How to add line numbers to default playpen?

[adamchalmers]

I notice that the Ace editor can be configured to show/hide line numbers by setting showLineNumbers, but mdbook explicitly sets this to false.

I couldn't see a way to pass configuration from my mdbook project's .toml to override this. IMO it would be a big improvement if book authors could configure their editor to show or hide line numbers.

[andymac-2]

@Michael-F-Bryan I would like to take on this issue. I apologize if you're the wrong person to ping.

[Michael-F-Bryan]

Thanks for volunteering to help, @andymac-2!

At a glance, you would need to add a new show-line-numbers option to the HtmlConfig so it's configurable from book.toml under the output.html table.

From there you'll have to figure out how to tell Ace to show/hide line numbers (probably by playing with from the generated HTML, around here somewhere). The context info passed to each handlebars template is done [in the make_data() function][3].

I didn't have much to do with the frontend and am not actively working on mdbook, but @ehuss or @Dylan-DPC may be able to point you in the right direction.

[andymac-2]

Already done ;) PR #1035 has the required implementation, and updates the docs accordingly. Thanks for your help! You're the first name that pops up on the CONTRIBUTORS file