Custom Selector Engine
Looking to create my first custom selector engine. Im referencing these docs: https://playwright.dev/docs/extensibility#custom-selector-engines
My question is. How do i properly create a selector. I also have been referencing this as well. https://www.browserstack.com/guide/playwright-selectors
This is a snippet from the previously mentioned docs.
playwright.selectors.register('data-testid', {
create(root, target) {
return root.querySelector(`[data-testid="${target}"]`);
},
});
// Use your custom selector
await page.locator('data-testid=myTestId');```
I get an error when trying to create a selector.
Above my test , i have this function.
```const rectSelectorEngine = () => ({
// 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));
},
});```
```const urls = await page.$$('div[class = "canvas sectionCanvas"]');```
I will want to use this as my selector. This returns 4 rect elements on the DOM.
```await selectors.register("selector", rectSelectorEngine, {
create(root, selector) {
return page.$$('div[class = "canvas sectionCanvas"]');
},
});```
my create method throws an error.This thread is trying to answer question "How do I properly create a custom selector engine using Playwright?"
ohhh i think i need to speicify the selector in my rectSelectorEngine func
// Returns the first element matching given selector in the root's subtree.
query(root, selector) {
return root.querySelector('div[class = "canvas sectionCanvas"]');
},
// Returns all elements matching given selector in the root's subtree.
queryAll(root, selector) {
return Array.from(root.querySelectorAll('div[class = "canvas sectionCanvas"]'));
},
});```
Maybe like this? Ill give it a shot and report back
Related Ask AI answer for "What is the process to register a custom selector engine in Playwright?".
Answer
Creating a Custom Selector Engine in Playwright
Creating a custom selector engine in Playwright involves a few steps.
Registering the Selector Engine
First, you need to register your custom selector engine using the selectors.register() method. This method requires a create function, a query function, and a queryAll function.
Here's an example of how to register a custom engine that queries elements based on their tag name:
import { selectors } from '@playwright/test';
const createTagNameEngine = () => ({
query(root: Document | ShadowRoot | Element, selector: string) {
return root.querySelector(selector);
},
queryAll(root: Document | ShadowRoot | Element, selector: string) {
return Array.from(root.querySelectorAll(selector));
},
});
await selectors.register('tag', createTagNameEngine);Using the Custom Selector Engine
Once registered, you can use your custom selector engine by prefixing the selector with its name. For example:
const button = page.locator('tag=button');You can also combine your custom selectors with built-in locators and use them in any methods that support selectors. For example:
await page.locator('tag=div').getByText('Click me').click();And you can perform assertions on elements selected using your custom engine:
await expect(page.locator('tag=button')).toHaveCount(3);Remember to register your selectors before creating any pages in Playwright. For more details, check out Mastering Playwright Test Automation: Your Comprehensive Cheat Sheet.
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