I'm working on an MVVM project, so I have folders in my project like Models, ViewModels, Windows, etc. Whenever I create a new class, Visual Studio automatically adds the folder name to the namespace designation instead of just keeping the project-level namespace. So, adding a new class to the ViewModels folder would result in the namespace, MyProject.ViewModels
instead of just MyProject
.
When I first encountered this, it annoyed me. My class names are pretty clear, sometimes even containing the name of the folder in them (e.g., ContactViewModel
). I quickly found myself manually removing the folder name on the namespaces. I even tried at one point to create a custom class template (see this question), but I couldn't get that to work, so continued doing it manually.
I've begun to wonder, though, if this convention exists for a good reason that I'm just not seeing. I could see it being useful if you for some reason had lots of sets of identical class names organized into folders, but that doesn't seem like a particularly common scenario.
Questions:
- Why is it common convention for namespace names to reflect folder structure?
- Do you abide by this convention? Why?
I also feel the pain with this 'by default' behaviour in Visual Studio.
Visual Studio also tries to set a namespace/directory match when you put your LinqToSql
.dbml
files in their own directory. Whenever I edit the.dbml
, I have to remember to:.dbml.designer.cs
filenamespace
declarationThere's a way to stop this behaviour, though. It involves creating a custom class template.
i was annoyed by this as well but working with and refactoring projects with large codebases quickly taught me otherwise. Having embraced the concept i think that it's a very good way to structure your code "physically" as well as logically. When you have a large project and the namespaces do not match up to the folders it becomes difficult to locate files quickly. It's also that much more difficult to remember where things are...
Also, if ReSharper recommends it, then it's probably a good idea. E.g. R# will complain if your class' namespace does not match its folder name.
Before namespaces were introduced in C++ all C types were in the global namespace. Namespaces were created to segregate types into logical containers so it was clear what type is being referred to. This also applies to C#.
Assemblies are a deployment decision. If you look at the .Net framework a given assembly will contain multiple different namespaces.
Folder are to organize files on disk.
The three have nothing to do with each other, however, it's often convenient that the assembly name, namespace and folder names are the same. Note that Java collapses folders and namespaces to be the same thing (limiting the developer's freedom to organize files and namespaces).
Often we choose to organize files in a project into multiple folders because it's easier for me or my team to navigate the files. Usually this file organization has nothing to do with the namespace design we use. I wish the VS team would not default the namespace to be the same as the folder name or at least give the option back to not have this be the default.
Don't suffer, either change the template for new classes or correct the namespace after the new file gets created.
One way of not following the convention is to create the file in the project root folder and then move it to the final sub-folder.
Anyhow, it is a convention I actually like. If I am splitting types into folders, then probably those types have some kind of conceptual grouping related to the folder. Therefore, it ends making some sense, their namespaces are also similar. Java takes this approach and enforces it with its package system. The biggest difference is that VS is only "suggesting" it to you, since neither the language or the CLR enforces it.
While I agree with everyone else, that a physical structure matching the logical structure is helpful, I have to say I also fight with Visual Studio's auto-naming. There are half a dozen reasons why I have to rename classes:
With thiose reasons, I've resigned myself to having to adjust those for every class I create. My strategy to avoid the issue is copying a file that has the namespace declaration I want, and then immediately delete the contents.
Same as you - I fought this for the longest time. Then I started considering why I created folders. I found myself starting to create folders to represent namespaces and packages instead of arbitrary buckets.
For instance, in an MVVM project, it might be helpful to put views and view models in a separate namespace. MVC will have a separate namespace for Models, Controllers, and Views. It is also beneficial to group classes by their feature.
Suddenly, the project feels more organized. It is easier for other developers to find where features are implemented.
If you standardize on your namespace practices, all of your projects will have the same predictable structure which will be a big win for maintenance.