* docs: update navigation and loading doc * dgozman comments * doclint
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Navigations
Playwright can navigate to URLs and handle navigations caused by page interactions. This guide covers common scenarios to wait for page navigations and loading to complete.
- Navigation lifecycle
- Scenarios initiated by browser UI
- Scenarios initiated by page interaction
- Advanced patterns
Navigation lifecycle
Playwright splits the process of showing a new document in a page into navigation and loading.
Navigations can be initiated by changing the page URL or by interacting with the page (e.g., clicking a link). Navigation ends when response headers have been parsed and session history is updated. The navigation intent may be canceled, for example, on hitting an unresolved DNS address or transformed into a file download. Only after the navigation succeeds, page starts loading the document.
Loading covers getting the remaining response body over the network, parsing, executing the scripts and firing load events:
page.url()
is set to the new url- document content is loaded over network and parsed
domcontentloaded
event is fired- page executes some scripts and loads resources like stylesheets and images
load
event is fired- page executes dynamically loaded scripts
networkidle
is fired when no new network requests are made for 500 ms
Scenarios initiated by browser UI
Navigations can be initiated by changing the URL bar, reloading the page or going back or forward in session history.
Auto-wait
Navigating to a URL auto-waits for the page to fire the load
event. If the page does a client-side redirect before load
, page.goto
will auto-wait for the redirected page to fire the load
event.
// Navigate the page
await page.goto('https://example.com');
Custom wait
Override the default behavior to wait until a specific event, like networkidle
.
// Navigate and wait until network is idle
await page.goto('https://example.com', { waitUntil: 'networkidle' });
Wait for element
In lazy-loaded pages, it can be useful to wait until an element is visible with page.waitForSelector
. Alternatively, page interactions like page.click
auto-wait for elements.
// Navigate and wait for element
await page.goto('https://example.com');
await page.waitForSelector('text=Example Domain');
// Navigate and click element
// Click will auto-wait for the element
await page.goto('https://example.com');
await page.click('text=Example Domain');
API reference
Scenarios initiated by page interaction
In the scenarios below, page.click
initiates a navigation and then waits for the navigation to complete.
Auto-wait
By default, page.click
will wait for the navigation step to complete. This can be combined with a page interaction on the navigated page which would auto-wait for an element.
// Click will auto-wait for navigation to complete
await page.click('text=Login');
// Fill will auto-wait for element on navigated page
await page.fill('#username', 'John Doe');
Custom wait
page.click
can be combined with page.waitForLoadState
to wait for a loading event.
await page.click('button'); // Click triggers navigation
await page.waitForLoadState('networkidle'); // This resolves after 'networkidle'
Wait for element
In lazy-loaded pages, it can be useful to wait until an element is visible with page.waitForSelector
. Alternatively, page interactions like page.click
auto-wait for elements.
// Click triggers navigation
await page.click('text=Login');
// Click will auto-wait for the element
await page.waitForSelector('#username', 'John Doe');
// Click triggers navigation
await page.click('text=Login');
// Fill will auto-wait for element
await page.fill('#username', 'John Doe');
Asynchronous navigation
Clicking an element could trigger asychronous processing before initiating the navigation. In these cases, it is recommended to explicitly call page.waitForNavigation
. For example:
- Navigation is triggered from a
setTimeout
- Page waits for network requests before navigation
await Promise.all([
page.click('a'), // Triggers a navigation after a timeout
page.waitForNavigation(), // Waits for the next navigation
]);
The Promise.all
pattern prevents a race condition between page.click
and page.waitForNavigation
when navigation happens quickly.
Multiple navigations
Clicking an element could trigger multiple navigations. In these cases, it is recommended to explicitly page.waitForNavigation
to a specific url. For example:
- Client-side redirects issued after the
load
event - Multiple pushes to history state
await Promise.all([
page.waitForNavigation({ url: '**/login' }),
page.click('a'), // Triggers a navigation with a script redirect
]);
The Promise.all
pattern prevents a race condition between page.click
and page.waitForNavigation
when navigation happens quickly.
Loading a popup
When popup is opened, explicitly calling page.waitForLoadState
ensures that popup is loaded to the desired state.
const [ popup ] = await Promise.all([
page.waitForEvent('popup'),
page.click('a[target="_blank"]'), // Opens popup
]);
await popup.waitForLoadState('load');
API reference
page.click(selector[, options])
page.waitForLoadState([state[, options]])
page.waitForSelector(selector[, options])
page.waitForNavigation([options])
page.waitForFunction(pageFunction[, arg, options])
Advanced patterns
For pages that have complicated loading patterns, page.waitForFunction
is a powerful and extensible approach to define a custom wait criteria.
await page.goto('http://example.com');
await page.waitForFunction(() => window.amILoadedYet());
// Ready to take a screenshot, according to the page itself.
await page.screenshot();