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  • Help, i cant reference my vars!

    - by SystemNetworks
    I have a sub-class(let's call it sub) and it contains all the function of an object in my game. In my main class(Let's call it main), i connect my sub to main. (Example sub Code: s = new sub(); Then I put my sub function at the update method. Code: s.myFunc(); Becuase in my sub, i have booleans, integers, float and more. The problem is that I don't want to connect my main class to use my main's int, booleans and others. If i connect it, it will have a stack overflow. This is what I put in my sub: Code: package javagame; import org.newdawn.slick.GameContainer; import org.newdawn.slick.Graphics; import org.newdawn.slick.Input; import org.newdawn.slick.state.StateBasedGame; public class Armory { package javagame; import org.newdawn.slick.GameContainer; import org.newdawn.slick.Graphics; import org.newdawn.slick.Input; import org.newdawn.slick.state.StateBasedGame; public class Store { public Integer wood; public Float probePositionX; public Float probePositionY; public Boolean StoreOn; public Boolean darkBought; public Integer money; public Integer darkEnergy; public Integer lifeLeft; public Integer powerLeft; public void darkStores(GameContainer gc, StateBasedGame sbg, GameContainer gc2) { Input input1 = gc.getInput(); //Player need wood to enter(200) If not there will be an error. if(wood>=200) { //Enter Store! if(input1.isKeyDown(Input.KEY_Q)) { //Player must be in this cord! if((probePositionX>393 && probePositionX<555) && (probePositionY< 271 && probePositionY>171)) { //The Store is On StoreOn=true; } } } } } In my main (update function) I put: Code: s.darkBought = darkBought; s.darkEnergy = darkEnergy; s.lifeLeft = lifeLeft; s.money = money; s.powerLeft = powerLeft; s.probePositionX = probePositionX; s.probePositionY = probePositionY; s.StoreOn = StoreOn; s.wood = wood; s.darkStores(gc, sbg, gc); The problem is when I go to the place, and I press q, nothing shows up. It should show another image. Is there anything wrong???

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  • how to write high quality GUI software with qt?

    - by Opetmar
    I want to write a project using QT library, so after learning the library and mastering it how should I start, what other libraries or things that I should learn? are there any other tools that will help me during the development or tools well help the end user to install the software and using it? What are the things that I should be aware? what are the things that I should avoid so it can run efficiently?

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  • Is there any tweak to bring back emblems in Nautilus?

    - by Achu
    I read the following dev email Removing 'Backgrounds and Emblems' and when i read this part: Note that this does not completely remove the ability for extensions (e.g. Dropbox) to add emblems programmatically by using the libnautilus-extension library, just the user-added emblems from the properties dialog/emblems sidebar. There is ability to bring emblems programmatically. So, How can i use libnautilus-extension library to add some emblems like Dropbox does? Or is there any tweak tool for this?

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  • is Microsoft LC random generator patented?

    - by user396672
    I need a very simple pseudo random generator (no any specific quality requirements) and I found Microsoft's variant of LCG algorithm used for rand() C runtime library function fit my needs (gcc's one seems too complex). I found the algorithm here: http://rosettacode.org/wiki/Linear_congruential_generator#C However, I worry the algorithm (including its "magic numbers" i.e coefficients) may by patented or restricted for use in some another way. Is it allowed to use this algorithm without any licence or patent restrictions or not? I can't use library rand() because I need my results to be exactly reproducible on different platforms

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  • Preferred way to render text in OpenGL

    - by dukeofgaming
    Hi, I'm about tu pick up computer graphics once again for an university project. For a previous project I used a library called ftgl that didn't leave me quite satisfied as it felt kind of heavy (I tried all rendering techniques, text rendering didn't scale very well). My question is, is there a good and efficient library for this?, if not, what would be the way to implement fast but nice looking text?. Some intended uses are: Floating object/character labels Dialogues Menus HUD Regards and thanks in advance. EDIT: Preferrably that it can load fonts

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  • Calling functions from different classes

    - by A Ron Hubbard Clevenger
    I'm writing a program and I'm supposed to check and see if a certain object is in the list before I call it. I set up the contains() method which is supposed to use the equals() method of the Comparable interface I implemented on my Golfer class but it doesn't seem to call it (I put print statements in to check). I can't seem to figure out whats wrong with the code, the ArrayUnsortedList class I'm using to go through the list even uses the correct toString() method I defined in my Golfer class but for some reason it won't use the equals() method I implemented. //From "GolfApp.java" public class GolfApp{ ListInterface <Golfer>golfers = new ArraySortedList<Golfer> (20); Golfer golfer; //..*snip*.. if(this.golfers.contains(new Golfer(name,score))) System.out.println("The list already contains this golfer"); else{ this.golfers.add(this.golfer = new Golfer(name,score)); System.out.println("This golfer is already on the list"); } //From "ArrayUnsortedList.java" protected void find(T target){ location = 0; found = false; while (location < numElements){ if (list[location].equals(target)) //Where I think the problem is { found = true; return; } else location++; } } public boolean contains(T element){ find(element); return found; } //From "Golfer.java" public class Golfer implements Comparable<Golfer>{ //..irrelavant code sniped..// public boolean equals(Golfer golfer) { String thisString = score + ":" + name; String otherString = golfer.getScore() + ":" + golfer.getName() ; System.out.println("Golfer.equals() has bee called"); return thisString.equalsIgnoreCase(otherString); } public String toString() { return (score + ":" + name); } My main problem seems to be getting the find function of the ArrayUnsortedList to call my equals function in the find() part of the List but I'm not exactly sure why, like I said when I have it printed out it works with the toString() method I implemented perfectly. I'm almost positive the problem has to do with the find() function in the ArraySortedList not calling my equals() method. I tried using some other functions that relied on the find() method and got the same results.

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  • Updating My Online Boggle Solver Using jQuery Templates and WCF

    With WebForms, each ASP.NET page's rendered output includes a <form> element that performs a postback to the same page whenever a Button control within the form is clicked, or whenever the user modifies a control whose AutoPostBack property is set to True. This model simplifies web page development, but carries with it some costs - namely, the large amount of data exchanged between the client and the server during a postback. On postback the browser sends the values of all of its form fields (including hidden ones, like view state, which may be quite large) to the server; the server then sends back the entire contents of the web page. While there are some scenarios where this amount of information needs to be exchanged, in many cases the user has performed some action that requires far less information to be exchanged. With a little bit of forethought and code we can have the browser and server exchange much less data, which leads to more responsive web pages and an improved user experience. Over the past several weeks I've been writing an article series on accessing server-side data from client script. Rather than rely solely on forms and postbacks, many websites use JavaScript code to asynchronously communicate with the server in response to the page loading or some other user action. The server, upon receiving the JavaScript-initiated request, returns just the data needed by the browser, which the browser then seamlessly integrates into the web page. There are a variety of technologies and techniques that can be employed to provide both the needed server- and client-side functionality. Last week's article, Using WCF Services with jQuery and the ASP.NET Ajax Library, explored using the Windows Communication Foundation, or WCF, to serve data from the web server and showed how to consume such a service using both the ASP.NET Ajax Library and jQuery. In a previous 4Guys article, Creating an Online Boggle Solver, I built an application to find all solutions in a game of Boggle. (Boggle is a word game trademarked by Parker Brothers and Hasbro that involves several players trying to find as many words as they can in a 4x4 grid of letters.) This article takes the lessons learned in Using WCF Services with jQuery and the ASP.NET Ajax Library and uses them to update the user interface for my online Boggle solver, replacing the existing WebForms-based user interface with a more modern and responsive interface. I also used jQuery Templates, a JavaScript-based templating library that is useful for displaying the results from a server-side service. Read on to learn more! Read More >

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  • Another question about handling game states

    - by Eva
    I'm making a game designed with the entity-component paradigm that uses systems to communicate between components as explained here. I've reached the point in my development that I need to add game states (such as paused, playing, level start, round start, game over, etc.), but I'm not sure how to do it with my framework. I've looked at this code example on game states which everyone seems to reference, but I don't think it fits with my framework. It seems to have each state handling its own drawing and updating. My framework has a SystemManager that handles all the updating using systems. For example, here's my RenderingSystem class: public class RenderingSystem extends GameSystem { private GameView gameView_; /** * Constructor * Creates a new RenderingSystem. * @param gameManager The game manager. Used to get the game components. */ public RenderingSystem(GameManager gameManager) { super(gameManager); } /** * Method: registerGameView * Registers gameView into the RenderingSystem. * @param gameView The game view registered. */ public void registerGameView(GameView gameView) { gameView_ = gameView; } /** * Method: triggerRender * Adds a repaint call to the event queue for the dirty rectangle. */ public void triggerRender() { Rectangle dirtyRect = new Rectangle(); for (GameObject object : getRenderableObjects()) { GraphicsComponent graphicsComponent = object.getComponent(GraphicsComponent.class); dirtyRect.add(graphicsComponent.getDirtyRect()); } gameView_.repaint(dirtyRect); } /** * Method: renderGameView * Renders the game objects onto the game view. * @param g The graphics object that draws the game objects. */ public void renderGameView(Graphics g) { for (GameObject object : getRenderableObjects()) { GraphicsComponent graphicsComponent = object.getComponent(GraphicsComponent.class); if (!graphicsComponent.isVisible()) continue; GraphicsComponent.Shape shape = graphicsComponent.getShape(); BoundsComponent boundsComponent = object.getComponent(BoundsComponent.class); Rectangle bounds = boundsComponent.getBounds(); g.setColor(graphicsComponent.getColor()); if (shape == GraphicsComponent.Shape.RECTANGULAR) { g.fill3DRect(bounds.x, bounds.y, bounds.width, bounds.height, true); } else if (shape == GraphicsComponent.Shape.CIRCULAR) { g.fillOval(bounds.x, bounds.y, bounds.width, bounds.height); } } } /** * Method: getRenderableObjects * @return The renderable game objects. */ private HashSet<GameObject> getRenderableObjects() { return gameManager.getGameObjectManager().getRelevantObjects( getClass()); } } Also all the updating in my game is event-driven. I don't have a loop like theirs that simply updates everything at the same time. I like my framework because it makes it easy to add new GameObjects, but doesn't have the problems some component-based designs encounter when communicating between components. I would hate to chuck it just to get pause to work. Is there a way I can add game states to my game without removing the entity-component design? Does the game state example actually fit my framework, and I'm just missing something?

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  • Sprite Animation Toolkits for iPhone

    - by Mike Eggleston
    Does anyone know of any good (and preferably free) Sprite Animation Toolkits/Libraries for iOS development? This library should be able to handle the collision detection and the movement of the sprites. Back in the 90's there was a Pascal library called Sprite Animation Toolkit by Ingemar Ragnemalm that handled a lot of the heft to create animations and the such. I am just wondering if there is anything like that in the iOS world?

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  • Good GUI for OpenGL

    - by Cristina
    I am starting to learn OpenGL with FreeGLUT using the Superbible and the knowledge i have from my elementary graphics to brush up on my skills. To get more from this experience i want to integrate a GUI to overwrite the one FreeGLUT uses, now my question is this: is this thing possible and what library should i use? Some characteristics for the library: Open source Multi-platform (Linux and Windows) C/C++ If you have any other recommendations please feel free to post them along with your answers for my problem.

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  • Ubuntu App Contest - Open Source Libraries

    - by Chao
    I just found out about and started looking into the Ubuntu App Contest, and I wanted to double check the contest's stance on using open source libraries built by others that are freely available on the web. I read through the rules and some of the other Q&As, and it sounds like using these libraries would not be allowed (since it could mean the app isn't built from scratch, and the library would not be in the Ubuntu archive - although I could bundle the library with the app), and I just wanted to verify this assumption. Thanks! Chao

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  • Training v. Teaching

    - by Chris Gardner
    Originally posted on: http://geekswithblogs.net/freestylecoding/archive/2014/05/28/training-v.-teaching.aspxAs some of you may know, I recently accepted a position to teach an undergraduate course at my alma mater. Yesterday, I had my first day in an academic classroom. I immediately noticed a difference with the interactions between the students. They don't act like students in a professional training or conference talk. I wanted to use this opportunity to enumerate some of those differences. The immediate thing I noticed was the lack of open environment. This is not to say the class was hostile towards me. I am used to entering the room, bantering with audience, loosening everyone a bit, and flowing into the discussion. A purely academic audience does not banter. At least, they do not banter on day one. I think I can attribute this to two factors. This first is a greater perception of authority. In a training or conference environment, I am an equal with the audience. This is true even if I am being a subject matter expert. We're all professionals. We're all there to learn from each other, share our stories, and enjoy the journey. In the academic classroom, there was a distinct class difference. I had forgotten about this distinction; I had the professional familiarity with the staff by the time I completed my masters. This leads to the other distinction. These was an expectation of performance. At conference and professional training, there is generally no (immediate) grading. This may be a preparation for a certification exam, but I'm not the one responsible for delivering the exam. This was not the case in the academic classroom. These students are battling for points, and I am the sole arbiter. These students are less likely to let the material wash over them, applying the material to their past experiences. They were down taking notes. I don't want to leave the impression that there was no interact in the classroom. I spent a good deal of time doing problems with the class on the whiteboard. I tried to get the class to help me work out the steps. This opened up a few of them. After every conference or training class, I always get a few people that will email me afterward to continue the conversation. I am very curious to see if anybody comes to my office hours tomorrow. However, that is a curiosity that will have to wait until tomorrow.

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  • What is the use of Association, Aggregation and Composition (Encapsulation) in Classes

    - by SahilMahajanMj
    I have gone through lots of theories about what is encapsulation and the three techniques of implementing it, which are Association, Aggregation and Composition. What i found is, Encapsulation Encapsulation is the technique of making the fields in a class private and providing access to the fields via public methods. If a field is declared private, it cannot be accessed by anyone outside the class, thereby hiding the fields within the class. For this reason, encapsulation is also referred to as data hiding. Encapsulation can be described as a protective barrier that prevents the code and data being randomly accessed by other code defined outside the class. Access to the data and code is tightly controlled by an interface. The main benefit of encapsulation is the ability to modify our implemented code without breaking the code of others who use our code. With this feature Encapsulation gives maintainability, flexibility and extensibility to our code. Association Association is a relationship where all object have their own lifecycle and there is no owner. Let’s take an example of Teacher and Student. Multiple students can associate with single teacher and single student can associate with multiple teachers but there is no ownership between the objects and both have their own lifecycle. Both can create and delete independently. Aggregation Aggregation is a specialize form of Association where all object have their own lifecycle but there is ownership and child object can not belongs to another parent object. Let’s take an example of Department and teacher. A single teacher can not belongs to multiple departments, but if we delete the department teacher object will not destroy. We can think about “has-a” relationship. Composition Composition is again specialize form of Aggregation and we can call this as a “death” relationship. It is a strong type of Aggregation. Child object dose not have their lifecycle and if parent object deletes all child object will also be deleted. Let’s take again an example of relationship between House and rooms. House can contain multiple rooms there is no independent life of room and any room can not belongs to two different house if we delete the house room will automatically delete. The question is: Now these all are real world examples. I am looking for some description about how to use these techniques in actual class code. I mean what is the point for using three different techniques for encapsulation, How these techniques could be implemented and How to choose which technique is applicable at time.

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  • Microsoft Offloaded Data Transfer (ODX)

    - by Charles Cline
    For all you admins and other technical people out there who have watched the Windows OS spool the data from network storage to your workstation and then back to network storage, watch for Offloaded Data Transfer (ODX).  I saw ODX at TechEd a few weeks ago and the data movement is primarily kept at the backend storage network.  EMC and other storage vendors are already posting about when they will have this functionality.Here's some information about it:http://msdn.microsoft.com/en-us/library/windows/desktop/hh848056(v=vs.85).aspxhttp://msdn.microsoft.com/en-us/library/windows/desktop/hh848056(v=vs.85).aspx

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  • Stairway to SQL PowerShell Level 7: SQL Server PowerShell and the Basics of SMO

    In this level we begin our journey into the SQL Server SMO space. SMO stands for Shared Management Objects and is a library written in .NET for use with SQL Server. The SMO library is available when you install SQL Server Management Tools or you install it separately. FREE eBook – "45 Database Performance Tips for Developers"Improve your database performance with 45 tips from SQL Server MVPs and industry experts. Get the eBook here.

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  • NUMA-aware constructs for java.util.concurrent

    - by Dave
    The constructs in the java.util.concurrent JSR-166 "JUC" concurrency library are currently NUMA-oblivious. That's because we currently don't have the topology discovery infrastructure and underpinnings in place that would allow and enable NUMA-awareness. But some quick throw-away prototypes show that it's possible to write NUMA-aware library code. I happened to use JUC Exchanger as a research vehicle. Another interesting idea is to adapt fork-join work-stealing to favor stealing from queues associated with 'nearby' threads.

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  • Creating an object that is ready to be used & unset properties - with IoC

    - by GetFuzzy
    I have a question regarding the specifics of object creation and the usage of properties. A best practice is to put all the properties into a state such that the object is useful when its created. Object constructors help ensure that required dependencies are created. I've found myself following a pattern lately, and then questioning its appropriateness. The pattern looks like this... public class ThingProcesser { public List<Thing> CalculatedThings { get; set; } public ThingProcesser() { CalculatedThings = new List<Thing>(); } public double FindCertainThing() { CheckForException(); foreach (var thing in CalculatedThings) { //do some stuff with things... } } public double FindOtherThing() { CheckForException(); foreach (var thing in CalculatedThings) { //do some stuff with things... } } private void CheckForException() { if (CalculatedThings.Count < 2) throw new InvalidOperationException("Calculated things must have more than 2 items"); } } The list of items is not being changed, just looked through by the methods. There are several methods on the class, and to avoid having to pass the list of things to each function as a method parameter, I set it once on the class. While this works, does it violate the principle of least astonishment? Since starting to use IoC I find myself not sticking things into the constructor, to avoid having to use a factory pattern. For example, I can argue with myself and say well the ThingProcessor really needs a List to work, so the object should be constructed like this. public class ThingProcesser { public List<Thing> CalculatedThings { get; set; } public ThingProcesser(List<Thing> calculatedThings) { CalculatedThings = calculatedThings; } } However, if I did this, it would complicate things for IoC, and this scenario hardly seems appropriate for something like the factory pattern. So in summary, are there some good guidelines for when something should be part of the object state, vs. passed as a method parameter? When using IoC, is the factory pattern the best way to deal with objects that need created with state? If something has to be passed to multiple methods in a class, does that render it a good candidate to be part of the objects state?

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  • Print Problem in Ubuntu 10.10

    - by Michael
    There are many different Print dialogs but one is very common and is used by Gimp, Shutter, Evloution and Simple Scan. In all these apps the "Page Size" and "Orientation" are disabled. The same dialog in Firefox, Thunderbird and GEdit works OK. I program in Gambas3 which uses this dialog in conjunction with the GTK+ library and it also has these options disabled. If I use the QT4 library then a different print dialog is displayed with no problems. Anybody else notice this problem and found a solution?

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  • Learning Issued Token in Federated Service

    - by Lijo
    I would like to learn federated WCF service. I have the following in my system. • Windows XP • Visual Studio 2010 Express • SQL Server 2008 Express Is it possible to create a federated service sample with this infrastructure? Is there any article for that? UPDATE Federation: http://msdn.microsoft.com/en-us/library/ms730908.aspx Federation Sample: http://msdn.microsoft.com/en-us/library/aa355045.aspx

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  • How can I cleanly and elegantly handle data and dependancies between classes

    - by Neophyte
    I'm working on 2d topdown game in SFML 2, and need to find an elegant way in which everything will work and fit together. Allow me to explain. I have a number of classes that inherit from an abstract base that provides a draw method and an update method to all the classes. In the game loop, I call update and then draw on each class, I imagine this is a pretty common approach. I have classes for tiles, collisions, the player and a resource manager that contains all the tiles/images/textures. Due to the way input works in SFML I decided to have each class handle input (if required) in its update call. Up until now I have been passing in dependencies as needed, for example, in the player class when a movement key is pressed, I call a method on the collision class to check if the position the player wants to move to will be a collision, and only move the player if there is no collision. This works fine for the most part, but I believe it can be done better, I'm just not sure how. I now have more complex things I need to implement, eg: a player is able to walk up to an object on the ground, press a key to pick it up/loot it and it will then show up in inventory. This means that a few things need to happen: Check if the player is in range of a lootable item on keypress, else do not proceed. Find the item. Update the sprite texture on the item from its default texture to a "looted" texture. Update the collision for the item: it might have changed shape or been removed completely. Inventory needs to be updated with the added item. How do I make everything communicate? With my current system I will end up with my classes going out of scope, and method calls to each other all over the place. I could tie up all the classes in one big manager and give each one a reference to the parent manager class, but this seems only slightly better. Any help/advice would be greatly appreciated! If anything is unclear, I'm happy to expand on things.

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  • Why are there so many string classes in the face of std::string?

    - by fish
    It seems to me that many bigger C++ libraries end up creating their own string type. In the client code you either have to use the one from the library (QString, CString, fbstring etc., I'm sure anyone can name a few) or keep converting between the standard type and the one the library uses (which most of the time involves at least one copy). So, is there a particular misfeature or something wrong about std::string (just like auto_ptr semantics were bad)? Has it changed in C++11?

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  • Copying Properties between 2 Different Types&hellip;

    - by Shawn Cicoria
    I’m not sure where I had seen some of this base code, but this comes up time & time again on projects. Here’s a little method that copies all the R/W properties (public) between 2 distinct class definitions: It’s called as follows: private static void Test1() { MyClass obj1 = new MyClass() { Prop1 = "one", Prop2 = "two", Prop3 = 100 }; MyOtherClass obj2 = null; obj2 = CopyClass(obj1); Console.WriteLine(obj1); Console.WriteLine(obj2); } namespace Space1 { public class MyClass { public string Prop1 { get; set; } public string Prop2 { get; set; } public int Prop3 { get; set; } public override string ToString() { var rv = string.Format("MyClass: {0} Prop2: {1} Prop3 {2}", Prop1, Prop2, Prop3); return rv; } } } namespace Space2 { public class MyOtherClass { public string Prop1 { get; set; } public string Prop2 { get; set; } public int Prop3 { get; set; } public override string ToString() { var rv = string.Format("MyOtherClass: {0} Prop2: {1} Prop3 {2}", Prop1, Prop2, Prop3); return rv; } } Source of the method: /// /// Provides a Copy of Public fields between 2 distinct classes /// /// Source class name /// Target class name /// Instance of type Source /// An instance of type Target copying all public properties matching name from the Source. public static T CopyClass(S source) where T : new() { T target = default(T); BindingFlags flags = BindingFlags.Public | BindingFlags.Instance; if (source == null) { return (T)target; } if (target == null) target = new T(); PropertyInfo[] objProperties = target.GetType().GetProperties(flags); foreach (PropertyInfo pi in objProperties) { string name = pi.Name; PropertyInfo sourceProp = source.GetType().GetProperty(name, flags); if (sourceProp == null) { throw new ApplicationException(string.Format("CopyClass - object type {0} & {1} mismatch in property:{2}", source.GetType(), target.GetType(), name)); } if (pi.CanWrite && sourceProp.CanRead) { object sourceValue = sourceProp.GetValue(source, null); pi.SetValue(target, sourceValue, null); } else { throw new ApplicationException(string.Format("CopyClass - can't read/write a property object types {0} & {1} property:{2}", source.GetType(), target.GetType(), name)); } } return target; }

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  • Does similar Titles considered duplicates relating to SEO

    - by Uri
    I have built a testing service and I wonder if I should be concerned that search engines will consider similar titles as duplicates. For example: Some URLs title can be differed from others by only one word such as "Senior" and "Junior" Title A: C++ Online Test for Juniors Title B: C++ Online Test for Seniors Another example is with the "+" sign: Title A: C Standard Library Online Test for Seniors Title B: C++ Standard Library Online Test for Seniors Should I assume search engines will understand there is a difference in the titles? And the titles are not duplicated?

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  • The term "interface" in C++

    - by Flexo
    Java makes a clear distinction between class and interface. (I believe C# does also, but I have no experience with it). When writing C++ however there is no language enforced distinction between class and interface. Consequently I've always viewed interface as a workaround for the lack of multiple inheritance in Java. Making such a distinction feels arbitrary and meaningless in C++. I've always tended to go with the "write things in the most obvious way" approach, so if in C++ I've got what might be called an interface in Java, e.g.: class Foo { public: virtual void doStuff() = 0; ~Foo() = 0; }; and I then decided that most implementers of Foo wanted to share some common functionality I would probably write: class Foo { public: virtual void doStuff() = 0; ~Foo() {} protected: // If it needs this to do its thing: int internalHelperThing(int); // Or if it doesn't need the this pointer: static int someOtherHelper(int); }; Which then makes this not an interface in the Java sense anymore. Instead C++ has two important concepts, related to the same underlying inheritance problem: virtual inhertiance Classes with no member variables can occupy no extra space when used as a base "Base class subobjects may have zero size" Reference Of those I try to avoid #1 wherever possible - it's rare to encounter a scenario where that genuinely is the "cleanest" design. #2 is however a subtle, but important difference between my understanding of the term "interface" and the C++ language features. As a result of this I currently (almost) never refer to things as "interfaces" in C++ and talk in terms of base classes and their sizes. I would say that in the context of C++ "interface" is a misnomer. It has come to my attention though that not many people make such a distinction. Do I stand to lose anything by allowing (e.g. protected) non-virtual functions to exist within an "interface" in C++? (My feeling is the exactly the opposite - a more natural location for shared code) Is the term "interface" meaningful in C++ - does it imply only pure virtual or would it be fair to call C++ classes with no member variables an interface still?

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  • Is this a valid implementation of the repository pattern?

    - by user1578653
    I've been reading up about the repository pattern, with a view to implementing it in my own application. Almost all examples I've found on the internet use some kind of existing framework rather than showing how to implement it 'from scratch'. Here's my first thoughts of how I might implement it - I was wondering if anyone could advise me on whether this is correct? I have two tables, named CONTAINERS and BITS. Each CONTAINER can contain any number of BITs. I represent them as two classes: class Container{ private $bits; private $id; //...and a property for each column in the table... public function __construct(){ $this->bits = array(); } public function addBit($bit){ $this->bits[] = $bit; } //...getters and setters... } class Bit{ //some properties, methods etc... } Each class will have a property for each column in its respective table. I then have a couple of 'repositories' which handle things to do with saving/retrieving these objects from the database: //repository to control saving/retrieving Containers from the database class ContainerRepository{ //inject the bit repository for use later public function __construct($bitRepo){ $this->bitRepo = $bitRepo; } public function getById($id){ //talk directly to Oracle here to all column data into the object //get all the bits in the container $bits = $this->bitRepo->getByContainerId($id); foreach($bits as $bit){ $container->addBit($bit); } //return an instance of Container } public function persist($container){ //talk directly to Oracle here to save it to the database //if its ID is NULL, create a new container in database, otherwise update the existing one //use BitRepository to save each of the Bits inside the Container $bitRepo = $this->bitRepo; foreach($container->bits as $bit){ $bitRepo->persist($bit); } } } //repository to control saving/retrieving Bits from the database class BitRepository{ public function getById($id){} public function getByContainerId($containerId){} public function persist($bit){} } Therefore, the code I would use to get an instance of Container from the database would be: $bitRepo = new BitRepository(); $containerRepo = new ContainerRepository($bitRepo); $container = $containerRepo->getById($id); Or to create a new one and save to the database: $bitRepo = new BitRepository(); $containerRepo = new ContainerRepository($bitRepo); $container = new Container(); $container->setSomeProperty(1); $bit = new Bit(); $container->addBit($bit); $containerRepo->persist($container); Can someone advise me as to whether I have implemented this pattern correctly? Thanks!

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