class-selectors.md

class: Selectors

• since: v1.8

Selectors can be used to install custom selector engines. See extensibility for more information.

async method: Selectors.register

• since: v1.8

Selectors must be registered before creating the page.

Usage

An example of registering selector engine that queries elements based on a tag name:

const { selectors, firefox } = require('playwright');  // Or 'chromium' or 'webkit'.

(async () => {
  // Must be a function that evaluates to a selector engine instance.
  const createTagNameEngine = () => ({
    // Returns the first element matching given selector in the root's subtree.
    query(root, selector) {
      return root.querySelector(selector);
    },

    // Returns all elements matching given selector in the root's subtree.
    queryAll(root, selector) {
      return Array.from(root.querySelectorAll(selector));
    }
  });

  // Register the engine. Selectors will be prefixed with "tag=".
  await selectors.register('tag', createTagNameEngine);

  const browser = await firefox.launch();
  const page = await browser.newPage();
  await page.setContent(`<div><button>Click me</button></div>`);

  // Use the selector prefixed with its name.
  const button = page.locator('tag=button');
  // We can combine it with built-in locators.
  await page.locator('tag=div').getByText('Click me').click();
  // Can use it in any methods supporting selectors.
  const buttonCount = await page.locator('tag=button').count();

  await browser.close();
})();

// Script that evaluates to a selector engine instance. The script is evaluated in the page context.
String createTagNameEngine = "{\n" +
  "  // Returns the first element matching given selector in the root's subtree.\n" +
  "  query(root, selector) {\n" +
  "    return root.querySelector(selector);\n" +
  "  },\n" +
  "  // Returns all elements matching given selector in the root's subtree.\n" +
  "  queryAll(root, selector) {\n" +
  "    return Array.from(root.querySelectorAll(selector));\n" +
  "  }\n" +
  "}";
// Register the engine. Selectors will be prefixed with "tag=".
playwright.selectors().register("tag", createTagNameEngine);
Browser browser = playwright.firefox().launch();
Page page = browser.newPage();
page.setContent("<div><button>Click me</button></div>");
// Use the selector prefixed with its name.
Locator button = page.locator("tag=button");
// Combine it with built-in locators.
page.locator("tag=div").getByText("Click me").click();
// Can use it in any methods supporting selectors.
int buttonCount = (int) page.locator("tag=button").count();
browser.close();

import asyncio
from playwright.async_api import async_playwright

async def run(playwright):
    tag_selector = """
      {
          // Returns the first element matching given selector in the root's subtree.
          query(root, selector) {
              return root.querySelector(selector);
          },
          // Returns all elements matching given selector in the root's subtree.
          queryAll(root, selector) {
              return Array.from(root.querySelectorAll(selector));
          }
      }"""

    # Register the engine. Selectors will be prefixed with "tag=".
    await playwright.selectors.register("tag", tag_selector)
    browser = await playwright.chromium.launch()
    page = await browser.new_page()
    await page.set_content('<div><button>Click me</button></div>')

    # Use the selector prefixed with its name.
    button = await page.query_selector('tag=button')
    # Combine it with built-in locators.
    await page.locator('tag=div').get_by_text('Click me').click()
    # Can use it in any methods supporting selectors.
    button_count = await page.locator('tag=button').count()
    print(button_count)
    await browser.close()

async def main():
    async with async_playwright() as playwright:
        await run(playwright)

asyncio.run(main())

from playwright.sync_api import sync_playwright

def run(playwright):
    tag_selector = """
      {
          // Returns the first element matching given selector in the root's subtree.
          query(root, selector) {
              return root.querySelector(selector);
          },
          // Returns all elements matching given selector in the root's subtree.
          queryAll(root, selector) {
              return Array.from(root.querySelectorAll(selector));
          }
      }"""

    # Register the engine. Selectors will be prefixed with "tag=".
    playwright.selectors.register("tag", tag_selector)
    browser = playwright.chromium.launch()
    page = browser.new_page()
    page.set_content('<div><button>Click me</button></div>')

    # Use the selector prefixed with its name.
    button = page.locator('tag=button')
    # Combine it with built-in locators.
    page.locator('tag=div').get_by_text('Click me').click()
    # Can use it in any methods supporting selectors.
    button_count = page.locator('tag=button').count()
    print(button_count)
    browser.close()

with sync_playwright() as playwright:
    run(playwright)

using Microsoft.Playwright;

using var playwright = await Playwright.CreateAsync();
// Script that evaluates to a selector engine instance. The script is evaluated in the page context.
await playwright.Selectors.RegisterAsync("tag", new()
{
    Script = @"{
    // Returns the first element matching given selector in the root's subtree.
    query(root, selector) {
        return root.querySelector(selector);
      },
      // Returns all elements matching given selector in the root's subtree.
      queryAll(root, selector) {
        return Array.from(root.querySelectorAll(selector));
      }
    }"
});

await using var browser = await playwright.Chromium.LaunchAsync();
var page = await browser.NewPageAsync();
await page.SetContentAsync("<div><button>Click me</button></div>");
// Use the selector prefixed with its name.
var button = page.Locator("tag=button");
// Combine it with built-in locators.
await page.Locator("tag=div").GetByText("Click me").ClickAsync();
// Can use it in any methods supporting selectors.
int buttonCount = await page.Locator("tag=button").CountAsync();

param: Selectors.register.name

• since: v1.8

• name <[string]>

Name that is used in selectors as a prefix, e.g. {name: 'foo'} enables foo=myselectorbody selectors. May only contain [a-zA-Z0-9_] characters.

param: Selectors.register.script

• since: v1.8
• langs: js

• script <[function]|[string]|[Object]>
  • path ?<[path]> Path to the JavaScript file. If path is a relative path, then it is resolved relative to the current working directory. Optional.
  • content ?<[string]> Raw script content. Optional.

Script that evaluates to a selector engine instance. The script is evaluated in the page context.

param: Selectors.register.script

• since: v1.8
• langs: java

• script <[string]|[path]>

Script that evaluates to a selector engine instance. The script is evaluated in the page context.

option: Selectors.register.script

• since: v1.8
• langs: csharp

• script <[string]>

Script that evaluates to a selector engine instance. The script is evaluated in the page context.

option: Selectors.register.path

• since: v1.8
• langs: csharp

• path <[path]>

Script that evaluates to a selector engine instance. The script is evaluated in the page context.

option: Selectors.register.contentScript

• since: v1.8

• contentScript <[boolean]>

Whether to run this selector engine in isolated JavaScript environment. This environment has access to the same DOM, but not any JavaScript objects from the frame's scripts. Defaults to false. Note that running as a content script is not guaranteed when this engine is used together with other registered engines.

method: Selectors.setTestIdAttribute

• since: v1.27

Defines custom attribute name to be used in [method: Page.getByTestId]. data-testid is used by default.

param: Selectors.setTestIdAttribute.attributeName

• since: v1.27

• attributeName <[string]>

Test id attribute name.