Rust Playpen Integration

[zslayton]

Some of the Rust devs have put together a site that lets you experiment with Rust code, seeing output as well as asm/ir.

It would be really helpful to provide a link to launch each of the source files in the playpen so readers could toy with the examples on their own.

The site understands links in the format:

http://playtest.rust-lang.org/?code=fn+main()+{+println!(%22foo%22)+}&run=1

There's also a CORS-enabled API that supports directly submitting code via POST if that's more interesting.

I'm happy to help code this if someone can describe the best way to go about adding this functionality.

[japaric]

I think this is a great idea! And I have been thinking about how to implement it for a while.

Because the site is statically built using gitbook from an input markdown file, the simplest way to implement this (that I can think of) is to add a link with the code attached to the URL (like your example link).

We already have a preprocessing step that reads an input markdown, looks for a string that looks like {hello.rs} and replaces it with the actual source code.

We could modify update.rs to also look for a string like {hello.run}, read the source code (hello.rs), escape it into:

http://playtest.rust-lang.org/?code=%2F%2F%20the%20main%20function%0Afn%20main()%20%7B%0A%20%20%20%20%2F%2F%20print%20to%20the%20console%0A%20%20%20%20println!(%22Hello%20World%22)%3B%0A%7D&run=1

And then replace the {hello.run} string with a link like this: Rust this code! (or "Try this code!", or use an image)

The hardest part of this approach would be to escape the rust code. Maybe libhtml (rust-lang/rust#13896) can help with this?

The alternative way is to create a gitbook plugin to accomplish this with client-side javascript (but I can't think of any benefit of doing it that way, other than it may look prettier)

There's also a CORS-enabled API that supports directly submitting code via POST if that's more interesting.

My web-foo is noob-level :P. Can this be implemented with client-side javascript in a static website? And, is there any benefit over just using a link with the code attached to the URL?

[zslayton]

This seems like a good approach! I'm afraid I don't have time this evening, but I'll open a pull request in the next couple of days to add this feature if libhtml is up to the task of encoding Rust.

Can this be implemented with client-side javascript in a static website? And, is there any benefit over just using a link with the code attached to the URL?

Thanks to CORS it can be implemented client-side, yes. However, as you mention there isn't much benefit to doing this way unless you wanted to offer functionality above and beyond that of the Rust playpen. We'd have to put together our own display and controls.

[japaric]

So I just went ahead and implemented this :P. It's working locally and I'm testing that all the examples work as expected in the playpen.

I ended up implementing a URL encoder myself (it was easy, special chars are expressed as hexadecimal, e.g. %20 for "space"). And just inserted a plain link to the playpen that looks like "Try hello.rs in the playpen!". (Perhaps, later we could replace the text with a nice looking button)

Thanks a lot for opening this issue, it pushed me to actually think this through and implement it!

I'll ping you after I update the site, so you can let me know what you think.

[zslayton]

So I just went ahead and implemented this :P. It's working locally and I'm testing that all the examples work as expected in the playpen.

Ha! Great!

Thanks a lot for opening this issue, it pushed me to actually think this through and implement it!

My pleasure. Thanks for maintaining rustbyexample.com, I've pointed a lot of people to it!

[japaric]

My pleasure. Thanks for maintaining rustbyexample.com, I've pointed a lot of people to it!

\o/

I'm closing this issue, since we now have a basic integration with the playpen.

@zslayton you migth be interested in tackling #73 :P

[zslayton]

Very cool! You should post the update to /r/rust so people can see the new functionality!

[japaric]

I already did. See this thread