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  • How do I map common properties in NHibernate

    - by Ian Oakes
    In the database I'm working with, every table repeats the same nine columns and I don't want to have to supply the same properties in each of my entities to map these columns. I've tried adding properties to a common base class and adding them to the sub class's mapping file, but this doesn't work. I've read the documentation around inheritance mapping but this did not help. What is the best way to map columns that repeat accross multiple tables in NHibernate?

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  • How to implement service layer in Zend Framework?

    - by takeshin
    I'm looking for some good resources to learn how to implement internal service layer in Zend Framework. This is interesting post, but with no concrete code samples. Where to put service classes (/application/modules/modulename/services/?); How to autoload them (custom autoloader?) Most common services (user, authentication, cart, cache, feed?) Sample implementations (any github repos?) Good practices?

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  • A good free BON diagram generator?

    - by Audel
    Hello I need to create a static BON diagram which represents a set of clusters, classes and their relationships(inheritance and client-supplier). Does anyone know a good diagram generator I can get for free? The BON diagram is similar to the C sharp's class diagram but this one is generated by Eiffel studio =/ any diagram generators recommendations are welcome ;D Thanks in advance .

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  • How do I move from being a software developer to being a software architect?

    - by Nestor
    I mean... Should I start programming less and designing more? Should I stop reading programming books, and start reading more books about pattern designs, etc? Should I stop focusing primarily on Microsoft technologies and open up my horizons with other technologies (in order to get a broader perspective)? How should I change my mind set in general (perhaps less detail oriented) ? etc I'm looking for concrete advice, especially from your own experience!

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  • Is there any reason for an object pool to not be treated as a singleton?

    - by Chris Charabaruk
    I don't necessarily mean implemented using the singleton pattern, but rather, only having and using one instance of a pool. I don't like the idea of having just one pool (or one per pooled type). However, I can't really come up with any concrete situations where there's an advantage to multiple pools for mutable types, at least not any where a single pool can function just as well. What advantages are there to having multiple pools over a singleton pool?

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  • xsd and wsdl incorrect file

    - by Gandalf StormCrow
    How to fix corrupted xsd and wsdl files, is there any IDE which can suggest what is wrong? such as eclipse for java code when pressing CTRL + 1 , or where can I find books tutorials to understand formatting of these file types better? thank you Here is concrete message error I have [ERROR] 'item' is already defined line 223 of file:/C:/project/src/main/resources/schema.xsd [ERROR] (related to above error) the first definition appears here line 22 of file:/C:/project/src/main/resources/schema.xsd

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  • How do I use xStream to output Java Objects with List properties?

    - by Zachary Spencer
    Hello, I am trying to output some Java objects as JSON, they have List properties which I want to be formatted as { "People" : [ { "Name" : "Bob" } , { "Name" : "Jim" } ] } However, I cannot figure out how to do this with XStream. It always outputs as { "Person" : { "Name" : "Bob" }, "Person" : { "Name" : "Bob" } Is there a way to fix this? I've put together some sample code with a unit test in github if you need something more concrete to play with: http://gist.github.com/371358 Thanks!

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  • What is the minimum interface that has the Count property in .Net

    - by SoMoS
    Hello, I need to change a method that has one parameter that takes a serie of objects. I need to find the lowest Interface (in inheritance tree) that has the Count property. Until now I was using the IEnumerable but as this has not Count I need to change it to the wider interface possible so the method can work with the biggest number of types of series (collections, lists, arrays, etc). Thanks in advance.

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  • What is "branch-on-sign expressions"?

    - by Pavel Shved
    As far as I understand the "branch-on-sign" is the name of some kind of if statement that does something depending on sign. I'm not sure that it's just if (x<0) then ... else .... However, the name "branch-on-sign" seems to denote something very concrete. So, what is it? Perhaps, it's language-specific, but I don't really know. Probably, it's related to embedded development.

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  • Usage of @specialized in traits

    - by paradigmatic
    I have a trait and an implementation looking like: trait Foo[A] { def bar[B >: A: Ordering]: Foo[B] } class FooImpl[A]( val a: A, val values: List[Foo[A]] ) extends Foo[A] { def bar[B >: A] = { /* concrete implementation */} } I would like to use the @specialized annotation on A and B to avoid autoboxing. Do I need to use it in both trait and implementation, only in implementation, or only in trait ?

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  • Repeating fields in similar database tables

    - by user1738833
    I have been tasked with working on a database that I have never seen before and I'm looking at the DB structure. Some of the central and most heavily queried and joined tables look like virtual duplicates of each other. Here's a massively simplified representation of the situation, with business-sensitive information changed, listing hypothetical table names and fields: TopLevelGroup: PK_TLGroupId, DisplaysXOnBill, DisplaysYOnBill, IsInvoicedForJ, IsInvoicedForK SubGroup: PK_SubGroupId, FK_ParentTopLevelGroupId, DisplaysXOnBill, DisplaysYOnBill, IsInvoicedForJ, IsInvoicedForK SubSubGroup: PK_SubSUbGroupId, FK_ParentSubGroupId, DisplaysXOnBill, DisplaysYOnBill, IsInvoicedForJ, IsInvoicedForK I haven't listed the types of the fields as I don't think it's particularly important to the situation. In addition, it's worth saying that rather than four repeated fields as in the example above, I'm looking at 86 repeated fields. For the most part, those fields genuinely do represent "facts" about the primary table entity, so it's not automatically wrong for that reason. In addition, the "groups" represented here have a property inheritance relationship. If DisplaysXOnBill is NULL in the SubSubGroup, it takes the value of DisplaysXOnBillfrom it's parent, the SubGroup, and so-on up to the TopLevelGroup. Further, the requirements will never require that the model extends beyond three levels, so there is no need for flexibility in that area. Is there a design smell from several tables which describe very similar entities having almost identical fields? If so, what might be a better design of the example above? I'm using the phrase "design smell" to indicate a possible problem. Of course, in any given situation, a particular design might well be the best solution. I'm looking for a more general answer - wondering what might be wrong with this design and what might be the better design were that the case. Possibly related, but not primary questions: Is this database schema in a reasonably normal form (e.g. to 3NF), insofar as can be told from the information I've provided. I can't see a problem with the requirements of 2NF and 3NF, except in their inheriting the requirements of 1NF. Is 1NF satisfied though? Are repeating groups allowed in different tables? Is there a best-practice method for implementing the inheritance relationship in a database as I require? The method above feels clunky to me because any query on the SubSubGroup necessarily needs to join onto the SubGroup and the TopLevelGroup tables to collect inherited facts, which can make even trivial joins requiring facts from the SubSubGroup table rather long-winded. There are, of course, political considerations to making a relatively large change like this. For the purpose of this question, I'm happy to ignore that fact in the interests of keeping the answers ring-fenced to the technical problem.

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  • Tile map collision detection

    - by hero
    There are many topics like this, but none with concrete answers. I am drawing a tile-map in the traditional way (two for loops) and keeping my player centered except when the edges of the map is reached. How would I create collision detection? I need to know how to translate tile location in the array to screen coordinates I think.

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  • What features would you like to see removed from C++?

    - by Justin Ethier
    This question was inspired by what-features-would-you-like-to-see-added-to-c. anBasically, C++ is a great general-purpose language. But perhaps too general and feature-rich... multiple inheritance, operator overloading, manual memory management, templates, smart pointers, virtual destructors, legacy frameworks (think MFC), and I could just go on. Is there any one feature / aspect of C++ that you would like taken away, to make our lives easier as C++ developers? One feature per answer, please.

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  • C# - calling ext. DLL function containing Delphi "variant record" parameter

    - by CaldonCZE
    Hello, In external (Delphi-created) DLL I've got the following function that I need to call from C# application. function ReadMsg(handle: longword; var Msg: TRxMsg): longword; stdcall; external 'MyDll.dll' name 'ReadMsg'; The "TRxMsg" type is variant record, defined as follows: TRxMsg = record case TypeMsg: byte of 1: (accept, mask: longword); 2: (SN: string[6]); 3: (rx_rate, tx_rate: word); 4: (rx_status, tx_status, ctl0, ctl1, rflg: byte); end; In order to call the function from C#, I declared auxiliary structure "my9Bytes" containing array of bytes and defined that it should be marshalled as 9 bytes long array (which is exactly the size of the Delphi record). private struct my9Bytes { [MarshalAs(UnmanagedType.ByValArray, ArraySubType = UnmanagedType.U1, SizeConst = 9)] public byte[] data; } Then I declared the imported "ReadMsg" function, using the "my9bytes" struct. [DllImport("MyDll.dll")] private static extern uint ReadMsg(uint handle, ref my9Bytes myMsg); I can call the function with no problem... Then I need to create structure corresponding to the original "TRxMsg" variant record and convert my auxiliary "myMsg" array into this structure. I don't know any C# equivalent of Delphi variant array, so I used inheritance and created the following classes. public abstract class TRxMsg { public byte typeMsg; } public class TRxMsgAcceptMask:TRxMsg { public uint accept, mask; //... } public class TRxMsgSN:TRxMsg { public string SN; //... } public class TRxMsgMRate:TRxMsg { public ushort rx_rate, tx_rate; //... } public class TRxMsgStatus:TRxMsg { public byte rx_status, tx_status, ctl0, ctl1, rflg; //... } Finally I create the appropriate object and initialize it with values manually converted from "myMsg" array (I used BitConverter for this). This does work fine, this solution seems to me a little too complicated, and that it should be possible to do this somehow more directly, without the auxiliary "my9bytes" structures or the inheritance and manual converting of individual values. So I'd like to ask you for a suggestions for the best way to do this. Thanks a lot!

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  • Why can't you call abstract functions from abstract classes in PHP?

    - by incrediman
    I've set up an abstract parent class, and a concrete class which extends it. Why can the parent class not call the abstract function? //foo.php <?php abstract class AbstractFoo{ abstract public static function foo(); public static function getFoo(){ return self::foo();//line 5 } } class ConcreteFoo extends AbstractFoo{ public static function foo(){ return "bar"; } } echo ConcreteFoo::getFoo(); ?> Error: Fatal error: Cannot call abstract method AbstractFoo::foo() in foo.php on line 5

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  • Writing SDK documentation, need useful beginner tutorials

    - by David Rutten
    I'm currently writing SDK documentation for one of our products, but for obvious reasons I don't want to talk about the essentials of OOP. Does anyone know any good online teaching material that explain (aimed at absolute beginners) concepts such as classes, inheritance, constructors, instances etc.? Preferably urls that are likely to survive for a couple of years to come... It's a DotNET SDK and we're including only VB and C# samples, so C++ or Delphi or Lisp material is not that useful.

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  • Ninject with Object Initializers and LINQ

    - by Alexander Kahoun
    I'm new to Ninject so what I'm trying may not even be possible but I wanted to ask. I free-handed the below so there may be typos. Let's say I have an interface: public interface IPerson { string FirstName { get; set; } string LastName { get; set;} string GetFullName(); } And a concrete: public class Person : IPerson { public string FirstName { get; set; } public string LastName { get; set; } public string GetFullName() { return String.Concat(FirstName, " ", LastName); } } What I'm used to doing is something like this when I'm retrieving data from arrays or xml: public IEnumerable<IPerson> GetPeople(string xml) { XElement persons = XElement.Parse(xml); IEnumerable<IPerson> people = ( from person in persons.Descendants("person") select new Person { FirstName = person.Attribute("FName").Value, LastName = person.Attribute("LName").Value }).ToList(); return people; } I don't want to tightly couple the concrete to the interface in this manner. I haven't been able to find any information in regards to using Ninject with LINQ to Objects or with object initializers. I may be looking in the wrong places, but I've been searching for a day now with no luck at all. I was contemplating putting the kernel into an singleton instance and seeing if that would work, but I'm not sure that it will plus I've heard that passing your kernel around is a bad thing. I'm trying to implement this in a class library currently. If this is not possible, does anyone have any examples or suggestions as to what the best practice is in this case? Thanks in advance for the help. EDIT: Based on some of the answers I feel I should clarify. Yes, the example above appears short lived but it was simply an example of one piece that I was trying to do. Let's give a bigger picture. Say instead of XML I am gathering all my data through a 3rd party web service and I'm creating an interface for it, the data could be a defined object in the wsdl or it could sometimes be an xml string. IPerson could be used for both the Person object and a User object. I will be doing this inside of a separate class library, because it needs to be portable and will be used in other projects, and handing it to an MVC3 Web Application and the objects will be used in javascript as well. I appreciate all the input so far.

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  • C#: Abstract classes need to implement interfaces?

    - by bguiz
    My test code in C#: namespace DSnA { public abstract class Test : IComparable { } } Results in the following compiler error: error CS0535: 'DSnA.Test' does not implement interface member 'System.IComparable.CompareTo(object)' Since the class Test is an abstract class, why does the compiler require it to implement the interface? Shouldn't this requirement only be compulsory for concrete classes?

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  • How to determine if a .NET Type is a custom struct?

    - by SztupY
    Hi! How to write a simple method, that checks whether a concrete type is a custom struct (created with public struct { };) or not. Checking Type.IsValueType is not enough, because it is also true to int, long, etc, and adding a check to !IsPrimitiveType won't exclude decimal, DateTime and maybe some other value types. I know that most of the built in value types are actually "structs", but I only want to check for "custom structs" These questions are mostly the same but without the answer I need: #1 #2 #3

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  • Did Java invent interfaces?

    - by Jordão
    I know about C++ pure virtual classes, but Java went one step further and created a first-class (no pun intended) concept for multiple-interface (not implementation) inheritance, the interface. It's now a staple of major statically-typed languages. Did Java invent the interface concept? Or did it appear in older languages also as a first-class concept?

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  • What are great _specific_ usability guidelines?

    - by Jilles
    Usability is extremely important, and yet there are so many products that violate a lot of rules. There are several questions on StackOverflow that are about usability (see: link1, link2, link3), however what I feel is missing still is a comprehensive list of usability "tactics": concrete examples of what (not) to do for a web application. Please don't add references to books. Please list one example per answer so that we can use the voting to actually prioritize the list.

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  • Array performance question

    - by Konrad
    I am very familiar with STL vector (and other container) performance guarantees, however I can't seem to find anything concrete about plain arrays. Are pointer arithmetic and [] methods constant or linear time?

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  • How to create a dynamic array of an Abstract class?

    - by outsyncof
    Lets say I have an abstract class Cat that has a few concrete subclasses Wildcat, Housecat, etc. I want my array to be able to store pointers to a type of cat without knowing which kind it really is. When I try to dynamically allocate an array of Cat, it doesn't seem to be working. Please help? Cat* catArray = new Cat[200];

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