puppeteer.page.evaluatehandle.md

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Page.evaluateHandle

Page.evaluateHandle() method

Signature:

class Page {
  evaluateHandle<
    Params extends unknown[],
    Func extends EvaluateFunc<Params> = EvaluateFunc<Params>
  >(
    pageFunction: Func | string,
    ...args: Params
  ): Promise<HandleFor<Awaited<ReturnType<Func>>>>;
}

Parameters

Parameter	Type	Description
pageFunction	Func | string	a function that is run within the page
args	Params	arguments to be passed to the pageFunction

Returns:

Promise<HandleFor<Awaited<ReturnType<Func>>>>

Remarks

The only difference between page.evaluate and page.evaluateHandle is that evaluateHandle will return the value wrapped in an in-page object.

If the function passed to page.evaluteHandle returns a Promise, the function will wait for the promise to resolve and return its value.

You can pass a string instead of a function (although functions are recommended as they are easier to debug and use with TypeScript):

Example 1

const aHandle = await page.evaluateHandle('document');

Example 2

JSHandle instances can be passed as arguments to the pageFunction:

const aHandle = await page.evaluateHandle(() => document.body);
const resultHandle = await page.evaluateHandle(body => body.innerHTML, aHandle);
console.log(await resultHandle.jsonValue());
await resultHandle.dispose();

Most of the time this function returns a JSHandle, but if pageFunction returns a reference to an element, you instead get an ElementHandle back:

Example 3

const button = await page.evaluateHandle(() =>
  document.querySelector('button')
);
// can call `click` because `button` is an `ElementHandle`
await button.click();

The TypeScript definitions assume that evaluateHandle returns a JSHandle, but if you know it's going to return an ElementHandle, pass it as the generic argument:

const button = await page.evaluateHandle<ElementHandle>(...);