Modify Capture Page Screenshot keyword not fail if browser is not open.

[aaltat]

For new users, it might be confusing when the Open Browser keyword fails due some invalid configuration and then also the Capture Page Screenshot keyword also fails. It might be good idea not to raise exception if browser is not open when running Capture Page Screenshot keyword

[alexandrul]

What should it do in this case? Get a screenshot of the desktop (hoping for some helpful message dialogs) or create an empty file?

[pekkaklarck]

I was initially thinking it should just log a message that a screenshot cannot be taken because browser is not open. Taking a screenshot of the desktop is a valid idea too. Should probably somehow separate that from normal case anyway.

[pekkaklarck]

The simplest solution could be adding something like this to the beginning of the keyword:

if not self.browser:
    self.info('Cannot take screenshot because browser is not not open')
    return

but, as already discussed, taking a screenshot of the entire desktop might be even better. Either way, I don't think this needs any documentation changes but a new acceptance test is needed.

Ar you @alexandrul interested to look at this?

[aaltat]

Taking a screen shot from a desktop might be problematic, because there might not be a desktop running. Example if using headless chrome or PhantomJS. Also there are other scenarios which might prevent taking a screen shot from a desktop, although it might be running. Example running the browser using the Selenium grid causes some problems.

Perhaps it would be best to split the issue in two parts. First make the change Pekka suggested, because it's easy to do and there is a low risk doing it. Then in separate issue, investigate is it possible to find a solution that would work in most use cases and in cross platform way.

[pekkaklarck]

It's a good point that it's not always possible to take a screenshot of the desktop. Let's not complicate this unnecessarily and just do the simple thing that avoids the annoying warning. I would even open a separate issue about taking a screenshot of the desktop unless someone really needs such functionality. It's anyway possible to use Robot's Screenshot library for that purpose if needed.

[aaltat]

The original issue is now done. If there is a need to take a screen capture from the desktop, separate issue should be raised.