Populate second combo depend first combo value from json response in sencha

[vijayakumar84]

Hi
I am trying to populate secondcombo depend on the first combo from json response like displaying subcategory value in second combo using category value in first combo.My all values are coming from json array response I am trying to set root property dynamically and load the store of second combo box in controller in first combo change function .but its not populating data can anybody tell what is problem .How to fix it? .I have post below code for change function of first combo

 
valueChange:function(combo, ewVal, oldVal,optionsVal) {
    for(var i=0;i<tempstore.getCount();i++){
          var record = tempstore.getAt(i);

//checking for user selection id  with store id 
 if(record.get('categoryId')==ewVal)         
 {
   value="category.category1.category["+i+"].subCategory.subCategory";
tempsecondCompostore.getProxy().getReader().setRootProperty(value);    
tempsecondCompostore.load();
cmbSecond.setStore(tempsecondCompostore);

mdSecond.setDisplayField('subCategoryName');
cmdSecond.setValueField('subCategoryId');
 break;
       }
      }

This is My second Combo Model

Ext.define('Test.model.SubCategoryModel', {
    extend : 'Ext.data.Model',
    fields : [
     {
      name:'subCategoryName',
      type:'string'
     
     },
     {
      name:'subCategoryId',
      type:'string'
     }
     
    
    ]
    
});

This is My store

Ext.define('Test.store.SubCategoryStore', {
    extend : 'Ext.data.Store',
    storeId : 'secondcombo',
    model : 'Test.model.SubCategoryModel',
    //autoLoad : 'true',
    proxy : {
        type : 'ajax',
        url : 'data.json',
        reader : {
            type : 'json',
            rootProperty:'category.category1.category[0].subCategory.subCategory
        }
    }


});

In View displaying combo

xtype: 'fieldset',
            width:400,
            heigth:200,
            items: [
                {
                    xtype: 'selectfield',
                    label: 'Select',
                    store : 'secondcombo',
                    width:400,
                    heigth:200,
                    queryMode: 'local',
                    displayField :'subCategoryName',
                    valueField :'subCategoryId',
                    id:'cmbSecond'
        
      


                }
            ]

Thanks

[mitchellsimoens]

First thing, are you getting any messages in the console? Your model and store aren't 100% compliant with ST2