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This pulls in the types (based on the DefinitelyTyped repo) for `page.$eval` (and the `$eval` method on other classes). The `$eval` method is quite hard to type due to the way we wrap and unwrap ElementHandles that are passed to / returned from the `pageFunction` that users provide. Longer term we can improve the types by providing type overloads as DefinitelyTyped does but I've deferred that for now (see the `TODO` in the code for more details).
39 lines
1.5 KiB
Markdown
39 lines
1.5 KiB
Markdown
<!-- Do not edit this file. It is automatically generated by API Documenter. -->
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[Home](./index.md) > [puppeteer](./puppeteer.md) > [ElementHandle](./puppeteer.elementhandle.md) > [$eval](./puppeteer.elementhandle._eval.md)
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## ElementHandle.$eval() method
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This method runs `document.querySelector` within the element and passes it as the first argument to `pageFunction`<!-- -->. If there's no element matching `selector`<!-- -->, the method throws an error.
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If `pageFunction` returns a Promise, then `frame.$eval` would wait for the promise to resolve and return its value.
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<b>Signature:</b>
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```typescript
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$eval<ReturnType>(selector: string, pageFunction: (element: Element, ...args: unknown[]) => ReturnType | Promise<ReturnType>, ...args: SerializableOrJSHandle[]): Promise<WrapElementHandle<ReturnType>>;
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```
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## Parameters
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| Parameter | Type | Description |
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| --- | --- | --- |
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| selector | string | |
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| pageFunction | (element: Element, ...args: unknown\[\]) => ReturnType \| Promise<ReturnType> | |
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| args | [SerializableOrJSHandle](./puppeteer.serializableorjshandle.md)<!-- -->\[\] | |
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<b>Returns:</b>
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Promise<[WrapElementHandle](./puppeteer.wrapelementhandle.md)<!-- --><ReturnType>>
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## Example
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```js
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const tweetHandle = await page.$('.tweet');
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expect(await tweetHandle.$eval('.like', node => node.innerText)).toBe('100');
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expect(await tweetHandle.$eval('.retweets', node => node.innerText)).toBe('10');
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```
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