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  • asp.net mvc checkbox hierarchy

    - by mazhar
    I want to create a checkboxes hierarchy like this in mvc2.How would I be able to achieve this in the most simplest manner. Administrator Manage User Add Edit Delete View Manage Feature Add Edit Delete View Moderator Manage User Add Edit Delete View Manage Feature Add Edit Delete View

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  • Class hierarchy of objective c in iphone -for xcode

    - by vijay
    i want to know what is the hierarchy we have in xcode first we have to get window and from that i have to understand completely if i use the class as property of another like this //child inherits the parents @interface child:parent { // parent *parentobject; child *child; } then what is the difference b/w the class behaviour while using the as property for another class then what is contrast between the inheritance and property

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  • The concept of an Intent in Android?

    - by Mohit Deshpande
    I don't really understand the use and concept of an Intent. I DO understand that an activity are one visual interface and one endeavour that the user can partake in. I THINK an intent is used to launch and communicate between different activities. If so, then how would you accomplish that? A code sample would be helpful.

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  • Single Table Per Class Hierarchy with an abstract superclass using Hibernate Annotations

    - by Andy Hull
    I have a simple class hierarchy, similar to the following: @Entity @Table(name="animal") @Inheritance(strategy=InheritanceType.SINGLE_TABLE) @DiscriminatorColumn(name="animal_type", discriminatorType=DiscriminatorType.STRING) public abstract class Animal { } @Entity @DiscriminatorValue("cat") public class Cat extends Animal { } @Entity @DiscriminatorValue("dog") public class Dog extends Animal { } When I query "from Animal" I get this exception: "org.hibernate.InstantiationException: Cannot instantiate abstract class or interface: Animal" If I make Animal concrete, and add a dummy discriminator... such as @DiscriminatorValue("animal")... my query returns my cats and dogs as instances of Animals. I remember this being trivial with HBM based mappings but I think I'm missing something when using annotations. Can anyone help? Thanks!

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  • Understanding Node.js and concept of non-blocking I/O

    - by Saif Bechan
    Recently I became interested in using Node.js to tackle some of the parts of my web-application. I love the part that its full JavaScript and its very light weight so no use anymore to call an JavaScript-PHP call but a lighter JavaScript-JavaScript call. I however do not understand all the concepts explained. Basic concepts Now in the presentation for Node.js Ryan Dahl talks about non-blocking IO and why this is the way we need to create our programs. I can understand the theoretical concept. You just don't wait for a response, you go ahead and do other things. You make a callback for the response, and when the response arrives millions of clock-cycles later, you can fire that. If you have not already I recommend to watch this presentation. It is very easy to follow and pretty detailed. There are some nice concepts explained on how to write your code in a good manner. There are also some examples given and I am going to work with the basic example given. Examples The way we do thing now: puts("Enter your name: "); var name = gets(); puts("Name: " + name); Now the problem with this is that the code is halted at line 1. It blocks your code. The way we need to do things according to node puts("Enter your name: "); gets(function (name) { puts("Name: " + name); }); Now with this your program does not halt, because the input is a function within the output. So the programs continues to work without halting. Questions Now the basic question I have is how does this work in real-life situations. I am talking here for the use in web-applications. The application I am writing does I/O, bit is still does it in am blocking matter. I think that most of the time, if not all, you need to block, because you have to wait on what the response is you have to work with. When you need to get some information from the database, most of the time this data needs to be verified before you can further with the code. Example 1 If you take a login for example. You have to wait for the database to response to return, because you can not do anything else. I can't see a way around this without blocking. Example 2 Going back to the basic example. The use just request something from a database which does not need any verification. You still have to block because you don't have anything to do more. I can not come up with a single example where you want to do other things while you wait for the response to return. Possible answers I have read that this frees up recourses. When you program like this it takes less CPU or memory usage. So this non-blocking IO is ONLY meant to free up recourses and does not have any other practical use. Not that this is not a huge plus, freeing up recourses is always good. Yet I fail to see this as a good solution. because in both of the above examples, the program has to wait for the response of the user. Whether this is inside a function, or just inline, in my opinion there is a program that wait for input. Resources I looked at I have looked at some recourses before I posted this question. They talk a lot about the theoretical concept, which is quite clear. Yet i fail to see some real-life examples where this is makes a huge difference. Stackoverflow: What is in simple words blocking IO and non-blocking IO? Blocking IO vs non-blocking IO; looking for good articles tidy code for asynchronous IO Other recources: Wikipedia: Asynchronous I/O Introduction to non-blocking I/O The C10K problem

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  • chomsky hierarchy and programming languages

    - by dader51
    Hi, I'm trying to learn some aspects of the CH ( chomsky hierarchy ) which are related to PL ( programming languages ), and i still have to read the Dragon Book. I've read that most of the PL can be parsed as CFG ( context free grammar ). In term of computational power, it equals the one of a pushdown non deterministic automaton. Am I right ? If it's true, then how could a CFG holds a UG ( unrestricted grammar, which is turing complete ) ? I'm asking because, even if PL are CFG they are actually used to describe TM (turing machines ) and through UG. I think that's because of at least two different levels of computing, the first, which is the parsing of a CFG focuses on the syntax related to the structure ( representation ? ) of the language, while the other focuses on the semantic ( sense, interpretation of the data itself ? ) related to the capabilities of the pl which is turing complete. Again, are these assumptions rights ? thanx a lot.

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  • Generating a Call Hierarchy for dynamicly invoked method

    - by Maxim Veksler
    Hello, Today's world of dynamic invoke, reflection and runtime injection just doesn't play well with traditional tools such as ctags, doxygen and CDOC. I am searching for a method call hierarchy visualization tool that can display both static and dynamic method invocations. It should be easy to use, light during execution and provide helpful detailed information about the recorded runtime session. Now I guess Callgrind could be considered a valid solution for the family C. What tool / technique could you suggest to create a call graph for both static and dynamic method invocation for JVM based bytecode? The intended end result is a graphical display (preferably interactive) which can show path from main() to each method that was invoked. During research for this post I stumbled upon javashot, it seems that this is the kind of approach I'm aiming at, I would prefer that this would be integrated into a kind of profiler or alike which than can be used from within my IDE (Eclipse, IntelliJ, Netbeans and alike). Thank you, Maxim.

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  • How to design this class hierarchy?

    - by devoured elysium
    I have defined an Event class: Event and all the following classes inherit from Event: AEvent BEvent CEvent DEvent Now, with the info I gather from all these Event classes, I will make a chart. With AEvent and BEvent, I will generate points for that chart, while with CEvent and DEvent I will paint certain regions of the chart. Now, how should I signal this in my class hierarchy? Should I make AEvent and BEvent inherit from PointEvent while CEvent and DEvent inherit from RegionEvent, being that both RegionEvent and PointEvent inherit from Event? Should I add a field with an Enum to Event with 2 values, Point and Region, and each of the child classes set their value to it? Should I use some kind of pattern here? Which one? Thanks.

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  • Storing website hierarchy in Sql Server 2008

    - by Mika Kolari
    I want to store website page hierarchy in a table. What I would like to achieve is efficiently 1) resolve (last valid) item by path (e.g. "/blogs/programming/tags/asp.net,sql-server", "/blogs/programming/hello-world" ) 2) get ancestor items for breadcrump 3) edit an item without updating the whole tree of children, grand children etc. Because of the 3rd point I thought the table could be like ITEM id type slug title parentId 1 area blogs Blogs 2 blog programming Programming blog 1 3 tagsearch tags 2 4 post hello-world Hello World! 2 Could I use Sql Server's hierarchyid type somehow (especially point 1, "/blogs/programming/tags" is the last valid item)? Tree depth would usually be around 3-4. What would be the best way to achieve all this?

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  • Specialization hierarchy in a domain-model

    - by devoured elysium
    I'm trying to make the domain model of a management system. I have the following kinds of persons in this system: employee manager top mananger I decided to define a User, from where employee, manager and top manager will specialize from. What I don't know is what kind of specialization hierarchy I should choose from. I thought of two ways: or Which might be preferable and why? As a long time coder, every time I try to do a domain-model, I have to fight against the idea of trying to think in how I'm going to code this. From what I've understood, I should not think about those matters in the domain-model, only in object relationships. I don't have to think of code duplication or any of these kind of details here, so I can't really pick any of the options over the other. Thanks

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  • Polymorphic functions with parameters from a class hierarchy

    - by myahya
    Let's say I have the following class hierarchy in C++: class Base; class Derived1 : public Base; class Derived2 : public Base; class ParamType; class DerivedParamType1 : public ParamType; class DerivedParamType2 : public ParamType; And I want a polymorphic function, func(ParamType), defined in Base to take a parameter of type DerivedParamType1 for Derived1 and a parameter of type DerivedParamType2 for Derived2. How would this be done without pointers, if possible?

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  • CTE to build a list of departments and managers (hierarchical)

    - by Milky Joe
    I need to generate a list of users that are managers, or managers of managers, for company departments. I have two tables; one details the departments and one contains the manager hierarchy (simplified): CREATE TABLE [dbo].[Manager]( [ManagerId] [int], [ParentManagerId] [int]) CREATE TABLE [dbo].[Department]( [DepartmentId] [int], [ManagerId] [int]) Basically, I'm trying to build a CTE that will give me a list of DepartmentIds, together with all ManagerIds that are in the manager hierarchy for that department. So... Say Manager 1 is the Manager for Department 1, and Manager 2 is Manager 1's Manager, and Manager 3 is Manager 2's Manager, I'd like to see: DepartmentId, ManagerId 1, 1 1, 2 1, 3 Basically, managers are able to deal with all of their sub-manager's departments. Building the CTE to return the Manager hierarchy was fairly simple, but I'm struggling to inject the Departments in there: WITH DepartmentManagers AS ( SELECT ManagerId, ParentManagerId, 0 AS Depth From Manager UNION ALL SELECT Manager.ManagerId, Manager.ParentManagerId, DepartmentManagers.Depth + 1 AS Depth FROM Manager INNER JOIN DepartmentManagers ON DepartmentManagers.ManagerId = Manager.ParentManagerId ) Can anyone help?

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  • Types in Union or Concat cannot be constructed with hierarchy

    - by user927777
    I am trying to run a query very similar to the following: (from bs in DataContext.TblBookShelf join b in DataContext.Book on bs.BookID equals b.BookID where bs.BookShelfID == bookShelfID select new BookItem { Categories = String.Join("<br/>", b.BookCategories.Select(x => x.Name).DefaultIfEmpty().ToArray()), Name = b.Name, ISBN = b.ISBN, BookType = "Shelf" }).Union(from bs in DataContext.TblBookShelf join bi in DataContext.TblBookInventory on bs.BookID equals bi.BookID select new BookItem { Categories = String.Join("<br/>", bi.BookCategories.Select(x => x.Name).DefaultIfEmpty().ToArray()), Name = bi.Name, ISBN = bi.ISBN, BookType = "Inventory" }); I am receiving "Types in Union or Concat cannot be constructed with hierarchy" after the statement executes, I need to to be able to get a list of categories to display with each book. If anyone could shed some light on a possible solution, it would be greatly appreciated.

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  • Looking for a .NET 3.5 / J2EE architecture concept comparison article/chart

    - by Edward Tanguay
    We are thinking about combining .NET technology with Java technology (WCF, JBoss/ESB, MOM, WPF, WF) and I need to have a high-level idea of what are the apples and oranges in the .NET 3.5 and Java worlds. Does anyone know of a good, clear article or better yet a simple chart which answers questions such as: WCF in the Java world is __ the equivalent of WPF in the Java world is _ the closes thing to JBoss in the .NET world is _ the JVM and CLR are essentially the same except for these differences: .... in the Java world you don't have the concept of WF/WCF/WPF, instead you have .... there is no "LINQ" in the Java world yet, but you can use ___ the closest you get to ADO.NET Data Services in the Java world is .... I'm not looking to debate this so I'm not looking for "fighting points", I just need a neutral what-is-what chart comparing the two worlds.

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  • issue about Concept of JFrame, JLabel and ContentPane

    - by Sun Hong Kim
    I just study window programming with awt. I see through several codes but I can not get concepts of JFrame, JLabel and ContentPane. I think JFrame only make outer Frame. ContentPane is container that contain JLabel that has contents(text, button, radio etc...). I don't know this is correct T.T Why I ask this is I failed combine the contents. I can not make TextField and InternalFrame at a time. I want to know the concept. I hope you take my question right.

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  • ASP.NET MVC: What's the difference in concept between Service and Repository

    - by Richard77
    Hello, The question I'm asking is kind of subjective. I've seen twice, while exercising with real projects such as StoreFront, both Repository and Services. Sometimes they can just be folders or projects attached to the solution. But they contain classes and interfaces. So, I'd like to know what goes to the repository and what goes to the services. So far, I was familiar with repositories (we put methods and properties in the repository to reduce the complexity in the controller). How about the services? So, ASP.NET MVC: What's the difference in concept between Service and Repository? (Maybe none) My question is Kind of subjective, but I'd like to make sure that I'm not missing anything. Thanks for helping

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  • Understanding the concept of inheritance in Java

    - by Nirmal
    Hello All.... I am just refreshing the oops features of the java. So, I have a little confusion regarding inheritance concept. For that I have a following sample code : class Super{ int index = 5; public void printVal(){ System.out.println("Super"); } } class Sub extends Super{ int index = 2; public void printVal(){ System.out.println("Sub"); } } public class Runner { public static void main(String args[]){ Super sup = new Sub(); System.out.println(sup.index+","); sup.printVal(); } } Now above code is giving me output as : 5,Sub. Here, we are overriding printVal() method, so that is understandable that it is accessing child class method only. But I could not understand why it's accessing the value of x from Super class... Thanks in advance....

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  • CSS Sprites : Mysterious Concept Explored ?

    - by Rachel
    I have 3 different images and now I want to create an sprite using css so that I am reducing HTTP Request. I am totally new to this concept and have not idea as to how to approach this. Can anyone suggest me what would be best bet for me ? Also I have seen there are some CSS Sprite generator engines where in you submit .zip folder containing your images and than they would combine it. I tried doing that but did not understood of what was happening and so any guidance regarding creating and using CSS sprites would be highly appreciated. Update: I have gone through the AList Part but it was not very clear to me. Can anyone explain the use case of CSS Sprites using an example ? Thanks.

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  • Java Inheritance Concept Understanding

    - by Nirmal
    Hello All.... I am just refreshing the oops features of the java. So, I have a little confusion regarding inheritance concept. For that I have a following sample code : class Super{ int index = 5; public void printVal(){ System.out.println("Super"); } } class Sub extends Super{ int index = 2; public void printVal(){ System.out.println("Sub"); } } public class Runner { public static void main(String args[]){ Super sup = new Sub(); System.out.println(sup.index+","); sup.printVal(); } } Now above code is giving me output as : 5,Sub. Here, we are overriding printVal() method, so that is understandable that it is accessing child class method only. But I could not understand why it's accessing the value of x from Super class... Thanks in advance....

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  • Android: The concept for detecting changes of an opened file

    - by niko
    I wrote an application for video recording which stores the recording to a file. Currently I am looking for a way to implement some kind of "listener" to listen for file changes. The concept I would like to implement is the following: Check the file on a set period of time (for example one second), extract changes (get the data that was written in the last period) and do something with these data. I would be very thankful if anyone of you could give any suggestion or point to any useful resource that could help to solve the given problem.

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