puppeteer.executioncontext.evaluatehandle.md

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ExecutionContext.evaluateHandle

ExecutionContext.evaluateHandle() method

Evaluates the given function.

Unlike evaluate, this method returns a handle to the result of the function.

This method may be better suited if the object cannot be serialized (e.g. Map) and requires further manipulation.

Signature:

class ExecutionContext {
  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	The function to evaluate.
args	Params	Additional arguments to pass into the function.

Returns:

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

A handle to the result of evaluating the function. If the result is a Node, then this will return an element handle.

Example 1

const context = await page.mainFrame().executionContext();
const handle: JSHandle<typeof globalThis> = await context.evaluateHandle(() =>
  Promise.resolve(self)
);

Example 2

A string can also be passed in instead of a function.

const handle: JSHandle<number> = await context.evaluateHandle('1 + 2');

Example 3

Handles can also be passed as args. They resolve to their referenced object:

const bodyHandle: ElementHandle<HTMLBodyElement> = await context.evaluateHandle(
  () => {
    return document.body;
  }
);
const stringHandle: JSHandle<string> = await context.evaluateHandle(
  body => body.innerHTML,
  body
);
console.log(await stringHandle.jsonValue()); // prints body's innerHTML
// Always dispose your garbage! :)
await bodyHandle.dispose();
await stringHandle.dispose();