Rules for HasOne and BelongsTo Associations in ExtJS

extjs-model-assoc-hasone

// Rules for HasOne and BelongsTo Associations in ExtJS
// source :http://extjs-tutorials.blogspot.ca/2012/05/extjs-belongsto-association-rules.html
// Put the proxy in the model, unless you have a very good reason not to [1]
// Always use fully qualified model name
// Always set the getterName
// Always set the setterName
// Always set the associationKey, if the foreign object is returned in the same response as this object
// Always set the foreignKey, if you want to load the foreign object at will
// Consider changing the instanceName to something shorter
// The getter behaves differently depending on whether the foreign object is loaded or not. If it's loaded, the foreign object is returned. Otherwise, you need to pass in a callback to get it.
// You should set the name property if you plan to override this association.
// You do not need a belongsTo relationship for a hasMany to work
// Set the primaryKey property if the id field of the parent model is not "id"
// Sometimes you need to use uses or requires for the belongsTo association. Watch out for circular references though.
// Calling setter() function does not seem to set the instance. Set object.belongsToInstance = obj  if calling the setter().

Ext.define('Assoc.model.PhoneNumber', {
    extend:'Ext.data.Model',

    fields:[
        'number',
        'contact_id'
    ],

    belongsTo:[
    {
      name:'contact',
      instanceName:'contact',
      model:'Assoc.model.Contact',
      getterName:'getContact',
      setterName:'setContact',
      associationKey:'contacts',
      foreignKey:'contact_id'
    }
    ],

    proxy:{
        type:'ajax',
        url:'assoc/data/phone-numbers.json',
        reader:{
            type:'json',
             root:'phoneNumbers'
        }
    }
});

/*
 * Assuming Contact model uses an AJAX proxy with url 'contacts', and its id field is "id", 
 * the below function call will make an http request like this:
 * /contacts?id=88
 */

var pn = new Assoc.model.PhoneNumber( { contact_id:88 } );

pn.getContact( function(contact, operation){ 
  console.log('tried to load contact. this.contact is now set to the contact');
} );

/* you can call phoneNumber.setContact(contact). This will set contact_id on the phone number, BUT it won't set the contact instance on phonenumber, which is likely a bug: */

var contact = new Assoc.model.Contact({id:77});

var phoneNumber = new Assoc.model.PhoneNumber();

phoneNumber.setContact(contact);

console.log(phoneNumber.get('contact_id')) //77

console.log(phoneNumber.contact) //undefined

phoneNumber.contact = contact; //you need to do this if you want to use that reference in the future.