan
    This is an extension / next step of this question I asked a few minutes ago. I've a Delphi application with a main form and a thread. Every X seconds the thread makes a web services request for a remote object. It then posts back to the main form which handles updating the UI with the new information. I was previously using a TTimer object in my thread, and when the TTimer callback function ran, it ran in the context of the main thread (but the remote web services request did work). This rather defeated the purpose of the separate thread, and so I now have a simple loop and sleep routine in my thread's Execute function. The problem is, an exception is thrown when returning from GetIMySOAPService(). procedure TPollingThread.Execute; var SystemStatus : TCWRSystemStatus; begin while not Terminated do begin sleep(5000); try SystemStatus := GetIMySOAPService().GetSystemStatus; PostMessage( ParentHandle, Integer(apiSystemStatus), Integer(SystemStatus), 0 ); SystemStatus.DataContext := nil; LParam(SystemStatus) := 0; except end; end; end; Can anyone advise as to why this exception is being thrown when calling this function from the thread? I'm sure I'm overlooking something fundamental and simple. Thanks, Duncan

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  • UIViewController memory management

    - by jAmi
    Hi I have a very basic issue of memory management with my UIViewController (or any other object that I create); The problem is that in Instruments my Object allocation graph is always rising even though I am calling release on then assigning them nil. I have 2 UIViewController sub-classes each initializing with a NIB; I add the first ViewController to the main window like [window addSubView:first.view]; Then in my first ViewController nib file I have a Button which loads the second ViewController like : -(IBAction)loadSecondView{ if(second!=nil){ //second is set as an iVar and @property (nonatomic, retain)ViewController2* sceond; [second release]; second=nil; } second=[[ViewController2* second]initWithNibName:@"ViewController2" bundle:nil]; [self.view addSubView:second.view]; } In my (second) ViewController2 i have a button with an action method -(IBAction) removeSecond{ [self.view removeFromSuperView]; } Please let me know if the above scheme works in a managed way for memory...? In Instruments It does not show release of any allocation and keeps the bar status graph keeps on rising.

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  • Working with datetime type in Quickbooks My Time files

    - by jakemcgraw
    I'm attempting to process Quickbooks My Time imt files using PHP. The imt file is a plaintext XML file. I've been able to use the PHP SimpleXML library with no issues but one: The numeric representations of datetime in the My Time XML files is something I've never seen before: <object type="TIMEPERIOD" id="z128"> <attribute name="notes" type="string"></attribute> <attribute name="start" type="date">308073428.00000000000000000000</attribute> <attribute name="running" type="bool">0</attribute> <attribute name="duration" type="double">3600</attribute> <attribute name="datesubmitted" type="date">310526237.59616601467132568359</attribute> <relationship name="activity" type="1/1" destination="ACTIVITY" idrefs="z130"></relationship> </object> You can see that attritube[@name='start'] has a value of: 308073428.00000000000000000000 This is not Excel based method of storage 308,073,428 is too many days since 1900-01-00 and it isn't Unix Epoch either. So, my question is, has anyone ever seen this type of datetime representation?

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  • Can I get rid of this read lock?

    - by Pieter
    I have the following helper class (simplified): public static class Cache { private static readonly object _syncRoot = new object(); private static Dictionary<Type, string> _lookup = new Dictionary<Type, string>(); public static void Add(Type type, string value) { lock (_syncRoot) { _lookup.Add(type, value); } } public static string Lookup(Type type) { string result; lock (_syncRoot) { _lookup.TryGetValue(type, out result); } return result; } } Add will be called roughly 10/100 times in the application and Lookup will be called by many threads, many of thousands of times. What I would like is to get rid of the read lock. How do you normally get rid of the read lock in this situation? I have the following ideas: Require that _lookup is stable before the application starts operation. The could be build up from an Attribute. This is done automatically through the static constructor the attribute is assigned to. Requiring the above would require me to go through all types that could have the attribute and calling RuntimeHelpers.RunClassConstructor which is an expensive operation; Move to COW semantics. public static void Add(Type type, string value) { lock (_syncRoot) { var lookup = new Dictionary<Type, string>(_lookup); lookup.Add(type, value); _lookup = lookup; } } (With the lock (_syncRoot) removed in the Lookup method.) The problem with this is that this uses an unnecessary amount of memory (which might not be a problem) and I would probably make _lookup volatile, but I'm not sure how this should be applied. (John Skeets' comment here gives me pause.) Using ReaderWriterLock. I believe this would make things worse since the region being locked is small. Suggestions are very welcome.

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  • URL equals and checking Internet access

    - by James P.
    On http://java.sun.com/j2se/1.5.0/docs/api/java/net/URL.html it states that: Compares this URL for equality with another object. If the given object is not a URL then this method immediately returns false. Two URL objects are equal if they have the same protocol, reference equivalent hosts, have the same port number on the host, and the same file and fragment of the file. Two hosts are considered equivalent if both host names can be resolved into the same IP addresses; else if either host name can't be resolved, the host names must be equal without regard to case; or both host names equal to null. Since hosts comparison requires name resolution, this operation is a blocking operation. Note: The defined behavior for equals is known to be inconsistent with virtual hosting in HTTP. According to this, equals will only work if name resolution is possible. Since I can't be sure that a computer has internet access at a given time, should I just use Strings to store addresses instead? Also, how do I go about testing if access is available when requested?

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  • State Animation on ListBox ItemTemplate

    - by Peanut
    I have a listbox which reads from Observable collection, and is ItemTemplate'ed: <DataTemplate x:Key="DataTemplate1"> <Grid x:Name="grid" Height="47.333" Width="577" Opacity="0.495"> <Image HorizontalAlignment="Left" Margin="10.668,8,0,8" Width="34" Source="{Binding ImageLocation}"/> <TextBlock Margin="56,8,172.334,8" TextWrapping="Wrap" Text="{Binding ApplicationName}" FontSize="21.333"/> <Grid x:Name="grid1" HorizontalAlignment="Right" Margin="0,10.003,-0.009,11.33" Width="26" Opacity="0" RenderTransformOrigin="0.5,0.5"> <Image HorizontalAlignment="Stretch" Margin="0" Source="image/downloads.png" Stretch="Fill" MouseDown="Image_MouseDown" /> </Grid> </Grid> </DataTemplate> <ListBox x:Name="searchlist" Margin="8" ItemTemplate="{DynamicResource DataTemplate1}" ItemsSource="{Binding SearchResults}" SelectionChanged="searchlist_SelectionChanged" ItemContainerStyle="{DynamicResource ListBoxItemStyle1}" /> In general, my question is "What is the easiest way to do Animation on Particular Items in this listbox As they are selected? Basically the image inside the "grid1" will be setting its opacity to 1, slowly. I would prefer to use states, but I do not know of any way to just tell blend and xaml to "When a selected item is changed, change the image opacity to 1 over a period of .3 seconds". Infact, I have been doing this in the .cs file using the VisualStateManager. Also, there is another issue. When the selected index is changed, we goto the CS file and look at SelectedItem. SelectedItem returns an instance of the Object in which it was bound to (The object inside the observable collection), and NOT an instance of the DataTemplate/ListItem etc. So how am I able to pull the correct image out of this list? State animation with VisualStateManager I can handle fine if its just normal things, but when it comes to generated listboxes' items, I'm lost. Thanks

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  • 1. Get the Current Document Library 2. Create a Folder "MetaFolder" if it's not already present

    - by Rosh Malai
    All I want to do is to create a folder "MetaFolder" inside a document library. User can be on any document library and I would like to create this folder after item is added (so on itemAdded event handler). I do NOT want workflow so please dont suggest workflow. This code works but I have to hardcode the url but need to get url from current url. also need to verify the folder uHippo does not exists in the current doc library... Thanks public override void ItemAdded(SPItemEventProperties properties) { base.ItemAdded(properties); using (SPSite currentSite = new SPSite(properties.WebUrl)) using (SPWeb currentWeb = currentSite.OpenWeb()) { // This code works and creates Folder in the "My TEST Doc library" //SPList docLib = currentWeb.Lists["My TEST Doc Library"]; //SPListItem folder = docLib.Folders.Add(docLib.RootFolder.ServerRelativeUrl, SPFileSystemObjectType.Folder, "My folder"); //folder.Update(); string doclibname = "Not a doclib"; //SPList doclibList = currentWeb.GetList(HttpContext.Current.Request.RawUrl); // NOT WORKING. Tried properties.weburl SPList doclibList = currentWeb.GetListFromUrl("https://mycompanyportal/sites/testsitecol/testwebsite/My%20TEST%20Doc%20Library/Forms/AllItems.aspx"); if (null != doclibList) { doclibname = doclibList.Title; } // this section also not working. // getting Object reference not set to an instance of an object or something like that. //if (currentWeb.GetFolder("uHippo").Exists == false) //{ SPListItem folder = doclibList.Folders.Add(doclibList.RootFolder.ServerRelativeUrl, SPFileSystemObjectType.Folder, "uHippo"); folder.Update(); //} } }

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  • Creating a function in Postgresql that does not return composite values

    - by celenius
    I'm learning how to write functions in Postgresql. I've defined a function called _tmp_myfunction() which takes in an id and returns a table (I also define a table object type called _tmp_mytable) -- create object type to be returned CREATE TYPE _tmp_mytable AS ( id integer, cost double precision ); -- create function which returns query CREATE OR REPLACE FUNCTION _tmp_myfunction( id integer ) RETURNS SETOF _tmp_mytable AS $$ BEGIN RETURN QUERY SELECT id, cost FROM sales WHERE id = sales.id; END; $$ LANGUAGE plpgsql; This works fine when I use one id and call it using the following approach: SELECT * FROM _tmp_myfunction(402); What I would like to be able to do is to call it, but to use a column of values instead of just one value. However, if I use the following approach I end up with all values of the table in one column, separated by commas: -- call function using all values in a column SELECT _tmp_myfunction(t.id) FROM transactions as t; I understand that I can get the same result if I use SELECT _tmp_myfunction(402); instead of SELECT * FROM _tmp_myfunction(402); but I don't know how to construct my query in such a way that I can separate out the results.

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  • Checking for nil in view in Ruby on Rails

    - by seaneshbaugh
    I've been working with Rails for a while now and one thing I find myself constantly doing is checking to see if some attribute or object is nil in my view code before I display it. I'm starting to wonder if this is always the best idea. My rationale so far has been that since my application(s) rely on user input unexpected things can occur. If I've learned one thing from programming in general it's that users inputting things the programmer didn't think of is one of the biggest sources of run-time errors. By checking for nil values I'm hoping to sidestep that and have my views gracefully handle the problem. The thing is though I typically for various reasons have similar nil or invalid value checks in either my model or controller code. I wouldn't call it code duplication in the strictest sense, but it just doesn't seem very DRY. If I've already checked for nil objects in my controller is it okay if my view just assumes the object truly isn't nil? For attributes that can be nil that are displayed it makes sense to me to check every time, but for the objects themselves I'm not sure what is the best practice. Here's a simplified, but typical example of what I'm talking about: controller code def show @item = Item.find_by_id(params[:id]) @folders = Folder.find(:all, :order => 'display_order') if @item == nil or @item.folder == nil redirect_to(root_url) and return end end view code <% if @item != nil %> display the item's attributes here <% if @item.folder != nil %> <%= link_to @item.folder.name, folder_path(@item.folder) %> <% end %> <% else %> Oops! Looks like something went horribly wrong! <% end %> Is this a good idea or is it just silly?

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  • How to approach parallel processing of messages?

    - by Dan
    I am redesigning the messaging system for my app to use intel threading building blocks and am stumped trying to decide between two possible approaches. Basically, I have a sequence of message objects and for each message type, a sequence of handlers. For each message object, I apply each handler registered for that message objects type. The sequential version would be something like this (pseudocode): for each message in message_sequence <- SEQUENTIAL for each handler in (handler_table for message.type) apply handler to message <- SEQUENTIAL The first approach which I am considering processes the message objects in turn (sequentially) and applies the handlers concurrently. Pros: predictable ordering of messages (ie, we are guaranteed a FIFO processing order) (potentially) lower latency of processing each message Cons: more processing resources available than handlers for a single message type (bad parallelization) bad use of processor cache since message objects need to be copied for each handler to use large overhead for small handlers The pseudocode of this approach would be as follows: for each message in message_sequence <- SEQUENTIAL parallel_for each handler in (handler_table for message.type) apply handler to message <- PARALLEL The second approach is to process the messages in parallel and apply the handlers to each message sequentially. Pros: better use of processor cache (keeps the message object local to all handlers which will use it) small handlers don't impose as much overhead (as long as there are other handlers also to be run) more messages are expected than there are handlers, so the potential for parallelism is greater Cons: Unpredictable ordering - if message A is sent before message B, they may both be processed at the same time, or B may finish processing before all of A's handlers are finished (order is non-deterministic) The pseudocode is as follows: parallel_for each message in message_sequence <- PARALLEL for each handler in (handler_table for message.type) apply handler to message <- SEQUENTIAL The second approach has more advantages than the first, but non-deterministic ordering is a big disadvantage.. Which approach would you choose and why? Are there any other approaches I should consider (besides the obvious third approach: parallel messages and parallel handlers, which has the disadvantages of both and no real redeeming factors as far as I can tell)? Thanks!

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