Mesh#onDismount is broken

[alexanderGugel]

Steps to reproduce

1. Create a node
2. Mount the node
3. Add a Mesh to the node
4. Dismount the node via removeChild on parent

Example (self-contained)

'use strict';

var DOMElement = require('famous/dom-renderables/DOMElement');
var FamousEngine = require('famous/core/FamousEngine');
var Mesh = require('famous/webgl-renderables/Mesh');

FamousEngine.init();

var scene = FamousEngine.createScene();

var parent = scene.addChild();
var child = parent.addChild();

var mesh = new Mesh(parent);
mesh.setGeometry('Sphere');

setTimeout(function () {
    scene.removeChild(parent);
}, 1000);

var domElement = new DOMElement(child, {
    properties: {
        background: 'blue'
    }
});

parent
    .setSizeMode('absolute', 'absolute', 'absolute')
    .setAbsoluteSize(250, 250, 250)
    .setAlign(0.5, 0.5)
    .setMountPoint(0.5, 0.5)
    .setOrigin(0.5, 0.5);

var spinner = parent.addComponent({
    onUpdate: function(time) {
        parent.setRotation(time / 1000, time / 2000, time / 3000);
        parent.requestUpdateOnNextTick(spinner);
    }
});

parent.requestUpdate(spinner);

Relevant code sample

setTimeout(function () {
    scene.removeChild(parent);
}, 1000);

Error

Uncaught TypeError: Cannot read property 'split' of null

Cause

The commands sent by Mesh#onDismount are incorrect. They don't include a node location/ path. Therefore the compositor can't split the command.

/**
 * Queues the command for dismounting Mesh
 *
 * @method
 *
 * @return {undefined} undefined
 */
Mesh.prototype.onDismount = function onDismount () {
    this._initialized = false;
    this._changeQueue.push(Commands.GL_REMOVE_MESH);

    this._requestUpdate();
};

[alexanderGugel]

There is a similar problem with Mesh#onOpacityChange, Mesh#onSizeChange, Mesh#onTransformChange, Mesh#onHide, Mesh#onShow.

Basically, the issue is code like this:

Mesh.prototype.onShow = function onShow () {
    this._changeQueue.push(Commands.GL_MESH_VISIBILITY, true);

    this._requestUpdate();
};

We can't simply append the command to the change queue at this point. The WITH commands hasn't been sent at this point. Therefore the commands won't be interpreted correctly by the Compositor.

[CompSciFutures]

Bug #439 might also be relevant.