Pass parameter from AsciiDoc CLI to HAML template

Hi, I'd like to provide slightly different markup in document.html.haml depending on whether or not we're compiling for local, dev, qa, or production.

I was thinking the easiest way would be to pass a flag into the AsciiDoctor CLI.

My wheelhouse is web front-end development, so I'm a little out of my depth.

I searched through the documentation, found this option in the CLI:
-a, --attribute=ATTRIBUTE

I tried to figure out how an attribute might show up (if it shows up) in HAML, but didn't get very far.

Any help would be greatly appreciated, thank you!

Welcome!

To obtain the value inside content use #{@document.attr :cosa}, where "cosa" is the name of the attribute you passed to the cli. Also, to check if it is present use #{@document.attr? :cosa}.
You can also obtain attributes defined in the docs with this.

If you are not in content, for instance and if, remove the surrouding #{}.

Thanks, that was extremely helpful!

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Updating my example per discussion (see the original below)

For posterity, my ascii doctor command is:
asciidoctor -T pantheon/templates/haml/html5 -a pantheonenv=localwebassets dev-assets/ascii-doc-styleguide.adoc

-a env=localwebassets being the part that sets the variable for HAML

Pantheon is the name of the project, so I'm namespacing env with that.

Then in HAML I have:
    - if (@document.attr :pantheonenv) == 'localwebassets'
      %link(rel="stylesheet" href="https://static.redhat.com/libs/redhat/redhat-font/2/webfonts/red-hat-font.css")
      %link(rel="stylesheet" href="rhdocs.css")

Alternatively you can use this syntax for the condition, but I prefer the above.
    - if @document.attr? :pantheonenv, 'localwebassets'


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Original post:

For posterity, my ascii doctor command is:
asciidoctor -T pantheon/templates/haml/html5 -a env=localwebassets dev-assets/ascii-doc-styleguide.adoc

-a env=localwebassets being the part that sets the variable for HAML

Then in HAML I have:

    - if @document.attr? :env, 'localwebassets'
      %link(rel="stylesheet" href="https://static.redhat.com/libs/redhat/redhat-font/2/webfonts/red-hat-font.css")
      %link(rel="stylesheet" href="rhdocs.css")

Very confused why I'm using @document.attr? :env, instead of @document.attr? :env ==, BUT I confirmed the if statement evaluates properly if the var is different.

Thanks again!

It it helps, under the hood all templates get an insance of the Asciidoctor processor (https://github.com/asciidoctor/asciidoctor/blob/88bc891d6a0143f3a2142f41d29cabe3cb21fe3f/lib/asciidoctor/document.rb#L49). The attributes are stored in a hashmap, thus the "colon" notation.

Then, for each template, an instance of the correspondent node/block matching that part of he document in the AST. So, if in doubt you can check the code to see the property names.

Truth, I am not familiar with Ruby, but this with some trial & error has helped me a couple of times when using templates and also extensions.

Oh, nice!

I've never done anything for a Ruby backend, but knowing where the data is prepped for the template is _extremely_ helpful.

Ahh, makes sense about naming it env. Thanks for taking the time @mojavelinux

Sorry, I didn't explain my confusion well, it's that this:

(@document.attr? :env) == 'localwebassets'

Evaluates to false. I don't really understand the comma syntax and can't find any documentation on it... I figured out it existed by looking through the rest of the templates.

Doesn't seem to be something this project has to fill in since I'm guessing it's a HAML thing, but I can't even find particularly good documentation on HAML, for instance the official docs don't seem to cover if statements:
http://haml.info/docs/yardoc/file.REFERENCE.html

The best docs I can find are in Stack Overflow

If there's interest in porting the the templating syntax to something like nunjucks, mustache, or some other template language that has a more docs I would definitely be interested in helping!

AsciiDoc(ter) is going to be a good sized part of my job at Redhat through the end of the year.

Gooootcha, thanks!