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wildcard

Experimental

import { wildcard } from "@c11/engine.runtime";

Overview​

wildcard allow selecting arbitrarily deep paths from state.

They are meant to be used by producer to obtain more powerful triggers.

Example​

For example:

cons titleWatchProducer: producer = ({
  title = observe.todos[wildcard].title
}) => { ... }

titleWatchProducer will re-run whenever any todo's title changes.

What changed?​

wildcard triggers producer whenever anything on the matching path changes, but producer won't know what exactly has changed. To get information about exactly what has changed, wildcard can be assigned to another arg, to get information about exactly which path has received the change. For example,

const prod: producer = ({
  id = wildcard,
  title = observe.todos[arg.id].title
}) => { ... }

id will contain the changed todo's ID.

Assign the wildcard to an arg is also the only way to use wildcard with update operator. Only observe can make use of wildcard directly in its path.