How to get value from another JSON for new store?

This is my configuration,

Model1:

fields: [

{

name:'id',

type: 'int'

},

{

name:'url',

type: 'string'

},

]

Store1:

proxy: {

type: 'ajax',

url: 'data1.json',

reader: {

type: 'json',

rootProperty:'aaData',

}

},

Model2:

fields: [

{

name:'text',

type: 'string'

}]

Store2:

proxy: {

type: 'ajax',

url: '????', <--- from store 1?

reader: {

type: 'json',

rootProperty:'aaData',

}

},

How I can complete Store 2 by getting the url from Store 1? Let say if id=1 and url is ur1, id=2 and url is url2 and so on? Please advice. Thanks.

How to get value from another JSON for new store?