Question

I’m new to extjs and I’m trying to work on a Tree view.

I am building an “API Explorer” and there are simply too many nodes to send as a single json object (a few million nodes). What I wanted to do instead was send the first layer of categories as json initially, then on expand do an ajax request to get all of that category’s children.

I’m not sure how to do this or if it’s possible. Can anyone lead me in the right direction?

Answer 1

Actually that is the “normal” way as suggested by the documentation. Have a look at any of the Tree examples.

You basically set up an Ext.data.TreeStore with a Proxy, e.g. an Ext.data.proxy.Ajax:

xtype: 'treepanel',
loadMask: {msg: 'Loading...'},
store: Ext.create('Ext.data.TreeStore', {
    proxy: {
        type: 'ajax',
        url: 'get-nodes.php'
    }
})

Each time the user expands one of the nodes, the URL will be hit with the parameter node set to the id of the expanded node and should return an array of the children of this node. These children must not have a children property theirselves, otherwise they would be considered already loaded and would not be loaded on expansion.