How to click a dynamic link with in a drupal 8 website using xpath/css selector while automating through Selenium and Python

问题

I am trying to click on an edit tab link, and its in the form of a hyperlink in an unordered list.

Here is the HTML:

<li><a href="/node/2658/edit" data-drupal-link-system-path="node/2658/edit">Edit</a></li>

I have been trying to use driver.find_element_by_link_text('Edit') to find the element, however always get a NoSuchElementException.

I have also used the by partial text fxn, with all variations of the html, and receive the same error.

There is also the following html I found that includes the proper link:

<link rel="edit-form" href="/node/2658/edit" />

Is there a selenium function I can use to go to this edit page?

回答1:

As per the HTML you shared the value of href and data-drupal-link-system-path attributes clearly seems to be dynamic due to the presence of the value 2658. So you need to construct a dynamic locator to locate the element.

As the desired element is a dynamic element so to locate and click() on the element you have to induce WebDriverWait for the element_to_be_clickable() and you can use either of the following Locator Strategies:

Using CSS_SELECTOR:

WebDriverWait(driver, 20).until(EC.element_to_be_clickable((By.CSS_SELECTOR, "li>a[href$='edit'][data-drupal-link-system-path^='node']"))).click()

Using XPATH:

WebDriverWait(driver, 20).until(EC.element_to_be_clickable((By.XPATH, "//li/a[contains(@href, 'edit') and starts-with(@data-drupal-link-system-path, 'node')][text()='Edit']"))).click()

Note : You have to add the following imports :

from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.common.by import By
from selenium.webdriver.support import expected_conditions as EC

Explanation of the dynamic CSS_SELECTOR

To consider only the static part of href and data-drupal-link-system-path attributes you can use the following wildcards in css-selectors:

$ : To indicate an attribute value ends with
^ : To indicate an attribute value starts with

So the most granular css_selector would be :

li>a[href$='edit'][data-drupal-link-system-path^='node']

Explanation of the dynamic XPATH

To consider only the static part of href and data-drupal-link-system-path attributes you can use the following functions of xpath:

contains() : To indicate an attribute value contains
starts-with() : To indicate an attribute value starts with

So the most granular xpath would be :

//li/a[contains(@href, 'edit') and starts-with(@data-drupal-link-system-path, 'node')][text()='Edit']

Reference

You can find a couple of relevant discussions in:

How to find element by part of its id name in selenium with python
Java Selenium webdriver expression finding dynamic element by ccs that starts with and ends with
How to get selectors with dynamic part inside using Selenium with Python?
Finding elements by CSS selector with ChromeDriver (Selenium) in Python

tl; dr

You can find a detailed discussion on NoSuchElementException in:

Selenium “selenium.common.exceptions.NoSuchElementException” when using Chrome

来源：https://stackoverflow.com/questions/59777770/how-to-click-a-dynamic-link-with-in-a-drupal-8-website-using-xpath-css-selector

标签

python

selenium

xpath

css-selectors

webdriverwait