addon.tab.redux (Redux)

Scratch Addons supports getting and modifying Redux state!

Keep in mind

  • Redux is only available on scratch-www pages (the ones with the thicker navigation bar) and the editor.
  • Some extensions conflict with Scratch Addons' Redux feature. Do not use this when unnecessary.
  • We expect readers to have basic knowledge on Redux and Scratch’s reducers.

Get Redux state

addon.tab.redux.state stores current Redux state. For example, to get message count: addon.tab.redux.state.messageCount.messageCount

Wait for Redux state

addon.tab.redux.waitForState() returns a Promise that will resolve when the Redux state meets the given condition.

Parameter Type Required Description
condition Function Yes A function that takes Redux state as a parameter and returns whether to keep waiting or not.
options Object No
Property Type Required Default Description
actions String | String[] No All possible values The action(s) to check for.

Events

You must first call addon.tab.redux.initialize() for Scratch Addons to be able to listen for state changes.

Use addon.tab.redux.addEventListener("statechanged", callback) to add event listeners for state changes. The callback can have one argument which is a CustomEvent with following attributes:

  • action: Dispatched action. See Redux docs for what it means.
  • prev: Previous state.
  • next: Next state.

Dispatching event

You can dispatch events using addon.tab.redux.dispatch(eventObject). Event object must have type attribute and can have other attributes. For details on what to dispatch, read reducer codes on scratch-www, scratch-gui or scratch-paint:


Last updated at 16 January 2022 by lisa-wolfgang on commit 9df7a19. Improve this page.