Use newer language- class name prefix

[djui]

This change makes it partly possible to use Jekyll+RedCarpet+Prism.js without using a plugin.

Another change will respect Jekyll's pygments configuration option and not render the code block using Pygments. Together, these two changes allow using prism.js with Jekyll out of the box.

[mattr-]

I don't see a problem with this. 👍 from me.

[caspervonb]

Neat, was looking to patch this in today myself.

[parkr]

This is only one change. Where's the other?

My biggest concern is that this breaks all the CSS styles people have written for custom code highlighting :/ No backwards-compatibility, unless you set class="lang language-lang".

[djui]

The other one is in a separate pull-request ( #1038 ) because they can be seen separate.

I agree with the backwards-compatibility point. Using both class names would be a sufficient solution.

[parkr]

Great! Keep it backwards-compatible, fix the tests and we're good to go.

[Rowno]

Any chance you can add a something like a data-lang attribute? I was adding language labels to my code block using the CSS below, but this change breaks it. 😢

code:before {
    content: attr(class);
}

[parkr]

The diff here doesn't reflect the changes entirely. We now use class="<lang> language-<lang>" when writing codeblocks, thus merely adding language-<lang> to the list. Nothing we changed could have ruined the code you have already written, as far as I can tell! :)

[Rowno]

It ruined it because now I get css language-css etc in my labels (instead of just css), which is why I suggested adding a data-lang attribute.

[parkr]

Gah, sorry, I didn't even really process the code. Late-night brain mode :) I am weary about adding more attributes :/

[Rowno]

Oh well, it was nice while it lasted. 😞

[parkr]

Tell you what: submit a PR and we'll talk it over with @mattr-. I may be weary, but I'm not opposed. :)

[Rowno]

Done #1066