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  • asp.mvc model design

    - by Radu D
    Hi, I am pretty new to MVC and I am looking for a way to design my models. I have the MVC web site project and another class library that takes care of data access and constructing the business objects. If I have in that assembly a class named Project that is a business object and I need to display all projects in a view ... should I make another model class Project? In this case the classes will be identical. Do I gain something from doing a new model class? I don't like having in views references to objects from another dll ... but i don't like duplicating the code neither. Did you encounter the same problem?

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  • What design pattern shall I use in this question?

    - by iyad al aqel
    To be frank, this is a homework question, so I'll tell you my opinion. Can you let me know my mistakes rather than giving me the solution? This is the question : Assume a restaurant that only offers the following two types of meals: (a) a full meal and (b)an economic meal. The full meal consists of the following food items and is served in the following order: 1. Appetizer 2. Drink 3. Main dish 4. Dessert Meanwhile the economic meal consists of the following food items and is served in the following order: 1. Drink 2. Main dish Identify the most appropriate design pattern that can be used to allow a customer to only order using one of the two types of meals provided and that the meal components must be served in the given order. I'm confused between the Factory and the Iterator and using them both together. Using the factory Pattern we can create the two meals full and economic and provide the user with with a base object class that will decide upon. But how can we enforce the ordering of the elements, I thought of using the iterator along that will iterate through the the composite of the two created factories sort of speak. What do you think?

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  • What are the virtues of using XML comments in .NET?

    - by Michal Czardybon
    I can't understand the virtues of using XML comments. I know they can be converted into nice documentation external to the code, but the same can be achieved with the much more concise DOxygen syntax. In my opinion the XML comments are wrong, because: They obfuscate the comments and the code in general. (They are more difficult to read by humans). Less code can be viewed on a single screen, because "summary" and "/summary" take additional lines. They suggest that all method parameters have to be commented, whereas 90% of them are obvious and SHOULD be left not commented. The only problem I have with this is that my point of view seems to be in minority. Why?

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  • Naming remote proxy classes

    - by Tobbe
    What are some good names for the client and server side classes that communicate over the network when implementing a remote proxy? The classes are often called stub and skelleton but I don't find those names very "intention revealing". Are there any other (better) alternatives?

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  • how to wrap a function that only takes individual elements to make it take a list

    - by stevejb
    Hello, Say I have a function handed to me that I cannot change and must use as is. This function takes several objects in the form of oldFunction( object1, object2, object3, ...) where ... are other arguments. I want to write a wrapper to take a list of objects. My idea was this. sjb.ListWrapper <- function(myList,...) { lLen <- length(myList) myStr <- "" for( i in 1:lLen) { myStr <- paste(myStr, "myList[[", i , "]],",sep="") } myCode <- paste("oldFunction(", myStr, "...)") eval({myCode}) } However, the issue is that I want to use this from Sweave and I need the output of oldFunction to be printed. What is the right way to do this? Thanks.

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  • Pattern for UI configuration

    - by TERACytE
    I have a Win32 C++ program that validates user input and updates the UI with status information and options. Currently it is written like this: void ShowError() { SetIcon(kError); SetMessageString("There was an error"); HideButton(kButton1); HideButton(kButton2); ShowButton(kButton3); } void ShowSuccess() { SetIcon(kError); std::String statusText (GetStatusText()); SetMessageString(statusText); HideButton(kButton1); HideButton(kButton2); ShowButton(kButton3); } // plus several more methods to update the UI using similar mechanisms I do not likes this because it duplicates code and causes me to update several methods if something changes in the UI. I am wondering if there is a design pattern or best practice to remove the duplication and make the functionality easier to understand and update. I could consolidate the code inside a config function and pass in flags to enable/disable UI items, but I am not convinced this is the best approach. Any suggestions and ideas?

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  • Java interface and abstract class issue

    - by George2
    Hello everyone, I am reading the book -- Hadoop: The Definitive Guide, http://www.amazon.com/Hadoop-Definitive-Guide-Tom-White/dp/0596521979/ref=sr_1_1?ie=UTF8&s=books&qid=1273932107&sr=8-1 In chapter 2 (Page 25), it is mentioned "The new API favors abstract class over interfaces, since these are easier to evolve. For example, you can add a method (with a default implementation) to an abstract class without breaking old implementations of the class". What does it mean (especially what means "breaking old implementations of the class")? Appreciate if anyone could show me a sample why from this perspective abstract class is better than interface? thanks in advance, George

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  • Concept of WNDCLASSEX, good programming habits and WndProc for system classes

    - by luiscubal
    I understand that the Windows API uses "classes", relying to the WNDCLASS/WNDCLASSEX structures. I have successfully gone through windows API Hello World applications and understand that this class is used by our own windows, but also by Windows core controls, such as "EDIT", "BUTTON", etc. I also understand that it is somehow related to WndProc(it allows me to define a function for it) Although I can find documentation about this class, I can't find anything explaining the concept. So far, the only thing I found about it was this: A Window Class has NOTHING to do with C++ classes. Which really doesn't help(it tells me what it isn't but doesn't tellme what it is). In fact, this only confuses me more, since I'd be tempted to associate WNDCLASSEX to C++ classes and think that "WNDCLASSEX" represents a control type . So, my first question is What is it? In second place, I understand that one can define a WndProc in a class. However, a window can also get messages from the child controls(or windows, or whatever they are called in the Windows API). How can this be? Finally, when is it a good programming practise to define a new class? Per application(for the main frame), per frame, one per control I define(if I create my own progress bar class, for example)? I know Java/Swing, C#/Windows.Form, C/GTK+ and C++/wxWidgets, so I'll probably understand comparisons with these toolkits.

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  • Expose subset of a class - design question

    - by thanikkal
    Suppose i have a product class with about close to 100 properties. Now for some operations (Say tax calculation) i dont really need this bulky product type, rather only a subset that has price related properties. I am not sure if i should create different snap shots(class) of products that just has the properties that i am interested in. what would be the ideal approach so that i don't unnecessarily pass around unsought fluff? Thanks in advance.

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  • strategy for observer pattern?

    - by fayer
    I want to use observer pattern for a logging system. We have got logObservers and logObservables. The class that will have to log something will implement iLogObservable and include these methods: private $logObservers = array(); public function addLogObserver($logObserver) { $this->logObservers[] = $logObserver; } public function removeLogObserver($logObserver) { $this->logObservers[] = $logObserver; } public function write($type, $message) { foreach($this->logObservers as $logObserver) { $logObserver->log($level, $message); ; } } Then I noticed, that a lot of classes that will use logging will have these methods and I have to copy paste. So isn't it better to have these methods in a class I call LogObservable or just Log and then use strategy (instantiate this class inside all classes that will have to log). When I change the methods in Log, all logObservables will be affected. However, I have not seen anyone use observer pattern with strategy pattern yet, but it seems to be very efficient and remove the duplications. What do you think?

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  • Simple but good pattern for EJB

    - by Sara
    What would you suggest as a good and practical but simple pattern for a soloution with: HTML + JSP (as a view/presentation) SERVLETS (controller, request, session-handling) EJB (persistence, businesslogic) MySQL DB And is it necessary to use an own layer of DAO for persistence? I use JPA to persist objects to my DB. Should I withdraw business logic from my EJB? Sources online all tell me different things and confuses me...

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  • Do the UI first with SketchFlow - Do I concern about the UI look?

    - by stacker
    There is no questions: UI-First Software Development. But what does it takes to do the UI first? I started to build a website, a complicated one, and know I start to concern about the UI. Instead to start coding html+css, I decided to start with SkecthFlow. now, I'm very confused. Do I want to build a exact sketch? meaning to think about colors, fonts make sure that the button will look like a web link... etc, or just build the application sketch flow? meaning put a textboxes and buttons. Do I need to implement every thing in SketchFlow first? I'm looking for best practice.

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  • How to allow for modular development while still running in same JVM?

    - by Marcus
    Our current app runs in a single JVM. We are now splitting up the app into separate logical services where each service runs in its own JVM. The split is being done to allow a single service to be modified and deployed without impacting the entire system. This reduces the need to QA the entire system - just need to QA the interaction with the service being changed. For interservice communication we use a combination of REST, an MQ system bus, and database views. What I don't like about this: REST means we have to marshal data to/from XML DB views couple the systems together which defeats the whole concept of separate services MQ / system bus is added complexity There is inevitably some code duplication between services You have set up n JBoss server configurations, we have to do n number of deployments, n number of set up scripts, etc, etc. Is there a better way to structure an internal application to allow modular development and deployment while allowing the app to run in a single JVM (and achieving the associated benefits)?

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  • How to save objects using Multi-Threading in Core Data?

    - by Konstantin
    I'm getting some data from the web service and saving it in the core data. This workflow looks like this: get xml feed go over every item in that feed, create a new ManagedObject for every feed item download some big binary data for every item and save it into ManagedObject call [managedObjectContext save:] Now, the problem is of course the performance - everything runs on the main thread. I'd like to re-factor as much as possible to another thread, but I'm not sure where I should start. Is it OK to put everything (1-4) to the separate thread?

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  • Calling DI Container directly in method code (MVC Actions)

    - by fearofawhackplanet
    I'm playing with DI (using Unity). I've learned how to do Constructor and Property injection. I have a static container exposed through a property in my Global.asax file (MvcApplication class). I have a need for a number of different objects in my Controller. It doesn't seem right to inject these throught the constructor, partly because of the high quantity of them, and partly because they are only needed in some Actions methods. The question is, is there anything wrong with just calling my container directly from within the Action methods? public ActionResult Foo() { IBar bar = (Bar)MvcApplication.Container.Resolve(IBar); // ... Bar uses a default constructor, I'm not actually doing any // injection here, I'm just telling my conatiner to give me Bar // when I ask for IBar so I can hide the existence of the concrete // Bar from my Controller. } This seems the simplest and most efficient way of doing things, but I've never seen an example used in this way. Is there anything wrong with this? Am I missing the concept in some way?

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  • Is there a difference here?

    - by HotHead
    Please consider following code: 1. uint16 a = 0x0001; if(a < 0x0002) { // do something } 2. uint16 a = 0x0001; if(a < uint16(0x0002)) { // do something } 3. uint16 a = 0x0001; if(a < static_cast<uint16>(0x0002)) { // do something } 4. uint16 a = 0x0001; uint16 b = 0x0002; if(a < b) { // do something } What compiler does in backgorund and what is the best (and correct) way to do above testing? p.s. sorry, but I couldn't find the better title :) Thank you in advance!

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  • Implementing the procducer-consumer with .NET 4.0 new

    - by bitbonk
    With alle the new paralell programming features in .NET 4.0, what would be a a simple and fast way to implement the producer-consumer pattern (where at least one thread is producing and enqueuing task items and one other thread executes (dequeues) these tasks). Can we benfit from all these new APIs? What is your preferred implementation of this pattern?

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  • Events and references pattern

    - by serhio
    In a project I have the following relation between BO and GUI By e.g. G could represent a graphic with time lines, C a TimeLine curve, P - points of that curve and T the time that represents each point. Each GUI object is associated with the BO corresponding object. When T changes GUI P captures the Changed event and changes its location. So, when G should be modified, it modifies internally its objects and as result T changes, P moves and the GuiG visually changes, everything is OK. But there is an inconvenient of this architecture... BO should not be recreated, because this will breack the link between BO and GUIO. In particular, GUI P should always have the same reference of T. If in a business logic I do by e.g. P1.T = new T(this.T + 10) GUI_P1 will not move anymore, because it wait an event from the reference of former P1.T object, that does not belongs to P1 anymore. So the solution was to always modify the existing objects, not to recreate it. But here is an other inconvenient: performance. Say I have a ready newC object that should replace the older one. Instead of doing G1.C = newC I should do foreach T in foreach P in C replace with T from P from newC. Is there an other more optimal way to do it?

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  • What policies are standard for programmers?

    - by Shehket's Apprentice
    My office is about has proposed implementing some extremely strict (I would consider them draconian) policies regarding programmers, and our access due to security concerns (note, we have never had a security breach). While I can theoretically get used to them, I'd like to ask about what is considered good security policy for programmers, specifically in the area of access policies, and what is too much? Any answers to this question are greatly appreciated as they directly relate to my ability to write code, and I can't find anything so far on Google. Edit: Most of the security policies that concern me are about access to my machine and to the code. According to these proposed policies, I'd need management approval to access either, which means that I'd be forced to get management to unlock my computer anytime I leave my desk as my computer is always locked when I'm not at my desk.

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  • creational pattern for instances depending on multiple subclass instances

    - by markusw
    I have a problem, for that I was not able to identify a suitable design pattern. I want to create instances depending on a given type that has been passed to a factory method. What I am doing until now is the following: T create(SuperType x) { if (x instanceof SubType1) { // do some stuff and return a new SubType extends T } else if (x instanceof SubType2) { // do some stuff and return a new SubType extends T } else if ... } else { throw new UnSupportedOperationException("nothing defined for " + x); } } It seems not to be best pratice for me. Has anybody an idea how to solve this in a better way?

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  • How to release a simple program

    - by Zenya
    What is the best practice for releasing a simple software? Suppose I created a very small simple and useful program or a tool and would like to share it with everyone by uploading it to my web-site. Do I need a license and which one? (I read http://www.gnu.org/ and http://www.fsf.org/ but still cannot decide - there are too many of them.) Do I need to put somewhere a copyright and what is the basic principles of creating "Copyright" string? How can I make a user, who is going to download and install my program, to believe that my program doesn't contain viruses or a malicious code?

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  • Best practice with respect to NPE and multiple expressions on single line

    - by JRL
    I'm wondering if it is an accepted practice or not to avoid multiple calls on the same line with respect to possible NPEs, and if so in what circumstances. For example: getThis().doThat(); vs Object o = getThis(); o.doThat(); The latter is more verbose, but if there is an NPE, you immediately know what is null. However, it also requires creating a name for the variable and more import statements. So my questions around this are: Is this problem something worth designing around? Is it better to go for the first or second possibility? Is the creation of a variable name something that would have an effect performance-wise? Is there a proposal to change the exception message to be able to determine what object is null in future versions of Java ?

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  • What is there so useful in the Decorator Pattern? My example doesn't work

    - by Green
    The book says: The decorator pattern can be used to extend (decorate) the functionality of a certain object I have a rabbit animal. And I want my rabbit to have, for example, reptile skin. Just want to decorate a common rabbit with reptile skin. I have the code. First I have abstract class Animal with everythig that is common to any animal: abstract class Animal { abstract public function setSleep($hours); abstract public function setEat($food); abstract public function getSkinType(); /* and more methods which for sure will be implemented in any concrete animal */ } I create class for my rabbit: class Rabbit extends Animal { private $rest; private $stomach; private $skinType = "hair"; public function setSleep($hours) { $this->rest = $hours; } public function setFood($food) { $this->stomach = $food; } public function getSkinType() { return $this->$skinType; } } Up to now everything is OK. Then I create abstract AnimalDecorator class which extends Animal: abstract class AnimalDecorator extends Animal { protected $animal; public function __construct(Animal $animal) { $this->animal = $animal; } } And here the problem comes. Pay attention that AnimalDecorator also gets all the abstract methods from the Animal class (in this example just two but in real can have many more). Then I create concrete ReptileSkinDecorator class which extends AnimalDecorator. It also has those the same two abstract methods from Animal: class ReptileSkinDecorator extends AnimalDecorator { public function getSkinColor() { $skin = $this->animal->getSkinType(); $skin = "reptile"; return $skin; } } And finaly I want to decorate my rabbit with reptile skin: $reptileSkinRabbit = ReptileSkinDecorator(new Rabbit()); But I can't do this because I have two abstract methods in ReptileSkinDecorator class. They are: abstract public function setSleep($hours); abstract public function setEat($food); So, instead of just re-decorating only skin I also have to re-decorate setSleep() and setEat(); methods. But I don't need to. In all the book examples there is always ONLY ONE abstract method in Animal class. And of course it works then. But here I just made very simple real life example and tried to use the Decorator pattern and it doesn't work without implementing those abstract methods in ReptileSkinDecorator class. It means that if I want to use my example I have to create a brand new rabbit and implement for it its own setSleep() and setEat() methods. OK, let it be. But then this brand new rabbit has the instance of commont Rabbit I passed to ReptileSkinDecorator: $reptileSkinRabbit = ReptileSkinDecorator(new Rabbit()); I have one common rabbit instance with its own methods in the reptileSkinRabbit instance which in its turn has its own reptileSkinRabbit methods. I have rabbit in rabbit. But I think I don't have to have such possibility. I don't understand the Decarator pattern right way. Kindly ask you to point on any mistakes in my example, in my understanding of this pattern. Thank you.

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