title: Using Jsonp in proxy in model in extjs 4.2.1
body: <p>I am calling rest web service from sencha extjs 4.2.1 in model .My  model is</p>
  
  <pre><code>Ext.define('AM.model.User', {
      extend: 'Ext.data.Model',
      fields: [
      {name: 'subCategoryName',  type: 'string'},
      ],
      proxy:{
      type : 'jsonp',
      callbackKey: 'callback',
  
              url: 'http://192.168.1.10:8080/CredoCustomerConnect/subcategory/getsubcategorylist/1/1/0',
           headers: {
               'Accept': 'application/json'
           },
            callback: function( data ) {             
               console.log("callback" + data);        
      },
      listeners: {
                 load: function() {   
                     console.log("in load");
                  }
                     },
  
         reader: {
             type: 'json',
             rootProperty:'subcategory'
             }
          }
  
  }); 
  </code></pre>
  
  <p>When I call the url  <code>'http://192.168.1.10:8080/CredoCustomerConnect/subcategory/getsubcategorylist/1/1/0',</code></p>
  
  <p>in the browser , I am getting the result like</p>
  
  <pre><code>callback({"listException":"false","listSize":"5","nextPage":"false","pageNumber":"0","subcategory":[{"isException":"false","categoryId":"1","categoryName":"Solutions","productSize":"4","subCategoryDescription":"Oracle Consulting","subCategoryId":"1","subCategoryName":"Oracle Consulting"},],"totalRecords":"5"})
  </code></pre>
  
  <p>But I am not seeing any data in grid view.</p>
  
  <p>Rest Web service method is  </p>
  
  <pre><code>@GET
       @Path("getsubcategorylist/{categoryId}/{userId}/{pageNumber}")
       @Consumes("application/x-www-form-urlencoded")
       //@Produces({MediaType.APPLICATION_JSON})
       @Produces({"application/javascript"})
       public JSONWithPadding   getSubCategorylist(@PathParam("categoryId") int categoryId,@PathParam("userId")int userId,@PathParam("pageNumber") int pageNumber, @QueryParam("callback") String callback)
       {
  
           SubCategoryList subCategory = new SubCategoryList();
           SubCategoryEntityHandler handler = new SubCategoryEntityHandler();
           try {
               subCategory =  handler.getSubCategoriesList(categoryId,pageNumber);
  
               return new JSONWithPadding(
                          new GenericEntity&lt;SubCategoryList&gt;(subCategory) {
                          },callback);
  
          } catch (Exception e) {
              e.printStackTrace();
              subCategory.setListException(true);
              subCategory.setListMessage(e.getMessage());
                          return new JSONWithPadding(
                      new GenericEntity&lt;SubCategoryList&gt;(subCategory) {
                      }, "callback");
          }    
       }
  </code></pre>
  
  <p>My store is </p>
  
  <pre><code> Ext.define('AM.store.Users', {
          extend: 'Ext.data.Store',
  
          config: {
          model: 'AM.model.User',
  
  
          }
      });
  </code></pre>
  
  <p>My view is </p>
  
  <pre><code>Ext.define('AM.view.user.List' ,{
      extend: 'Ext.grid.Panel',
      alias: 'widget.userlist',
  
      title: 'All Users',
      store: 'Users',
  
      initComponent: function() {
  
  
          this.columns = [
              {header: 'Subject',  dataIndex: 'subCategoryName',  flex: 1},
  
          ];
  
          this.callParent(arguments);
      }
  });
  </code></pre>
  
  <p>There is no error in console. But I am not seeing any data in grid.
  How to resolve this?</p>