Helper for constructing links suitable for use_course()

[jennybc]

Provide more help (and a convenient place of docs) re: how to get "download" links for GitHub, DropBox, Google Drive.

If possible, also a way to make short links from usethis.

[maelle]

Maybe relevant, https://github.com/ottlngr/tinycc

[jennybc]

Relevant to RStudio folks, note that Rebrandly has an API: https://developers.rebrandly.com/docs

[jennybc]

Example: consider this GitHub repo

https://github.com/jennybc/explore-libraries

The correct use_course() call is

use_course("https://github.com/jennybc/explore-libraries/archive/master.zip")

It would be nicer to say `use_course("jennybc/explore-libraries"). This reduces the need to create short links.

[cwickham]

I'm going to work on this for tidy-dev-day, but if someone else at dev-day wants to help, I'd love to work together.

[cwickham]

OK, to not bite off too much at once, I'll focus on the github repo use case, use_course("jennybc/explore-libraries"). Essentially turning the recommendations about URLs for Github (and Dropbox?) in ?use_course_details into things that happen automatically.

API questions for @jennybc , how should this work from a user's perspective:

• Somehow automatically identify that a user is specifying a user/repo form of link: use_course("jennybc/explore-libraries")? But how to distinguish this from a shortlink minus the http, e.g. use_course("bit.ly/explore-libraries")?

• Make the user identify this is a github link via an argument (which might have a useful default?), use_course("jennybc/explore-libraries", github = TRUE), or use_course("jennybc/explore-libraries", host = "github")? But this defeats the purpose of less typing.

• A different function name, use_github_course("jennybc/explore-libraries")?

Either way, we need to keep mind how to generalise to other common sources, i.e. Dropbox.

[cwickham]

Answers based on in-person discussion:

• use_course() should identify a github style shortlink and expand to the required URL: use_course("https://github.com/jennybc/explore-libraries/archive/master.zip")

• Distinguish between github and shortlinks via a shortlink whitelist bit.ly, rtsd.io

• Look into repo spec to help.