How to default select a childnodes in extjs - extjs

Question

I am having a breadcrumb toolbar where I have to display childnode default selected. I am using a treestore and root is what i am creating and then making an ajax call to get the childnodes. In my view I am default selecting a selection : pStore.getRoot().childNodes[2], its giving me null.
even pStore.getRoot().firstChild is giving null. Nor sure what i am missing.
Any help is appreciated.
Thanks!
Store
Ext.define('Online.store.Publications',
{
extend : 'Ext.data.TreeStore',
alias : 'store.Publications',
nodeParam : 'id',
autoLoad : true,
root : {
text : 'Pubs ►',
id : 'pub',
expanded : true,
iconCls : 'doc-folder',
leaf : false
},
rootVisible : false,
proxy : {
type : 'ajax',
noCache : false,
url : Online.getBaseURL()+'/nPub/getPublicationsJSON',
reader : {
type : 'json'
},
timeout : 60000,
}
}
});
View
Ext.define('Online.view.Breadcrumb', {
extend : 'Ext.toolbar.Toolbar',
xtype : 'navigation-toolbar',
id : 'navigation-toolbar',
requires : [
'Online.view.BreadcrumbController'
],
controller : 'breadcrumb',
reference : 'navigation-toolbar',
initComponent : function() {
var pStore = Ext.create('store.Publications');
));
Ext.apply(this, {
items : [
{
xtype : 'breadcrumb',
id : 'navigation-breadcrumb',
reference : 'breadcrumb',
useSplitButtons : false,
flex : 0.85,
showIcons : false,
useArrows : true,
bind : {
selection : '{id}'
},
store : pStore,
selection : pStore.getRoot(),
autoLoad : false,
rootVisible : fals
}
]
});
this.callParent();
}
});

Answer 1

Ext.define('Online.view.Breadcrumb', {
extend : 'Ext.toolbar.Toolbar',
xtype : 'navigation-toolbar',
id : 'navigation-toolbar',
requires : [
'Online.view.BreadcrumbController'
],
controller : 'breadcrumb',
reference : 'navigation-toolbar',
initComponent : function() {
var pStore = Ext.create('store.Publications');
var PChilds;
));
Ext.apply(this, {
items : [
{
xtype : 'breadcrumb',
id : 'navigation-breadcrumb',
reference : 'breadcrumb',
useSplitButtons : false,
flex : 0.85,
showIcons : false,
useArrows : true,
bind : {
selection : '{id}'
},
store : pStore,
selection :'',
autoLoad : false,
rootVisible : fals
}
]
});
***pStore.on('load', function(store, records) {
PChilds = pStore.getRootNode().childNodes[0]
var nodeObj = this.items.items[1];
nodeObj.setSelection(PChilds);
},this);***
this.callParent();
}
});