pythonseleniumdompolymershadow-dom

How to read text that is under #shadow-root (user-agent)


I am using Selenium (Python) for automating a web page. I am trying to get text from an input field that is under #shadow-root (user-agent). Xpath I used:

driver.find_element_by_xpath("**//*/p-calendar/span/input**").text

is not returning anything. Attached the screenshot of my DOM element. Requirement: To get text from the shadow root : 01:01

#shadow-root (user-agent)


Solution

  • As per @hayatoito's (creator of Shadow DOM) comment:

    The original motivation of introducing a closed shadow tree is "Never allow an access to a node in a closed shadow tree, via any APIs, from outside", AFAIK. Like that we can not access a node in the internal hidden shadow tree which is used in <video> element, in Blink.

    In fact, I designed a closed shadow tree in such a way. If there is a way to access a node in a closed shadow tree, it should be considered as a bug of the spec.

    I think it's totally okay to have an API to allow an access in the layer of Chrome apps or extensions. However, for a normal web app, I think the current agreement is "Never allow it".

    If we allowed it, that means we do not need a closed shadow tree. Just having an open shadow tree is enough, I think.

    Furhter @Supersharp in his comment below his own answer within the discussion How to get element in user-agent shadow root with JavaScript? mentions:

    #shadow-root (user-agent) are browser vendors native implementation so they are not documented and will never be accessible. Only open Shadow DOM are, as per the specs


    WebDriver perspective

    Recently, @AutomatedTester [David Burns, Chief Bacon Officer, Mozilla Corporation] initiated a discussion on WebDriver - Testability of web components

    Currently Selenium Team is open for accepting pull requests for the same.


    Reference

    You can find a couple of relevant detailed discussions in:


    Outro

    Here you can find a relevant discussion on How to automate shadow DOM elements using selenium?