HeadingView not destroyed when parent View is destroyed

[oliverfoster]

Subject of the issue

HeadingView instances are created when required:

adapt-contrib-core/js/headings.js

Lines 6 to 13 in d66704f

	initialize() {
	this.listenTo(Adapt, 'view:render', this.onViewRender);
	}
	onViewRender(view) {
	const $headingSeats = view.$('.js-heading');
	$headingSeats.each((index, el) => new HeadingView({ el, model: view.model }));
	}

When a contentobject is destroyed it removes its descendant views but not the HeadingView as it has no handle to them:

adapt-contrib-core/js/views/contentObjectView.js

Lines 144 to 157 in d66704f

	remove() {
	const type = this.constructor.type;
	this.preRemove();
	Adapt.trigger(`${type}View:remove contentObjectView:remove view:remove`, this);
	this._isRemoved = true;
	wait.for(end => {
	if (this.isJSX) {
	ReactDOM.unmountComponentAtNode(this.el);
	}
	this.$el.off('onscreen.adaptView');
	this.findDescendantViews().reverse().forEach(view => {
	view.remove();
	});

If a floating HeadingView model is _isComplete updated, it will rerender its ariaLabel:

adapt-contrib-core/js/views/headingView.js

Line 7 in d66704f

this.listenTo(this.model, 'change:_isComplete', this.updateAria);

This is a memory leak.

[oliverfoster]

I missed the contentObjectView in the fix when adding preRemove and remove events.

adapt-contrib-core/js/views/contentObjectView.js

Lines 144 to 168 in de6fcd9

	remove() {
	const type = this.constructor.type;
	this.preRemove();
	Adapt.trigger(`${type}View:remove contentObjectView:remove view:remove`, this);
	this._isRemoved = true;
	wait.for(end => {
	if (this.isJSX) {
	ReactDOM.unmountComponentAtNode(this.el);
	}
	this.$el.off('onscreen.adaptView');
	this.findDescendantViews().reverse().forEach(view => {
	view.remove();
	});
	this.setChildViews(null);
	super.remove();
	_.defer(() => {
	Adapt.trigger(`${type}View:postRemove contentObjectView:postRemove view:postRemove`, this);
	this.trigger('postRemove');
	});
	end();
	});
	return this;
	}