Executing Javascript on Selenium/PhantomJS

Question

I'm using PhantomJS via Selenium Webdriver in Python and I'm trying to execute a piece of JavaScript on the page in hopes of returning a piece of data:

from selenium import webdriver

driver = webdriver.PhantomJS("phantomjs.cmd") # or add to your PATH
driver.set_window_size(1024, 768) # optional
driver.get('http://google.com') # EXAMPLE, not actual URL

driver.save_screenshot('screen.png') # save a screenshot to disk
jsres = driver.execute('$("#list").DataTable().data()')
print(jsres)

However when run, it reports KeyError. I was unable to find much documentation on the commands available, so I'm a bit stuck here.

Solution

The method created for executing javascript is called execute_script(), not execute():

driver.execute_script('return $("#list").DataTable().data();')

FYI, execute() is used internally for sending webdriver commands.

Note that if you want something returned by javascript code, you need to use return.

Also note that this can throw Can't find variable: $ error message. In this case, locate the element with selenium and pass it into the script:

# explicitly wait for the element to become present
wait = WebDriverWait(driver, 10)
element = wait.until(EC.presence_of_element_located((By.ID, "list")))

# pass the found element into the script
jsres = driver.execute_script('return arguments[0].DataTable().data();', element)
print(jsres)