Search Results

Search found 29508 results on 1181 pages for 'object initializers'.

Page 575/1181 | < Previous Page | 571 572 573 574 575 576 577 578 579 580 581 582  | Next Page >

• Flex component setActualSize

  - by dlots

  I am a little confused about the setActualSize method. It appears from what I've read, that if it is not called on a component by its parent, the component will not be rendered. So it appears that setActualSize is a critical method that is directly bound to rendering the UIComponent. It also appears that the width and height properties of UIComponent override the functionality of the width and height properties of flash.display.DisplayObject, in that they are not directly bound to the rendering of the object but are virtual values that are mainly used by the getExplicitOrMeasured when the parent of the component calls the component's setActualSize method. So the question are: 1) Why isn't the default behavior of every component to just call setActualSize(getExplicitOrMeasuredWidth(),getExplicitOrMeasuredHeight()) on itself? 2) I guess this question stems from the above question and the behavior as I understand it as described above: does setActualSize change the visibility of the component? It appears that that the behavior is that a component is not rendered until setActualSize is called, but if it contains display object children itself (expected behavior as it can calculate measure on itself) and is added to the display list, the only reason why flash isn't rendering it, is because its not visible. 3) Relating to question #1, does updateDisplayList of UIComponent have a method that goes through its children calling setActualSize on each of them?

  Read the article

• Detect whether or not a specific attribute was valid on the model

  - by Sir Code-A-Lot

  Having created my own validation attribute deriving from System.ComponentModel.DataAnnotations.ValidationAttribute, I wish to be able to detect from my controller, whether or not that specific attribute was valid on the model. My setup: public class MyModel { [Required] [CustomValidation] [SomeOtherValidation] public string SomeProperty { get; set; } } public class CustomValidationAttribute : ValidationAttribute { public override bool IsValid(object value) { // Custom validation logic here } } Now, how do I detect from the controller whether validation of CustomValidationAttribute succeeded or not? I have been looking at the Exception property of ModelError in the ModelState, but I have no way of adding a custom exception to it from my CustomValidationAttribute. Right now I have resorted to checking for a specific error message in the ModelState: public ActionResult PostModel(MyModel model) { if(ModelState.Where(i => i.Value.Errors.Where((e => e.ErrorMessage == CustomValidationAttribute.SharedMessage)).Any()).Any()) DoSomeCustomStuff(); // The rest of the action here } And changed my CustomValidationAttribute to: public class CustomValidationAttribute : ValidationAttribute { public static string SharedMessage = "CustomValidationAttribute error"; public override bool IsValid(object value) { ErrorMessage = SharedMessage; // Custom validation logic here } } I don't like relying on string matching, and this way the ErrorMessage property is kind of misused. What are my options?

  Read the article

• check if two subsets of integers are equal using equals method

  - by MAS

  I have this java method in class called IntArray. The class has methods to add integers to a set or remove integers from a set,check size of a set, and check if 2 sets are equal. the 2 sets are created using 2 different objects of type IntArray in main, lets say object A and B. equals method supposed to check if two sets of integers are equal. for example set A = {1,2,3} and B = {1,2,3,4}. The method still return true even though one set is a subset of the other set. What exactly I am doing wrong? Thanks. //part of the code in main IntArray A = new IntArray(); IntArray B = new IntArray(); if(A.equals(B)) System.out.println("A and B are equal"); //equals method in IntArray class public boolean equals(Object b) { if (b instanceof IntArray) { IntArray A = (IntArray) b; for (int i = 0; i < data.length; i++) if (countOccurrences(data[i]) != A.countOccurrences(data[i])) return false; return true; } else return false; }

  Read the article

• What is a simple way to add a timer to a method

  - by John

  The following is in C#. I'm trying to do something very simple (I think). I have a method that loads an XML document XDocument doc = XDocument.Load(uri); , but I don't want to tie up pc resources if there are issues (connectivity, document size, etc.). So I'd like to be able to add a timeout variable that will cut the method off after a given number of seconds. I'm a newbie when it comes to asynchronous programming and find it confusing that there are so many examples written so many different ways . . . and none of them appear simple. I'd like a simple solution, if possible. Here's my thoughts so far on possible solution paths: 1) A method that wraps the existing load public XDocument LoadXDocument(string uri, int timeout){ //code } 2) A wrapper, but as an extension method XDocument doc = XDocument.LoadWithTimeout(string uri, int timeout); 3) A generic extension method. Object obj = SomeStaticClass.LoadWithTimeout(??? method, int timeout); 3), on its face seems really nice, because it would mean being able to generically add timeouts to many different method calls and not specifically tied to one type of object, but I suspect that it is either i)impossible or ii) very difficult. Please assist. Thanks.

  Read the article

• i have this code but when i run it i get an exception:

  - by nisnis84

  i have this code but when i run it i get an exception: java.security.AccessControlException: access denied (java.net.SocketPermission 127.0.0.1:8081 connect,resolve) this is the code, the server running good but the client dont work <OBJECT classid="clsid:8AD9C840-044E-11D1-B3E9-00805F499D93" width="615" height="360" codebase="http://java.sun.com/products/plugin/autodl/jinstall-1_4-windows-i586.cab#Version=1,4,0,mn"> <PARAM name="code" value="client/LlamaChat.class"> <PARAM name="archive" value="LlamaChat.jar"> <PARAM name="type" value="application/x-java-applet;version=1.4"> <PARAM name="scriptable" value="true"> <PARAM name="username" value="[replace with username]"> <PARAM name="port" value="[replace with port]"> <COMMENT> <EMBED type="application/x-java-applet;version=1.4" width="615" height="360" code="client/LlamaChat.class" archive="LlamaChat.jar" pluginspage="http://java.sun.com/j2se/1.4.1/download.html" username="nis" port="8081" <NOEMBED> No Java 1.4 plugin </NOEMBED></EMBED> </COMMENT> </OBJECT>

  Read the article

• How to Bind a Command in WPF

  - by MegaMind

  Sometimes we used complex ways so many times, we forgot the simplest ways to do the task. I know how to do command binding, but i always use same approach. Create a class that implements ICommand interface and from the view model i create new instance of that class and binding works like a charm. This is the code that i used for command binding public partial class MainWindow : Window { public MainWindow() { InitializeComponent(); DataContext = this; testCommand = new MeCommand(processor); } ICommand testCommand; public ICommand test { get { return testCommand; } } public void processor() { MessageBox.Show("hello world"); } } public class MeCommand : ICommand { public delegate void ExecuteMethod(); private ExecuteMethod meth; public MeCommand(ExecuteMethod exec) { meth = exec; } public bool CanExecute(object parameter) { return false; } public event EventHandler CanExecuteChanged; public void Execute(object parameter) { meth(); } } But i want to know the basic way to do this, no third party dll no new class creation. Do this simple command binding using a single class. Actual class implements from ICommand interface and do the work.

  Read the article

• Why wouldn't an embedded silverlight control work in a page?

  - by rsteckly

  Hi, I have a silverlight application project in my solution. The other project is a web application project that has a .xap file in ClientBin. When I created the silverlight project, it asked if I wanted the asp.net application to host it (and I said yes). In the root directory, there is a test page for the silverlight control. That loads the control. In another directory, I insert the SAME asp markup to get the silverlight control to launch again. Nothing happens. Why would the silverlight launch on one page and not on the other? Can people help point me to documentation about dependencies that I might not know about? I've put a reference to Silverlight.js on the page as well. Here's the markup: <div id="silverlightControlHost"> <object data="data:application/x-silverlight-2," type="application/x-silverlight-2" width="100%" height="100%"> <param name="source" value="../ClientBin/Editor.xap"/> <param name="onError" value="onSilverlightError" /> <param name="background" value="white" /> <param name="minRuntimeVersion" value="3.0.40818.0" /> <param name="autoUpgrade" value="true" /> <a href="http://go.microsoft.com/fwlink/?LinkID=149156&v=3.0.40818.0" style="text-decoration:none"> <img src="http://go.microsoft.com/fwlink/?LinkId=108181" alt="Get Microsoft Silverlight" style="border-style:none"/> </a> </object><iframe id="_sl_historyFrame" style="visibility:hidden;height:0px;width:0px;border:0px"></iframe></div> </div>

  Read the article

• How do I put all the types matching a particular C# interface in an IDictionary?

  - by Kevin Brassen

  I have a number of classes all in the same interface, all in the same assembly, all conforming to the same generic interface: public class AppleFactory : IFactory<Apple> { ... } public class BananaFactory : IFactory<Banana> { ... } // ... It's safe to assume that if we have an IFactory<T> for a particular T that it's the only one of that kind. (That is, there aren't two things that implement IFactory<Apple>.) I'd like to use reflection to get all these types, and then store them all in an IDictionary, where the key is typeof(T) and the value is the corresponding IFactory<T>. I imagine eventually we would wind up with something like this: _map = new Dictionary<Type, object>(); foreach(Type t in [...]) { object factoryForType = System.Reflection.[???](t); _map[t] = factoryForType; } What's the best way to do that? I'm having trouble seeing how I'd do that with the System.Reflection interfaces.

  Read the article

• Failed to create a 'System.Windows.RoutedEventHandler' from the text 'Button_Click'

  - by ay89

  In my windows phone 8 application, while trying to create a dependency property I am always getting this exception. what I am doing wrong, plz guide me. {System.Windows.Markup.XamlParseException: Failed to create a 'System.Windows.RoutedEventHandler' from the text 'Button_Click'. [Line: 108 Position: 66] at System.Windows.Application.LoadComponent(Object component, Uri resourceLocator) at com.sap.View.HomePage.InitializeComponent() at com.sap.View.HomePage..ctor()} this is code-behind of Header public static readonly DependencyProperty MenuClickProperty = DependencyProperty.Register("MenuClick", typeof(RoutedEventHandler), typeof(Header), new PropertyMetadata(OnMenuClickHandlerChanged)); public RoutedEventHandler MenuClick { get { return (RoutedEventHandler)GetValue(MenuClickProperty); } set { SetValue(MenuClickProperty, new RoutedEventHandler(value)); } } private static void OnMenuClickHandlerChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) { Header header = d as Header; header.OnMenuClickHandlerPropertyChanged(e); } private void OnMenuClickHandlerPropertyChanged(DependencyPropertyChangedEventArgs e) { MenuButton.Click += MenuClick; } this is in my user control (Header) <Button Click="{Binding Path=MenuClick, Source={RelativeSource Mode=Self}}" /> this is how i am including control on my Page: <myControls:Header Title="{Binding Title}" MenuClick="Button_Click" /> this is in code-behind: public void Button_Click(object sender, RoutedEventArgs e) { OpenSettings(); }

  Read the article

• How do I post back information from a webpage that has post-generated content?

  - by meanbunny

  Ok so I am very new to html and the web. Right now I am trying to generate list items on the fly and then have them post back to the web server so I know what the person is trying to obtain. Here is the code for generating the list items: foreach (var item in dataList) { MyDataList.InnerHtml += "<li><a runat='server' onclick='li_Click' id='" + item.Name + "-button'></a></li>"; } Further down I have my click event. protected void li_Click(object sender, EventArgs e) { //How do I determine here which item was actually clicked? } My question is how do I determine which list item was clicked? Btw, the code running behind is C#. EDIT 1 LinkButton link = new LinkButton(); link.ID = "all-button"; link.Text = "All"; link.Click += new EventHandler(link_Click); MyDataList.Controls.Add(link); Then below I have my link_Click event that never seems to hit a breakpoint. void link_Click(object sender, EventArgs e) { if (sender != null) { if (sender.GetType() == typeof(LinkButton)) { LinkButton button = (LinkButton)sender; if (button.ID == "all-button") { } } } } I know this has to be possible I just cant figure out what I am missing. Edit 2 Ok ok I think I know what the problem is. I was trying to add a second list inside of another list. This was causing the whole thing to have problems. It is working now.

  Read the article

• How to convert a rectangle to TRBL CSS rect value?

  - by VLostBoy

  I'm not quite sure how to put this, but here goes... The css clip attribute is defined like so: rect(top, right, bottom, left). However, I'm exploring the use of a custom Rectangle 'class' to encapsulate some operations. The rectangle class has the attributes height, width and x, y. The x and y values are encapsulated in a Point object, and the height and width are encapsulated in a Dimension object, the rectangle being a composite of a point (its top-left location) and a dimension (width and height). So far so good. I though it would be pretty simple on the basis of having the rectangles x, y, width and height values to define the css rect attribute in terms of top, right, bottom, left, but I've become hopelessly confused- I've been googling for a while, and I can't seem to find any documentation as to what the TRBL values actually are or what they represent. For example, should I be thinking in terms of co-ordinates, in which case, surely I can describe the rectangle as a css rect using the rectangles x position for Top, x position + width for Right, the rectangles height + y for Bottom and its y position for Left... but thats a load of BS, surely? Also, surely rect is actually an inset, or have I just inverted my understanding of clip? I'd appreciate some advice. What I want to be able to do is (i) Define a rectangle using x, y, width and height (ii)Express the rectangle in TRBL form so that I can manipulate a divs clipping behaviour (iii)Change x, y, width or height and recalculate in terms of TRBL and goto (ii) I appreciate there are some other factors here, and some intermediary transforms to be done, but I've confused myself pretty badly- Can anyone give me some pointers?

  Read the article

• Apply [ThreadStatic] attribute to a method in external assembly

  - by Sen Jacob

  Can I use an external assembly's static method like [ThreadStatic] method? Here is my situation. The assembly class (which I do not have access to its source) has this structure public class RegistrationManager() { private RegistrationManager() {} public static void RegisterConfiguration(int ID) {} public static object DoWork() {} public static void UnregisterConfiguration(int ID) {} } Once registered, I cannot call the DoWork() with a different ID without unregistering the previously registered one. Actually I want to call the DoWork() method with different IDs simultaneously with multi-threading. If the RegisterConfiguration(int ID) method was [ThreadStatic], I could have call it in different threads without problems with calls, right? So, can I apply the [ThreadStatic] attribute to this method or is there any other way I can call the two static methods same time without waiting for other thread to unregister it? If I check it like the following, it should work. for(int i=0; i < 10; i++) { new Thread(new ThreadStart(() => Checker(i))).Start(); } public string Checker(int i) { public static void RegisterConfiguration(i); // Now i cannot register second time public static object DoWork(i); Thread.Sleep(5000); // DoWork() may take a little while to complete before unregistered public static void UnregisterConfiguration(i); }

  Read the article

• Silverlight Timer problem

  - by jose

  Hello, I am developing a Silverlight application with custom animations. I want to update the variable animationCounter every 1 milissecond, so that in one second the value is 1000. I've tried DispatcherTimer and System.Threading.Timer. this way: DispatcherTimer timer = new DispatcherTimer(); (...) timer.Interval = new TimeSpan(0, 0, 0, 0, 1); timer.Tick += new EventHandler(timer_Tick); (...) (...) void timer_Tick(object sender, EventArgs e) { animationCounter++; Dispatcher.BeginInvoke(() => txtAnimationCounter.Text = animationCounter.ToString()); } with System.Threading.Timer System.Threading timer = null; timer = new System.Threading.Timer(UpdateAnimationCounter, 0, 1); void UpdateAnimationCounter(object state) { animationCounter++; Dispatcher.BeginInvoke(() => txtAnimationCounter.Text = animationCounter.ToString()); } Both of them are setting AnimationCounter around 100 in one second. Should be 1000. I don't know why. Is there anything I'm missing. Thanks

  Read the article

• problem with converting simple code from Winform to silverlight app.

  - by Sara

  Hi. I have this code for window form application and I have been attempting to convert it to a Silverlight application but it does not work!. There is a Textbox and I attached KeyDown event handler to it. when the user press the arrow key ( left or right) while the focus on the textbox, it will write . or -. When it is window form i used e.KeyCode and Keys.Right and its works great but when it is silverlight I used e.Key and key.Right and the program doesn't work good because the arrows do the 2 functions moving and write ./-. How I can work this out in Silverlight? (My English not good) The code ( window form): private void textBox1_KeyDown(object sender, KeyEventArgs e) { if (sender is TextBox) { TextBox textBox = (TextBox)sender; if (e.KeyCode == Keys.Left || e.KeyCode == Keys.Right) { e.Handled = true; char insert; if (e.KeyCode == Keys.Left) { insert = '.'; } else { insert = '-'; } int i = textBox.SelectionStart; textBox.Text = textBox.Text.Insert(i, insert.ToString()); textBox.Select(i + 1, 0); } } } (and Silverlight): private void textBox1_KeyDown(object sender, KeyEventArgs e) { if (sender is TextBox) { TextBox textBox = (TextBox)sender; if (e.Key == Key.Left || e.Key == Key.Right) { e.Handled = true; char insert; if (e.Key == Key.Left) { insert = '.'; } else { insert = '-'; } int i = textBox.SelectionStart; textBox.Text = textBox.Text.Insert(i, insert.ToString()); textBox.Select(i + 1, 0); } } } I don't understand, is there huge different effect between using Keycode/Keys and Key/Key or because something else?

  Read the article

• Why does my simple event handling example not work?

  - by njreed

  I am trying to make a simple event handler. (Note, I'm not trying to implement a full-blown publish/subscribe model; I'm just interested in why my example doesn't work as I think it should) var myObj = (function () { var private = "X"; function triggerEvent(eventName) { if (this[eventName]) { this[eventName](); } } // Setter / Getter function getProp() { return private; } function setProp(value) { private = value; triggerEvent("onPropChange"); } // Public API return { // Events "onPropChange": null, // Fires when prop value is changed // Methods "getProp": getProp, "setProp": setProp }; })(); // Now set event handler myObj.onPropChange = function () { alert("You changed the property!"); }; myObj.setProp("Z"); // --> Nothing happens. Wrong // Why doesn't my alert show? I set the onPropChange property of my object to a simpler handler function but it is not being fired. I have debugged this and it seems that in triggerEvent the variable this is referencing the global window object. I thought it should reference myObj (which is what I need). Can someone explain the error in my thinking and how I correct this? Help much appreciated. jsFiddle here

  Read the article

• Iphone Core Data Internal Inconsistency

  - by kiyoshi

  This question has something to do with the question I posted here: http://stackoverflow.com/questions/1230858/iphone-core-data-crashing-on-save however the error is different so I am making a new question. Now I get this error when trying to insert new objects into my managedObjectContext: *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '"MailMessage" is not a subclass of NSManagedObject.' But clearly it is: @interface MailMessage : NSManagedObject { .... And when I run this code: NSManagedObjectModel *managedObjectModel = [[self.managedObjectContext persistentStoreCoordinator] managedObjectModel]; NSEntityDescription *entity =[[managedObjectModel entitiesByName] objectForKey:@"MailMessage"]; NSManagedObject *newObject = [[NSManagedObject alloc] initWithEntity:entity insertIntoManagedObjectContext:self.managedObjectContext]; It runs fine when I do not present an MFMailComposeViewController, but if I run this code in the - (void)mailComposeController:(MFMailComposeViewController*)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError*)error { method, it throws the above error when creating the newObject variable. The entity object when I use print object produces the following: (<NSEntityDescription: 0x1202e0>) name MailMessage, managedObjectClassName MailMessage, renamingIdentifier MailMessage, isAbstract 0, superentity name (null), properties { in both cases, so I don't think the managedObjectContext is completely invalid. I have no idea why it would say MailMessage is not a subclass of NSManagedObject at that point, and not at the other. Any help would be appreciated, thanks in advance.

  Read the article

• Zend_Db Enum Values [Closed]

  - by scopus

  I find this solution $metadata = $result->getTable()->info('metadata'); echo $metadata['Continent']['DATA_TYPE']; Hi, I want to get enum values in Zend_Db. My Code: $select = $this->select(); $result = $select->fetchAll(); print_r($result->getTable()); Output: Example Object ( [_name] => country [query] => Zend_Db_Table_Select Object ( [_info:protected] => Array ( [schema] => [name] => country [cols] => Array ( [0] => Code [1] => Continent ) [primary] => Array ( [1] => Code ) [metadata] => Array ( [Continent] => Array ( [SCHEMA_NAME] => [TABLE_NAME] => country [COLUMN_NAME] => Continent [COLUMN_POSITION] => 3 [DATA_TYPE] => enum('Asia','Europe','North America','Africa','Oceania','Antarctica','South America') [DEFAULT] => Asia [NULLABLE] => [LENGTH] => [SCALE] => [PRECISION] => [UNSIGNED] => [PRIMARY] => [PRIMARY_POSITION] => [IDENTITY] => ) I see enum values in data_type but i don't get this values. How can get data_type?

  Read the article

• [VB.Net] TreeView update bug in the .net framework

  - by CFP

  Consider the following code: Dim Working As Boolean = False Private Sub TreeView1_AfterCheck(ByVal sender As Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterCheck If Working Then Exit Sub Working = True e.Node.Checked = Not e.Node.Checked Working = False End Sub Private Sub TreeView1_MouseClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles TreeView1.MouseClick If e.Button = Windows.Forms.MouseButtons.Right Then MsgBox("Checked = " & TreeView1.SelectedNode.Checked) End Sub Where TreeView1 is a TreeView added to the form, with CheckBoxes set to true and one node added. The code basically cancel any node checking occuring on the form. Single-clicking the top node to check it works well : your click is immediately canceled. Yet if you double-click the checkbox, it will display a tick. But verifying the check state through a right click will yield a Checked = False dialog. How come? Is it a bug (I'm using the latest .Net Framework 4.0, and he same occurs in 2.0), or am I doing something wrong here? Is there a work around? Thanks! EDIT: Additionally, the MouseDoubleClick event is not raised before you click once again.

  Read the article

• TreeView update bug in the VB.NET

  - by CFP

  Consider the following code: Dim Working As Boolean = False Private Sub TreeView1_AfterCheck(ByVal sender As Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterCheck If Working Then Exit Sub Working = True e.Node.Checked = Not e.Node.Checked Working = False End Sub Private Sub TreeView1_MouseClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles TreeView1.MouseClick If e.Button = Windows.Forms.MouseButtons.Right Then MsgBox("Checked = " & TreeView1.SelectedNode.Checked) End Sub Where TreeView1 is a TreeView added to the form, with CheckBoxes set to true and one node added. The code basically cancel any node checking occuring on the form. Single-clicking the top node to check it works well : your click is immediately canceled. Yet if you double-click the checkbox, it will display a tick. But verifying the check state through a right click will yield a Checked = False dialog. How come? Is it a bug (I'm using the latest .Net Framework 4.0, and he same occurs in 2.0), or am I doing something wrong here? Is there a work around? Thanks! EDIT: Additionally, the MouseDoubleClick event is not raised before you click once again. EDIT 2: Posted a bug report at Microsoft Connect

  Read the article

• threading and getting COM port of attached phone

  - by I__

  i have the following code: using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using System.Threading; namespace WindowsFormsApplication1 { public partial class Form1 : Form { public Form1() { InitializeComponent(); } public class ThreadWork { public static void DoWork() { } } private void Form1_Load(object sender, EventArgs e) { ThreadStart myThreadDelegate = new ThreadStart(ThreadWork.DoWork); Thread myThread = new Thread(myThreadDelegate); myThread.Start(); // Begin communications serialPort1.Open(); serialPort1.Write("AT+CMGF=1\r\n"); //Thread.Sleep(500); serialPort1.Write("AT+CNMI=2,2\r\n"); //Thread.Sleep(500); serialPort1.Write("AT+CSCA=\"+4790002100\"\r\n"); //Thread.Sleep(500); } private void serialPort1_DataReceived_1(object sender, System.IO.Ports.SerialDataReceivedEventArgs e) { string response = serialPort1.ReadLine(); this.BeginInvoke(new MethodInvoker(() => textBox1.AppendText(response + "\r\n"))); } } } what i am trying to do is send AT COMMANDS to my phone which is attached to the computer through USB how do i know how to configure the properties of the serial port? (like which COM is the phone on [it's attached through USB], what about baudrate and databits?) when i run the program nothing really happens, i would like to send AT COMMANDS to my phone and the textbox is there to receive the response from my phone this is my first time using threads. am i using them correctly? what is the purpose of it in the current example? is it to just have a delay between send a response? what am i doing wrong?

  Read the article

• Immutability and shared references - how to reconcile?

  - by davetron5000

  Consider this simplified application domain: Criminal Investigative database Person is anyone involved in an investigation Report is a bit of info that is part of an investigation A Report references a primary Person (the subject of an investigation) A Report has accomplices who are secondarily related (and could certainly be primary in other investigations or reports These classes have ids that are used to store them in a database, since their info can change over time (e.g. we might find new aliases for a person, or add persons of interest to a report) If these are stored in some sort of database and I wish to use immutable objects, there seems to be an issue regarding state and referencing. Supposing that I change some meta-data about a Person. Since my Person objects immutable, I might have some code like: class Person( val id:UUID, val aliases:List[String], val reports:List[Report]) { def addAlias(name:String) = new Person(id,name :: aliases,reports) } So that my Person with a new alias becomes a new object, also immutable. If a Report refers to that person, but the alias was changed elsewhere in the system, my Report now refers to the "old" person, i.e. the person without the new alias. Similarly, I might have: class Report(val id:UUID, val content:String) { /** Adding more info to our report */ def updateContent(newContent:String) = new Report(id,newContent) } Since these objects don't know who refers to them, it's not clear to me how to let all the "referrers" know that there is a new object available representing the most recent state. This could be done by having all objects "refresh" from a central data store and all operations that create new, updated, objects store to the central data store, but this feels like a cheesy reimplementation of the underlying language's referencing. i.e. it would be more clear to just make these "secondary storable objects" mutable. So, if I add an alias to a Person, all referrers see the new value without doing anything. How is this dealt with when we want to avoid mutability, or is this a case where immutability is not helpful?

  Read the article

• Configure nHibernate for multiple-project solution

  - by NoOne

  Hello, Im doing a project with C# winforms. This project is composed by: Client project: Windows Forms where user will do CRUD operations on the models; Server project; Common Project: This project will hold the models (in the image only have the model Item); ListSingleton: Remote Object that will do the operations on the models; I already have all the communication working, but now I need to work on the persistence of the data in a mysql database. I was trying to use nHibernate but I’m having some troubles. My main problem is how to organize my hibernate configuration. In which project do I keep the mapping? Common project? In which project do I keep the hibernate configuration file (App.config)? ListSingleton project? In which project do I do this: Configuration cfg = new Configuration(); cfg.AddXmlFile("Item.hbm.xml"); ISessionFactory factory = cfg.BuildSessionFactory(); ISession session = factory.OpenSession(); ITransaction transaction = session.BeginTransaction(); Item newItem = new Item("BLAA"); // Tell NHibernate that this object should be saved session.Save(newItem); // commit all of the changes to the DB and close the ISession transaction.Commit(); session.Close(); In the ListSingleton project? Altho I had reference to the Common Project in the ListSingleton I keep getting error in the addXml line… My mapping is correct because I tried with a one-project solution and it worked :X

  Read the article

• .NET port with Java's Map, Set, HashMap

  - by Nikos Baxevanis

  I am porting Java code in .NET and I am stuck in the following lines that (behave unexpectedly in .NET). Java: Map<Set<State>, Set<State>> sets = new HashMap<Set<State>, Set<State>>(); Set<State> p = new HashSet<State>(); if (!sets.containsKey(p)) { ... } The equivalent .NET code could possibly be: IDictionary<HashSet<State>, HashSet<State>> sets = new Dictionary<HashSet<State>, HashSet<State>>(); HashSet<State> p = new HashSet<State>(); if (!sets.containsKey(p)) { /* (Add to a list). Always get here in .NET (??) */ } However the code comparison fails, the program think that "sets" never contain Key "p" and eventually results in OutOfMemoryException. Perhaps I am missing something, object equality and identity might be different between Java and .NET. I tried implementing IComparable and IEquatable in class State but the results were the same. Edit: What the code does is: If the sets does not contain key "p" (which is a HashSet) it is going to add "p" at the end of a LinkedList. The State class (Java) is a simple class defined as: public class State implements Comparable<State> { boolean accept; Set<Transition> transitions; int number; int id; static int next_id; public State() { resetTransitions(); id = next_id++; } // ... public int compareTo(State s) { return s.id - id; } public boolean equals(Object obj) { return super.equals(obj); } public int hashCode() { return super.hashCode(); }

  Read the article

• Strange befaviour of spring transaction support for JPA + Hibernate +@Transactional annotation

  - by abovesun

  I found out really strange behavior on relatively simple use case, probably I can't understand it because of not deep knowledges of spring @Transactional nature, but this is quite interesting. I have simple User dao that extends spring JpaDaoSupport class and contains standard save method: @Transactional public User save(User user) { getJpaTemplate().persist(user); return user; } If was working fine until I've add new method to same class: User getSuperUser(), this method should return user with isAdmin == true, and if there is no super user in db, method should create one. Thats how it was looking like: public User createSuperUser() { User admin = null; try { admin = (User) getJpaTemplate().execute(new JpaCallback() { public Object doInJpa(EntityManager em) throws PersistenceException { return em.createQuery("select u from UserImpl u where u.admin = true").getSingleResult(); } }); } catch (EmptyResultDataAccessException ex) { User admin = new User('login', 'password'); admin.setAdmin(true); save(admin); // THIS IS THE POINT WHERE STRANGE THING COMING OUT } return admin; } As you see code is strange forward and I was very confused when found out that no transaction was created and committed on invocation of save(admin) method and no new user wasn't actually created despite @Transactional annotation. In result we have situation: when save() method invokes from outside of UserDAO class - @Transactional annotation counted and user successfully created, but if save() invokes from inside of other method of the same dao class - @Transactional annotation ignored. Here how I was change save() method to force it always create transaction. public User save(User user) { getJpaTemplate().execute(new JpaCallback() { public Object doInJpa(EntityManager em) throws PersistenceException { em.getTransaction().begin(); em.persist(user); em.getTransaction().commit(); return null; } }); return user; } As you see I manually invoke begin and commit. Any ideas?

  Read the article

• How do I execute queries upon DB connection in Rails?

  - by sycobuny

  I have certain initializing functions that I use to set up audit logging on the DB server side (ie, not rails) in PostgreSQL. At least one has to be issued (setting the current user) before inserting data into or updating any of the audited tables, or else the whole query will fail spectacularly. I can easily call these every time before running any save operation in the code, but DRY makes me think I should have the code repeated in as few places as possible, particularly since this diverges greatly from the ideal of database agnosticism. Currently I'm attempting to override ActiveRecord::Base.establish_connection in an initializer to set it up so that the queries are run as soon as I connect automatically, but it doesn't behave as I expect it to. Here is the code in the initializer: class ActiveRecord::Base # extend the class methods, not the instance methods class << self alias :old_establish_connection :establish_connection # hide the default def establish_connection(*args) ret = old_establish_connection(*args) # call the default # set up necessary session variables for audit logging # call these after calling default, to make sure conn is established 1st db = self.class.connection db.execute("SELECT SV.set('current_user', 'test@localhost')") db.execute("SELECT SV.set('audit_notes', NULL)") # end "empty variable" err ret # return the default's original value end end end puts "Loaded custom establish_connection into ActiveRecord::Base" sycobuny:~/rails$ ruby script/server = Booting WEBrick = Rails 2.3.5 application starting on http://0.0.0.0:3000 Loaded custom establish_connection into ActiveRecord::Base This doesn't give me any errors, and unfortunately I can't check what the method looks like internally (I was using ActiveRecord::Base.method(:establish_connection), but apparently that creates a new Method object each time it's called, which is seemingly worthless cause I can't check object_id for any worthwhile information and I also can't reverse the compilation). However, the code never seems to get called, because any attempt to run a save or an update on a database object fails as I predicted earlier. If this isn't a proper way to execute code immediately on connection to the database, then what is?

  Read the article

< Previous Page | 571 572 573 574 575 576 577 578 579 580 581 582  | Next Page >