How to represent UML Relations with Backbone-Relational?

Question

I have Class Diagram looking like this :

ModelA 1------* ModelB 1------* ModelC 1------* ModelD

Edit :

The Data looks like that

Data :

{   "Titel" : "ModelA",
    "ModelA" : [
        {
          "Titel" : "ModelB1",
          "ModelB1" : [
                              {
              "Titel" : "ModelC1",
                              "ModelC1":[
                                { "Titel" : "ModelD1"   },
                                { "Titel" : "ModelD2"   },
                                { "Titel" : "ModelD3"   }
                              },
                              {
              "Titel" : "ModelC2",
                              "ModelC2":[
                                { "Titel" : "ModelD21"   },
                                { "Titel" : "ModelD22"   },
                                { "Titel" : "ModelD23"   }
                              },
                              ]
                 },
                 {
          "Titel" : "ModelB2",
          "ModelB2" : [
                              {
              "Titel" : "ModelC1",
                              "ModelC1":[
                                { "Titel" : "ModelD1"   },
                                { "Titel" : "ModelD2"   },
                                { "Titel" : "ModelD3"   }
                              },
                              {
              "Titel" : "ModelC2",
                              "ModelC2":[
                                { "Titel" : "ModelD21"   },
                                { "Titel" : "ModelD22"   },
                                { "Titel" : "ModelD23"   }
                              },
                              ]
                 }]
 }

I create those RelationalModel :

ModelA :

ModelA = Backbone.RelationalModel.extend({

  relations:[{
    type: Backbone.HasMany,
    key: 'modelb',
    relatedModel: 'ModelB',
    collectionType: 'ModelBCollection',
    reverseRelation:{
      key: 'belong To',
      includeInJSON: 'id'
    }
  }] });

ModelB :

ModelB = Backbone.RelationalModel.extend({

  relations:[{
    type: Backbone.HasMany,
    key: 'modelc',
    relatedModel: 'ModelC',
    collectionType: 'ModelCCollection',
    reverseRelation:{
      key: 'belong To',
      includeInJSON: 'id'
    }
  }] });

ModelC :

ModelC = Backbone.RelationalModel.extend({

  relations:[{
    type: Backbone.HasMany,
    key: 'modeld',
    relatedModel: 'ModelD',
    collectionType: 'ModelDCollection',
    reverseRelation:{
      key: 'belong To',
      includeInJSON: 'id'
    }
  }] });

ModelD :

ModelD = Backbone.Model.extend({ });

Collections :

 ModelACollection = Backbone.Collection.extend({ model: ModelA });
 ModelBCollection = Backbone.Collection.extend({ model: ModelB });
 ModelCCollection = Backbone.Collection.extend({ model: ModelC });
 ModelDCollection = Backbone.Collection.extend({ model: ModelD });

and i do this in the Router :

Router :

var obja = new ModelACollection(data);
var objb = new ModelBCollection(data.objb);
var objc = new ModelCCollection(data.objc);
var objd = new ModelDCollection(data.objd);

all get fetched but with many warning (firefox, chrome) looks like this :

Warning :

Relation=%o; no model, key or relatedModel (%o, %o, %o) .... 

1. What is the meaning of this Warning?
2. That's the right to represent this Class Relation with Backbone-relational isn't?

if not?

How can i represent this as a Backbone ModelRelational?

Answer 1

In Model A you are defining

key: 'modelb'

which links to Model B. However, key should be "a string. References an attribute name on relatedModel" (based on the docs). And I cannot see and model field called modelb