ExtJs4 How to assign a model to a store at creation? - extjs

Question

I'm defining a store and I want to dynamically assign a Model for it at creation. So if I create my DropDownStore and I don't pass a model config with it it needs to rely on the default model(DropDownModel).
Here is my DropDownModel + DropDownStore:
Ext.define('DropDownModel', {
extend: 'Ext.data.Model',
fields: [
{ name: 'Id', type: 'int' },
{ name: 'Name', type: 'string' }
]
});
Ext.define('DropDownStore', {
extend: Ext.data.Store,
proxy: {
type: 'ajax',
actionMethods: { read: 'POST' },
reader: {
type: 'json',
root: 'data'
}
},
constructor: function(config) {
var me = this;
if (config.listUrl) {
me.proxy.url = config.listUrl;
}
me.model = (config.model) ? config.model : 'DropDownModel'; //This line creates some weird behaviour
me.callParent();
//If the URL is present, load() the store.
if (me.proxy.url) {
me.load();
}
}
});
This is a creation of the DropDownStore with a dynamic model:
Ext.define('RelationModel', {
extend: 'Ext.data.Model',
fields: [
{ name: 'Id', type: 'int' },
{ name: 'RelationName', type: 'string' },
{ name: 'RelationOppositeName', type: 'string' }
]
});
...//a random combobox
store: Ext.create('DropDownStore', {
listUrl: 'someprivateurl',
model: 'RelationModel'
})
...
When I edit the line in the constructor method to
me.model = (config.model) ? config.model : undefined
It works like expected for the dynamic model but not anymore for the default models.
If I let it be
me.model = (config.model) ? config.model : 'DropDownModel';
It works for the default models and not for the dynamic model.
How can I assign a model to a store at creation?

Answer 1

constructor: function(config) {
var me = this;
if (config.listUrl) {
me.proxy.url = config.listUrl;
}
me.callParent();
if (config.extraFields) {
me.model.setFields(config.extraFields);
}
//If the URL is present, load() the store.
if (me.proxy.url) {
me.load();
}
}
store: Ext.create('DropDownStore', {
listUrl: 'someprivateurl',
extraFields: [
{ name: 'Id', type: 'int' },
{ name: 'RelationName', type: 'string' },
{ name: 'RelationOppositeName', type: 'string' }
]
}),