ember.js - Many-to-many relationships with ember-data models -

i new emberjs , i'm working on new project. application has 3 models namely member, project , task.

1. a member can have many tasks , task can have many members (many-to-many)
2. a project can have many tasks , task can belong 1 project (one-to-many)
3. a project can have many members , member can have many projects (many-to-many)

for 1 , 2, fine.

however, relationship between project , members, member can either simple member of project or project manager.

in database schema, represented relationship having additional table called project_members , had additional field called 'role' can either 0 (meaning simple member) or 1 (meaning project manager).

what best way represent using ember-data models? how should represent relationship , how , should include additional 'role' field?

thanks

not sure if work since haven't tried having multiple attributes point 1 model add these attribute in project model like

projectmanager: ds.belongsto('member'), members: ds.hasmany('member') 

then member model

projectmanagerto: ds.hasmany('project') projects: ds.hasmany('project') 

or if have anyway of knowing project manager member model data can use computed property.

projectmanager: function() {   // logic determine of members project manager }.property('members')