Breeze navigation properties not loaded

Question

I have the following many to many model between Project and UserProfile entities. As many to many relationships is not supported in Breeze yet, I am exposing the middle entity ProjectMember as well. So the server side code looks like the following:

public class Project
{
   public int ProjectId { get; set; }
   public String Name { get; set; }
   public virtual List<ProjectMember> ProjectMembers { get; set; }
}

public class UserProfile
{
    [Key]
    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int UserId { get; set; }
    public virtual List<ProjectMember> ProjectMembers { get; set; }
}

public class ProjectMember
{
    public int ProjectId { get; set; }
    [ForeignKey("ProjectId")]
    public Project Project { get; set; }

    public int UserId { get; set; }
    [ForeignKey("UserId")]
    public UserProfile UserProfile { get; set; }
}

The metadata returned from the server seems to be the right one:

The navigation property seem to be properly sent out by the server.

When I request a project from the client by doing:

var query = entityQuery.from("Projects")
                       .where('projectId', '==', projectId)
                       .expand("projectMembers");

The returned JSon data is the one expected:

However, the Project.ProjectMembers navigation property is not properly constructed on the client side as you see from the screenshot below:

I went through the tutorials, the breeze documentation, the SO questions related to navigation properties and I still don't see what I am doing wrong.

Question: Given the information above, why is Breeze not loading the ProjectMembers navigation property?

Answer 1

I would start by checking the EntityManager's metadataStore to make sure that the ProjectMember entityType can be found. You can do this after your first query via

var projectMemberType = myEntityManager.metadataStore.getEntityType("ProjectMember");

If the projectMemberType is not found then the problem has to do with the metadata not being brought down correctly.

Another possibility, have you defined a key for the ProjectMember type ( presumably a two part key)?