Ylem Component does not re-render when props changes

[ivospinheiro]

Components implemented based on Ylem.Component are not updating the when props changes.

Here is a small example based on the Ylem sample CodeSandBox that reproduces the issue:
https://codesandbox.io/s/ylem-paginated-grid-demo-gnn6d?fontsize=14

[ivospinheiro]

I've debugged the code and it seems to be related with the following lines of code:

ylem/lib/observer-component.js

Lines 40 to 49 in 1cf16a2

	shouldComponentUpdate(props, state) {
	if (!this.observer
	|| (super.shouldComponentUpdate && !super.shouldComponentUpdate(props, state))
	|| !this.shouldUpdate) {
	return false;
	}
	this.shouldUpdate = false;
	return true;

React.Component does not provide a default implementation for shouldComponentUpdate.

[BigAB]

Interesting. I wonder if that ever worked or did something change.

I'll try to look at this when I can.

[christopherjbaker]

I believe that super.shouldComponentUpdate is leftover from a slightly different implementation; but since it is always undefined, it won't be the cause of any issues.

In our tests, we primarily bind props to the store to manage updates. (That's not to say your example shouldn't work, only identifying why it was missed in our tests).
https://github.com/bitovi/ylem/blob/master/test/component.js#L82-L98

[christopherjbaker]

I also wanted to link the CodeSandbox that Ivo had created: https://codesandbox.io/s/ylem-props-issue-lmscf

[frank-dspeed]

i think its related to can-observer.js inside lib its doing

		this.onDependencyChange = (newVal, oldVal) => {
			this.dependencyChange(newVal, oldVal);
		};

but the function depenedencyChange has no arguments :)

	dependencyChange() {
		queues.deriveQueue.enqueue(this.onUpdate, this, [], { priority: this.order });
	}