getComputedInstance • tldraw Docs

Retrieves the underlying computed instance for a given property created with the computed decorator.

function getComputedInstance<Obj extends object, Prop extends keyof Obj>(
  obj: Obj,
  propertyName: Prop,
): Computed<Obj[Prop] extends () => infer Value ? Value : Obj[Prop]>;

Example

class Counter {
  max = 100;
  count = atom("count", 0);

  @computed getRemaining() {
    return this.max - this.count.get();
  }
}

const c = new Counter();
const remaining = getComputedInstance(c, "getRemaining");
remaining.get() === 100; // true
c.count.set(13);
remaining.get() === 87; // true

Parameters

Name	Description
`obj`	`Obj;` The object
`propertyName`	`Prop;` The property name

Returns

Computed<
  Obj[Prop] extends () => infer Value ? Value : Obj[Prop]
>;