title: is there any way to re-render checkbox in ext js?
body: <p>i have following code</p>
  
  <pre><code>    extend: 'Ext.container.Viewport',
      initComponent: function () {
          var me = this;
          me.items = [
              {
                  xtype: 'checkbox',
                  fieldLabel: 'RPTest',
                  itemId:'chk1'
              },
              {
                  xtype: 'button',
                  text: 'test',
                  handler: function () {
                      me.chk1.setBoxLabel(me.chk1.fieldLabel);
                      me.chk1.boxLabelAlign = 'before';
  
                      me.chk1.setFieldLabel('');
                  }
              }
          ];
          me.callParent(arguments);
          me.chk1 = me.down('#chk1');
      }
  })
  </code></pre>
  
  <p>i want to update <strong>boxLabelAlign</strong> property whenever user click button property values changes but DOM doesn't update i have tried updateLayout() of checkbox but it doesn't works. so is there any solution of these problem? or is there any way to update DOM?? </p>