A forked copy of the CORS Anywhere intended for Observable Notebook usage.
All Documentation for Cors Anywhere can be found in that GitHub repo.
In Observable, sometimes you'll need to access a resource that does not have CORS enabled. The standard fix for this would be to prepend https://cors-anywhere.herokuapp.com to your resource and you'd be good to go. However, that server is offered as a demo and you'll get rate-limited.
So, CORS Anywhere Observable offers the same service, but allows you to run your personal copy of CORS Anywhere specifically for your Observable Notebooks.
All you have to do is Deploy this app to heroku (button above), then add an env var "CORSANYWHERE_WHITELIST" with a single domain:
Now, you'll have your own CORS Anywhere server that will only proxy requests that come from your own Observable Notebooks!
If someone forks your notebook, then their requests won't work anymore - since the requests would come from their notebook.
So, if you want a warning whenever someone forks your notebook, you can add a cell to all of your notebooks that checks the host domain of the notebook and show a warning message if it's not yours.
For example, for me, I have something like:
(window.location.host.slice(0,6)!=='asg017')? 'Warning message here!': '';
I have a generic warning message under my toolbox so I could import it easily in all of my notebooks.
Differences between CORS Anywhere and this CORS Anywhere Observable server are:
Copyright (C) 2013 - 2016 Rob Wu firstname.lastname@example.org
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