title: ExtJS Store add extraParams when creating store in view
body: <p>I have my ExtJS 4.2.1 Application and Inside my view:</p>
  
  <pre><code>xtype: 'combobox',
      itemId: 'cboEmployeeNumber',
      width: 180,
      store: Ext.create('App.store.employee.EmployeeCombo', {
          // here I want to set extraParams maybe like
          // proxy.extraParams:{ employerId:0}
      }),
  </code></pre>
  
  <p>I can do that inside my controller:</p>
  
  <pre><code>onEmployeeBeforeQuery: function(queryPlan, eOpts) {
          var me = this,
              employerId = me.getEditRequest().down('#cboEmployer').getValue(),
              store = me.getEditRequest().down('#cboEmployee').getStore()
  
          store.getProxy().extraParams = {
              employerId: employerId
          };
      },
  </code></pre>
  
  <p>But how can I do this in my view when creating the store?</p>
  
  <p>Thanks.</p>