$$eval<T> method

Future<T?> $$eval<T>(
  1. String selector,
  2. @Language('js') String pageFunction, {
  3. List? args,
})

This method runs document.querySelectorAll within the element and passes it as the first argument to pageFunction. If there's no element matching selector, the method throws an error.

If pageFunction returns a Promise, then frame.$$eval would wait for the promise to resolve and return its value.

Examples:

<div class="feed">
  <div class="tweet">Hello!</div>
  <div class="tweet">Hi!</div>
</div>

var feedHandle = await page.$('.feed');
expect(
    await feedHandle.$$eval('.tweet', 'nodes => nodes.map(n => n.innerText)'),
    equals(['Hello!', 'Hi!']));

Parameters:

  • A selector to query page for
  • pageFunction: Function to be evaluated in browser context
  • args: Arguments to pass to pageFunction

Returns: Future which resolves to the return value of pageFunction

Implementation

Future<T?> $$eval<T>(String selector, @Language('js') String pageFunction,
    {List<dynamic>? args}) async {
  var arrayHandle = await evaluateHandle(
      //language=js
      'function _(element, selector) {return Array.from(element.querySelectorAll(selector));}',
      args: [selector]);

  var result = await arrayHandle.evaluate<T>(pageFunction, args: args);
  await arrayHandle.dispose();
  return result;
}