I have written a (Python) script using Selenium to automate some downloads from Box (I'm aware there is a Box API, but I'm accessing school resources and I'm not sure that the API would interact well with the school's external authentication). The script works using the Chrome driver in non-headless mode, but not in headless.
The step where I'm having issues is an attempt to query the status of downloads. I think my script is actually able to execute the downloads correctly: I've added some code from SO to disable security defaults that prevent downloading in headless mode.
I've successfully queried the download status using two methods (both executing Javascript in Chrome):
- Selenium (Python) - waiting for a download process to complete using Chrome web driver
- https://gist.github.com/ic0n/a38b354cac213e5aa50c55a0d8b87a0b
Both stop working when I switch to headless mode.
Here's the actual code I'm using:
# Headless Chrome disables downloads by default (at least as of 2017).
# https://stackoverflow.com/questions/45631715/downloading-with-chrome-headless-and-selenium
def enable_download_in_headless_chrome(driver, download_dir):
# add missing support for chrome "send_command" to selenium webdriver
driver.command_executor._commands["send_command"] = \
("POST", '/session/$sessionId/chromium/send_command')
params = {
'cmd': 'Page.setDownloadBehavior',
'params': {'behavior': 'allow', 'downloadPath': download_dir},
}
return driver.execute("send_command", params)
def get_top_download_state(driver):
"""Call this after running driver.get("chrome://downloads")."""
[state, percent, progress] = driver.execute_script("""
var item = downloads.Manager.get().items_[0];
var state = item.state;
var percent = item.percent;
var progress = item.progressStatusText;
return [state, percent, progress];
""")
return state, percent, progress
Errors for the first method say that downloads is not defined. Errors for the second method say that you can't get the shadowRoot property of null (presumably the query selectors are just finding nothing).
