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Page.queryObjects() method

This method iterates the JavaScript heap and finds all objects with the given prototype.

Signature:

class Page {
abstract queryObjects<Prototype>(
prototypeHandle: JSHandle<Prototype>
): Promise<JSHandle<Prototype[]>>;
}

Parameters

Parameter

Type

Description

prototypeHandle

JSHandle<Prototype>

a handle to the object prototype.

Returns:

Promise<JSHandle<Prototype[]>>

Promise which resolves to a handle to an array of objects with this prototype.

Example

// Create a Map object
await page.evaluate(() => (window.map = new Map()));
// Get a handle to the Map object prototype
const mapPrototype = await page.evaluateHandle(() => Map.prototype);
// Query all map instances into an array
const mapInstances = await page.queryObjects(mapPrototype);
// Count amount of map objects in heap
const count = await page.evaluate(maps => maps.length, mapInstances);
await mapInstances.dispose();
await mapPrototype.dispose();