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  • In the JSON spec, what does "Since the first two characters of a JSON text will always be ASCII characters" mean?

    - by dan gibson
    The spec is http://www.ietf.org/rfc/rfc4627.txt?number=4627 It contains this: Encoding JSON text SHALL be encoded in Unicode. The default encoding is UTF-8. Since the first two characters of a JSON text will always be ASCII characters [RFC0020], it is possible to determine whether an octet stream is UTF-8, UTF-16 (BE or LE), or UTF-32 (BE or LE) by looking at the pattern of nulls in the first four octets. What does it mean "Since the first two characters of a JSON text will always be ASCII characters [RFC0020]"? I've looked at RFC0020 but couldn't find anything about it. JSON could be {" or { " (ie whitespace before the quote.

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  • VS 2010 Entity Repository Error Class member EntityBase.id is unmapped.

    - by Steve
    In my project I have it set up so that all the tables in the DB has the property "id" and then I have the entity objects inherit from the EntityBase class using a repository pattern. I then set the inheritance modifier for "id" property in the dbml file o/r designer to "overrides" Public MustInherit Class EntityBase MustOverride Property id() As Integer End Class Public MustInherit Class RepositoryBase(Of T As EntityBase) Protected _Db As New DataClasses1DataContext Public Function GetById(ByVal Id As Integer) As T Return (From a In _Db.GetTable(Of T)() Where a.id = Id).SingleOrDefault End Function End Class Partial Public Class Entity1 Inherits EntityBase End Class Public Class TestRepository Inherits RepositoryBase(Of Entity1) End Class the line Return (From a In _Db.GetTable(Of T)() Where a.id = Id).SingleOrDefault however produces the error "Class member EntityBase.id is unmapped" when i use VS 2010 using the 4.0 framework but I never received that error with the old one. Any help would be greatly appreciated. Thanks in advance.

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  • Why should I use MVVM when it breaks built in functionality

    - by Jakob
    I'm struggling to grasp why MVVM is really a good pattern to implement in riaserivces, To me there's nothing but trouble to it, it just add's another tier that I have to code. I Get that I could change the UI, but really I don't need to. Instead i won't be able to user out of the box functionality with riaservices, datagrid, dataform all controls require some implementation. Why can't it just be simple? Is there really no way to get MVVM to automatically set "IsBusy" and all the dataform edit functionality. It's like reinventing the wheel to me, and it seems that I'd be able to write code much faster just using riaservices

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  • String Functions in IIS Url Rewritting Module

    - by Nariman
    The IIS URL Rewrite Module ships with 3 built-in functions: * ToLower - returns the input string converted to lower case. * UrlEncode - returns the input string converted to URL-encoded format. This function can be used if the substitution URL in rewrite rule contains special characters (for example non-ASCII or URI-unsafe characters). * UrlDecode - decodes the URL-encoded input string. This function can be used to decode a condition input before matching it against a pattern. The functions can be invoked by using the following syntax: {function_name:any_string} The question is: can this list be extended by introducing a Replace function that's available for changing values within a rewrite rule action or condition?

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  • JSF tags not being rendered as HTML

    - by Toto
    I'm following the Java EE firstcup tutorial using Netbeans and Glassfish. When I execute the JSF web tier I've been instructed to code, the browser gets the same JSF markup coded in the .xhtml file, and the tags are not rendered as HTML tags. I know this by using the view source code in my browser. For example, for this code: <html xmlns="http://www.w3.org/1999/xhtml" xmlns:f="http://java.sun.com/jsf/core" xmlns:h="http://java.sun.com/jsf/html"> <h:head> <title>Page title here</title> </h:head> <h:body> <h2> <h:outputText value="#{bundle.WelcomeMessage}" /> </h2> </h:body> </html> The browser should get something like: <html ...> <head> <title>Page title here</title> </head> <body> <h2> the welcome message goes here </h2> </body> </html> Right? Well, my browser is getting jsf code (the first piece of code above) and not the html code (the second piece of code above). It seems to be a configuration problem in netbeans or glassfish but don't know what. Any ideas? This is my web.xml file: <?xml version="1.0" encoding="UTF-8"?> <web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"> <context-param> <param-name>javax.faces.PROJECT_STAGE</param-name> <param-value>Development</param-value> </context-param> <servlet> <servlet-name>Faces Servlet</servlet-name> <servlet-class>javax.faces.webapp.FacesServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>Faces Servlet</servlet-name> <url-pattern>/firstcup/*</url-pattern> </servlet-mapping> <session-config> <session-timeout> 30 </session-timeout> </session-config> <welcome-file-list> <welcome-file>greetings.xhtml</welcome-file> </welcome-file-list> </web-app> This is my faces-config.xml file: <?xml version='1.0' encoding='UTF-8'?> <!-- =========== FULL CONFIGURATION FILE ================================== --> <faces-config version="2.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facesconfig_2_0.xsd"> <application> <resource-bundle> <base-name>firstcup.web.WebMessages</base-name> <var>bundle</var> </resource-bundle> <locale-config> <default-locale>en</default-locale> <supported-locale>es</supported-locale> </locale-config> </application> <navigation-rule> <from-view-id>/greetings.xhtml</from-view-id> <navigation-case> <from-outcome>success</from-outcome> <to-view-id>/response.xhtml</to-view-id> </navigation-case> </navigation-rule> </faces-config> Moreover: The url I'm entering in the browser is http://localhost:8081/firstcup/ but I've also tried: http://localhost:8081/firstcup/greetings.xhtml I've checked Glassfish logs and there's no information about not being able to load FacesServlet

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  • Is it possible to listen to relational database update?

    - by Morgan Cheng
    Is it possible to listen to relation database update? For example, my web app want to send data update to client through Comet technology. I can have the program to poll the database periodically, but that would not be performant and scalable. If app can hood to a "event handler" of database, then app can get notification every time given database table data is updated. This sounds more promising, but I didn't find any concrete example for it. This is listener pattern. Does common relational database support such feature?

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  • Is it a bad idea to use the new Dynamic Keyword as a replacement switch statement?

    - by WeNeedAnswers
    I like the new Dynamic keyword and read that it can be used as a replacement visitor pattern. It makes the code more declarative which I prefer. Is it a good idea though to replace all instances of switch on 'Type' with a class that implements dynamic dispatch. class VistorTest { public string DynamicVisit(object obj) { return Visit((dynamic)obj); } private string Visit(string str) { return "a string was called with value " + str; } private string Visit(int value) { return "an int was called with value " + value; } }

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  • design patterns for hierarchical structures

    - by JLBarros
    Anyone knows some design patterns for hierarchical structures? For example, to manage inventory categories, accounting chart of accounts, divisions of human resources, etc.. Thank you very much in advance EDIT: Thanks for your interest. I am looking for a better way of dealing with hierarchical items to which they should apply operations depending on the level of hierarchy. I have been studying the patterns by Martin Fowler, for example Accounting, but I wonder if there are other more generic. The problem is that operations apply to the items must be possible to change even at run time and may depend on other external variables. I thought of a kind of strategy pattern but would like to combine it with the fact that it is a hierarchical scheme. I would appreciate any reference to hierarchical patterns and you'll take care of them in depth.

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  • Styling a list as tabs with a background overflowing into content

    - by Litso
    I couldn't think of any better way to name this question, but I'll explain. I have a mediawiki website with a background pattern (like parchment) behind the articles. At the top of each article I want to have tabs like wikipedia does (with page | talk | edit etc links). The problem is, the tabs should seamlessly fit with the article's background and I can't figure out if this is actually possible. The way I was trying to do it was positioning the list inside the actual content div and give the <li items a transparent background, but as far as I can see there's no way to color the rest of the <ul's background black without affecting the <li's in there. Anyone have an idea? (example url: http://dev.mansonwiki.com/wiki/Sandbox )

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  • Proper design a Model-Controller in Cocoa?

    - by legege
    Hi, I'm trying to design a simple Cocoa application and I would like to have a clear and easy to understand software architecture. Of course, I'm using a basic MVC design and my question concerns the Model layer. For my application, the Model represents data fetched on the Internet with a XML-RPC API. I'm planning to use Core Data to represent a locally fetched version. How should the data be loaded initially? I'm reading the Cocoa Design Pattern book, and they talk about a Model-Controller that is centric to the Model. How would that be done? Thanks!

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  • Routing Error in Chapter 7.1.2 of the Ruby on Rails Tutorial

    - by user2985910
    I've been working through the tutorial for the past few days, and finally hit a snag in chapter 7. It is in this step where the line in routes.rb: get "users/new" is replaced with resource :users After I do this, I get a routing error when visiting http://localhost:3000/users/1 - No route matches [GET] "/users/1" instead of the other "Unknown Action" error shown here. Per the instructions, my routes.db file looks like this: SampleApp::Application.routes.draw do resource :users root "static_pages#home" match '/signup', to: 'users#new', via: 'get' match '/help', to: 'static_pages#help', via: 'get' match '/about', to: 'static_pages#about', via: 'get' match '/contact', to: 'static_pages#contact', via: 'get' end Output from 'rake routes' shows: Prefix Verb URI Pattern Controller#Action users POST /users(.:format) users#create new_users GET /users/new(.:format) users#new edit_users GET /users/edit(.:format) users#edit GET /users(.:format) users#show PATCH /users(.:format) users#update PUT /users(.:format) users#update DELETE /users(.:format) users#destroy root GET / static_pages#home signup GET /signup(.:format) users#new help GET /help(.:format) static_pages#help about GET /about(.:format) static_pages#about contact GET /contact(.:format) static_pages#contact Does anyone have any insight to get past this? Many thanks.

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  • How useful are design patterns when it comes to web programming?

    - by Raja
    Background: My organization uses Microsoft .Net (3.5) with SQL Server 2005 as back end. With RAD being the norm and Agile being the widely used process. I have always found using design patterns difficult since it involves a bit more understanding and bit more training. Can you give me some examples where design patterns have solved real time problems in Web programming? What is the criteria for using any design pattern? What is the benefit reaped from it. I know it is a general question but this would help me a bunch.

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  • regular expression and escaping

    - by pstanton
    Sorry if this has been asked, my search brought up many off topic posts. I'm trying to convert wildcards from a user defined search string (wildcard is "*") to postgresql like wildcard "%". I'd like to handle escaping so that "%" => "\%" and "\*" => "*" I know i could replace \* with something else prior to replacing * and then swap it back, but i'd prefer not to and instead only convert * using a pattern that selects it when not proceeded by \. String convertWildcard(String like) { like = like.replaceAll("%", "\\%"); like = like.replaceAll("\\*", "%"); return like; } Assert.assertEquals("%", convertWildcard("*")); Assert.assertEquals("\%", convertWildcard("%")); Assert.assertEquals("*", convertWildcard("\*")); // FAIL Assert.assertEquals("a%b", convertWildcard("a*b")); Assert.assertEquals("a\%b", convertWildcard("a%b")); Assert.assertEquals("a*b", convertWildcard("a\*b")); // FAIL ideas welcome.

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  • Recommendations with hierarchical data on non-relational databases?

    - by Luki
    I'm developing an web application that uses a non-relational database as a backend (django-nonrel + AppEngine). I need to store some hierarchical data (projects/subproject_1/subproject_N/tasks), and I'm wondering which pattern should I use. For now I thought of: Adjacency List (store the item's parent id) Nested sets (store left and right values for the item) In my case, the depth of nesting for a normal user will not exceed 4-5 levels. Also, on the UI, I would like to have a pagination for the items on the first level, to avoid to load too many items at the first page load. From what I understand so far, nested sets are great when the hierarchy is used more for displaying. Adjacency lists are great when editing on the tree is done often. In my case I guess I need the displaying more than the editing (when using nested sets, even if the display would work great, the above pagination could complicate things on editing). Do you have any thoughts and advice, based on your experience with the non-relational databases?

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  • javascript singleton question

    - by Shawn
    I just read a few threads on the discussion of singleton design in javascript. I'm 100% new to the Design Pattern stuff but as I see since a Singleton by definition won't have the need to be instantiated, conceptually if it's not to be instantiated, in my opinion it doesn't have to be treated like conventional objects which are created from a blueprint(classes). So my wonder is why not just think of a singleton just as something statically available that is wrapped in some sort of scope and that should be all. From the threads I saw, most of them make a singleton though traditional javascript new function(){} followed by making a pseudo constructor. Well I just think an object literal is enough enough: var singleton = { dothis: function(){}, dothat: function(){} } right? Or anybody got better insights? [update] : Again my point is why don't people just use a simpler way to make singletons in javascript as I showed in the second snippet, if there's an absolute reason please tell me. I'm usually afraid of this kind of situation that I simplify things to much :D

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  • Is it possible to create nested classes in PHP as it is in C#?

    - by Edward Tanguay
    In C# you can have nested classes like this, which are useful if you have classes which do not have meaning outside the scope of one particular class, e.g. in a factory pattern: public abstract class BankAccount { private BankAccount() {} private sealed class SavingsAccount : BankAccount { ... } private sealed class CheckingAccount : BankAccount { ... } public BankAccount MakeSavingAccount() { ... } public BankAccount MakeCheckingAccount() { ... } } Is this possible in PHP? I've read that it was planned for PHP 5, then cancelled, then planned again, but can't find definitive info. Does anyone know how to create nested classes (classes within the scope of another class) as in the above C# example using PHP 5.3?

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  • Unit Testing User Interface. What is an effective way ?

    - by pierocampanelli
    I have an accounting & payroll client/server application where there are several input form with complex data validation rules. I am finding an effective way to perform unit testing of user interface. For complex validation rules I mean: "Disable button X if I Insert a value in textfield Y" "Enable a combobox if I insert a value in a textfield" ...... ...... Most promising pattern i have found is suggested by M. Fowler (http://martinfowler.com/eaaDev/ModelViewPresenter.html). Have you any experience about Unit Testing of User Interface? As technology stack I am using: .NET 3.5 & Windows Forms Widget Library.

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  • How to specify unique container styles for heterogenous hierarchies using SL3 and TreeView control

    - by rcecil
    Hello, Just look for strategies that have been successful in rendering hierarchies that represent inheritance structures using SL3/4 TreeViews. I need to render certain nodes differently than others, depending upon what kind of container they are (a choice between things, or simply a list of related things, etc.) So far, I've been very successful with the DataTemplate route: I've been able to use a technique described in Ted Glaza's post "Easy DataTemplateSelectors in Silverlight" (you may have retrieve a Google cache of this page). SO what I'm trying to discover is something on the order of a StyleSelector, not a DataTemplateSelector. I'm considering leveraging my current implementations of Glaza's pattern of selector objects to somehow detect the node type and set the ItemContainerStyle there, but it doesn't seem clear right now. Thanks for your thoughts.

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  • C#: Creating an editable object inside a PictureBox

    - by ET
    My goal is to let the user click on a specific location on a map to add a Placemark, and then edit the placemark by click its icon (change its name, move it around, etc). I am using a PictureBox to show the map, and by registering the MouseDoubleClick event I am drawing an Image on the map with GDI+ DrawImage() method. The problem is that after the placemark's Image was drawn, it does not editable: the user cant click the icon and move it around, change its name etc. Is there any other design pattern I can follow? maybe using other controls... ?

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  • Key Value Observation (ala Cocoa) in GWT ?

    - by user179997
    Hi all, There are these 2 frameworks out there in the same "cloud application" space as GWT: Sproutcore and Cappuccino. Cappuccino is Cocoa for the web, Sproutcore is Cocoa-like and one very central idea in both is Key Value Observation where the framework itself provides the glue to change all dependencies of an object when it changes, and you only have to declare those dependencies. If that was too poorly expressed please see this presentation: http://www.infoq.com/presentations/subelsky-sproutcore-intro Since the pattern reduces the amount of code you type it reduces the number of bugs. Maybe it's too much to ask but I would like to have that and all the benefits of Eclipse/compiler that come with GWT. Is there support for this in GWT, or a library already developed? Or maybe there is support in some of the component libraries for GWT out there? Thanks

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  • Process a batch of items, return an object to report on status

    - by Naeem Sarfraz
    I'm looking for a pattern (or good practice) for the following scenario: My function List<BatchItemResponse> Process(List<BatchItem> Data) {..} will process a list of data, and return info on where each item in the batch could be processed. struct BatchItemResponse { int BatchItemID; bool Processed; string Description; } Any thoughts? Is what I've proposed as good as it gets?

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  • Why use hashing to create pathnames for large collections of files?

    - by Stephen
    Hi, I noticed a number of cases where an application or database stored collections of files/blobs using a has to determine the path and filename. I believe the intended outcome is a situation where the path never gets too deep, or the folders ever get too full - too many files (or folders) in a folder making for slower access. EDIT: Examples are often Digital libraries or repositories, though the simplest example I can think of (that can be installed in about 30s) is the Zotero document/citation database. Why do this? EDIT: thanks Mat for the answer - does this technique of using a hash to create a file path have a name? Is it a pattern? I'd like to read more, but have failed to find anything in the ACM Digital Library

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  • How to deal with the new line character in the Silverlight TextBox

    - by Ian Oakes
    When using a multi-line TextBox (AcceptsReturn="True") in Silverlight, line feeds are recorded as \r rather than \r\n. This is causing problems when the data is persisted and later exported to another format to be read by a Windows application. I was thinking of using a regular expression to replace any single \r characters with a \r\n, but I suck at regex's and couldn't get it to work. Because there may be a mixture of line endings just blindy replacing all \r with \r\n doesn't cut it. So two questions really... If regex is the way to go what's the correct pattern? Is there a way to get Silverlight to respect it's own Environment.NewLine character in TextBox's and have it insert \r\n rather just a single \r?

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  • Do I still have to implement a singleton class by hand in .net, even when using .Net4.0?

    - by Hamish Grubijan
    Once the singleton pattern is understood, writing subsequent singleton classes in C# is a brainless exercise. I would hope that the framework would help you by providing an interface or a base class to do that. Here is how I envision it: public sealed class Schablone : ISingleton<Schablone> { // Stuff forced by the interface goes here // Extra logic goes here } Does what I am looking for exist? Is there some syntactic sugar for constructing a singleton class - whether with an interface, a class attribute, etc.? Can one write a useful and bullet-proof ISingleton themselves? Care to try? Thanks!

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  • php regex to split invoice line item description

    - by user1053700
    I am attempting to split strings like the following: An item (Item A) which may contain 89798 numbers and letters @ $550.00 4 of Item B @ $420.00 476584 of Item C, with a larger quantity and different currency symbol @ £420.00 into: array( 0 => 1 1 => "some item which may contain 89798 numbers and letters" 2 => $550.00 ); does that make sense? I am looking for a regex pattern which will split the quantity, description, and price (including symbol). the strings will always be: qty x description @ price+symbol so i assume the regex would be something like: `(match a number and only a number) x (get description letters and numbers before the @ symbol) @ (match the currency symbol and price)` How should I approach this?

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