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• What is the advantage of placing "{" on the same line as a conditional statement?

  - by DrLazer

  I have kind of got used to it now but in the past if i had to work on a piece of code someone else had written with the brackets placed in this way I would have to go through and change it all. Why would anybody do this, I can't think of a single advantage but lots of disadvantages.

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• Method returns an IDisposable - Should I dispose of the result, even if it's not assigned to anythin

  - by mjd79

  This seems like a fairly straightforward question, but I couldn't find this particular use-case after some searching around. Suppose I have a simple method that, say, determines if a file is opened by some process. I can do this (not 100% correctly, but fairly well) with this: public bool IsOpen(string fileName) { try { File.Open(fileName, FileMode.Open, FileAccess.Read, FileShare.None); } catch { // if an exception is thrown, the file must be opened by some other process return true; } } (obviously this isn't the best or even correct way to determine this - File.Open throws a number of different exceptions, all with different meanings, but it works for this example) Now the File.Open call returns a FileStream, and FileStream implements IDisposable. Normally we'd want to wrap the usage of any FileStream instantiations in a using block to make sure they're disposed of properly. But what happens in the case where we don't actually assign the return value to anything? Is it still necessary to dispose of the FileStream, like so: try { using (File.Open(fileName, FileMode.Open, FileAccess.Read, FileShare.None)); { /* nop */ } } catch { return true; } Should I create a FileStream instance and dispose of that? try { using (FileStream fs = File.Open(fileName, FileMode.Open, FileAccess.Read, FileShare.None)); } ... Or are these totally unnecessary? Can we simply call File.Open and not assign it to anything (first code example), and let the GC dispose of it right away?

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• Is it advisable to have an interface as the return type?

  - by wb

  I have a set of classes with the same functions but with different logic. However, each class function can return a number of objects. It is safe to set the return type as the interface? Each class (all using the same interface) is doing this with different business logic. protected IMessage validateReturnType; <-- This is in an abstract class public bool IsValid() <-- This is in an abstract class { return (validateReturnType.GetType() == typeof(Success)); } public IMessage Validate() { if (name.Length < 5) { validateReturnType = new Error("Name must be 5 characters or greater."); } else { validateReturnType = new Success("Name is valid."); } return validateReturnType; } Are there any pitfalls with unit testing the return type of an function? Also, is it considered bad design to have functions needing to be run in order for them to succeed? In this example, Validate() would have to be run before IsValid() or else IsValid() would always return false. Thank you.

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• Is the provider model using the factory pattern?

  - by Blankman

  Hi, Is the provider model really just the factory pattern?

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• Can I use an abstract class instead of a private __construct() when creating a singleton in PHP?

  - by Pheter

  When creating a Singleton in PHP, I ensure that it cannot be instantiated by doing the following: class Singleton { private function __construct() {} private function __clone() {} public static function getInstance() {} } However, I realised that defining a class as 'abstract' means that it cannot be instantiated. So is there anything wrong with doing the following instead: abstract class Singleton { public static function getInstance() {} } The second scenario allows me to write fewer lines of code which would be nice. (Not that it actually makes much of a difference.)

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• Javascript object encapsulation that tracks changes

  - by Raynos

  Is it possible to create an object container where changes can be tracked Said object is a complex nested object of data. (compliant with JSON). The wrapper allows you to get the object, and save changes, without specifically stating what the changes are Does there exist a design pattern for this kind of encapsulation Deep cloning is not an option since I'm trying to write a wrapper like this to avoid doing just that. The solution of serialization should only be considered if there are no other solutions. An example of use would be var foo = state.get(); // change state state.update(); // or state.save(); client.tell(state.recentChange()); A jsfiddle snippet might help : http://jsfiddle.net/Raynos/kzKEp/ It seems like implementing an internal hash to keep track of changes is the best option. [Edit] To clarify this is actaully done on node.js on the server. The only thing that changes is that the solution can be specific to the V8 implementation.

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• Refactoring one large list of C# properties/fields

  - by dotnetdev

  If you take a look at http://www.c-sharpcorner.com/UploadFile/dhananjaycoder/activedirectoryoperations11132009113015AM/activedirectoryoperations.aspx, there is a huge list of properties for AD in one class. What is a good way to refactor such a large list of (Related) fields? Would making seperate classes be adequate or is there a better way to make this more manageable? Thanks

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• MVC: User Message Stack implementations

  - by SDReyes

  How would you implement a user message stack in ASP.Net MVC (you set messages for the user in any place inside your app. and they are shown as hints of your app to the user anywhere inside the app) e.g.:

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• What do you do in your source control repository when you start a rewrite of a program?

  - by Max Schmeling

  I wrote an application a while back and have been maintaining it for a while now, but it's gotten to the point where there's several major new features to be added, a ton of changes that need made, and I know quite a few things I could do better, so I'm starting a rewrite of the entire program (using bits and pieces from original). My question is, what do you do with SVN at this point? Should I put the new version somewhere else, or should I delete the files I no longer need, add the new files, and just treat it like normal development in SVN? How have you handled this in the past?

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• Writing my own implementation of stl-like Iterator in C++.

  - by Negai

  Good evening everybody, I'm currently trying to understand the intrinsics of iterators in various languages i.e. the way they are implemented. For example, there is the following class exposing the list interface. template<class T> class List { public: virtual void Insert( int beforeIndex, const T item ) throw( ListException ) =0 ; virtual void Append( const T item ) =0; virtual T Get( int position ) const throw( ListException ) =0; virtual int GetLength() const =0; virtual void Remove( int position ) throw( ListException ) =0; virtual ~List() =0 {}; }; According to GoF, the best way to implement an iterator that can support different kinds of traversal is to create the base Iterator class (friend of List) with protected methods that can access List's members. The concrete implementations of Iterator will handle the job in different ways and access List's private and protected data through the base interface. From here forth things are getting confusing. Say, I have class LinkedList and ArrayList, both derived from List, and there are also corresponding iterators, each of the classes returns. How can I implement LinkedListIterator? I'm absolutely out of ideas. And what kind of data can the base iterator class retrieve from the List (which is a mere interface, while the implementations of all the derived classes differ significantly) ? Sorry for so much clutter. Thanks.

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• Design pattern: Polymorphism for list of objects

  - by ziang

  Suppose I have a class A, and A1, A2 inherits from A. There are 2 functions: List<A1> getListA1(){...} List<A2> getListA2(){...} Now I want to do something similar to both A1 and A2 in another function public void process(List<A>){...} If I want to pass the instance of either ListA1 or ListA2, of course the types doesn't match because the compiler doesn't allow the coercion from List< A1 to List< A. I can't do something like this: List<A1> listA1 = getListA1(); List<A> newList = (List<A>)listA1; //this is not allowed. So what is the best approach to the process()? Is there any way to do it in a universal way rather than write the similar code to both List and List?

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• A cross-platform application WPF, ASP.NET, Silverlight, WP7, XAML

  - by J. Lennon

  Considering the fact that all applications will interact with the web project (which will use the cloud or web services).. Is there any way to share my class models between applications? If yes, what is the best way to do it? About sending / receiving data from the Webservice, serialize and deserialize, how can I do this in a simple way without having to manually populate the objects? Any information about this applications would be really helpful!

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• What do you call the concept of dynamic data definition?

  - by DJTripleThreat

  Maybe this is simpler and more straightforward then what I'm thinking but I can't seem to find this concept on google anywhere. The concept is this: You have a table in a database and the table has a specified number of columns. However, it has been asked of me by previous clients that there also be a set of dynamic user defined columns that can be added on the fly. What is this concept called and is it considered a design pattern?

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• best-practice on C header files with #ifndef #define #endif

  - by guest

  what is concerned best practice regarding the following "pattern"? #ifndef BLAFOO_H #define BLAFOO_H /* ... * ... */ #endif /* BLAFOO_H */ how should i name the header in the #define directive? i've seen all from said BLAFOO_H to __BLAFOO_H to _BLAFOO_H_ etc..

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• Is it considered bad practice to have ViewModel objects hold the Dispatcher?

  - by stiank81

  My WPF application is structured using the MVVM pattern. The ViewModels will communicate asynchronously with a server, and when the requested data is returned a callback in the ViewModel is triggered, and it will do something with this data. This will run on a thread which is not the UI Thread. Sometimes these callbacks involve work that needs to be done on the UI thread, so I need the Dispatcher. This might be things such as: Adding data to an ObservableCollection Trigger Prism commands that will set something to be displayed in the GUI Creating WPF objects of some kind. I try to avoid the latter, but the two first points here I find to be reasonable things for ViewModels to do. So; is it okay to have ViewModels hold the Dispatcher to be able to Invoke commands for the UI thread? Or is this considered bad practice? And why?

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• Best practice: How to persist simple data without a database in django?

  - by Infinity

  I'm building a website that doesn't require a database because a REST API "is the database". (Except you don't want to be putting site-specific things in there, since the API is used by mostly mobile clients) However there's a few things that normally would be put in a database, for example the "jobs" page. You have master list view, and the detail views for each job, and it should be easy to add new job entries. (not necessarily via a CMS, but that would be awesome) e.g. example.com/careers/ and example.com/careers/77/ I could just hardcode this stuff in templates, but that's no DRY- you have to update the master template and the detail template every time. What do you guys think? Maybe a YAML file? Or any better ideas? Thx

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• Is it a good or bad practice to call instance methods from a java constructor?

  - by Steve

  There are several different ways I can initialize complex objects (with injected dependencies and required set-up of injected members), are all seem reasonable, but have various advantages and disadvantages. I'll give a concrete example: final class MyClass { private final Dependency dependency; @Inject public MyClass(Dependency dependency) { this.dependency = dependency; dependency.addHandler(new Handler() { @Override void handle(int foo) { MyClass.this.doSomething(foo); } }); doSomething(0); } private void doSomething(int foo) { dependency.doSomethingElse(foo+1); } } As you can see, the constructor does 3 things, including calling an instance method. I've been told that calling instance methods from a constructor is unsafe because it circumvents the compiler's checks for uninitialized members. I.e. I could have called doSomething(0) before setting this.dependency, which would have compiled but not worked. What is the best way to refactor this? Make doSomething static and pass in the dependency explicitly? In my actual case I have three instance methods and three member fields that all depend on one another, so this seems like a lot of extra boilerplate to make all three of these static. Move the addHandler and doSomething into an @Inject public void init() method. While use with Guice will be transparent, it requires any manual construction to be sure to call init() or else the object won't be fully-functional if someone forgets. Also, this exposes more of the API, both of which seem like bad ideas. Wrap a nested class to keep the dependency to make sure it behaves properly without exposing additional API:class DependencyManager { private final Dependency dependency; public DependecyManager(Dependency dependency) { ... } public doSomething(int foo) { ... } } @Inject public MyClass(Dependency dependency) { DependencyManager manager = new DependencyManager(dependency); manager.doSomething(0); } This pulls instance methods out of all constructors, but generates an extra layer of classes, and when I already had inner and anonymous classes (e.g. that handler) it can become confusing - when I tried this I was told to move the DependencyManager to a separate file, which is also distasteful because it's now multiple files to do a single thing. So what is the preferred way to deal with this sort of situation?

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• DataObjects.NET: a good (flawless, documented, support) ORM?

  - by David_CSharp

  I am looking for ORM frameworks, came along to NHibernate, Genome, L2S, Entity Framework and now the DataObjects.NET.. So far a I read the documentation it seems pretty cabable, but have you ever tried this ORM? Any issues/bugs with DO.NET would be approciated :)

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• commad design pattern usage

  - by sagie

  Hi. I've read 3 descriptions of the command design pattern: wikipedia, dofactory and source making. In all of them, the UML shows a relation between the client to the receiver & the concrete command, but no relation to the invoker. But in all 3 examples the client is the one that initiates the invoker and call its Execute method. I think that should be a relation to the invoker as well. Am I missing somthing in here? Maybe even a basic UML knowladge?

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• Adding behaviour to a set of classes

  - by devoured elysium

  I have defined an Event class: Event and all the following classes inherit from Event: SportEventType1 SportEventType2 SportEventType3 SportEventType4 Right now I will only have SportEvents but I don't know if in the future I'll want some other kind of events that doesn't even have anything to do with Sports. Later, I will want to draw some graphics with info taken from Events, and the drawing logic can be a bit complex. But, for the moment, I think I shouldn't think of how the drawing will be done and I believe that maybe it'd be better if that drawing part was not put as an integral part of the Event/SportEventX class chain. I am looking for solutions for this problem. I know I could just make Event have an instance variable(attribute, for the java crowds) pointing to something as an IDrawInterface, but that would make the Event class "assume" it will be later used for drawing. I would like to make the Event class oblivious to this if possible. Thanks!

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• Double use of variables?

  - by Vaccano

  I have read that a variable should never do more than one thing. Overloading a variable to do more than one thing is bad. Because of that I end up writing code like this: (With the customerFound variable) bool customerFound = false; Customer foundCustomer = null; if (currentCustomer.IsLoaded) { if (customerIDToFind = currentCustomer.ID) { foundCustomer = currentCustomer; customerFound = true; } } else { foreach (Customer customer in allCustomers) { if (customerIDToFind = customer.ID) { foundCustomer = customer; customerFound = true; } } } if (customerFound) { // Do something } But deep down inside, I sometimes want to write my code like this: (Without the foundCustomer variable) Customer foundCustomer = null; if (currentCustomer.IsLoaded) { if (customerIDToFind = currentCustomer.ID) { foundCustomer = currentCustomer; } } else { foreach (Customer customer in allCustomers) { if (customerIDToFind = customer.ID) { foundCustomer = customer; } } } if (foundCustomer != null) { // Do something } Does this secret desires make me an evil programmer? (i.e. is the second case really bad coding practice?)

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• Zend_Form: Is this really the way we should be doing things?

  - by Francis Daigle

  OK. I understand how to use Zend_Form and it's implementation of the decorator pattern. My question is, is this the best way to be going about creating forms? Shouldn't a documents forms be left to to the front-end rather than generating forms programmatically? Doesn't this kinda violate the whole idea of keeping things separate? I mean, really, even providing that you have a good understanding of the methodology being employed, does it really save one that much time? I guess what I'm looking for is some guidance as to what might be considered 'best practice'. I'm not saying that Zend_Form doesn't have it's place, I'm just wondering if it should be used in all cases (or not). And this has nothing to do with validation. I'm just thinking that something more akin to using the 'ViewScript' approach might be more appropriate in most cases. Your thoughts?

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• How to have the controller change its behavior depending on the view?

  - by Ian Boyd

  If from one view a user enters some invalid data, e.g.:     E-mail: [email protected]     then i want the controller to: not place the data into the model color the text box reddish not allow the user to save But it's possible that if the user enters the same invalid data in a different view i want the controller to: place the data into the model color the text box reddish allow the user to save But it's possible that if the user enters the same invalid data in a different view i want the controller to: place the data into the model color the text box bluish allow the user to save And it's possible that another view will: place the data into the model leave the text box uncolored allow the user to save And it's possible that another view will: auto-correct the data, placing it into the model color the text-box reddish allow the user to have And it's possible for another view to: auto-correct the data, placing it into the model update the view with the new data color the text-box bluish allow the user to save [ad infinitum] Without using n-controllers for n-views, how do i do this?

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• How much to put in a Repository class?

  - by chobo

  When using the repository pattern is it recommended to have one Repository class for each database table? Would I also map one service layer class to one repository class. I'm having a hard time trying to understand how much stuff one repository or service layer class should have. Thanks!

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• Decorator that can take both init args and call args?

  - by digitala

  Is it possible to create a decorator which can be __init__'d with a set of arguments, then later have methods called with other arguments? For instance: from foo import MyDecorator bar = MyDecorator(debug=True) @bar.myfunc(a=100) def spam(): pass @bar.myotherfunc(x=False) def eggs(): pass If this is possible, can you provide a working example?

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