ExtJS 4: TreeStore with both static and dynamically-loaded data?

Question

I'm making a TreePanel that looks like this:

At the moment I have it "mocked up" with the following code:

treePanel.setRootNode({
    text: 'Root',
    expanded: true,
    children: [
        {
            text: 'General Settings',
            icon: kpc.cfg.baseUrl.img+'/icon_gears-bluegreen.gif',
            leaf: true
        },
        {
            text: 'Users',
            icon: kpc.cfg.baseUrl.img+'/icon_users-16x16.gif',
            expanded: true,
            children: [
                {
                    text: 'Dummy User 1',
                    icon: kpc.cfg.baseUrl.img+'/icon_user-suit.gif',
                    leaf: true
                },
                {
                    text: 'Dummy User 2',
                    icon: kpc.cfg.baseUrl.img+'/icon_user-suit.gif',
                    leaf: true
                },
                {
                    text: 'Dummy User 3',
                    icon: kpc.cfg.baseUrl.img+'/icon_user-suit.gif',
                    leaf: true
                },
                {
                    text: 'Dummy User 4',
                    icon: kpc.cfg.baseUrl.img+'/icon_user-suit.gif',
                    leaf: true
                }
            ]
        }
    ]
});

How can I load the individual users dynamically (i.e., via a store)? In other words, how do I make a TreeStore that is a mixture of both static and dynamically-loaded items?

Thanks!

Answer 1

The solution that worked best for me was to:

1. create two tree stores--one with the static content, another set up to load my User models from the server.
2. "graph" the dynamically-loaded tree onto the static tree.

I wrote up a little tutorial that includes a runnable demo here (in case anyone wants a more detailed answer), but at a high level the code looks like this:

Ext.define('demo.UserModel', {
    extend: 'Ext.data.Model',
    fields: ['id', 'name', 'profile_image_url']
});


var userTreeStore = Ext.create('Ext.data.TreeStore', {

    model: 'demo.UserModel',

    proxy: {
        type: 'jsonp',
        url : 'https://myserver/getusers',
        reader: {
            type: 'json',
            root: 'users'
        }
    },

    listeners: {

        // Each demo.UserModel instance will be automatically 
        // decorated with methods/properties of Ext.data.NodeInterface 
        // (i.e., a "node"). Whenever a UserModel node is appended
        // to the tree, this TreeStore will fire an "append" event.
        append: function( thisNode, newChildNode, index, eOpts ) {

            // If the node that's being appended isn't a root node, then we can 
            // assume it's one of our UserModel instances that's been "dressed 
            // up" as a node
            if( !newChildNode.isRoot() ) {
                newChildNode.set('leaf', true);

                newChildNode.set('text', newChildNode.get('name'));
                newChildNode.set('icon', newChildNode.get('profile_image_url'));
            }
        }
    }
});

userTreeStore.setRootNode({
    text: 'Users',
    leaf: false,
    expanded: false // If this were true, the store would load itself 
                    // immediately; we do NOT want that to happen
});

var settingsTreeStore = Ext.create('Ext.data.TreeStore', {
    root: {
        expanded: true,
        children: [
            {
                text: 'Settings',
                leaf: false,
                expanded: true,
                children: [
                    {
                        text: 'System Settings',
                        leaf: true
                    },
                    {
                        text: 'Appearance',
                        leaf: true
                    } 
                ]
            }
        ]
    }
});

// Graft our userTreeStore into the settingsTreeStore. Note that the call
// to .expand() is what triggers the userTreeStore to load its data.
settingsTreeStore.getRootNode().appendChild(userTreeStore.getRootNode()).expand();

Ext.create('Ext.tree.Panel', {
    title: 'Admin Control Panel',
    store: settingsTreeStore,
});