NavigationListener

Added in 1.15.0

Kotlin |Java

@WebNavigationClient.ExperimentalNavigationCallback
interface NavigationListener

Page identification and lifecycle APIs.

This class provides callbacks to identify the different stages of navigation. For more information about the navigation lifecycle, please see the Life of a Navigation Presentation.

Note: These navigation callbacks only fire for navigations happening on the main frame.

Navigation lifecycle events:

onNavigationStarted
Potentially zero or more onNavigationRedirected events
onNavigationCompleted
If the navigation commits and is not a same-document navigation, potentially any combination and order of zero or one of each of:

Summary

Public functions
`Unit`	`onFirstContentfulPaint(page: Page, loadTimeUs: Long)` Called when the page achieves "First Contentful Paint".
`Unit`	`onFirstContentfulPaintMillis(page: Page, durationMillis: Long)` Called when the page achieves "First Contentful Paint".
`Unit`	`onLargestContentfulPaintMillis(page: Page, durationMillis: Long)` Called when the page fires a "Largest Contentful Paint" event.
`Unit`	`onNavigationCompleted(navigation: Navigation)` Called when a navigation completes.
`Unit`	`onNavigationRedirected(navigation: Navigation)` Called when a navigation is redirected.
`Unit`	`onNavigationStarted(navigation: Navigation)` Called when a navigation starts, including same-document navigations.
`Unit`	`onPageDeleted(page: Page)` Called when any Page is evicted/destroyed.
`Unit`	`onPageDomContentLoadedEvent(page: Page)` Called when the `DOMContentLoaded` event is fired for the current page.
`Unit`	`onPageLoadEvent(page: Page)` Called when the `window.load` event is fired for the current page.
`Unit`	`onPerformanceMarkMillis(page: Page, markName: String, markTimeMillis: Long)` Called when the page registers a performance mark.

Public functions

onFirstContentfulPaint

Added in 1.15.0

fun onFirstContentfulPaint(page: Page, loadTimeUs: Long): Unit

Called when the page achieves "First Contentful Paint".

See First Contentful Paint (FCP) for a definition.

Parameters
`page: Page`	The Page for which the First Contentful Paint occurred.
`loadTimeUs: Long`	Navigation to First Contentful Paint load time in microseconds.

onFirstContentfulPaintMillis

Added in 1.16.0-alpha03

fun onFirstContentfulPaintMillis(page: Page, durationMillis: Long): Unit

Called when the page achieves "First Contentful Paint".

See First Contentful Paint (FCP) for a definition.

This method is called only if NAVIGATION_LISTENER_V2 is supported. You can check whether that flag is supported using isFeatureSupported.

Parameters
`page: Page`	The Page for which the First Contentful Paint occurred.
`durationMillis: Long`	Navigation to First Contentful Paint duration in milliseconds.

onLargestContentfulPaintMillis

Added in 1.16.0-alpha03

fun onLargestContentfulPaintMillis(page: Page, durationMillis: Long): Unit

Called when the page fires a "Largest Contentful Paint" event.

See Largest Contentful Paint (LCP) for a definition.

This method is called only if NAVIGATION_LISTENER_V2 is supported. You can check whether that flag is supported using isFeatureSupported.

Parameters
`page: Page`	The Page for which the Largest Contentful Paint occurred.
`durationMillis: Long`	Navigation to Largest Contentful Paint duration in milliseconds.

Added in 1.15.0

fun onNavigationCompleted(navigation: Navigation): Unit

Called when a navigation completes.

The navigation might not have actually committed (e.g., results in 204/download/cancelled), but those that do they will have committed by this point.

Parameters
`navigation: Navigation`	The Navigation object representing the completed navigation.

Added in 1.15.0

fun onNavigationRedirected(navigation: Navigation): Unit

Called when a navigation is redirected.

Parameters
`navigation: Navigation`	The Navigation object representing the redirected navigation.

Added in 1.15.0

fun onNavigationStarted(navigation: Navigation): Unit

Called when a navigation starts, including same-document navigations.

Note: These navigation callbacks only fire for navigations happening on the main frame.

Parameters
`navigation: Navigation`	The Navigation object representing the started navigation.

onPageDeleted

Added in 1.15.0

fun onPageDeleted(page: Page): Unit

Called when any Page is evicted/destroyed. This can occur immediately on navigation, or later if the page is BFCached and subsequently evicted.

Parameters
`page: Page`	The Page that was evicted or destroyed.

onPageDomContentLoadedEvent

Added in 1.15.0

fun onPageDomContentLoadedEvent(page: Page): Unit

Called when the DOMContentLoaded event is fired for the current page.

Parameters
`page: Page`	The Page for which the `DOMContentLoaded` event fired.

onPageLoadEvent

Added in 1.15.0

fun onPageLoadEvent(page: Page): Unit

Called when the window.load event is fired for the current page.

Parameters
`page: Page`	The Page for which the `window.load` event fired.

onPerformanceMarkMillis

Added in 1.16.0-alpha03

fun onPerformanceMarkMillis(page: Page, markName: String, markTimeMillis: Long): Unit

Called when the page registers a performance mark.

See Performance: mark() method for a definition.

This method is called only if NAVIGATION_LISTENER_V2 is supported. You can check whether that flag is supported using isFeatureSupported.

Parameters
`page: Page`	The Page for which the performance mark was registered.
`markName: String`	The name of the performance mark.
`markTimeMillis: Long`	The time of the performance mark in milliseconds since Performance.timeOrigin.