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  • Repository pattern with lazying loading using POCO

    - by Simon G
    Hi, I'm in the process of starting a new project and creating the business objects and data access etc. I'm just using plain old clr objects rather than any orms. I've created two class libraries: 1) Business Objects - holds all my business objects, all this objects are light weight with only properties and business rules. 2) Repository - this is for all my data access. The majority of my objects will have child list in and my question is what is the best way to lazy load these values as I don't want to bring back unnecessary information if I dont need to. I've thought about when using the "get" on the child property to check if its "null" and if it is call my repository to get the child information. This has two problems from what I can see: 1) The object "knows" how to get itself I would rather no data access logic be held in the object. 2) This required both classes to reference each other which in visual studio throws a circular dependency error. Does anyone have any suggestions on how to overcome this issue or any recommendations on my projects layout and where it can be improved? Thanks

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  • TypeInitializeException on MVVM pattern

    - by Mohit Deshpande
    System.TypeInitializationException was unhandled Message=The type initializer for 'SmartHomeworkOrganizer.ViewModels.MainViewModel' threw an exception. Source=SmartHomeworkOrganizer TypeName=SmartHomeworkOrganizer.ViewModels.MainViewModel StackTrace: at SmartHomeworkOrganizer.ViewModels.MainViewModel..ctor() at SmartHomeworkOrganizer.App.OnStartup(Object sender, StartupEventArgs e) in C:\Users\Mohit\Documents\Visual Studio 2010\Projects\SmartHomeworkOrganizer\SmartHomeworkOrganizer\App.xaml.cs:line 21 at System.Windows.Application.OnStartup(StartupEventArgs e) at System.Windows.Application.<.ctor>b__0(Object unused) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) at System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) at System.Windows.Threading.DispatcherOperation.InvokeImpl() at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state) at System.Threading.ExecutionContext.runTryCode(Object userData) at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Windows.Threading.DispatcherOperation.Invoke() at System.Windows.Threading.Dispatcher.ProcessQueue() at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) at System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Boolean isSingleParameter) at System.Windows.Threading.Dispatcher.Invoke(DispatcherPriority priority, Delegate method, Object arg) at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam) at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg) at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame) at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame) at System.Windows.Threading.Dispatcher.Run() at System.Windows.Application.RunDispatcher(Object ignore) at System.Windows.Application.RunInternal(Window window) at System.Windows.Application.Run(Window window) at System.Windows.Application.Run() at SmartHomeworkOrganizer.App.Main() in C:\Users\Mohit\Documents\Visual Studio 2010\Projects\SmartHomeworkOrganizer\SmartHomeworkOrganizer\obj\Debug\App.g.cs:line 0 at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart() InnerException: System.ArgumentException Message=Default value type does not match type of property 'Score'. Source=WindowsBase StackTrace: at System.Windows.DependencyProperty.ValidateDefaultValueCommon(Object defaultValue, Type propertyType, String propertyName, ValidateValueCallback validateValueCallback, Boolean checkThreadAffinity) at System.Windows.DependencyProperty.ValidateMetadataDefaultValue(PropertyMetadata defaultMetadata, Type propertyType, String propertyName, ValidateValueCallback validateValueCallback) at System.Windows.DependencyProperty.RegisterCommon(String name, Type propertyType, Type ownerType, PropertyMetadata defaultMetadata, ValidateValueCallback validateValueCallback) at System.Windows.DependencyProperty.Register(String name, Type propertyType, Type ownerType, PropertyMetadata typeMetadata, ValidateValueCallback validateValueCallback) at System.Windows.DependencyProperty.Register(String name, Type propertyType, Type ownerType, PropertyMetadata typeMetadata) at SmartHomeworkOrganizer.ViewModels.MainViewModel..cctor() in C:\Users\Mohit\Documents\Visual Studio 2010\Projects\SmartHomeworkOrganizer\SmartHomeworkOrganizer\ViewModels\MainViewModel.cs:line 72 InnerException: This bit of code throws a System.ArgumentException before the TypeInitializeException. It says: "Default value type does not match type of property Score": public static readonly DependencyProperty ScoreProperty = DependencyProperty.Register("Score", typeof(float), typeof(MainViewModel), new UIPropertyMetadata(0.0)); Here is the .NET property: public float Score { get { return (float) GetValue(ScoreProperty); } set { SetValue(ScoreProperty, value); } }

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  • Extract known pattern substring from NSString (without regex)

    - by d11wtq
    I'm really tempted to drop RegexKit (or my own libpcre wrapper) into my project in order to do this, but before I do that I want to know how Cocoa developers manage to do half of this basic stuff without really convoluted code or without linking with RegexKit or another regular expression library. I find it gobsmacking that Cocoa does not include any regular expression matching features. I've so accustomed to using regular expressions for all kinds of things that I'm lost without them. I can do what I need without them, but the code would be rather convoluted. So, Cocoa devs, I ask you, what's the "Cocoa way" to do this... The problem is an everyday problem in programming as far as I'm concerned. Cocoa must have ways of doing this with the built-in features. Note that the position of the elements I want to match changes, and sometimes "quotes" are present. Whitespace is variable. Take the following strings: Content-Type: application/xml; charset=utf-8 Content-Type: text/html; charset="iso-8859-1" Content-Type: text/plain; charset=us-ascii Content-Type: text/plain; name="example.txt"; charset=utf-8 From all of these strings, how would you go about determining the mime type (e.g. text/plain) and the charset (e.g. utf-8) using just the built-in Cocoa classes? I'd end up performing a series of -rangeOfString: and substring calls, with conditional checks to deal with the optional quotes etc. Is there a way to do this with NSScanner? The NSScanner class seems to have a pretty naive API to me. Something like C's sscanf() that works for NSString objects would be an ideal fit. Most of my string parsing needs are simple such as this example so maybe regular expressions, while I'm accustomed to them, are overkill?

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  • Strategy pattern and "action" classes explosion

    - by devoured elysium
    Is it bad policy to have lots of "work" classes(such as Strategy classes), that only do one thing? Let's assume I want to make a Monster class. Instead of just defining everything I want about the monster in one class, I will try to identify what are its main features, so I can define them in interfaces. That will allow to: Seal the class if I want. Later, other users can just create a new class and still have polymorphism by means of the interfaces I've defined. I don't have to worry how people (or myself) might want to change/add features to the base class in the future. All classes inherit from Object and they implement inheritance through interfaces, not from mother classes. Reuse the strategies I'm using with this monster for other members of my game world. Con: This model is rigid. Sometimes we would like to define something that is not easily achieved by just trying to put together this "building blocks". public class AlienMonster : IWalk, IRun, ISwim, IGrowl { IWalkStrategy _walkStrategy; IRunStrategy _runStrategy; ISwimStrategy _swimStrategy; IGrowlStrategy _growlStrategy; public Monster() { _walkStrategy = new FourFootWalkStrategy(); ...etc } public void Walk() { _walkStrategy.Walk(); } ...etc } My idea would be next to make a series of different Strategies that could be used by different monsters. On the other side, some of them could also be used for totally different purposes (i.e., I could have a tank that also "swims"). The only problem I see with this approach is that it could lead to a explosion of pure "method" classes, i.e., Strategy classes that have as only purpose make this or that other action. In the other hand, this kind of "modularity" would allow for high reuse of stratagies, sometimes even in totally different contexts. What is your opinion on this matter? Is this a valid reasoning? Is this over-engineering? Also, assuming we'd make the proper adjustments to the example I gave above, would it be better to define IWalk as: interface IWalk { void Walk(); } or interface IWalk { IWalkStrategy WalkStrategy { get; set; } //or something that ressembles this } being that doing this I wouldn't need to define the methods on Monster itself, I'd just have public getters for IWalkStrategy (this seems to go against the idea that you should encapsulate everything as much as you can!) Why? Thanks

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  • Regex pattern failing

    - by Scott Chamberlain
    I am trying to strip out all things that are in a string that are not a letter number or space so I created the regex private static Regex _NonAlphaChars = new Regex("[^[A-Za-z0-9 ]]", RegexOptions.Compiled); however When I call _NonAlphaChars.Replace("Scott,", ""); it returns "Scott," What am I doing wrong that it is not matching the ,?

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  • how does data clustering help in image or pattern recognition

    - by anon
    I have been playing around with different data clustering algorithms working on finding clusters between random data points represented an nodes, I keep reading that data clustering is used for image recognition. I am failing to make the connection, how does clustering data help in recognizing an image or in facial recognition. can someone explain this?

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  • Regex one-to-one mapping pattern replace

    - by polygenelubricants
    How would you use regex to write a function that replaces all lowercase letters with uppercase and vice versa? Note: this is NOT a homework question. See also my previous explorations of regex: Regex split into overlapping strings (Alan Moore's answer is especially instructive) Can you use zero-width matching regex in String split? (my solution exploits a known Java regex bug with regards to non-obvious length lookbehind!)

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  • WPF MVVM Pattern, ViewModel DataContext question

    - by orangecl4now
    I used this side to create my demo application http://windowsclient.net/learn/video.aspx?v=314683 The site was very useful in getting my started and in their example, they created a file called EmployeeRepository.cs which appears to be the source for the data. In their example, the data was hard-wired in code. So I'm trying to learn how to get the data from a data source (like a DB). In my specific case, I want to get the data from a Microsoft Access DB. (READ ONLY, So I'll only use SELECT commands). using System.Collections.Generic; using Telephone_Directory_2010.Model; namespace Telephone_Directory_2010.DataAccess { public class EmployeeRepository { readonly List<Employee> _employees; public EmployeeRepository() { if (_employees == null) { _employees = new List<Employee>(); } _employees.Add(Employee.CreateEmployee("Student One", "IT201", "Information Technology", "IT4207", "Building1", "Room650")); _employees.Add(Employee.CreateEmployee("Student Two", "IT201", "Information Technology", "IT4207", "Building1", "Room650")); _employees.Add(Employee.CreateEmployee("Student Three", "IT201", "Information Technology", "IT4207", "Building1", "Room650")); } public List<Employee> GetEmployees() { return new List<Employee>(_employees); } } } I found another example where an Access DB is used but it doesn't comply with MVVM. So I was trying to figure out how to add the DB file to the project, how to wire it up and bind it to a listbox (i'm not that far yet). Below is my modified file using System.Collections.Generic; using Telephone_Directory_2010.Model; // integrating new code with working code using Telephone_Directory_2010.telephone2010DataSetTableAdapters; using System.Windows.Data; namespace Telephone_Directory_2010.DataAccess { public class EmployeeRepository { readonly List<Employee> _employees; // start // integrating new code with working code private telephone2010DataSet.telephone2010DataTable employeeTable; private CollectionView dataView; internal CollectionView DataView { get { if (dataView == null) { dataView = (CollectionView) CollectionViewSource.GetDefaultView(this.DataContext); } return dataView; } } public EmployeeRepository() { if (_employees == null) { _employees = new List<Employee>(); } telephone2010TableAdapter employeeTableAdapter = new telephone2010TableAdapter(); employeeTable = employeeTableAdapter.GetData(); this.DataContext = employeeTable; } public List<Employee> GetEmployees() { return new List<Employee>(_employees); } } } I get the following error messages when building Error 1 'Telephone_Directory_2010.DataAccess.EmployeeRepository' does not contain a definition for 'DataContext' and no extension method 'DataContext' accepting a first argument of type 'Telephone_Directory_2010.DataAccess.EmployeeRepository' could be found (are you missing a using directive or an assembly reference?) C:\Projects\VS2010\Telephone Directory 2010\Telephone Directory 2010\DataAccess\EmployeeRepository.cs 23 90 Telephone Directory 2010

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  • MVC and repository pattern data effeciency

    - by Shawn Mclean
    My project is structured as follows: DAL public IQueryable<Post> GetPosts() { var posts = from p in context.Post select p; return posts; } Service public IList<Post> GetPosts() { var posts = repository.GetPosts().ToList(); return posts; } //Returns a list of the latest feeds, restricted by the count. public IList<PostFeed> GetPostFeeds(int latestCount) { List<Post> post - GetPosts(); //CODE TO CREATE FEEDS HERE return feeds; } Lets say the GetPostFeeds(5) is supposed to return the 5 latest feeds. By going up the list, doesn't it pull down every single post from the database from GetPosts(), just to extract 5 from it? If each post is say 5kb from the database, and there is 1 million records. Wont that be 5GB of ram being used per call to GetPostFeeds()? Is this the way it happens? Should I go back to my DAL and write queries that return only what I need?

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  • javascript regular expression search a pattern A(xyz).

    - by Paul
    I need to find all substrings from a string that starting with a given string following with a left bracket and then any legal literal and then the right bracket. For example, a string is abcd(xyz)efcd(opq), I want to a function that returns "cd(xyz)" and "cd(opq)". I wrote a regular expression, but it returns only cd( and cd(...

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  • What'd be a good pattern on Doctrine to have multiple languages

    - by PERR0_HUNTER
    Hi! I have this challenge which consist in having a system that offers it's content in multiple languages, however a part of the data contained in the system is not translatable such as dates, ints and such. I mean if I have a content on the following YAML Corporativos: columns: nombre: type: string(254) notnull: true telefonos: type: string(500) email: type: string(254) webpage: type: string(254) CorporativosLang: columns: corporativo_id: type: integer(8) notnull: true lang: type: string(16) fixed: false ubicacion: type: string() fixed: false unsigned: false primary: false notnull: true autoincrement: false contacto: type: string() fixed: false unsigned: false primary: false notnull: true autoincrement: false tipo_de_hoteles: type: string(254) fixed: false unsigned: false primary: false notnull: true autoincrement: false paises: type: string() fixed: false unsigned: false primary: false notnull: true autoincrement: false relations: Corporativo: class: Corporativos local: corporativo_id foreign: id type: one foreignAlias: Data This would allow me to have different corporative offices, however the place of the corp, the contact and other things can be translate into a different language (lang) Now this code here would create me a brand new corporative office with 2 translations $corporativo = new Corporativos(); $corporativo->nombre = 'Duck Corp'; $corporativo->telefonos = '66303713333'; $corporativo->email = '[email protected]'; $corporativo->webpage = 'http://quack.com'; $corporativo->Data[0]->lang = 'en'; $corporativo->Data[0]->ubicacion = 'zomg'; $corporativo->Data[1]->lang = 'es'; $corporativo->Data[1]->ubicacion = 'zomg amigou'; the thing now is I don't know how to retrieve this data in a more friendly way, because if I'd like to access my Corporative info in english I'd had to run DQL for the corp and then another DQL for the specific translation in english, What I'd love to do is have my translatable fields available in the root so I could simply access them $corporativo = new Corporativos(); $corporativo->nombre = 'Duck Corp'; $corporativo->telefonos = '66303713333'; $corporativo->email = '[email protected]'; $corporativo->webpage = 'http://quack.com'; $corporativo->lang = 'en'; $corporativo->ubicacion = 'zomg'; this way the translatable fields would be mapped to the second table automatically. I hope I can explain my self clear :( any suggestions ?

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  • singleton pattern in Windows Activation Service

    - by Joshua
    Hello I have a few WCF services that are currently being self hosted, in a very basic NT Service. I want to expand my application to add provisioning of WCF Services, and updates, as well as isolation (I want each WCF Service to be in its own AppDomain). These WCF Services contain logic that needs to be run on a regular basis, pinging the database, and getting information from external devices so that when a request comes in the data is readily available. I'm thinking about trying out Windows Activation Service, because i really like the provisioning, and isolation that comes with a managed services infrastructure. If I didn't use WAS I would essentially have to write the same code myself. From what I understand though WAS does not really support the model of having a service that is running before someone actually calls a method on the service. the article I read here MSDN Article Link states "That means in essence that out-of-the-box WAS hosting is not something that is really suited for sessionful or singleton services. It is more suitable for stateless per-call services." it does say that "Out of the box" so I'm wondering if anyone has used WAS to host a WCF service that really behaves more like an NT Service (starting and stopping independantly of having a method called upon it). Or any other ideas would be great. I was planning on writting this infrastructure myself, to host WCF services in a custom ServiceHost, and put their execution in a seporate AppDomain, as well as allow for provision of these services after initial installation, along with updates. However, I would MUCH MUCH MUCH rather not own that code if I don't have to. thanks Joshua

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  • MVC and repository pattern data efficiency

    - by Shawn Mclean
    My project is structured as follows: DAL public IQueryable<Post> GetPosts() { var posts = from p in context.Post select p; return posts; } Service public IList<Post> GetPosts() { var posts = repository.GetPosts().ToList(); return posts; } //Returns a list of the latest feeds, restricted by the count. public IList<PostFeed> GetPostFeeds(int latestCount) { List<Post> post - GetPosts(); //CODE TO CREATE FEEDS HERE return feeds; } Lets say the GetPostFeeds(5) is supposed to return the 5 latest feeds. By going up the list, doesn't it pull down every single post from the database from GetPosts(), just to extract 5 from it? If each post is say 5kb from the database, and there is 1 million records. Wont that be 5GB of ram being used per call to GetPostFeeds()? Is this the way it happens? Should I go back to my DAL and write queries that return only what I need?

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  • Avoiding EXC_BAD_ACCESS when using the delegate pattern

    - by Kenny Winker
    A have a view controller, and it creates a "downloader" object, which has a reference to the view controller (as a delegate). The downloader calls back the view controller if it successfully downloads the item. This works fine as long as you stay on the view, but if you navigate away before the download is complete I get EXC_BAD_ACCESS. I understand why this is happening, but is there any way to check if an object is still allocated? I tried to test using delegate != nil, and [delegate respondsToSelector:], but it chokes. if (!self.delegate || ![self.delegate respondsToSelector:@selector(downloadComplete:)]) { // delegate is gone, go away quietly [self autorelease]; return; } else { // delegate is still around [self.delegate downloadComplete:result]; } I know I could, a) have the downloader objects retain the view controller b) keep an array of downloaders in the view controller, and set their delegate values to nil when I deallocate the view controller. But I wonder if there is an easier way, where I just test if the delegate address contains a valid object?

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  • how to fix: ctags null expansion of name pattern "\1"

    - by bua
    Hi, As the title points I have problem with ctags when trying to parse user-defined language. Basically I've followed those instructions. The quickest and easiest way to do this is by defining a new language using the program options. In order to have Swine support available every time I start ctags, I will place the following lines into the file $HOME/.ctags, which is read in every time ctags starts: --langdef=swine --langmap=swine:.swn --regex-swine=/^def[ \t]*([a-zA-Z0-9_]+)/\1/d,definition/ The first line defines the new language, the second maps a file extension to it, and the third defines a regular expression to identify a language definition and generate a tag file entry for it. I've tried different flags: b,e for regex. My definition of tag is: --regex-q=/^[ \t]*[^[:space:]]*[:space:]*:[:space:]*{/\l/f,function/b When I replace \1 with anything else (ascii caracter set ), It works. the output is: (--regex-q=/^[ \t]*[^[:space:]]*[:space:]*:[:space:]*{/my function name/f,function/b) !_TAG_FILE_FORMAT 2 /extended format; --format=1 will not append ;" to lines/ !_TAG_FILE_SORTED 1 /0=unsorted, 1=sorted, 2=foldcase/ !_TAG_PROGRAM_AUTHOR Darren Hiebert /[email protected]/ !_TAG_PROGRAM_NAME Exuberant Ctags // !_TAG_PROGRAM_URL http://ctags.sourceforge.net /official site/ !_TAG_PROGRAM_VERSION 5.8 // my function name file.q /^.ras.getLocation:{[u]$/;" f my function name file.q /^.a.getResource:{[u; pass]$/;" f my function name file.q /^.a.init:{$/;" f my function name file.q /^.a.kill:{[u; force]$/;" f my function name file.q /^.asdf.status:{[what; u]$/;" f my function name file.q /^.pc:{$/;" f Why \1 doesn't work? (I've tried all 1-9)

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  • .NET Membership with Repository Pattern

    - by Zac
    My team is in the process of designing a domain model which will hide various different data sources behind a unified repository abstraction. One of the main drivers for this approach is the very high probability that these data sources will undergo significant change in the near future and we don't want to be re-writing business logic when this happens. One data source will be our membership database which was originally implemented using the default ASP.Net Membership Provider. The membership provider is tied to the System.Web.Security namespace but we have a design guideline requiring that our domain model layer is not dependent upon System.Web (or any other implementation/environment dependency) as it will be consumed in different environments - nor do we want our websites directly communicating with databases. I am considering what would be a good approach to reconciling the MembershipProvider approach with our abstracted n-tier architecture. My initial feeling is that we could create a "DomainMembershipProvider" which interacts with the domain model and then implement objects in the model which deal with the repository and handle validation/business logic. The repository would then implement data access using our (as-yet undecided) ORM/data access tool. Are there are any glaring holes in this approach - I haven't worked closely with the MembershipProvider class so may well be missing something. Alternatively, is there an approach that you think will better serve the requirements I described above? Thanks in advance for your thoughts and advice. Regards, Zac

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  • Regex pattern help for phrase OR a character set

    - by andybaird
    I have a PHP regex that I want to fail if the matched word after /blog is just "feed". This MUST be done within the regex itself, not using any other PHP syntax. The regex currently looks like this: blog/([a-zA-Z0-9-]+) What would I add to this to properly negate the regex if "feed" is found after blog/ ?

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  • Why is there ambiguity in this diamond pattern?

    - by cambr
    #include <iostream> using namespace std; class A { public: void eat(){ cout<<"A";} }; class B: public A { public: void eat(){ cout<<"B";} }; class C: public A { public: void eat(){ cout<<"C";} }; class D: public B,C { public: void eat(){ cout<<"D";} }; int main(){ A *a = new D(); a->eat(); } I am not sure this is called diamond problem or not, but why doesn't this work? When I said, a->eat() (remember eat() is not virtual), there is only one possible eat() to call, that of A. Why then, do I get this error: 'A' is an ambiguous base of 'D'

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  • Interface design pattern / Java / Seam

    - by Walter White
    Hi all, Is this possible somehow? @Name("geolocationService") public interface GeolocationService { @Query("SELECT g FROM Geolocation geolocation INNER JOIN geolocation.deployment deployment WHERE geolocation.ipStart <= INET_ATON(:ipAddress) AND deployment.active = TRUE") Geolocation findByIpAddress(@NamedParameter("ipAddress")final String ipAddress); } public GeolocationAction { @In private GeolocationService geolocationService; @RequestParameter("ipAddress") private String ipAddress; @Out private Geolocation geolocation; public void find() { geolocation = geolocationService.findByIpAddress(ipAddress); } } Is it possible to do this without implementing the interface? What is required to make that work? I want to maintain less and do more. If I can intercept invocations of the geolocationService then I am golden, how would I do that? I don't want it to ever be instantiated, so it will always be null (I don't want the @Name and @In annotations either then). Walter

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  • Example with Visitor Pattern

    - by devoured elysium
    public class Song { public string Genre { get; protected set; } public string Name { get; protected set; } public string Band { get; protected set; } public Song(string name, string band, string genre) { Name = name; Genre = genre; Band = band; } } public interface IMusicVisistor { void Visit(List<Song> items); } public class MusicLibrary { List<Song> _songs = new List<Song> { ...songs ... }; public void Accept(IMusicVisitor visitor) { visitor.Visit(_songs); } } and now here's one Visitor I made: public class RockMusicVisitor : IMusicVisitor { public List<Song> Songs { get; protected set; } public void Visit(List<Song> items) { Songs = items.Where(x => x.Genre == "Rock").ToList(); } } Why is this any better than just putting a public property Songs and then letting any kind of class do with it anything that it wants to? This example comes from this post.

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  • how to identify an html div id which starts with some pattern using jquery

    - by dexter
    normally we use something like this to identify Id using jquery $("#PhotoId").html('some html'); here we get the html (say div) having id 'PhotoId' what if the id is partially dynamic i.e. lets say there are multiple photoes each id would start with 'PhotoId' EX. $("#PhotoId" + result.Id).html(some html'); NOW, i want to identify html(div) which starts with 'PhotoId' how can it be done

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  • MVC pattern and State Machine

    - by topright
    I think of a game as a state machine. Game States separate I/O processing, game logic and rendering into different classes: while (game_loop) { game->state->io_events(this); game->state->logic(this); game->state->rendering(); } You can easily change a game state in this approach. MVC separation works in more complex way: while (game_loop) { game->cotroller->io_events(this); game->model->logic(this); game->view->rendering(); } So changing Game States becomes error prone task (switch 3 MVC objects, not 1). What are practical ways of combining these 2 concepts?

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