Deep watch

[aleclarson]

Deep watch

[aleclarson]

Deep watch is essential, I think. You can use it to intercept immer patches!

Proposal

• The DeepWatcher class
  • extends Observable
  • has [__$willChange] method
  • adds itself to every nested observable it can find
  • has a dispose method
• The deepWatch function
  • returns a DeepWatcher instance
  • is a no-op when its argument is none of the following:
    • an observable object
    • a plain object

import {deepWatch, watch, addObserver} from 'react-galaxy'

let watcher = deepWatch(observableState)

// Using the raw observer API
addObserver(watcher, (base, prop, newValue) => {
  // `base` is always the parent object
  // `prop` is always a string or number
  // `newValue` is the new property value
  let oldValue = base[prop]
  assert(oldValue !== newValue)
})

// Intercept patches for all nested objects
watch(watcher, (patch: Patch, base: any) => {
  console.log({ base, patch })
})

// To reclaim memory
watcher.dispose()

And of course, you can re-render components when any property in the state tree changes. 😂

[aleclarson]

To discourage nesting of immutable objects in each other, we should add a deepTrack function and make track shallow. It's more explicit, too. Just like deepWatch!

edit: deepTrack will be released with v0.1.0

edit 2: But using deepTrack in selectors will be released with deepWatch

[aleclarson]

Let deepTrack(object, string) be a deepWatch combined with a Slot instance.