I am trying to create a new asp.net core web application using Razor pages. I want to add my db context in the startup.cs file, but I am using something called IDesign.
My DbContext entity is in a project that I am not allowed to reference. I need to somehow add my context either at the accessor layer or something else. I'm not super familiar with how services work for .net core.
I have a solution set up like this:
Clients Project
The project with the cshtml files, startupcs and all of that is here
Can only reference managers and utilities projects
Managers Project
Used for chaining calls to engines/accessors to accomplish tasks at a high level
Used to make calls to accessors
Can only reference accessors, engines, and utilities project
Engines Project
Used for business logic
Can only reference the accessors and utilities projects
Accessors Project
resource accessors. Hits dbs/services.
This is where my dbcontext class lives
can't reference anything except for utilities
Utilities Project
Used to store global classes and utility functions that apply to all projects
Can't reference anything
My problem is that if my DbContext lives in the accessors project, how do I pass that up from the managers so that I can use it in the clients? Has anyone had experience with this before?
Just to reiterate, I know that I could easily reference accessors project in the clients project and use the dbcontext from there. My problem is that I want to avoid being able to reference accessors so that other people who are working with this code aren't able to see any accessors classes.
You can add the DbContext related classes in a new project without the parts of the "Accessors" project. It will be similar to the "Utilities" project, which can be used/referenced by all projects. This way your "Clients" project knows what a DbContext object is and how to use it, but it doesn't know how to get one (unless it has a connection string and connects to the database directly using the DbContext class). This would be the responsible of the "Managers" or "Accessors" project.
The references chain will look like this:
Related
What is the recommended folder structure for a IoC C# project? For a MVVM project, the standard is to create folders named Views and ViewModels (and where do you put interfaces and unit testing classes?)
What about a DLL project, that has no views, but exposes many classes to be created via IoC, which folders should be in my project?
Also as I'm starting to refactor code into IoC, I'm running into issues with the SettingsFile class that contains data that is serialized into a file. It contains a few methods:
void SetDefaultValues()
SettingsFile Load()
void Save()
string Validate()
SettingsFile Copy()
The main issue is with Load, as deserializing the object creates a new hard instance of the class, bypassing the principles of IoC. What's the right way of handling the scenario?
I'm thinking of moving all code outside of that class so that this class is only responsible for being serialized/deserialized without any code, and then excluding it from IoC. Is this the right thing to do? It's a similar problem when using Entity Framework and using any auto-generated table classes.
Thanks
The answer is to separate data classes from behavior classes. SettingsFile, as well as any EntityFramework class, contain purely data. Dependency Injection via IoC applies only to behaviors classes.
I am working on a WPF project using MVVM pattern. In solution, I have viewmodels,models,views and properties.As per requirment, I need to access the same classes(view models, models, properties) from another class library in same project. I do not want to add the reference to the class library as it is an exe file and a heavy component which has got so many classes which i do not require. So, is there any solution for this. How can i access same classes(view model,model,propeties) in a solution from another class library in same project?
Thanks & Regards
You have two choices. First one, is to refactor your exe in order to extract the reusable classes to a separate dll. Then, just add a reference to this new dll.
The other is to use reflection to access the members of the exe, which is the worst option, even worse than simply adding a reference to the big old exe.
I suggest breaking down your solution further in more projects, For example separate projects for Model, View and ViewModel or perhaps breaking down even further and then add reference only to the library you need. That way you are not exposing everything.
The other option is reflection which may be cumbersome to use and make your code ugly.
I am pretty new to MVC and I am currently working on an MVC 3 project in visual studio and I want to create a method or variable that is accessible globally. When I say globally I mean available in my web project, service layer project, and data layer project.
I guess when I say global I mean global to the entire solution.
I tried creating a class in the solution items folder and referencing in my web project but its not letting me add a reference to the class since it is not a DLL.
I am a little confused with how to do this. Any suggestion would be appreciated. Also keep in mind that though I am a programmer I am still somewhat new to MVC and programming.
Edit: I have also tried adding a method in the global.asax file but was unable to call it
You should create a shared assembly where you define the class. You can then add a reference to the shared assembly from all projects that need the feature.
The class that you want to be "global" sounds like some sort of service. I suppose this is the kind of thing you may want to do with a logging service for example.
Using a logging service as an example it is generally best practice for the interface to the logging service be defined in a lightweight contracts type assembly. Then any of your assemblies that require an implementation of ILoggingService should inject the necessary implementation using an IoC container such as Autofac or MEF.
This pattern is pretty common and allows you to share common services while keeping implementations loosely coupled. Also this pattern will lead to highly testable code as fake implementations can be injected with Moq
I'm working on WPF MVVM project which contains following projects,
Domain,
ViewModels,
Infrastructure,
Views
and for example I need IFileService that provide some operations with file and doesn't contains any business logic, I'm sure that the implementation of this interface FileService will be in Infrastructure project, but I have question where to put the IFileService interface
I need to use this interface in ViewModels project, if I will put it in this projects its mean that Infrastructure will have reference on ViewModels that is not good I think, if I will put it in Domain which contains business related classes the same.
Help me what is the best to organize structure and references between projects and where to put interfaces like IFileService?
Hmm, why not creating an additional project like DAL or DataLayer? It provides the model classes, which I'm also missing in your listing. You could also put the interface IFileService there although I would prefer working with DataProviders or Repositories (that's my prefered option), so that the VMs are not aware from where the data was loaded.
IMHO The project Infrastructure shouldn't not contain any sofisticated logic. I would put some useful methods and classes there and keep it as simple and clean as possible, so that it could be referenced everywhere. Probably, you won't even need it.
The unique rule I use for my MVVM project is, all projects have a reference to my Infrastructure project and my Infrastructure project has no reference to my other project.
So IMHO, IFileService, and interfaces in general, should be in the Infrastructure project. Then it is up to you decide where to put the implementation. The Infrastructure project usually has very basic logic implementation and final implementation goes to a dedicated project.
The only exception I sometimes add to this rule is when I base my development on an existing MVVM framework, then Infrastructure might reference it too but I try to avoid this approach.
You should put the IFileService interface to Infrastructure project. because this will make it available to every project as this is the core project right. and you might have diffrent implemantations e.g. syncronious file reader and asyncronius file reader. so the implemantation could go into your modules or ViewModels.
I'm having a couple of problems with circular reference/dependency that I've been sitting on all day. Something must be wrong with my thought process, I just don't get it.
Here are my projects:
Flip.Main (ASP.NET MVC)
Flip.Domain (C# DLL)
Flip.Services (C# DLL)
Flip.Utility (C# DLL)
Current References/Dependencies:
Flip.Main -> Flip.Domain, Flip.Services, Flip.Utility
Flip.Services -> Flip.Domain, Flip.Utility
Flip.Domain -> Flip.Utility
I wanted to structure my project in a way that my services project has all services, my domain project the model, repository and 'fluent' extensions to query the model, and the main and utility project are pretty much self explanatory.
Problems encountered:
1) I have an EmailService in my Flip.Services project, which needs to send out localized emails. All localization is done in Flip.Main's App_GlobalResources. No idea how to get the strongly typed emails and other localized resources now to my service layer as Flip.Main already depends on the service layer and therefore I can have it depend back to the Main project.
2) I have business classes, e.g. CustomerSearchFilter which represents a strongly typed search query. I want those business classes outside of the Flip.Domain project because they are not part of the domain model. However, in my CustomerSearchFilter class I have domain class instances (e.g. CustomerGroup) so it needs to know about domain classes. At the same time my Fluent interface in my Flip.Domain project needs to know what CustomerSearchFilter is so I can apply it to my IQueryable interface. Circular reference again.
3) I have a custom [AuthorizeSessionState] attribute which I use to decorate specific controller actions in my ASP.NET MVC Flip.Main project. This is an ActionFilterAttribute which needs to instantiate my SessionService who resides in my Flip.Services project. I can't put this into my Utility class though (because Flip.Services already references Flip.Utility). I don't think they should be in Flip.Main either - do I have to make another project for this!?
(20 more)
I feel like I'm making a mistake somewhere down the line, especially when I read that others usually don't encounter circular reference problems. Help?
Use interfaces for all non-trivial classes. Place interfaces in a different assembly from implementation.
The question comes down to what you separate by namespace and what you separate by DLL. If you have a good reason to keep EVERYTHING modular, you have to work really hard. But if each of these dlls only have a class or two in them, perhaps you could merge them together?
Take a few minutes and sort out the procedures ... create an identifier for each project (FM, FS, FD, FU). List each publicly accessible procedure on a page and then add an identifier for a project, if that project uses the procedure ...
Then you can see which procedure needs to be in (or accessible to) which project.
Hope that helps!
You can put your localized email strings in Flip.Services. The downside is that you have two places to maintain localized resources. You can also have a separate dll for all your resources to minimize the place to edit resources.
You have to move the fluent interface to an other dll or make CustomerSearchFilter part of the domain.
You will need to add more projects or rearrange your structure and use namespaces to create the separation.
It sounds like your building on concrete implementations instead of interfaces/contracts. As Ima suggests define interfaces that describe what a certain class should be able to do. Use this interface when you declare properties, parameters and the like. Keep the interfaces separate from the implementaion and both the implementation and the projects that uses the interface can reference the interface project.
You then get the nice option of using dependency injection making your code easier to test as an a side
In the "tiers" of a domain, repositories and services live at the same logical level, above the domain in an infrastructure role. I would suggest moving your repository implementations (queries, etc.) outside of the domain itself. That solves #2 at least.