SignalNode

The storage of a signal: its value, its equality and the computations that read it.

The storage of a signal: its value, its equality and the computations that read it. Exported from @shadow-js/core/extend as SignalNode; create one with createSignalNode, read it with readSignal and write it with writeSignal, which notifies its readers. Build a custom primitive on it the way useSignal does.

Import#

import { SignalNode } from "@shadow-js/core/extend";

Signature#

class Signal<T = unknown> implements Source

Members#

Name	Type	Description
`T`	`T = unknown`
`kind`	`readonly kind: number`	Always 0, the kind of a signal.
`value`	`value: T`	The current value. Assigning it directly notifies no one: use `writeSignal`, or call `notify` after the assignment.
`equals`	`equals: Equals<T>`	Decides whether a write is a change; `false` treats every write as one.
`observers`	`observers: Edges<Computation> \| null`	The computations that read this signal in their last run, as pairs (see Source.observers).
`stamp`	`stamp`	Stamp of the last computation run that tracked this signal (dedupes repeated reads).
`name`	`name: string \| undefined`	Label shown by devtools and diagnostics.

Examples#

import { createSignalNode, readSignal, SignalNode, writeSignal } from "@shadow-js/core/extend";

const count = createSignalNode<number>(0, Object.is, "count");
writeSignal(count, 1);
console.log(readSignal(count), count instanceof SignalNode); // 1 true