onDocumentChange not called on block type change

Hi @ianstormtaylor! I notice that if the block type changes (without any change to the text), the onDocumentChange is not being fired. Is that expected?

Intuitively, I would expect that a change in block type would be considered a material change in document, to invoke this event.

Here is a JSFiddle demonstrating this - https://jsfiddle.net/urr1z99g/1/

Steps to Reproduce

1. Open console.
2. Click on ‘Toggle Heading’ to start a heading.
3. At this point, I would expect the onDocumentChange and onChange to be fired.

Thank you!

[erquhart]

Here’s a workaround for now:

1. Keep using onDocumentChange to avoid needless updates.
2. For externally initiated transforms (via buttons, keydown, etc), call the onChange method from your Editor instance directly, and pass in the transformed state.
3. Call setState after calling onChange.

Example:

handler = () => {
  const resolvedState = this.state.state.transform().setBlock('header-one').apply();
  this.ref.onChange(resolvedState);
  this.setState({ state: resolvedState });
}

This did not result in any additional renders of the Editor component in my testing.

@ianstormtaylor I did spend a fair amount of time looking into a proper fix, but this seems to go pretty deep into Slate’s update lifecycle, and it’ll take more time to figure out what’s happening when (and why), and ensuring that a fix doesn’t cause regressions. This workaround should at least take this issue out of blocker territory for most folks.

[vpontis]

So I took a little look at this problem. Yea, it does look like it’s a problem w/ all transformations that are called via Javascript.

onBeforeChange is called on Editor.componentWillReceiveProps. But onChange is called as a proxy through the EVENT_HANDLERS.

So here are some options:

• Add a custom EVENT_HANDLER for the transformations
• Somehow propagate onChange when in applyTransform
• Call onChange in the componentWillReceiveProps

@ianstormtaylor, what do you think? I’m still learning how everything is architected so I don’t have an opinion yet.