CodeAPI

ViewportMixin

Provides functionality for elements that can be scrolled into and out of view.

Table of Contents

FUNCTIONS

?
Perform actions on an object.
onViewportEnter( )

Adds an event handler that runs when an element is displayed in the viewable part of the current window.

onViewportLeave( )

Adds an event handler that runs when an element is no longer displayed in the viewable part of the current window.

onViewportEnter( )

Adds an event handler that runs when an element is displayed in the viewable part of the current window.

Description

An element enters the viewport when the page is scrolled to show any part of the element. An element also enters the viewport if it was hidden or collapsed and is then shown or expanded in the viewable part of the current window.

Note

Deprecation note: The $w parameter of event handlers is being deprecated. To get a scoped selector, use the $w.at() function and pass it the context property of the event parameter: $item = $w.at(event.context). To learn more, see here.

See Also

onViewportLeave( )

Syntax

function onViewportEnter(handler: EventHandler): Element
callback EventHandler(event: Event, $w: $w): void
PARAMETERS
?
The kind of data the property stores.
handler
function(event: Event, $w: $w)

The name of the function or the function expression to run when the element enters the viewport.

?
The kind of data the property stores.
event
The event that occurred.
$w

Deprecated: A selector function. The $w function enables event handlers to work with elements in repeaters and in the global scope.

RETURN VALUE
?
Value that a function evaluates to when it is finished running.
The element on which the event is now registered.

Examples

Get the ID of the element that has entered the viewport

$w("#myElement").onViewportEnter( (event) => {
  let targetId = event.target.id; // "myElement"
});

onViewportLeave( )

Adds an event handler that runs when an element is no longer displayed in the viewable part of the current window.

Description

An element leaves the viewport when the page is scrolled so that the elements is completely out of view. An element also leaves the viewport if it was shown or expanded and is then hidden or collapsed from the viewable part of the current window.

Note

Deprecation note: The $w parameter of event handlers is being deprecated. To get a scoped selector, use the $w.at() function and pass it the context property of the event parameter: $item = $w.at(event.context). To learn more, see here.

See Also

onViewportEnter( )

Syntax

function onViewportLeave(handler: EventHandler): Element
callback EventHandler(event: Event, $w: $w): void
PARAMETERS
?
The kind of data the property stores.
handler
function(event: Event, $w: $w)

The name of the function or the function expression to run when the element leaves the viewport.

?
The kind of data the property stores.
event
The event that occurred.
$w

Deprecated: A selector function. The $w function enables event handlers to work with elements in repeaters and in the global scope.

RETURN VALUE
?
Value that a function evaluates to when it is finished running.
The element on which the event is now registered.

Examples

Get the ID of the element that has entered the viewport

$w("#myElement").onViewportLeave( (event) => {
  let targetId = event.target.id; // "myElement"
});