With dataview example taken from documentation, if initComponent method is added to a dataview, TypeError is thrown:

Code:
Ext.onReady(function() {
  Ext.define('Image', {
    extend: 'Ext.data.Model',
    fields: [
      { name:'src', type:'string' },
      { name:'caption', type:'string' }
    ]
  });
  
  Ext.create('Ext.data.Store', {
    id:'imagesStore',
    model: 'Image',
    data: [
      { src:'http://www.sencha.com/img/20110215-feat-drawing.png', caption:'Drawing & Charts' },
      { src:'http://www.sencha.com/img/20110215-feat-data.png', caption:'Advanced Data' },
      { src:'http://www.sencha.com/img/20110215-feat-html5.png', caption:'Overhauled Theme' },
      { src:'http://www.sencha.com/img/20110215-feat-perf.png', caption:'Performance Tuned' }
    ]
  });
  
  var imageTpl = new Ext.XTemplate(
      '<tpl for=".">',
        '<div style="margin-bottom: 10px;" class="thumb-wrap">',
          '<img src="{src}" />',
          '<br/><span>{caption}</span>',
        '</div>',
      '</tpl>'
  );
  
  Ext.create('Ext.view.View', {
    store: Ext.data.StoreManager.lookup('imagesStore'),
    tpl: imageTpl,
    itemSelector: 'div.thumb-wrap',
    emptyText: 'No images available',
    renderTo: Ext.getBody(),
    
    // bug: plain initComponent causes throwing a TypeError
    initComponent: function() {
      this.callParent();
    }
  });
});
Upon execution above code throws following:
Code:
Uncaught TypeError: Cannot call method 'fill' of undefined
  Ext.define.refreshext-all-debug.js:59347
  Base.implement.callParentext-all-debug.js:3609
  Ext.define.refreshext-all-debug.js:100851
  (anonymous function)ext-all-debug.js:59578
  (anonymous function)
Damir Murat