Batching actions

[terrysahaidak]

Batching actions

[xaviergonz]

mobx only supports sync batches, so no. your best bet would be to delay all state mutations at the end of the flow

[xaviergonz]

In theory it should batch AFAIK, since it executes inside the same acttion

[xaviergonz]

Well actually you should probably wrap the array for each with a mobx action / runInAction (or even better, as much as possible from that method) if it is not inside a modelAction or reaction

[xaviergonz]

Summarizing, changes will batch as long as they are inside action, runInAction, reaction effect, modelAction or modelFlow

[terrysahaidak]

Cool, I will reopen it if I find a case where it's not, thank you!

[vojto]

Summarizing, changes will batch as long as they are inside action, runInAction, reaction effect, modelAction or modelFlow

Are you sure about this? I'm trying to do something like this:

@modelFlow
addNotes = _async(function* (this: NoteStore) {
  console.log('pushing note1')
  const note1 = Note.build({title: 'note1'})
  this.notes.push(note1)

  yield* _await(delay(50))

  console.log('pushing note2')
  const note2 = Note.build({title: 'note2'})
  this.notes.push(note2)

  console.log('all pushed!')
})

Then, I have this observer watching for changes of notes:

autorun(() => {
  console.log(`current notes count: ${this.notes.length}`)
})

The observer is getting called after each note is added. Isn't it supposed to be called once after entire modelFlow is finished?

[xaviergonz]

in model flows batches are done between yield and yield

[vojto]

Oh. Is there any way to get it to execute an entire flow like that in one batch?

[vojto]

Sorry to bother you again, but I have one more question:

What's the use of modelFlow if it doesn't really batch updates? You could just create async function on your model and use await, and it would be the same, no?

[xaviergonz]

the reason is the same than why mobx flow exists
https://www.mobxjs.com/best/actions.html