JSDoc: Namespace: Signals

Core Signals API for reactive state management. Provides primitives for creating reactive values, computed values, and async computations.

Source:

reactive.js, line 235

Methods

(static) batch(fn) → {*}

Alias for effect(). Batches multiple signal updates together.

Parameters:

Name	Type	Description
`fn`	function	Function containing signal updates

Source:

reactive.js, line 572

See:

Signals.effect

Returns:

Return value of the function

Type: *

(static) computed(fn, nameopt) → {ComputedSignal}

Creates a computed signal that automatically recalculates when dependencies change. Dependencies are tracked automatically when accessed inside the computation function.

Parameters:

Name	Type	Attributes	Default	Description
`fn`	function			Computation function that returns the computed value
`name`	string \| null	<optional>	null	Optional name for debugging

Source:

reactive.js, line 343

Throws:

If circular dependency is detected
Type Error

Returns:

Computed signal with dispose method

Type: ComputedSignal

Example

const firstName = Signals.create("John");
const lastName = Signals.create("Doe");
const fullName = Signals.computed(() => `${firstName.get()} ${lastName.get()}`);
console.log(fullName.get()); // "John Doe"

(static) computedAsync(fn, nameopt) → {ComputedSignal.<AsyncState>}

Creates a computed signal for async operations that tracks loading/error/data states. Automatically cancels previous execution when dependencies change.

Parameters:

Name	Type	Attributes	Default	Description
`fn`	function			Async computation function
`name`	string \| null	<optional>	null	Optional name for debugging

Source:

reactive.js, line 429

Returns:

Signal containing {status, data, error, loading}

Type: ComputedSignal.<AsyncState>

Example

const userId = Signals.create(1);
const userData = Signals.computedAsync(async (cancel) => {
  const response = await fetch(`/api/users/${userId.get()}`);
  if (cancel.cancelled) return;
  return response.json();
});
// userData.get() returns {status: "pending", data: undefined, error: null, loading: true}

(static) create(value, equalsopt, nameopt) → {Signal}

Creates a reactive signal that holds a single value. Signals track dependencies and notify subscribers when the value changes.

Parameters:

Name	Type	Attributes	Default	Description
`value`	*			Initial value
`equals`	function	<optional>	(a, b) => a === b	Equality function to determine if value changed
`name`	string \| null	<optional>	null	Optional name for debugging

Source:

reactive.js, line 255

Returns:

Signal object with get/set/subscribe methods

Type: Signal

Example

const count = Signals.create(0, undefined, "count");
count.set(5);
console.log(count.get()); // 5
count.subscribe(val => console.log("Changed:", val));

(static) effect(fn) → {*}

Batches multiple signal updates to prevent redundant recalculations. All updates within the function are queued and executed once at the end.

Parameters:

Name	Type	Description
`fn`	function	Function containing signal updates

Source:

reactive.js, line 553

Returns:

Return value of the function

Type: *

Example

Signals.effect(() => {
  count.set(1);
  count.set(2);
  count.set(3);
}); // Subscribers only notified once with value 3