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  • Modelbinding Failing VS2010 asp.net mvc2

    - by Rob Ellis
    The contactAddModel.Search always comes through as null - any ideas? View declaration <%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<rs30UserWeb.Models.StatusIndexModel>" %> ViewModels public class StatusIndexModel { public ContactAddModel contactAddModel; public StatusMessageModel statusMessageModel; } public class ContactAddModel { [Required(ErrorMessage="Contact search string")] [DisplayName("Contact Search")] public string Search { get; set; } } View content <% using (Html.BeginForm("AddContact", "Status")) { %> <div> <fieldset> <legend>Add a new Contact</legend> <div class="editor-label"> <%= Html.LabelFor(m => m.contactAddModel.Search) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(m => m.contactAddModel.Search)%> <%= Html.ValidationMessageFor(m => m.contactAddModel.Search)%> </div> <p> <input type="submit" value="Add Contact" /> </p> </fieldset> </div> <% } %> Controller [HttpPost] public ActionResult AddContact(Models.ContactAddModel model) { if (u != null) { } else { ModelState.AddModelError("contactAddModel.Search", "User not found"); } return View("Index"); }

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  • Quickly determine if a number is prime in Python for numbers < 1 billion

    - by Frór
    Hi, My current algorithm to check the primality of numbers in python is way to slow for numbers between 10 million and 1 billion. I want it to be improved knowing that I will never get numbers bigger than 1 billion. The context is that I can't get an implementation that is quick enough for solving problem 60 of project Euler: I'm getting the answer to the problem in 75 seconds where I need it in 60 seconds. http://projecteuler.net/index.php?section=problems&id=60 I have very few memory at my disposal so I can't store all the prime numbers below 1 billion. I'm currently using the standard trial division tuned with 6k±1. Is there anything better than this? Do I already need to get the Rabin-Miller method for numbers that are this large. primes_under_100 = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97] def isprime(n): if n <= 100: return n in primes_under_100 if n % 2 == 0 or n % 3 == 0: return False for f in range(5, int(n ** .5), 6): if n % f == 0 or n % (f + 2) == 0: return False return True How can I improve this algorithm?

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  • What is the name of this geometrical function?

    - by Spike
    In a two dimentional integer space, you have two points, A and B. This function returns an enumeration of the points in the quadrilateral subset bounded by A and B. A = {1,1} B = {2,3} Fn(A,B) = {{1,1},{1,2},{1,3},{2,1},{2,2},{2,3}} I can implement it in a few lines of LINQ. private void UnknownFunction(Point to, Point from, List<Point> list) { var vectorX = Enumerable.Range(Math.Min(to.X, from.X), Math.Abs(to.X - from.Y) + 1); var vectorY = Enumerable.Range(Math.Min(to.Y, from.Y), Math.Abs(to.Y - from.Y) + 1); foreach (var x in vectorX) foreach (var y in vectorY) list.Add(new Point(x, y)); } I'm fairly sure that this is a standard mathematical operation, but I can't think what it is. Feel free to tell me that it's one line of code in your language of choice. Or to give me a cunning implementation with lambdas or some such. But mostly I just want to know what it's called. It's driving me nuts. It feels a little like a convolution, but it's been too long since I was at school for me to be sure.

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  • Any book on designing and implementing a CRPG engine?

    - by Fabzter
    Hi! First, let me tell you, I am not really interested in making my own rpg engine (at least not in the near future, hehe), but I do feel like I want to understand the internals of how a rpg engine works. Why? Well, because I like to read about programming and design, It keeps me motivated and excited, and because I know I will learn a lot, for, even when I have been programming for some years now, I never stop considering myself an ignorant... there are simply SO many things involving a game engine (specially rpg ones, like branching storylines, and items and economics!) I'm eager to know. I've been searching (and thus, finding) lots of info online, but it is never focused in what I'm interested (most of it talks about the mathematics and AI algorithms implementation, which I know quite well), which is the design of overall structure, patterns, scripting engine, decision engine... damn, so many things I can't even imagine, since I've never done any game programming. I hope you know have an idea of how I feel, and how I want to learn for the sake of learning, and why would I want you to tell me if you know if there exist books touching the topics that interest me the most.

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  • How to configure SQLite to run with NHibernate where assembly resolves System.Data.SQLite?

    - by Michael Hedgpeth
    I am using the latest NHibernate 2.1.0Beta2. I'm trying to unit test with SQLite and have the configuration set up as: Dictionary<string, string> properties = new Dictionary<string, string>(); properties.Add("connection.driver_class", "NHibernate.Driver.SQLite20Driver"); properties.Add("dialect", "NHibernate.Dialect.SQLiteDialect"); properties.Add("connection.provider", "NHibernate.Connection.DriverConnectionProvider"); properties.Add("query.substitutions", "true=1;false=0"); properties.Add("connection.connection_string", "Data Source=test.db;Version=3;New=True;"); properties.Add("proxyfactory.factory_class", "NHibernate.ByteCode.LinFu.ProxyFactoryFactory, NHibernate.ByteCode.LinFu"); configuration = new Configuration(); configuration.SetProperties(properties); When I try to run it, I get the following error: NHibernate.HibernateException: The IDbCommand and IDbConnection implementation in the assembly System.Data.SQLite could not be found. Ensure that the assembly System.Data.SQLite is located in the application directory or in the Global Assembly Cache. If the assembly is in the GAC, use <qualifyAssembly/> element in the application configuration file to specify the full name of the assembly. at NHibernate.Driver.ReflectionBasedDriver..ctor(String driverAssemblyName, String connectionTypeName, String commandTypeName) in c:\CSharp\NH\nhibernate\src\NHibernate\Driver\ReflectionBasedDriver.cs: line 26 at NHibernate.Driver.SQLite20Driver..ctor() in c:\CSharp\NH\nhibernate\src\NHibernate\Driver\SQLite20Driver.cs: line 28 So it looks like I need to reference the assembly directly. How would I do this so I don't get this error anymore? I downloaded the latest assembly from here: http://sourceforge.net/projects/sqlite-dotnet2.

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  • Loading a UITableView From A Nib

    - by Garry
    Hi, I keep getting a crash when loading a UITableView. I am trying to use a cell defined in a nib file. I have an IBOutlet defined in the view controller header file: UITableViewCell *jobCell; @property (nonatomic, assign) IBOutlet UITableViewCell *jobCell; This is synthesised in the implementation file. I have a UITableViewCell created in IB and set it's identifier to JobCell. Here is the cellForRowAtIndexPath method: - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *cellIdentifier = @"JobCell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier]; if (cell == nil) { [[NSBundle mainBundle] loadNibNamed:@"JobsRootViewController" owner:self options:nil]; cell = jobCell; self.jobCell = nil; } // Get this job Job *job = [fetchedResultsController objectAtIndexPath:indexPath]; // Job title UILabel *jobTitle; jobTitle = (UILabel *)[cell viewWithTag:tagJobTitle]; jobTitle.text = job.title; // Job due date UILabel *dueDate; dueDate = (UILabel *)[cell viewWithTag:tagJobDueDate]; dueDate.text = [self.dateFormatter stringFromDate:job.dueDate]; // Notes icon UIImageView *notesImageView; notesImageView = (UIImageView *)[cell viewWithTag:tagNotesImageView]; if ([job.notes length] > 0) { // This job has a note attached to it - show the notes icon notesImageView.hidden = NO; } else { // Hide the notes icon notesImageView.hidden = YES; } // Job completed button // Return the cell return cell; } When I run the app - I get a hard crash and the console reports the following: objc[1291]: FREED(id): message style sent to freed object=0x4046400 I have hooked up all the outlets in IB correctly. What is the issue? Thanks,

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  • What Scheme Does Ghuloum Use?

    - by Don Wakefield
    I'm trying to work my way through Compilers: Backend to Frontend (and Back to Front Again) by Abdulaziz Ghuloum. It seems abbreviated from what one would expect in a full course/seminar, so I'm trying to fill in the pieces myself. For instance, I have tried to use his testing framework in the R5RS flavor of DrScheme, but it doesn't seem to like the macro stuff: src/ghuloum/tests/tests-driver.scm:6:4: read: illegal use of open square bracket I've read his intro paper on the course, An Incremental Approach to Compiler Construction, which gives a great overview of the techniques used, and mentions a couple of Schemes with features one might want to implement for 'extra credit', but he doesn't mention the Scheme he uses in the course. Update I'm still digging into the original question (investigating options such as Petit Scheme suggested by Eli below), but found an interesting link relating to Gholoum's work, so I am including it here. [Ikarus Scheme](http://en.wikipedia.org/wiki/Ikarus_(Scheme_implementation)) is the actual implementation of Ghuloum's ideas, and appears to have been part of his Ph.D. work. It's supposed to be one of the first implementations of R6RS. I'm trying to install Ikarus now, but the configure script doesn't want to recognize my system's install of libgmp.so, so my problems are still unresolved. Example The following example seems to work in PLT 2.4.2 running in DrEd using the Pretty Big (require lang/plt-pretty-big) (load "/Users/donaldwakefield/ghuloum/tests/tests-driver.scm") (load "/Users/donaldwakefield/ghuloum/tests/tests-1.1-req.scm") (define (emit-program x) (unless (integer? x) (error "---")) (emit " .text") (emit " .globl scheme_entry") (emit " .type scheme_entry, @function") (emit "scheme_entry:") (emit " movl $~s, %eax" x) (emit " ret") ) Attempting to replace the require directive with #lang scheme results in the error message foo.scm:7:3: expand: unbound identifier in module in: emit which appears to be due to a failure to load tests-driver.scm. Attempting to use #lang r6rs disables the REPL, which I'd really like to use, so I'm going to try to continue with Pretty Big. My thanks to Eli Barzilay for his patient help.

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  • Detecting UITableView scrolling

    - by Xeph
    Hi I've subclassed UITableView (as KRTableView) and implemented the four touch-based methods (touchesBegan, touchesEnded, touchesMoved, and touchesCancelled) so that I can detect when a touch-based event is being handled on a UITableView. Essentially what I need to detect is when the UITableView is scrolling up or down. However, subclassing UITableView and creating the above methods only detects when scrolling or finger movement is occuring within a UITableViewCell, not on the entire UITableView. As soon as my finger is moved onto the next cell, the touch events don't do anything. This is how I'm subclassing UITableView: #import "KRTableView.h" @implementation KRTableView - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { [super touchesBegan:touches withEvent:event]; NSLog(@"touches began..."); } - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { [super touchesMoved:touches withEvent:event]; NSLog(@"touchesMoved occured"); } - (void)touchesCancelled:(NSSet*)touches withEvent:(UIEvent *)event { [super touchesCancelled:touches withEvent:event]; NSLog(@"touchesCancelled occured"); } - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { [super touchesEnded:touches withEvent:event]; NSLog(@"A tap was detected on KRTableView"); } @end How can I detect when the UITableView is scrolling up or down?

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  • Generating All Permutations of Character Combinations when # of arrays and length of each array are

    - by Jay
    Hi everyone, I'm not sure how to ask my question in a succinct way, so I'll start with examples and expand from there. I am working with VBA, but I think this problem is non language specific and would only require a bright mind that can provide a pseudo code framework. Thanks in advance for the help! Example: I have 3 Character Arrays Like So: Arr_1 = [X,Y,Z] Arr_2 = [A,B] Arr_3 = [1,2,3,4] I would like to generate ALL possible permutations of the character arrays like so: XA1 XA2 XA3 XA4 XB1 XB2 XB3 XB4 YA1 YA2 . . . ZB3 ZB4 This can be easily solved using 3 while loops or for loops. My question is how do I solve for this if the # of arrays is unknown and the length of each array is unknown? So as an example with 4 character arrays: Arr_1 = [X,Y,Z] Arr_2 = [A,B] Arr_3 = [1,2,3,4] Arr_4 = [a,b] I would need to generate: XA1a XA1b XA2a XA2b XA3a XA3b XA4a XA4b . . . ZB4a ZB4b So the Generalized Example would be: Arr_1 = [...] Arr_2 = [...] Arr_3 = [...] . . . Arr_x = [...] Is there a way to structure a function that will generate an unknown number of loops and loop through the length of each array to generate the permutations? Or maybe there's a better way to think about the problem? Thanks Everyone!

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  • Keyboard input: how to separate keycodes received from user

    - by Iulian Serbanoiu
    Hello, I am writing an application involving user input from the keyboard. For doing it I use this way of reading the input: #include <stdio.h> #include <termios.h> #include <unistd.h> int mygetch( ) { struct termios oldt, newt; int ch; tcgetattr( STDIN_FILENO, &oldt ); newt = oldt; newt.c_lflag &= ~( ICANON | ECHO ); tcsetattr( STDIN_FILENO, TCSANOW, &newt ); ch = getchar(); tcsetattr( STDIN_FILENO, TCSANOW, &oldt ); return ch; } int main(void) { int c; do{ c = mygetch(); printf("%d\n",c); }while(c!='q'); return 0; } Everyting works fine for letters digits,tabs but when hiting DEL, LEFT, CTRL+LEFT, F8 (and others) I receive not one but 3,4,5 or even 6 characters. The question is: Is is possible to make a separation of these characters (to actually know that I only hit one key or key combination). What I would like is to have a function to return a single integer value for any type of input (letter, digit, F1-F12, DEl, PGUP, PGDOWN, CTRL+A, CTRL+ALT+A, ALT+LEFT, etc). Is this possible? I'm interested in an idea to to this, the language doesn't matter much, though I'd prefer perl or c. Thanks, Iulian

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  • Override ActiveRecord#save, Method Alias? Trying to mixin functionality into save method...

    - by viatropos
    Here's the situation: I have a User model, and two modules for authentication: Oauth and Openid. Both of them override ActiveRecord#save, and have a fair share of implementation logic. Given that I can tell when the user is trying to login via Oauth vs. Openid, but that both of them have overridden save, how do "finally" override save such that I can conditionally call one of the modules' implementations of it? Here is the base structure of what I'm describing: module UsesOauth def self.included(base) base.class_eval do def save puts "Saving with Oauth!" end def save_with_oauth save end end end end module UsesOpenid def self.included(base) base.class_eval do def save puts "Saving with OpenID!" end def save_with_openid save end end end end module Sequencer def save if using_oauth? save_with_oauth elsif using_openid? save_with_openid else super end end end class User < ActiveRecord::Base include UsesOauth include UsesOpenid include Sequencer end I was thinking about using alias_method like so, but that got too complicated, because I might have 1 or 2 more similar modules. I also tried using those save_with_oauth methods (shown above), which almost works. The only thing that's missing is that I also need to call ActiveRecord::Base#save (the super method), so something like this: def save_with_oauth # do this and that super.save # the rest end But I'm not allowed to do that in ruby. Any ideas for a clever solution to this?

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  • JQuery Autocomplete plugin not working with JQuery 1.4.1

    - by Russ Clark
    I've been using the JQuery Autocomplete plugin with JQuery version 1.3.2, and it has been working great. I recently updated JQuery in my project to version 1.4.2, and the Autocomplete plugin is now broken. The JQuery code to add items to a textbox on my web page doesn't seem to be getting called at all. Does anyone know if the JQuery Autocomplete plugin is incompatible with JQuery version 1.4.2, and if there is a fix for this problem? Here is some sample code I've built in an ASP.Net web site (which works fine if I change the JQuery file to jquery-1.3.2.js, but nothing happens using jquery-1.4.2.js): <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %> <!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 runat="server"> <title>Untitled Page</title> <script type="text/javascript" src="js/jquery-1.4.2.js" ></script> <script type="text/javascript" src="js/jquery.autocomplete.js" ></script> <script type="text/javascript"> $(document).ready(function() { var data = "Core Selectors Attributes Traversing Manipulation CSS Events Effects Ajax Utilities".split(" "); $(':input:text:id$=sapleUser').autocomplete(data); }); </script> </head> <body> <form id="form1" runat="server"> API Reference: <input id="sapleUser" autocomplete="off" type="text" runat="server" /> (try "C" or "E") </form> </body> </html>

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  • Random point on VideoDisplay isn't accurate enough

    - by Mike
    For a schoolassigment me and some buddies of mine are creating an application that is showing many similarities with the C-Mon & Kypski musicvideo on www.oneframeoffame.com. The application is being developed in Flex. We want to get a random point of a clip, let it pause so a user can mimic the pose and make a snapshot out of it. What i managed to do is get a random point of the movie. I did this by getting a random value between 0 and de total duration of the movie. But what i didn't managed to do is let the screen pause on every 24st of a frame. As the movie concist out of 24FPS. It looks like the the random value of the movie that is being requested is being rounded by the movie itself. As example: There appears to be no difference between the frames requested at 2.40 or 2.41. It appears it got something to do with keyframing i've read on the Adobe® Flex™ 3.5 Language Reference. The movie is a FLV file and i use the VideoDisplay object to display the movie. Does someone is familiar with this or knows a solution to my problem? Thanks in advance

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  • Jquery Ui DatePicker, attaches to textbox but only works once, then all click events are disabled.

    - by RubbleFord
    <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %> <!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 runat="server"> <title></title> <link rel="stylesheet" href="css/ui-lightness/jquery-ui-1.7.2.custom.css" type="text/css" media="all" /> <script type="text/javascript" src="js/jquery-1.3.2.min.js"></script> <script type="text/javascript" src="js/jquery-ui-1.7.2.custom.min.js"></script> <script type="text/javascript"> $(document).ready(function() { $('#date').datepicker(); }); </script> </head> <body> <%--<form id="form1" runat="server">--%> <div> <input type="text" id="date" /> </div> <%--</form>--%> </body> </html> I've attached a datepicker to a text box and the first time I click it, it works a treat and populates the text box with the current date. It works fine in IE7 Comp mode, Chrome and Firefox. It works once or twice on IE8 but locks the browser up after that. One interesting note is the host operating system is Windows 2008 R2. Any ideas?

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  • How to count term frequency for set of documents?

    - by ManBugra
    i have a Lucene-Index with following documents: doc1 := { caldari, jita, shield, planet } doc2 := { gallente, dodixie, armor, planet } doc3 := { amarr, laser, armor, planet } doc4 := { minmatar, rens, space } doc5 := { jove, space, secret, planet } so these 5 documents use 14 different terms: [ caldari, jita, shield, planet, gallente, dodixie, armor, amarr, laser, minmatar, rens, jove, space, secret ] the frequency of each term: [ 1, 1, 1, 4, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1 ] for easy reading: [ caldari:1, jita:1, shield:1, planet:4, gallente:1, dodixie:1, armor:2, amarr:1, laser:1, minmatar:1, rens:1, jove:1, space:2, secret:1 ] What i do want to know now is, how to obtain the term frequency vector for a set of documents? for example: Set<Documents> docs := [ doc2, doc3 ] termFrequencies = magicFunction(docs); System.out.pring( termFrequencies ); would result in the ouput: [ caldari:0, jita:0, shield:0, planet:2, gallente:1, dodixie:1, armor:2, amarr:1, laser:1, minmatar:0, rens:0, jove:0, space:0, secret:0 ] remove all zeros: [ planet:2, gallente:1, dodixie:1, armor:2, amarr:1, laser:1 ] Notice, that the result vetor contains only the term frequencies of the set of documents. NOT the overall frequencies of the whole index! The term 'planet' is present 4 times in the whole index but the source set of documents only contains it 2 times. A naive implementation would be to just iterate over all documents in the docs set, create a map and count each term. But i need a solution that would also work with a document set size of 100.000 or 500.000. Is there a feature in Lucene i can use to obtain this term vector? If there is no such feature, how would a data structure look like someone can create at index time to obtain such a term vector easily and fast? I'm not that Lucene expert so i'am sorry if the solution is obvious or trivial.

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  • Elegantly handling constraint violations in EJB/JPA environment?

    - by hallidave
    I'm working with EJB and JPA on a Glassfish v3 app server. I have an Entity class where I'm forcing one of the fields to be unique with a @Column annotation. @Entity public class MyEntity implements Serializable { private String uniqueName; public MyEntity() { } @Column(unique = true, nullable = false) public String getUniqueName() { return uniqueName; } public void setUniqueName(String uniqueName) { this.uniqueName = uniqueName; } } When I try to persist an object with this field set to a non-unique value I get an exception (as expected) when the transaction managed by the EJB container commits. I have two problems I'd like to solve: 1) The exception I get is the unhelpful "javax.ejb.EJBException: Transaction aborted". If I recursively call getCause() enough times, I eventually reach the more useful "java.sql.SQLIntegrityConstraintViolationException", but this exception is part of the EclipseLink implementation and I'm not really comfortable relying on it's existence. Is there a better way to get detailed error information with JPA? 2) The EJB container insists on logging this error even though I catch it and handle it. Is there a better way to handle this error which will stop Glassfish from cluttering up my logs with useless exception information? Thanks.

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  • How to scan an array for certain information

    - by Andrew Martin
    I've been doing an MSc Software Development conversion course, the main language of which is Java, since the end of September. We have our first assessed practical coming and I was hoping for some guidance. We have to create an array that will store 100 integers (all of which are between 1 and 10), which are generated by a random number generator, and then print out ten numbers of this array per line. For the second part, we need to scan these integers, count up how often each number appears and store the results in a second array. I've done the first bit okay, but I'm confused about how to do the second. I have been looking through the scanner class to see if it has any methods which I could use, but I don't see any. Could anyone point me in the right direction - not the answer, but perhaps which library it comes from? Code so far: import java.util.Random; public class Practical4_Assessed { public static void main(String[] args) { Random numberGenerator = new Random (); int[] arrayOfGenerator = new int[100]; for (int countOfGenerator = 0; countOfGenerator < 100; countOfGenerator++) arrayOfGenerator[countOfGenerator] = numberGenerator.nextInt(10); int countOfNumbersOnLine = 0; for (int countOfOutput = 0; countOfOutput < 100; countOfOutput++) { if (countOfNumbersOnLine == 10) { System.out.println(""); countOfNumbersOnLine = 0; countOfOutput--; } else { System.out.print(arrayOfGenerator[countOfOutput] + " "); countOfNumbersOnLine++; } } } } Thanks, Andrew

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  • WCF Callback Contract InvalidOperationException: Collection has been modified

    - by mrlane
    We are using a WCF service with a Callback contract. Communication is Asynchronous. The service contract is defined as: [ServiceContract(Namespace = "Silverlight", CallbackContract = typeof(ISessionClient),SessionMode = SessionMode.Allowed)] public interface ISessionService With a method: [OperationContract(IsOneWay = true)] void Send(Message message); The callback contract is defined as [ServiceContract] public interface ISessionClient With methods: [OperationContract(IsOneWay = true, AsyncPattern = true)] IAsyncResult BeginSend(Message message, AsyncCallback callback, object state); void EndSend(IAsyncResult result); The implementation of BeginSend and EndSend in the callback channel are as follows: public void Send(ActionMessage actionMessage) { Message message = Message.CreateMessage(_messageVersion, CommsSettings.SOAPActionReceive, actionMessage, _messageSerializer); lock (LO_backChannel) { try { _backChannel.BeginSend(message, OnSendComplete, null); } catch (Exception ex) { _hasFaulted = true; } } } private void OnSendComplete(IAsyncResult asyncResult) { lock (LO_backChannel) { try { _backChannel.EndSend(asyncResult); } catch (Exception ex) { _hasFaulted = true; } } } We are getting an InvalidOperationException: "Collection has been modified" on _backChannel.EndSend(asyncResult) seemingly randomly, and we are really out of ideas about what is causing this. I understand what the exception means, and that concurrency issues are a common cause of such exceptions (hence the locks), but it really doesn't make any sense to me in this situation. The clients of our service are Silverlight 3.0 clients using PollingDuplexHttpBinding which is the only binding available for Silverlight. We have been running fine for ages, but recently have been doing a lot of data binding, and this is when the issues started. Any help with this is appreciated as I am personally stumped at this time.

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  • Ordered delivery with NetNamedPipeBinding using oneWay calls

    - by Aseem Bansal
    Is it possible to guarantee ordered delivery with oneWay calls using namedPipe binding? I have a WCF service/client communicating using namedPipe binding. The client is exposing a callback contract in which all the methods in the callback are marked as OneWay. Something like this [ServiceContract(CallbackContract = typeof(IMyServiceCallback))] public interface IMyService { [OperationContract] void MyOperation(); } public interface IMyServiceCallback { [OperationContract(IsOneWay=true)] void MyCallback1(); [OperationContract(IsOneWay=true)] void MyCallback2(); } At the server side, the implementation of MyOperation method always calls MyCallback1 first and then MyCallback2 but I am observing that sometimes the client receives the calls in the incorrect order (MyCallback2 first and then MyCallback1). On searching the internet I found that the order is not guaranteed with oneway operation as mentioned here and also there is something called reliableSession which ensure message ordering. All the examples on the internet for reliable session are with TCP binding (and not a single one with NamedPipeBinding) and the tcpBinding also has a property called ReliableSession which is not present on the NetNamedPipeBinding. So I am not sure whether reliable session is expected to work with NetNamedPipeBinding or not. Question: Does reliable session work with namedPipeBinding? If yes, how? If no, Is there any other approach with which I can guarantee ordered delivery?

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  • "do it all" page structure and things to watch out for?

    - by Andrew Heath
    I'm still getting my feet wet in PHP (my 1st language) and I've reached the competency level where I can code one page that handles all sorts of different related requests. They generally have a structure like this: (psuedo code) <?php include 'include/functions.php'; IF authorized IF submit (add data) ELSE IF update (update data) ELSE IF list (show special data) ELSE IF tab switch (show new area) ELSE display vanilla (show default) ELSE "must be registered/logged-in" ?> <HTML> // snip <?php echo $output; ?> // snip </HTML> and it all works nicely, and quite quickly which is cool. But I'm still sorta feeling my way in the dark... and would like some input from the pros regarding this type of page design... is it a good long-term structure? (it seems easily expanded...) are there security risks particular to this design? are there corners I should avoid painting myself into? Just curious about what lies ahead, really...

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  • How to trace the connection pool in a Java Web application - DBMS_APPLICATION_INFO

    - by Cleiton Garcia
    Hello, I need improve the traceability in a Web Application that usually run on fixed db user. The DBA should have a fast access for the information about the heavy users that are degrading the database. 5 years ago, I implemented a .NET ORM engine which makes a log of user and the server using the DBMS_APPLICATION_INFO package. Using a wrapper above the connection manager with the following code: DBMS_APPLICATION_INFO.SET_MODULE('" + User + " - " + appServerMachine + "',''); Each time that a connection get a connection from the pool, the package is executed to log the information in the V$SESSION. Has anyone discover or implemented a solution for this problem using the Toplink or Hibernate? Is there a default implementation for this problem? I found here a solutions as I implemented 5 years ago, but I'd like to know with anyone have a better solution and integrated with the ORM. http://stackoverflow.com/questions/53379/using-dbmsapplicationinfo-with-jboss My application is above Spring, the DAO are implemented with JPA (using hibernate) and actually running directly in Tomcat, with plans to (next year) migrate to SAP Netwevare Application Server. Thanks.

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  • What is Ruby's analog to Python Metaclasses?

    - by Sean Copenhaver
    Python has the idea of metaclasses that, if I understand correctly, allow you to modify an object of a class at the moment of construction. You are not modifying the class, but instead the object that is to be created then initialized. Python (at least as of 3.0 I believe) also has the idea of class decorators. Again if I understand correctly, class decorators allow the modifying of the class definition at the moment it is being declared. Now I believe there is an equivalent feature or features to the class decorator in Ruby, but I'm currently unaware of something equivalent to metaclasses. I'm sure you can easily pump any Ruby object through some functions and do what you will to it, but is there a feature in the language that sets that up like metaclasses do? So again, Does Ruby have something similar to Python's metaclasses? Edit I was off on the metaclasses for Python. A metaclass and a class decorator do very similar things it appears. They both modify the class when it is defined but in different manners. Hopefully a Python guru will come in and explain better on these features in Python. But a class or the parent of a class can implement a __new__(cls[,..]) function that does customize the construction of the object before it is initialized with __init__(self[,..]).

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  • Why does my IMultiBindingConverter get an array of strings when used to set TextBox.Text?

    - by mcohen75
    Hi- I'm trying to use a MultiBinding with a converter where the child elements also have a converter. The XAML looks like so: <TextBlock> <TextBlock.Text> <MultiBinding Converter="{StaticResource localizedMessageConverter}" ConverterParameter="{x:Static res:Resources.RecordsFound}" > <Binding Converter="{StaticResource localizedMessageParameterConverter}" ConverterParameter="ALIAS" Path="Alias" Mode="OneWay" /> <Binding Converter="{StaticResource localizedMessageParameterConverter}" ConverterParameter="COUNT" Path="Count" Mode="OneWay" /> </MultiBinding> </TextBlock.Text> The problem I'm facing here is, whenever this is used with a TextBlock to specify the Text property, my IMultiValueConverter implementation gets an object collection of strings instead of the class returned by the IValueConverter. It seems that the ToString() method is called on the result of the inner converter and passed to the IMultiValueConverter. If used to specify the Content property of Label, all is well. It seems to me that the framework is assuming that the return type will be string, but why? I can see this for the MultiBinding since it should yield a result that is compatible with TextBlock.Text, but why would this also be the case for the Bindings inside a MultiBinding? If I remove the converter from the inner Binding elements, the native types are returned. In my case string and int.

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  • cross-platform scripting for windows, Linux, MacOS X

    - by karolrvn
    Hi. I'm looking for cross-platform scripting (language) for windows, Linux, MacOS X. I'm tired of .bat / bash . I would like to do things like for example ,,lock workstation'' at automatic login (I had this in X-Window but the solution was pretty ugly; now, I would like that on MS Windows and not that ugly :-) ). Generally: automate tasks. Or would I be better off with Windows Scripting Host? PowerShell also comes to mind, but that's seems to Windows-only for my taste. Can languages like Python, Ruby, (Java?) interact (elegantly? sensibly?) with WSH? Also things like DBUS, DCOM, etc come to mind as part of the picture. Currently I use a mixture of Java, .bat, bash, Ruby, Scala; some VBA for Excel. Which sometimes gets pretty ugly. I would like a cross-platform general solution with/using ,,native'' parts close to OS-specifics. Like e.g. Ruby driving some Windows-specific stuff (just a guess). What do You use? TIA

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  • Database Error Handling: What if You have to Call Outside service and the Transaction Fails?

    - by Ngu Soon Hui
    We all know that we can always wrap our database call in transaction ( with or without a proper ORM), in a form like this: $con = Propel::getConnection(EventPeer::DATABASE_NAME); try { $con->begin(); // do your update, save, delete or whatever here. $con->commit(); } catch (PropelException $e) { $con->rollback(); throw $e; } This way would guarantee that if the transaction fails, the database is restored to the correct status. But the problem is that let's say when I do a transaction, in addition to that transaction, I need to update another database ( an example would be when I update an entry in a column in databaseA, another entry in a column in databaseB must be updated). How to handle this case? Let's say, this is my code, I have three databases that need to be updated ( dbA, dbB, dbc): $con = Propel::getConnection("dbA"); try { $con->begin(); // update to dbA // update to dbB //update to dbc $con->commit(); } catch (PropelException $e) { $con->rollback(); throw $e; } If dbc fails, I can rollback the dbA but I can't rollback dbb. I think this problem should be database independent. And since I am using ORM, this should be ORM independent as well. Update: Some of the database transactions are wrapped in ORM, some are using naked PDO, oledb ( or whatever bare minimum language provided database calls). So my solution has to take care this. Any idea?

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