Allow for disabling of nbviewer

Currently, all notebooks from Github show a preview using nbviewer. In some situations this causes a “404: Not Found” message, even though everythign is correct (e.g. when trying to launch a file that is wrapped inside a Docker image).

For example: https://mybinder.org/v2/gh/crestdsl/crestdsl-demo-binder/master?filepath=GettingStarted.ipynb launches a notebook that is not in the repo, but in the Docker image that is launched by the repo.

I believe that providing an url-argument e.g. &preview=false could be useful in these situations to disable the preview (so users aren’t confused).

The concerned code places (as far as I see) are the ParameterizedMainHandler in main.py, where it would be necessary to extract the argument and pass it to the loading.html template. Code to add should be something like preview=self.get_argument('preview', True).

The other part is in the template itself (e.g. near Line 27 ) where a {% if preview %} can be added. (Line 30 already contains a condition that could also be easily extended…)

This issue is to allow feedback / opposition before starting implementing. Thus:

1. What do you think?
2. Is my current though process correct? or is my “very simple” solution not as simple after all?

PS: lacking time right now, so PR will come in a few weeks earliest.

[betatim]

With #934 we now don’t show the preview if it would contain an error so I’ll close this issue.

[fm75]

What is GHE?

Sorry, GitHub Enterprise. GitHub, but set up by enterprises, ordinarily not available from the internet.