How to resolve circular dependency in DbContext

asp.net-core c# entity-framework entity-framework-core

Question

I want to set the TenantId in my DbContext so that I can filter all queries using it.

I have set up the filter, but I am having difficulty getting the TenantId to the DbContext.

The reason for the difficulty is that the UserManager which is used to get the currently logged in user (and thus the TenantId) depends on the DbContext to get data from the database. So I cannot import the UserManager with Dependency Injection because it results in a circular dependency. The UserManager depends on the DbContext, and the DbContext depends on the UserManager.

Is there some other way to configure this?

1
3
3/26/2018 5:38:57 AM

Accepted Answer

If I understand your question correctly you have a situation like this:

public class UserManager : IUserManager
{
    public UserManager(IDBContext db, ... )
    {
        _context = db;
        ...
    }
    private IDBContext _context ;
    public UserInfo User {get; set;}
    // ... Some logic that fills User 
}

public class DBContext : IDBContext
{
    public DBContext(...)
    {
        ...
    }
    // ... Here you need UserInfo to filter.
}

Change the structure of you application a little, and make it like this:

public class UserProvider : IUserProvider
{
    public UserInfo User {get; set;}
}

public class UserManager : IUserManager
{
    public UserManager(IDBContext db, IUserProvider provider, ... )
    {
        _context = db;
        _userProvider = provider;
        ...
    }
    private IDBContext _context ;
    private IUserProvider _userProvider;

    // ... Some logic that fills _userProvider.UserInfo 
}

public class DBContext
{
    public DBContext(IUserProvider provider, ...)
    {
        _userProvider = provider;
        ...
    }
    private IUserProvider _userProvider;
    // ... Here you can use _userProvider.UserInfo
}

Only requirement: Register IUserProvider as a singleton in your Dependancy Injection Framework

0
3/26/2018 5:46:30 AM


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