KeyError: 'webSocketDebuggerUrl'

[brupelo]

Hi, sometimes this exception is yield:

Traceback (most recent call last):
  File "D:\sources\personal\www\www.todotrucos.info\posts\foo_post.py", line 33, in <module>
    wpp.run(filename=__file__, post_content=POST, tags=[], post_status="draft")
  File "D:\sources\personal\python\framework\web\wp_lib.py", line 280, in run
    print chrome.tabs
  File "d:\virtual_envs\py2710\lib\site-packages\chromote\__init__.py", line 122, in tabs
    return tuple(self._get_tabs())
  File "d:\virtual_envs\py2710\lib\site-packages\chromote\__init__.py", line 106, in _get_tabs
    yield ChromeTab(tab['title'], tab['url'], tab['webSocketDebuggerUrl'])
KeyError: 'webSocketDebuggerUrl'

And the code yielding that exception is very basic

chrome = Chromote()
print chrome.tabs

As i said, it happens sometimes but i don't know, any clue why?

Regards

[brupelo]

Actually, i think you can reproduce it if you open chrome dev tools in the browser (ctrl+shift+j).

[iiSeymour]

I can reproduce this when multiple clients are attached (which isn't supported by the protocol). Are you using Chromote and the browser at the same time?

[brupelo]

The simplest way to reproduce the issue is this:

1. Close all opened browsers and start a single chrome browser with the remote-debugging-port parameter:

chrome.exe -remote-debugging-port=9222

2. In that browser, open chrome dev tools (ctrl+shift+j)

3. Run the next code:

from chromote import Chromote

chrome = Chromote()
tab = chrome.tabs[0]

At this point the exception should appear

yield ChromeTab(tab['title'], tab['url'], tab['webSocketDebuggerUrl'])

If you close the chrome dev tools and run again the snippet the exception won't be launched.

Btw, cool project of yours!

[brupelo]

It's not real solution but locally I've patched _get_tabs:

   def _get_tabs(self):
        """
        Get all open browser tabs that are pages tabs
        """
        res = requests.get(self.url + '/json')
        for tab in res.json():
            if ('webSocketDebuggerUrl' in tab.keys()):
                if tab['type'] == 'page':
                    yield ChromeTab(tab['title'], tab['url'], tab['webSocketDebuggerUrl'])

So i can use chromote having multiple browsers where many tabs will be using the ChromeDevTools... I won't get them back of course but at least Chromote won't crash.

[iiSeymour]

Great, why not send a PR. My preference would be to drop the parens and explicate call to keys:

if 'webSocketDebuggerUrl' in tab:

[brupelo]

Nah, your choice, it's your baby ;-)

For my use-case i've tweaked my local copy like this:

    def _get_tabs(self):
        res = requests.get(self.url + '/json')
        for tab in res.json():
            if tab['type'] == 'page':
                if ('webSocketDebuggerUrl' not in tab.keys()):
                    yield ChromeTab(tab['title'], tab['url'], None)
                else:
                    yield ChromeTab(tab['title'], tab['url'], tab['webSocketDebuggerUrl'])

and adding one method to check "valid" tabs:

    def is_valid(self):
        return self._websocket_url is not None

That way i have all available tabs from my browsers, if i want to reload one tab i just check first if is valid or not, it works wonderfully... That way i can run my scripts while other tabs have opened the chrome-dev-tools, workflow is fast.