observeResize

Functioncommon/layout/observersv0.1.0

projects/common/layout/observers/resize-signal.ts

Info
API

Description#

Subscribes apply to size changes of element on host.

Re-applies on every observation and returns the teardown that disconnects the observer. On a host without ResizeObserver (SSR, jsdom) nothing is wired, apply never fires, and the returned teardown is a no-op. Unlike the media-query twin there is no synchronous seed: the first size is whatever the observer reports after the next layout.

Reach for this low-level form when the observed element or the box model is reactive and the subscription must follow it (re-wire per effect run via onCleanup); for a static target, createResizeSignal owns the teardown via DestroyRef.

Signature#

observeResize(host, element: Element, box: ResizeObserverBoxOptions, apply)

Parameters#

@paramhost

The window-like object to read ResizeObserver from.

@paramelementElement

The element to observe.

@paramboxResizeObserverBoxOptions

Which box model to report.

@paramapply

Receives the first entry of every observation batch.

Returns#

void

Teardown that disconnects the observer.