Expose Playwright's registerSelectorEngine()

[barambulka]

Is your feature request related to a problem? Please describe.
We are considering usage of Robot Framework Browser library. Our webapp UI is dynamically generated by SmartClient (which itself has its own selector/locator approach). When we were using Playwright exclusively, we implemented selector engine to work with SmartClient selectors/locators and registered it with Playwright. Switching to Robot Framework does not give us that ability.

Describe the solution you'd like
Expose Playwright's registerSelectorEngine() in Robot Framework Browser library via 'Register Selector Engine' keyword.

[aaltat]

Hmm, are you referring to this one https://playwright.dev/docs/api/class-selectors or are you meaning something else? If yes, what that else is in the Playwrights documentation?

[barambulka]

Hmm, are you referring to this one https://playwright.dev/docs/api/class-selectors or are you meaning something else? If yes, what that else is in the Playwrights documentation?

Yes, also described in more detail here: https://playwright.dev/docs/extensibility

My bad, I forgot the method's name was just the "register" when opening the feature request.

[aaltat]

This would require some research because those seem to come from Playwright test and not from Playwright API. We only support Playwright API. But there is some evidence that it might exist in the Playwright API too

[barambulka]

This would require some research because those seem to come from Playwright test and not from Playwright API. We only support Playwright API. But there is some evidence that it might exist in the Playwright API too

Thank you! I appreciate your help!

[aaltat]

@allcontributors please add @barambulka for ideas.

Would you be willing to do research and perhaps provide PR for the implementation?

[allcontributors]

@aaltat

I've put up a pull request to add @barambulka! 🎉

[barambulka]

@allcontributors please add @barambulka for ideas.

Would you be willing to do research and perhaps provide PR for the implementation?

I will try. Have been working on it since yesterday. I'm a QA and the learning curve is very steep for me :) I'll keep trying

[aaltat]

I think there are few steps.

1. Making a small PoC, most likely only in the Node side, to see is this possible at all in Playwright API
2. If yes, then we should think together about the architecture in the Browser library
3. Implement it

[barambulka]

1. Making a small PoC, most likely only in the Node side, to see is this possible at all in Playwright API

I think I did that. How can I share it with you to check if it is what's needed?

[aaltat]

Depends how large the PoC is. If it's only a single file in TypeScript, you can paste it here or put it in https://gist.githu If PoC needs something from this project, just create a PR.

[barambulka]

It's a single file.

const { selectors, webkit, chromium } = require('playwright');

(async () => {
  // Define a simple custom selector that selects elements by inner text
  await selectors.register('textcontent', () => ({
    // Called in the browser context
    query(root, selector) {
      return Array.from(root.querySelectorAll('*')).find(el => el.textContent.trim() === selector);
    },
    queryAll(root, selector) {
      return Array.from(root.querySelectorAll('*')).filter(el => el.textContent.trim() === selector);
    }
  }));

  const browser = await chromium.launch();
  const page = await browser.newPage();

  await page.setContent(`
    <div>Hello world</div>
    <div>Other content</div>
  `);

  const element = await page.locator('textcontent=Hello world').first();
  console.log(await element.textContent());  // Should log: "Hello world"

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

[aaltat]

Definitely looks like registering selector is possible from Playwright API. From that point of view, this is good to go.

Next step is to define an architecture for this feature.

1. When you look at your needs, how complex is the part that actually defines a custom selector? Is it something that would be good to define in a keyword argument as text? Or is it too long, complex or both and we should think something else than passing the TypeScript code as an argument?
2. Scope? It looks like from Playwright docs that selectors are registered for the duration of the test execution and selector can not be removed. If it can not, then there is no need for scope.
3. It seems that there is support also for path and content is Playwright API, support both might be good idea.