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  • MVC Design Pattern to Combine Multiple Models for use

    - by roverred
    In my design, I have multiple models and each model has a controller. I need to use all the models to process some operation. Most examples I see are pretty simple with 1 view, 1 controller, and 1 model. How would you get all these models together? Only ways I can think of are 1) Have a top-level controller which has a reference to every controller. Those controllers will have a getter/setter function for their model. Does this violate MVC because every controller should have a model? 2) Have an Intermediate class to combine every model into a one model. Then you create a controller for that new super model. Do you know of any better ideas? Thanks.

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  • "Collection Wrapper" pattern - is this common?

    - by Prog
    A different question of mine had to do with encapsulating member data structures inside classes. In order to understand this question better please read that question and look at the approach discussed. One of the guys who answered that question said that the approach is good, but if I understood him correctly - he said that there should be a class existing just for the purpose of wrapping the collection, instead of an ordinary class offering a number of public methods just to access the member collection. For example, instead of this: class SomeClass{ // downright exposing the concrete collection. Things[] someCollection; // other stuff omitted Thing[] getCollection(){return someCollection;} } Or this: class SomeClass{ // encapsulating the collection, but inflating the class' public interface. Thing[] someCollection; // class functionality omitted. public Thing getThing(int index){ return someCollection[index]; } public int getSize(){ return someCollection.length; } public void setThing(int index, Thing thing){ someCollection[index] = thing; } public void removeThing(int index){ someCollection[index] = null; } } We'll have this: // encapsulating the collection - in a different class, dedicated to this. class SomeClass{ CollectionWrapper someCollection; CollectionWrapper getCollection(){return someCollection;} } class CollectionWrapper{ Thing[] someCollection; public Thing getThing(int index){ return someCollection[index]; } public int getSize(){ return someCollection.length; } public void setThing(int index, Thing thing){ someCollection[index] = thing; } public void removeThing(int index){ someCollection[index] = null; } } This way, the inner data structure in SomeClass can change without affecting client code, and without forcing SomeClass to offer a lot of public methods just to access the inner collection. CollectionWrapper does this instead. E.g. if the collection changes from an array to a List, the internal implementation of CollectionWrapper changes, but client code stays the same. Also, the CollectionWrapper can hide certain things from the client code - from example, it can disallow mutation to the collection by not having the methods setThing and removeThing. This approach to decoupling client code from the concrete data structure seems IMHO pretty good. Is this approach common? What are it's downfalls? Is this used in practice?

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  • Designing web-based plugin systems correctly so they don't waste as many resources?

    - by Xeoncross
    Many CMS systems which rely on third parties for much of their code often build "plugin" or "hooks" systems to make it easy for developers to modify the codebase's actions without editing the core files. This usually means an Observer or Event design pattern. However, when you look at systems like wordpress you see that on every page they load some kind of bootstrap file from each of the plugin's folders to see if that plugin will need to run that request. Its this poor design that causes systems like wordpress to spend many extra MB's of memory loading and parsing unneeded items each page. Are there alternative ways to do this? I'm looking for ideas in building my own. For example, Is there a way to load all this once and then cache the results so that your system knows how to lazy-load plugins? In other words, the system loads a configuration file that specifies all the events that plugin wishes to tie into and then saves it for future requests? If that also performs poorly, then perhaps there is a special file-structure that could be used to make educated guesses about when certain plugins are unneeded to fullfil the request. Any ideas? If anyone wants an example of the "plugin" concept you can find one here.

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  • How do I implement repository pattern and unit of work when dealing with multiple data stores?

    - by Jason
    I have a unique situation where I am building a DDD based system that needs to access both Active Directory and a SQL database as persistence. Initially this wasnt a problem because our design was setup where we had a unit of work that looked like this: public interface IUnitOfWork { void BeginTransaction() void Commit() } and our repositories looked like this: public interface IRepository<T> { T GetByID() void Save(T entity) void Delete(T entity) } In this setup our load and save would handle the mapping between both data stores because we wrote it ourselves. The unit of work would handle transactions and would contain the Linq To SQL data context that the repositories would use for persistence. The active directory part was handled by a domain service implemented in infrastructure and consumed by the repositories in each Save() method. Save() was responsible with interacting with the data context to do all the database operations. Now we are trying to adapt it to entity framework and take advantage of POCO. Ideally we would not need the Save() method because the domain objects are being tracked by the object context and we would just need to add a Save() method on the unit of work to have the object context save the changes, and a way to register new objects with the context. The new proposed design looks more like this: public interface IUnitOfWork { void BeginTransaction() void Save() void Commit() } public interface IRepository<T> { T GetByID() void Add(T entity) void Delete(T entity) } This solves the data access problem with entity framework, but does not solve the problem with our active directory integration. Before, it was in the Save() method on the repository, but now it has no home. The unit of work knows nothing other than the entity framework data context. Where should this logic go? I argue this design only works if you only have one data store using entity framework. Any ideas how to best approach this issue? Where should I put this logic?

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  • Web scraping: how to get scraper implementation from text link?

    - by isme
    I'm building a java web media-scraping application for extracting content from a variety of popular websites: youtube, facebook, rapidshare, and so on. The application will include a search capability to find content urls, but should also allow the user to paste a url into the application if they already where the media is. Youtube Downloader already does this for a variety of video sites. When the program is supplied with a URL, it decides which kind of scraper to use to get the content; for example, a youtube watch link returns a YoutubeScraper, a Facebook fanpage link returns a FacebookScraper and so on. Should I use the factory pattern to do this? My idea is that the factory has one public method. It takes a String argument representing a link, and returns a suitable implementation of the Scraper interface. I guess the Factory would hold a list of Scraper implementations, and would match the link against each Scraper until it finds a suitable one. If there is no suitable one, it throws an Exception instead.

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  • nHibernate session - Using repository pattern in Web, windows, wcf etc...

    - by alex
    I recently posted a question which was answered by Bryan Watts, regarding generic repository for nHibernate. I'm trying to design my data access to allow various facets - from ASP.net, WCF and Windows Forms / Windows services. I'm a bit confused re: session management etc.. How would I handle this? I've been checking out code such as: http://membranecms.googlecode.com/svn/ and questions such as: http://stackoverflow.com/questions/1207833/nhibernate-linq-session-management But what do i do if i don't just do things in a web based environment..? Do i need to create different repositories for each client? Or do i pass in the ISession into the (for example) UserRepository constructor..? ... as a side note I'm using nHibernate.Linq Also using fluent nHibernate to config my mapping

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  • How do you code up a pattern matching block in scala?

    - by egervari
    How do you code a function that takes in a block of code that contains case statements? For instance, in my block of code, I don't want to code a match or a default case... looking something like this myApi { case Whatever() => // code for case 1 case SomethingElse() => // code for case 2 } And inside of my myApi(), it'll actually do the matches. Help?

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  • How do you code up a pattern matching code block in scala?

    - by egervari
    How do you code a function that takes in a block of code as a parameter that contains case statements? For instance, in my block of code, I don't want to do a match or a default case explicitly. I am looking something like this myApi { case Whatever() => // code for case 1 case SomethingElse() => // code for case 2 } And inside of my myApi(), it'll actually execute the code block and do the matches. Help?

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  • Unable to create application factory of class org.apache.wicket.spring.SpringWebApplicationFactory

    - by theJava
    org.apache.wicket.protocol.http.WebApplicationFactoryCreationException: Unable to create application factory of class org.apache.wicket.spring.SpringWebApplicationFactory at org.apache.wicket.protocol.http.WicketFilter.getApplicationFactory(WicketFilter.java:228) at org.apache.wicket.protocol.http.WicketFilter.init(WicketFilter.java:271) at org.apache.wicket.protocol.http.WicketFilter.init(WicketFilter.java:252) at org.mortbay.jetty.servlet.FilterHolder.doStart(FilterHolder.java:97) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:713) at org.mortbay.jetty.servlet.Context.startContext(Context.java:140) at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1282) at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:518) at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:499) at org.mortbay.jetty.plugin.Jetty6PluginWebAppContext.doStart(Jetty6PluginWebAppContext.java:115) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152) at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:156) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130) at org.mortbay.jetty.Server.doStart(Server.java:224) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) at org.mortbay.jetty.plugin.Jetty6PluginServer.start(Jetty6PluginServer.java:132) at org.mortbay.jetty.plugin.AbstractJettyMojo.startJetty(AbstractJettyMojo.java:454) at org.mortbay.jetty.plugin.AbstractJettyMojo.execute(AbstractJettyMojo.java:396) at org.mortbay.jetty.plugin.AbstractJettyRunMojo.execute(AbstractJettyRunMojo.java:210) at org.mortbay.jetty.plugin.Jetty6RunMojo.execute(Jetty6RunMojo.java:184) at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:107) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:195) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:148) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:140) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59) at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183) at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:314) at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:151) at org.apache.maven.cli.MavenCli.execute(MavenCli.java:445) at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:168) at org.apache.maven.cli.MavenCli.main(MavenCli.java:132) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290) at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230) at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409) at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352) 2010-12-28 14:51:46.213:INFO::Started [email protected]:8080 I am using Wicket 1.5 M3, Spring 3.0 and i am getting this error. Below is my Web.xml config. <?xml version="1.0" encoding="ISO-8859-1"?> <web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version="2.4"> <display-name>mysticpaste</display-name> <!-- There are three means to configure Wickets configuration mode and they are tested in the order given. 1) A system property: -Dwicket.configuration 2) servlet specific <init-param> 3) context specific <context-param> The value might be either "development" (reloading when templates change) or "deployment". If no configuration is found, "development" is the default. --> <filter> <filter-name>wicket.mysticpaste</filter-name> <filter-class> org.apache.wicket.protocol.http.WicketFilter </filter-class> <init-param> <param-name>applicationFactoryClassName</param-name> <param-value>org.apache.wicket.spring.SpringWebApplicationFactory</param-value> </init-param> </filter> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:com/mysticcoders/mysticpaste/spring/application-context.xml</param-value> </context-param> <listener> <listener-class> org.springframework.web.context.ContextLoaderListener </listener-class> </listener> <filter> <filter-name>wicket.session</filter-name> <filter-class>org.apache.wicket.protocol.http.servlet.WicketSessionFilter</filter-class> <init-param> <param-name>filterName</param-name> <param-value>wicket.mysticpaste</param-value> </init-param> </filter> <filter-mapping> <filter-name>wicket.session</filter-name> <url-pattern>/servlet/*</url-pattern> </filter-mapping> <filter> <filter-name>open.hibernate.session.in.view</filter-name> <filter-class>org.springframework.orm.hibernate3.support.OpenSessionInViewFilter</filter-class> </filter> <!-- Important! This filter mapping must come before Wicket's! --> <filter-mapping> <filter-name>open.hibernate.session.in.view</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app>

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  • Good case for a Null Object Pattern? (Provide some service with a mailservice)

    - by fireeyedboy
    For a website I'm working on, I made an Media Service object that I use in the front end, as well as in the backend (CMS). This Media Service object manipulates media in a local repository (DB); it provides the ability to upload/embed video's and upload images. In other words, website visitors are able to do this in the front end, but administrators of the site are also able to do this in the backend. I'ld like this service to mail the administrators when a visitor has uploaded/embedded a new medium in the frontend, but refrain from mailing them when they upload/embed a medium themself in the backend. So I started wondering whether this is a good case for passing a null object, that mimicks the mail funcionality, to the Media Service in the backend. I thought this might come in handy when they decide the backend needs to have implemented mail functionality as well. In simplified terms I'ld like to do something like this: Frontend: $mediaService = new MediaService( new MediaRepository(), new StandardMailService() ); Backend: $mediaService = new MediaService( new MediaRepository(), new NullMailService() ); How do you feel about this? Does this make sense? Or am I setting myself up for problems down the road?

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  • ASP.NET MVC - How to Unit Test boundaries in the Repository pattern?

    - by JK
    Given a basic repository interface: public interface IPersonRepository { void AddPerson(Person person); List<Person> GetAllPeople(); } With a basic implementation: public class PersonRepository: IPersonRepository { public void AddPerson(Person person) { ObjectContext.AddObject(person); } public List<Person> GetAllPeople() { return ObjectSet.AsQueryable().ToList(); } } How can you unit test this in a meaningful way? Since it crosses the boundary and physically updates and reads from the database, thats not a unit test, its an integration test. Or is it wrong to want to unit test this in the first place? Should I only have integration tests on the repository? I've been googling the subject and blogs often say to make a stub that implements the IRepository: public class PersonRepositoryTestStub: IPersonRepository { private List<Person> people = new List<Person>(); public void AddPerson(Person person) { people.Add(person); } public List<Person> GetAllPeople() { return people; } } But that doesnt unit test PersonRepository, it tests the implementation of PersonRepositoryTestStub (not very helpful).

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  • Is context inheritance, as shown by Head First Design Patterns' Duck example, irrelevant to strategy pattern?

    - by Korey Hinton
    In Head First Design Patterns it teaches the strategy pattern by using a Duck example where different subclasses of Duck can be assigned a particular behavior at runtime. From my understanding the purpose of the strategy pattern is to change an object's behavior at runtime. Emphasis on "an" meaning one. Could I further simplify this example by just having a Duck class (no derived classes)? Then when implementing one duck object it can be assigned different behaviors based on certain circumstances that aren't dependent on its own object type. For example: FlyBehavior changes based on the weather or QuackBehavior changes based on the time of day or how hungry a duck is. Would my example above constitute the strategy pattern as well? Is context inheritance (Duck) irrelevant to the strategy pattern or is that the reason for the strategy pattern? Here is the UML diagram from the Head First book:

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  • Servlet mapping url patterns

    - by Scobal
    I have the following urls that need mapping to two different servlets. Can anyone suggest a working url-pattern please? vehlocsearch-ws: /ws/vehlocsearch/vehlocsearch /ws/vehavailrate/vehavailratevehlocsearch /ws/vehavailrate/vehavailratevehlocsearch.wsdl vehavailrate-ws: /ws/vehavailrate/vehavailrate /ws/vehavailrate/vehavailratevehavailrate /ws/vehavailrate/vehavailratevehavailrate.wsdl So far I have this, which feels right, but isn't: <servlet-mapping> <servlet-name>vehlocsearch-ws</servlet-name> <url-pattern>*.vehlocsearch*</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>vehavailrate-ws</servlet-name> <url-pattern>*.vehavailrate*</url-pattern> </servlet-mapping> Note: I have no control over the incoming urls

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  • Retrieving the COM class factory for component error while generating word document

    - by TheDPQ
    Hello, I am trying to edit a word document from VB.NET using for the most part this code: How to automate Word from Visual Basic .NET to create a new document http://support.microsoft.com/kb/316383 It works fine on my machine but when i publish to the server i get the following error. Retrieving the COM class factory for component with CLSID {000209FF-0000-0000-C000-000000000046} failed due to the following error: 80070005. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.UnauthorizedAccessException: Retrieving the COM class factory for component with CLSID {000209FF-0000-0000-C000-000000000046} failed due to the following error: 80070005. The actual error happens when i try to just create a word application object Dim oWord As New Word.Application Using Visual Studio 2008 and VB.NET 3.5. I made a reference to the "Microsoft Word 10.0 Object Library" and i see Interop.Word.dll file in the bin directory. Using MS Office 2003 on development machine and Windows Server 2003 Still fairly new to .NET and don't have much knowledge about window server, but "UnauthorizedAccessException" sounds like a permission issue. I'm wondering if someone could point me in the right direction on what i might need to do to give my little application access to use word. Thank you so much for your time.

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  • PLKs and Web Service Software Factory

    - by Nix
    We found a bug in Web Service Software Factory a description can be found here. There has been no updates on it so we decided to download the code and fix it ourself. Very simple bug and we patched it with maybe 3 lines of code. However* we have now tried to repackage it and use it and are finding that this is seemingly an impossible process. Can someone please explain to me the process of PLKs? I have read all about them but still don't understand what is really required to distribute a VS package. I was able to get it to load and run using a PLK obtained from here, but i am assuming that you have to be a partner to get a functional PLK that will be recognized on other peoples systems? Every time i try and install this on a different computer I get a "Package Load Failure". Is the reason I am getting errors because I am not using a partner key? Is there any other way around this? For instance is there any way we can have an "internal" VS package that we can distribute? Edit Files I had to change to get it to work. First run devenv PostInstall.proj Generate your plks and replace ##Package PLK## (.resx files) --Just note that package version is not the class name but is "Web Service Software Factory: Modeling Edition" -- And you need to remove the new lines from the key ProductDefinitionRegistryFragment.wxi line 1252(update version to whatever version you used in plk) Uncomment all // [VSShell::ProvideLoadKey("Standard", Constant in .tt files.

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  • Nested factory methods in Objective-C

    - by StephenT
    What's the best way to handle memory management with nested factory methods, such as in the following example? @implementation MyClass + (MyClass *) SpecialCase1 { return [MyClass myClassWithArg:1]; } + (MyClass *) SpecialCase2 { return [MyClass myClassWithArg:2]; } + (MyClass *) myClassWithArg:(int)arg { MyClass *instance = [[[MyClass alloc] initWithArg:arg] autorelease]; return instance; } - (id) initWithArg:(int)arg { self = [super init]; if (nil != self) { self.arg = arg; } return self; } @end The problem here (I think) is that the autorelease pool is flushed before the SpecialCaseN methods return to their callers. Hence, the ultimate caller of SpecialCaseN can't rely on the result having been retained. (I get "[MyClass copyWithZone:]: unrecognized selector sent to instance 0x100110250" on trying to assign the result of [MyClass SpecialCase1] to a property on another object.) The reason for wanting the SpecialCaseN factory methods is that in my actual project, there are multiple parameters required to initialize the instance and I have a pre-defined list of "model" instances that I'd like to be able to create easily. I'm sure there's a better approach than this.

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  • Reset DRAC to factory defaults

    - by yakatz
    I put a DRAC that has not been used in a long time into a PowerEdge 1750 running CentOS 5.8. Because we run our DRACs on a separate network, we don't change the password from the default (root/calvin), but evidently someone changed this one. I tried the regular command line reset (racadm racresetcfg), but I get the following error: ERROR: Unable to perform requested operation. If the operation attempted was to configure DRAC, possible reason may be that Local Configuration using RACADM is disabled. This implies to me that racadm is able to communicate, but there is a setting on the DRAC that is preventing it from working. I was not able to find any references to this error in any Dell documentation. Has anyone seen this problem and/or know what I can do about it? (The DRAC is useless is I can't log in to it.)

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  • Format Factory not working for mov files

    - by LanguaFlash
    I have attempted multiple destination formats with no success. I am using Format Factor 2.30. I drag and drop a .mov file into FF, select all to mpg (or any format) then click Start. It thinks for a couple seconds and then jumps to 100%. When I open the file I get no sound or picture from the video. These mov files were created with a Canon SX10 camera. (It is my brother's camera so I'm not sure of the model.) Any suggestions? TMPGEnc is able to convert the files with the QTReader plug in so the video isn't corrupted or something. Thanks. Jeff

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  • Reset Windows system to factory defaults

    - by carlosz
    A friend just bought a netbook (HP mini 110) with Windows XP but it was the one used for testing in the store (the last one on storage) so it's somewhat filled with stuff from people testing the machine. How should I go about restoring the system to a ? As a first step I'm going to create a new User account and delete the old one (from the store). How do we change the name It's registered to? What other things should I take in account?

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  • Restoring factory recovery partition (samsung)

    - by user974896
    I have upgraded the HDD in a Samsung laptop and would like to restore the "Press F4 for recovery" partition. My new disk has three partitions, System, Windows, and Recovery. I did a dd of the recovery partition from the old HDD to the new. I also set the diag flag on the new HDD. F4 recovery still is not working. tldr: I mapped my new disk like my old disk with the exception of exact sizes. I did the recover partition from old to new via livecd. F4 recovery does not work

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  • Pass variable to regular expression pattern string in jquery

    - by phil
    Is that possible to pass variable into regular expression pattern string in jquery ( or javascript)? For example, I want to validate a zip code input field every time while user type in a character by passing variable i to the regular expression pattern. How to do it right? $('#zip').keyup( function(){ var i=$('#zip').val().length for ( i; i<=5; i++){ var pattern=/^[0-9]{i}$/; if ( !pattern.test( $('#zip').val() ) ) {$('#zip_error').css('display','inline');} else {$('#zip_error').css('display','none');} } })

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