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  • Is it possible to use 2 versions of jQuery on the same page?

    - by Ben McCormack
    NOTE: I know similar questions have already been asked here and here, but I'm looking for additional clarification as to how to make this work. I'm adding functionality to an existing web site that is already using an older version of the jQuery library (1.1.3.1). I've been writing my added functionality against the newest version of the jQuery library (1.4.2). I've tested the website using only the newer version of jQuery and it breaks functionality, so now I'm looking at using both versions on the same page. How is this possible? What do I need to do in my code to specify that I'm using one version of jQuery instead of another? For example, I'll put <script> tags for both versions of jQuery in the header of my page, but what do I need to do so that I know for sure in my calling code that I'm calling one version of the library or another? Maybe something like this: //Put some code here to specify a variable that will be using the newer //version of jquery: var $NEW = jQuery.theNewestVersion(); //Now when I use $NEW, I'll know it's the newest version and won't //conflict with the older version. $NEW('#personName').text('Ben'); //And when I use the original $ in code, or simply 'jquery', I'll know //it's the older version. $('#personName').doSomethingWithTheOlderVersion();

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  • Autocomplete Error Question - Ruby on Rails

    - by bgadoci
    I have built a very simple blog application using Ruby on Rails. New to both Ruby and Rails so excuse the stupid questions. I currently have two tables that relate to this question. I have a Post table and a Tag table. Basically I set it up such that Post has_many :tags and Tag belongs_to :post. I am using AJAX to process and display the tags in the show view of the post. I installed the auto_complete plugin and I am getting an error when I enter the letters in the text_field_with_auto_complete for tag creation. My suspicion is this is because the form is a remote_form_for or something I am doing wrong in the routes.rb. Here is the error and code: Error Processing PostsController#show (for 127.0.0.1 at 2010-04-13 23:25:46) [GET] Parameters: {"tag"=>{"tag_name"=>"f"}, "id"=>"auto_complete_for_tag_tag_name"} Post Load (0.1ms) SELECT * FROM "posts" WHERE ("posts"."id" = 0) ActiveRecord::RecordNotFound (Couldn't find Post with ID=auto_complete_for_tag_tag_name): app/controllers/posts_controller.rb:22:in `show' Rendered rescues/_trace (26.0ms) Rendered rescues/_request_and_response (0.2ms) Rendering rescues/layout (not_found) remote_form_for located in /views/posts/show.html.erb <% remote_form_for [@post, Tag.new] do |f| %> <p> <%= f.label :tag_name, "Tag" %><br/> <%= text_field_with_auto_complete :tag, :tag_name, {}, {:method => :get} %> </p> <p><%= f.submit "Add Comment" %></p> <% end %> tags_controller.rb (I'll spare you all the actions but added the following here) auto_complete_for :tag, :tag_name routes.rb map.resources :posts, :has_many => :comments map.resources :posts, :has_many => :tags map.resources :tags, :collection => {:auto_complete_for_tag_tag_name => :get }

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  • performance of large number calculations in python (python 2.7.3 and .net 4.0)

    - by g36
    There is a lot of general questions about python performance in comparison to other languages. I've got more specific example: There are two simple functions wrote in python an c#, both checking if int number is prime. python: import time def is_prime(n): num =n/2 while num >1: if n % num ==0: return 0 num-=1 return 1 start = time.clock() probably_prime = is_prime(2147483629) elapsed = (time.clock() - start) print 'time : '+str(elapsed) and C#: using System.Diagnostics; public static bool IsPrime(int n) { int num = n/2; while(num >1) { if(n%num ==0) { return false; } num-=1; } return true; } Stopwatch sw = new Stopwatch(); sw.Start(); bool result = Functions.IsPrime(2147483629); sw.Stop(); Console.WriteLine("time: {0}", sw.Elapsed); And times ( which are surprise for me as a begginer in python:)): Python: 121s; c#: 6s Could You explain where does this big diffrence come from ?

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  • Forwarding first responder to UIScrollView unsuccessful

    - by Winston
    Hello, I am trying to create an image cropping bpx whereby the underlying image can be zoomed an scrolled while the cropping "maskview" layer stays the same and the corners can be dragged in any direction. To achieve this, the ImageView is added to a UIScrollView, and this is added to the SelectionViewController.view . I then add the cropping "maskview" layer to the SelectionViewController.view. I did this instead of adding to the scrollview so that the cropping maskview won't be expanded when the underlying image expands. @interface SelectionViewController : UIViewController <UIScrollViewDelegate> { UIImageView *photoview; // Added to self.scrollview MaskedView *maskedview; // Added to self.view UIScrollView *scrollview; // Added to self.view } The maskview has first responder status and responds accordingly. However, the only event I am interested in the maskview is if any of the corners are dragged (this works fine). The problem I want to try to solve is two-fold: If it is a pinch or zoom gesture, I am trying to forward the responder to the UIScrollview using: [self.nextResponder touchesMoved:touches withEvent:event]; The scrollview does not seem to respond. I have confirmed that the self.nextResponder after the maskedview is the SelectionViewController's view itself. From there, it doesn't seem like the UIScrollview responds. It does respond fine if I remove the cropping maskedview. If I zoom in on the underlying image and the cropping maskview rectangle is still the same, I want to now crop the actual zoomed image. Let's say for the upper left hand corner of the crop box, how can I find what the coordinates translates to in the underlying UIImageView now that the image has been zoomed? Any insight into either of these questions would be appreciated. Thank you, Winston

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  • Why doesn't this jQuery snippet work in IE8 like it does in Chrome/Firefox (live demo included)?

    - by Siracuse
    I asked for help earlier on Stackoverflow involving highlighting spans with the same Class when a mouse hovers over any Span with that same Class. It is working great: http://stackoverflow.com/questions/2709686/how-can-i-add-a-border-to-all-the-elements-that-share-a-class-when-the-mouse-has $('span[class]').hover( function() { $('.' + $(this).attr('class')).css('background-color','green'); }, function() { $('.' + $(this).attr('class')).css('background-color','yellow'); } ) Here is an example of it in usage: http://dl.dropbox.com/u/638285/0utput.html However, it doesn't appear to work properly in IE8, while it DOES work in Chrome/Firefox. Here is a screenshot of it in IE8, with my mouse hovered over the " min) { min" section in the middle. As you can see, it highlighted the span that the mouse is hovering over perfectly fine. However, it has also highlighted some random spans above and below it that don't have the same class! Only the span's with the same Class as the one where the mouse is over should be highlighted green. In this screenshot, only that middle green section should be green. Here is a screenshot of it working properly in Firefox/Chrome with my mouse in the exact same position: This screenshot is correct as the span that the mouse is over (the green section) is the only one in this section that shares that class. Why is IE8 randomly green-highlighting spans when it shouldn't be (they don't share the same class) using my little jQuery snippet? Again, if you want to see it live I have it here: http://dl.dropbox.com/u/638285/0utput.html

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  • DQL delete from multiple tables (doctrine)

    - by singer
    Need to perform DQL delete from multple related tables. In SQL it is something like this: DELETE r1,r2 FROM ComRealty_objects r1, com_realty_objects_phones r2 WHERE r1.id IN (10,20) AND r2.id_object IN (10,20) I need to perform this statement using DQL, but I'm stuck on this :( <?php $dql = Doctrine_Query::create() ->delete('phones, comrealtyobjects') ->from('ComRealtyObjects comrealtyobjects') ->from('ComRealtyObjectsPhones phones') ->whereIn("comrealtyobjects.id", $ids) ->whereIn("phones.id_object", $ids); echo($dql->getSqlQuery()); ?> But DQL parser gives me this result: DELETE FROM `com_realty_objects_phones`, `ComRealty_objects` WHERE (`id` IN (?) AND `id_object` IN (?)) Searching google and stack overflow I found this(useful) topic: http://stackoverflow.com/questions/2247905/what-is-the-syntax-for-a-multi-table-delete-on-a-mysql-database-using-doctrine But this is not exactly my case - there was delete from single table. If there is a way to override dql parser behaviour? Or maybe some other way to delete records from multiple tables using doctrine. Note: If you are using doctrine behaviours(Doctrine_Record_Generator) you need first to initialize those tables using Doctrine_Core::initializeModels() to perform DQL operations on them.

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  • Is 1/0 a legal Java expression?

    - by polygenelubricants
    The following compiles fine in my Eclipse: final int j = 1/0; // compiles fine!!! // throws ArithmeticException: / by zero at run-time Java prevents many "dumb code" from even compiling in the first place (e.g. "Five" instanceof Number doesn't compile!), so the fact this didn't even generate as much as a warning was very surprising to me. The intrigue deepens when you consider the fact that constant expressions are allowed to be optimized at compile time: public class Div0 { public static void main(String[] args) { final int i = 2+3; final int j = 1/0; final int k = 9/2; } } Compiled in Eclipse, the above snippet generates the following bytecode (javap -c Div0) Compiled from "Div0.java" public class Div0 extends java.lang.Object{ public Div0(); Code: 0: aload_0 1: invokespecial #8; //Method java/lang/Object."<init>":()V 4: return public static void main(java.lang.String[]); Code: 0: iconst_5 1: istore_1 // "i = 5;" 2: iconst_1 3: iconst_0 4: idiv 5: istore_2 // "j = 1/0;" 6: iconst_4 7: istore_3 // "k = 4;" 8: return } As you can see, the i and k assignments are optimized as compile-time constants, but the division by 0 (which must've been detectable at compile-time) is simply compiled as is. javac 1.6.0_17 behaves even more strangely, compiling silently but excising the assignments to i and k completely out of the bytecode (probably because it determined that they're not used anywhere) but leaving the 1/0 intact (since removing it would cause an entirely different program semantics). So the questions are: Is 1/0 actually a legal Java expression that should compile anytime anywhere? What does JLS say about it? If this is legal, is there a good reason for it? What good could this possibly serve?

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  • Help needed in grokking password hashes and salts

    - by javafueled
    I've read a number of SO questions on this topic, but grokking the applied practice of storing a salted hash of a password eludes me. Let's start with some ground rules: a password, "foobar12" (we are not discussing the strength of the password). a language, Java 1.6 for this discussion a database, postgreSQL, MySQL, SQL Server, Oracle Several options are available to storing the password, but I want to think about one (1): Store the password hashed with random salt in the DB, one column Found on SO and elsewhere is the automatic fail of plaintext, MD5/SHA1, and dual-columns. The latter have pros and cons MD5/SHA1 is simple. MessageDigest in Java provides MD5, SHA1 (through SHA512 in modern implementations, certainly 1.6). Additionally, most RDBMSs listed provide methods for MD5 encryption functions on inserts, updates, etc. The problems become evident once one groks "rainbow tables" and MD5 collisions (and I've grokked these concepts). Dual-column solutions rest on the idea that the salt does not need to be secret (grok it). However, a second column introduces a complexity that might not be a luxury if you have a legacy system with one (1) column for the password and the cost of updating the table and the code could be too high. But it is storing the password hashed with a random salt in single DB column that I need to understand better, with practical application. I like this solution for a couple of reasons: a salt is expected and considers legacy boundaries. Here's where I get lost: if the salt is random and hashed with the password, how can the system ever match the password? I have theory on this, and as I type I might be grokking the concept: Given a random salt of 128 bytes and a password of 8 bytes ('foobar12'), it could be programmatically possible to remove the part of the hash that was the salt, by hashing a random 128 byte salt and getting the substring of the original hash that is the hashed password. Then re hashing to match using the hash algorithm...??? So... any takers on helping. :) Am I close?

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  • GET params in ruby-on-rails project - best practices?

    - by Lynn C
    I've inherited a little rails app and I need to extend it slightly. It's actually quite simple, but I want to make sure I'm doing it the right way... If I visit myapp:3000/api/persons it gives me a full list of people in XML format. I want to pass param in the URL so that I can return users that match the login or the email e.g. yapp:3000/api/persons?login=jsmith would give me the person with the corresponding login. Here's the code: def index if params.size > 2 # We have 'action' & 'controller' by default if params['login'] @person = [Person.find(:first, :conditions => { :login => params['login'] })] elsif params['email'] @persons = [Person.find(:first, :conditions => { :email => params['email'] })] end else @persons = Person.find(:all) end end Two questions... Is it safe? Does ActiveRecord protect me from SQL injection attacks (notice I'm trusting the params that are coming in)? Is this the best way to do it, or is there some automagical rails feature I'm not familiar with?

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  • Caching and accessing configuration data in ASP.NET MVC app.

    - by Sosh
    I'm about to take a look at how to implement internationalisation for an ASP.NET MVC project. I'm looking at how to allow the user to change languages. My initial though is a dropdownlist containing each of the supported langauages. Whoever a few questions have come to mind: How to store the list of supported languages? (e.g. just "en", "English"; "fr", "French" etc.) An xml file? .config files? If I store this in a file I'll have to cache this (at startup I guess). So, what would be best, load the xml data into a list (somehow) and store this list in the System.Web.Cache? Application State? How then to load this data into the view (for display in a dropdown)? Give the view direct access to the cache? Just want to make sure I'm going in the right direction here... Thank you.

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  • Is there a way to get an ASMX Web Service created in VS 2005 to receive and return JSON?

    - by Ben McCormack
    I'm using .NET 2.0 and Visual Studio 2005 to try to create a web service that can be consumed both as SOAP/XML and JSON. I read Dave Ward's Answer to the question How to return JSON from a 2.0 asmx web service (in addition to reading other articles at Encosia.com), but I can't figure out how I need to set up the code of my asmx file in order to work with JSON using jQuery. Two Questions: How do I enable JSON in my .NET 2.0 ASMX file? What's a simple jQuery call that could consume the service using JSON? Also, I notice that since I'm using .NET 2.0, I i'm not able to implement using System.Web.Script.Services.ScriptService. Here's my C# code for the demo ASMX service: using System; using System.Web; using System.Collections; using System.Web.Services; using System.Web.Services.Protocols; /// <summary> /// Summary description for StockQuote /// </summary> [WebService(Namespace = "http://tempuri.org/")] [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)] public class StockQuote : System.Web.Services.WebService { public StockQuote () { //Uncomment the following line if using designed components //InitializeComponent(); } [WebMethod] public decimal GetStockQuote(string ticker) { //perform database lookup here return 8; } [WebMethod] public string HelloWorld() { return "Hello World"; } } Here's a snippet of jQuery I found on the internet and tried to modify: $(document).ready(function(){ $("#btnSubmit").click(function(event){ $.ajax({ type: "POST", contentType: "application/json; charset=utf-8", url: "http://bmccorm-xp/WebServices/HelloWorld.asmx", data: "", dataType: "json" }) event.preventDefault(); }); });

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  • Reading a large file into Perl array of arrays and manipulating the output for different purposes

    - by Brian D.
    Hello, I am relatively new to Perl and have only used it for converting small files into different formats and feeding data between programs. Now, I need to step it up a little. I have a file of DNA data that is 5,905 lines long, with 32 fields per line. The fields are not delimited by anything and vary in length within the line, but each field is the same size on all 5905 lines. I need each line fed into a separate array from the file, and each field within the line stored as its own variable. I am having no problems storing one line, but I am having difficulties storing each line successively through the entire file. This is how I separate the first line of the full array into individual variables: my $SampleID = substr("@HorseArray", 0, 7); my $PopulationID = substr("@HorseArray", 9, 4); my $Allele1A = substr("@HorseArray", 14, 3); my $Allele1B = substr("@HorseArray", 17, 3); my $Allele2A = substr("@HorseArray", 21, 3); my $Allele2B = substr("@HorseArray", 24, 3); ...etc. My issues are: 1) I need to store each of the 5905 lines as a separate array. 2) I need to be able to reference each line based on the sample ID, or a group of lines based on population ID and sort them. I can sort and manipulate the data fine once it is defined in variables, I am just having trouble constructing a multidimensional array with each of these fields so I can reference each line at will. Any help or direction is much appreciated. I've poured over the Q&A sections on here, but have not found the answer to my questions yet. Thanks!! -Brian

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  • Can protobuf-net serialize this combination of interface and generic collection?

    - by tsupe
    I am trying to serialize a ItemTransaction and protobuf-net (r282) is having a problem. ItemTransaction : IEnumerable<KeyValuePair<Type, IItemCollection>></code> and ItemCollection is like this: FooCollection : ItemCollection<Foo> ItemCollection<T> : BindingList<T>, IItemCollection IItemCollection : IList<Item> where T is a derived type of Item. ItemCollection also has a property of type IItemCollection. I am serializing like this: IItemCollection itemCol = someService.Blah(...); ... SerializeWithLengthPrefix<IItemCollection>(stream, itemCol, PrefixStyle.Base128); My eventual goal is to serialize ItemTransaction, but am snagged with IItemCollection. Item and it's derived types can be [de]serialized with no issues, see [1], but deserializing an IItemCollection fails (serializing works). ItemCollection has a ItemExpression property and when deserializing protobuf can't create an abstract class. This makes sense to me, but I'm not sure how to get through it. ItemExpression<T> : ItemExpression, IItemExpression ItemExpression : Expression ItemExpression is abstract as is Expression How do I get this to work properly? Also, I am concerned that ItemTransaction will fail since the IItemCollections are going to be differing and unknown at compile time (an ItemTransaction will have FooCollection, BarCollection, FlimCollection, FlamCollection, etc). What am I missing (Marc) ? [1] http://stackoverflow.com/questions/2276104/protobuf-net-deserializing-across-assembly-boundaries

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  • How to properly develop and deploy features for existing asp.net applications on IIS

    - by Tomh
    My question actually consists of multiple questions. I'm frequently reading about companies who deploy a small subset of features for a select amount of customers using the live "database". Ruby on Rails and its ecosystem have deployment tools and database migrations to deploy or rollback such features in a live production or staging environment. My question, how is this done for an asp.net (mvc in particular) application? How do you test your newly released features against live data? Do you have any tools to modify the existing database and roll back changes if necessary? Do you make backups before deployment? Update Maybe I should point out that my question is not really clear, getting more answers here will help me phrase the question better. To make it easier I will describe a situation I'm commonly seeing with some of my clients. My clients have large deployments of popular web applications. They do not have staging/QA/testing servers. (yes this is not optimal). The data their apps consist of are images, xml files, user uploads and data in Sql Server. Having a few records, of their production database and a couple of dummy files is not a substitute of testing against real data in my opinion. How would you design a workflow that can create a acceptable environment to mimic a production environment before going live?

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  • Windows Live Messenger Activity SDK: Is it possible to use jQuery?

    - by Cheeso
    There's an SDK that lets developers build "activities" and games for use in Windows Live Messenger. The basic approach is to build a web app, that gets approved and hosted by Microsoft. questions Anyone done this? Can you use jQuery in that web app? how do you debug the thing, running within Windows Live Messenger? EDIT: I tried using jQuery, but couldn't get it to do much of anything. I also couldn't debug it at all, when running within the IM client. The IE8 F12 debug tools are not available in that context. I believe the embedded browser was silently not loading external script, and then silently throwing exceptions. So I backed off to use only script in the .HTM file. Since it is Windows Live Messenger, the embedded browser is IE, so the generality made possible in jQuery isn't strictly necessary. I was able to use old-skool DHTML interfaces to get done, what I needed. I'm still interested in seeing examples of what other people have produced in the way of WLM Activities or games, using the Messenger Activity SDK. I think Flash is possible, and I think XAML is also possible, but I haven't seen source code examples for any of those.

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  • How to make a small flash swf with ComboBox in Actionscript 3?

    - by Sint
    I have a pure Actionscript 3 project, using flash.* libraries, compiles down to about 6k (using mxmlc). Program handles about 1k shapes, a few sprites, a sockets connection, works great (tastes less filling). Now, how would I add a ComboBox control without incurring excessive bloat? More specificially, I would like to keep the size under 100k. So far I have tried: Adobe mx.controls ComboBoxexample - simple mxml example compiles to 200+k both on my main Linux Box using mxmlc and in Windows using Flash Builder 4 Yahoo Astra - uses mx libraries underneath(so as bloated as Adobe?), plus does not contain exact ComboBox Keith Peter's MinimalComps - seems small, but far from providing ComboBox functionality SPAS (Swing Package for Actionscript) - compiles to 130k, but alpha version of ComboBox does not let me adjust height... asuilib - compiles to 40k, unfortunately this ComboBox does not provide for scrolling items...if it does not fit on screen no way to scroll to it Now my questions: Is there a way to lower size for projects importing mx.controls ? Maybe there is a way to fix SPAS or asuilib ComboBoxes? Perhaps, there are some other libraries which provide a ComboBox(or DropList)?

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  • How are Scala closures transformed to Java objects?

    - by iguana
    I'm currently looking at closure implementations in different languages. When it comes to Scala, however, I'm unable to find any documentation on how a closure is mapped to Java objects. It is well documented that Scala functions are mapped to FunctionN objects. I assume that the reference to the free variable of the closure must be stored somewhere in that function object (as it is done in C++0x, e.g.). I also tried compiling the following with scalac and then decompiling the class files with JD: object ClosureExample extends Application { def addN(n: Int) = (a: Int) => a + n var add5 = addN(5) println(add5(20)) } In the decompiled sources, I see an anonymous subtype of Function1, which ought to be my closure. But the apply() method is empty, and the anonymous class has no fields (which could potentially store the closure variables). I suppose the decompiler didn't manage to get the interesting part out of the class files... Now to the questions: Do you know how the transformation is done exactly? Do you know where it is documented? Do you have another idea how I could solve the mystery?

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  • Dojo dialog, the iPad and the virtual keyboard issue

    - by Chris Butler
    Recently, I have been working on a project where the interface should work for desktop and tablets (in particular the iPad). One issue I am coming across is with a Dojo dialog on the iPad when text entry is taking place. Basically here is what happens: Load Dojo interface with buttons on iPad - OK Press button (touch) to show dialog (90% height and width) - OK Click on text box (touch) like DateTextBox or TimeTextBox - OK, the virtual keyboard is opened Click the date or time I want in the UI (touch) - OK, but I can't see all of the options since it is longer than the screen size... Try to scroll down (swipe up with two fingers or click 'next' in the keyboard) - not OK and the dialog repositions itself to have it's top at the top of the viewport area. Basically, the issue is that the dialog keeps trying to reposition itself. Am I able to stop dialog resizing and positioning if I catch the window onResize events? Does anyone else have this issue with the iPad and Dojo dialogs? Also, I found this StackOverflow topic on detecting the virtual keyboard, but it wasn't much help in this case... http://stackoverflow.com/questions/2593139/ipad-web-app-detect-virtual-keyboard-using-javascript-in-safari Thanks!

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  • I'm trying to grasp the concept of creating a program that uses a MS SQL database, but I'm used to r

    - by Sergio Tapia
    How can I make a program use a MS SQL server, and have that program work on whatever computer it's installed on. If you've been following my string of questions today, you'd know that I'm making an open source and free Help Desk suite for small and medium businesses. The client application. The client application is a Windows Forms app. On installation and first launch on every client machine, it'll ask for the address of the main Help Desk server. The server. Here I plan to handle all incoming help requests, show them to the IT guys, and provide WCF services for the Client application to consume. My dilemma lies in that, I know how to make the program run on my local machine; but I'm really stumped on how to make this work for everyone who wants to download and install the server bit on their Windows Server. Would I have to make an SQL Script and have it run on the MS SQL server when a user wants to install the 'server' application? Many thanks to all for your valuable time and effort to teach me. It's really really appreciated. :)

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  • Which is the best free ide/plugin for struts2?

    - by Shahensha
    Hello friends, I have just learnt struts 2 and now I have taken up a full fledged project in it. I learnt the basics of struts 2 in Netbeans with it's struts2 plugin. But I am not at all happy with it, as it is very basic and I end up doing most of the work. It is obviously better than plain-vanilla text editor, but still not at all near to what netbeans provides for springs and hibernate. I know because netbeans provides native support for springs and hibernate, it is meant to be better. I don't mind changing my IDE if i get better support for struts2! So my questions are Please list all the free IDEs where native support for struts2 is provided. And if possible please compare them. Please list all the plugins that are available for eclipse for struts2 development. I have heard there are better plugins in eclipse. Also, if there are better plugins in any other IDE (other than netbeans or eclipse of course), please list them giving links. Please give me some tips which I'll need before starting a full blown project in Struts2. I haven't worked on any project on Struts2. I have just finished reading Struts 2 in Action of Manning publications. Thanking you in advance! regards shahensha

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  • why unsigned int 0xFFFFFFFF is equal to int -1?

    - by conejoroy
    perhaps it's a very stupid question but I'm having a hard time figuring this out =) in C or C++ it is said that the maximum number a size_t (an unsigned int data type) can hold is the same as casting -1 to that data type. for example see http://stackoverflow.com/questions/1420982/invalid-value-for-sizet Why?? I'm confused.. I mean, (talking about 32 bit ints) AFAIK the most significant bit holds the sign in a signed data type (that is, bit 0x80000000 to form a negative number). then, 1 is 0x00000001.. 0x7FFFFFFFF is the greatest positive number a int data type can hold. then, AFAIK the binary representation of -1 int should be 0x80000001 (perhaps I'm wrong). why/how this binary value is converted to anything completely different (0xFFFFFFFF) when casting ints to unsigned?? or.. how is it possible to form a binary -1 out of 0xFFFFFFFF? I have no doubt that in C: ((unsigned int)-1) == 0xFFFFFFFF or ((int)0xFFFFFFFF) == -1 is equally true than 1 + 1 == 2, I'm just wondering why. thanks!

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  • ANTLR Tree Grammar and StringTemplate Code Translation

    - by Behrooz Nobakht
    I am working on a code translation project with a sample ANTLR tree grammar as: start: ^(PROGRAM declaration+) -> program_decl_tmpl(); declaration: class_decl | interface_decl; class_decl: ^(CLASS ^(ID CLASS_IDENTIFIER)) -> class_decl_tmpl(cid={$CLASS_IDENTIFIER.text}); The group template file for it looks like: group My; program_decl_tmpl() ::= << *WHAT?* >> class_decl_tmpl(cid) ::= << public class <cid> {} >> Based on this, I have these questions: Everything works fine apart from that what I should express in WHAT? to say that a program is simply a list of class declarations to get the final generated output? Is this approach averagely suitable for not so a high-level language? I have also studied ANTLR Code Translation with String Templates, but it seems that this approach takes much advantage of interleaving code in tree grammar. Is it also possible to do it as much as possible just in String Templates?

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  • How can I programmatically add more than just one view object to my view controller?

    - by BeachRunnerJoe
    I'm diving into iPhone OS development and I'm trying to understand how I can add multiple view objects to the "Left/Root" view of my SplitView iPad app. I've figured out how to programmatically add a TableView to that view based on the example code I found in Apple's online documentation... RootViewController.h @interface RootViewController : UITableViewController <NSFetchedResultsControllerDelegate, UITableViewDelegate, UITableViewDataSource> { DetailViewController *detailViewController; UITableView *tableView; NSFetchedResultsController *fetchedResultsController; NSManagedObjectContext *managedObjectContext; } RootViewController.m - (void)loadView { UITableView *newTableView = [[UITableView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame] style:UITableViewStylePlain]; newTableView.autoresizingMask = UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleWidth; newTableView.delegate = self; newTableView.dataSource = self; [newTableView reloadData]; self.view = newTableView; [newTableView release]; } but there are a few things I don't understand about it and I was hoping you veterans could help clear up some confusion. In the statement self.view = newTableView, I assume I'm setting the entire view to a single UITableView. If that's the case, then how can I add additional view objects to that view alongside the table view? For example, if I wanted to have a DatePicker view object and the TableView object instead of just the TableView object, then how would I programmatically add that? Referencing the code above, how can I resize the table view to make room for the DatePicker view object that I'd like to add? Thanks so much in advance for your help! I'm going to continue researching these questions right now.

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  • Why do IOExceptions occur in ReadableByteChannel.read()

    - by Steffen Heil
    Hi The specification of ReadableByteChannel.read() shows -1 as result value for end-of-stream. Moreover it specifies ClosedByInterruptExceptionas possible result if the thread is interrupted. Now I thought that would be all - and it is most of the time. However, now and then I get the following: java.io.IOException: Eine vorhandene Verbindung wurde vom Remotehost geschlossen at sun.nio.ch.SocketDispatcher.read0(Native Method) at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:25) at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:233) at sun.nio.ch.IOUtil.read(IOUtil.java:206) at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:236) at ... I do not unterstand why I don't get -1 in this case. Also this is not a clean exception, as I cannot catch it without catching any possible IOException. So here are my questions: Why is this exception thrown in the first place? Is it safe to assume that ANY exception thrown by read are about the socket being closed? Is all this the same for write()? And by the way: If I call SocketChannel.close() do I have to call SocketChannel.socket().close() as well or is this implied by the earlier? Thanks, Steffen

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  • Which articles I've should read before starting to make my custom drawn winforms app?

    - by Dmitriy Matveev
    Hello! I'm currently developing a windows forms application with a lot of user controls. Some of them are just custom drawn buttons or panels and some of them are a compositions of these buttons and panels inside of FlowLayoutPanels and TableLayoutPanels. And the window itself is also custom drawn. I don't have much experience in winforms development, but I've made a proper decomposition of proposed design into user controls and implementation is already almost finished. I've already solved many arisen problems during development by the help of the google, msdn, SO and several dirty hacks (when nothing were helping) and still experiencing some of them. There are a lot of gaps in my knowledge base, since I don't know answers to many questions like: When I should use things like double buffer, suspended layout, suspended redraw ? What should I do with the controls which shouldn't be visible at some moment ? Common performance pitfalls (I think I've fallen in in several ones) ? So I think there should be some great articles which can give some knowledge enough to avoid most common problems and improve performance and maintainability of my application. Maybe some of you can recommend a few?

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