URL Prefixes for static content

[arnavs]

One of the things @jlperla and I are working on in preparation for teaching is to remove dependence on local files in rst_files/_static/. Ideally we could just swap out the prefix in _static (that is, self.confdir + _static) with something like https://raw.githubusercontent.com/QuantEcon/lecture-source-jl/master/rst_files/, and then add a Jupinx setting.

For example, if we use commands like .. figure:: https://raw.githubusercontent.com/QuantEcon/lecture-source-jl/master/rst_files/_static/figures/arellano_bond_prices.png and swallow the exceptions thrown by Jupinx, then we get the desired behavior.

cc: @mmcky

[jlperla]

Yes. And, just to be clear, with a URL prefix you don't need to copy the files at all so I suspect that whole copy_asset could be skipped.

[mmcky]

Does anyone know if github has any rate limits for accessing raw files?

I know there is a limit of 5000 requests per hour on the general api. https://developer.github.com/v3/#rate-limiting

if the site pulls from raw.githubusercontent.com each time the site is loaded we may hit some github limits which could prevent images from loading. Just want to rule this out before implementing this.

[mmcky]

I think it would probably be better to embed the files in the notebook as attachments. https://nbformat.readthedocs.io/en/latest/format_description.html#cell-attachments

Can you remind me if there is a reason not to go this way?

I think it is better to be self contained then to link to images on an external service.

[jlperla]

Yes, if they are links, it should be to the hosted mages for the HTML site as opposed to github directly. But with a sphinx setting the prefix url could be swapped out in different builds.

I don't know jupyter well enough to know if cell attachments are a good idea, but I do know that:

• Jupyterlab and notebook have different security settings, which could cause grief. @sglyon might know more since I think he had to deal with this with Plotly
• The jupyter people told the julia crowd to stay away from embedding things in notebooks (e.g. https://github.com/JuliaLang/IJulia.jl/issues/673#issuecomment-424216949 )
• It isn't worth it if is difficult and would delay a launch, but if it is a minimal amount of work then we could try it in notebook and jupyterlab

[mmcky]

Yes, if they are links, it should be to the hosted mages for the HTML site as opposed to github directly. But with a sphinx setting the prefix url could be swapped out in different builds.

OK I see - so we will need to copy the static assets to the s3 hosting bucket anyway but we could add links in the notebooks as html calls rather than relative links.

[jlperla]

Yeah, that was my thinking... maybe there is a better way. Regardless, I don't think offline use of the notebooks is worth the trouble of embedding the static assets.

[mmcky]

PR submitted to allow this. @jlperla I have left the copy assets in place as it is useful having the _static folder to copy to the server.