Returns either null or the object handle itself, if the object handle is an instance of
ElementHandle.
Returns the return value of
pageFunction.
This method passes this handle as the first argument to
pageFunction.
If pageFunction
returns a [Promise], then handle.evaluate would wait for the promise to resolve and return its value.
Usage
const tweetHandle = await page.$('.tweet .retweets');
expect(await tweetHandle.evaluate(node => node.innerText)).toBe('10 retweets');
Function to be evaluated in the page context.
Optional argument to pass to
pageFunction.
Returns the return value of
pageFunction.
This method passes this handle as the first argument to
pageFunction.
If pageFunction
returns a [Promise], then handle.evaluate would wait for the promise to resolve and return its value.
Usage
const tweetHandle = await page.$('.tweet .retweets');
expect(await tweetHandle.evaluate(node => node.innerText)).toBe('10 retweets');
Function to be evaluated in the page context.
Optional arg: anyOptional argument to pass to
pageFunction.
Optional Returns the return value of
pageFunction
as a JSHandle.
This method passes this handle as the first argument to
pageFunction.
The only difference between jsHandle.evaluate and jsHandle.evaluateHandle is that jsHandle.evaluateHandle
returns JSHandle.
If the function passed to the jsHandle.evaluateHandle returns a [Promise], then jsHandle.evaluateHandle would
wait for the promise to resolve and return its value.
See page.evaluateHandle(pageFunction[, arg]) for more details.
Function to be evaluated in the page context.
Optional argument to pass to
pageFunction.
Returns the return value of
pageFunction
as a JSHandle.
This method passes this handle as the first argument to
pageFunction.
The only difference between jsHandle.evaluate and jsHandle.evaluateHandle is that jsHandle.evaluateHandle
returns JSHandle.
If the function passed to the jsHandle.evaluateHandle returns a [Promise], then jsHandle.evaluateHandle would
wait for the promise to resolve and return its value.
See page.evaluateHandle(pageFunction[, arg]) for more details.
Function to be evaluated in the page context.
Optional arg: anyOptional argument to pass to
pageFunction.
Optional The method returns a map with own property names as keys and JSHandle instances for the property values.
Usage
const handle = await page.evaluateHandle(() => ({ window, document }));
const properties = await handle.getProperties();
const windowHandle = properties.get('window');
const documentHandle = properties.get('document');
await handle.dispose();
Returns a JSON representation of the object. If the object has a toJSON function, it will not be called.
NOTE The method will return an empty JSON object if the referenced object is not stringifiable. It will throw an error if the object has circular references.
Generated using TypeDoc
JSHandle represents an in-page JavaScript object. JSHandles can be created with the page.evaluateHandle(pageFunction[, arg]) method.
JSHandle prevents the referenced JavaScript object being garbage collected unless the handle is exposed with jsHandle.dispose(). JSHandles are auto-disposed when their origin frame gets navigated or the parent context gets destroyed.
JSHandle instances can be used as an argument in page.$eval(selector, pageFunction[, arg, options]), page.evaluate(pageFunction[, arg]) and page.evaluateHandle(pageFunction[, arg]) methods.