Filters with multiple outputs

[denisdefreyne]

A filter can currently only generate a single piece of output. For some filters, being able to output multiple files is useful (e.g. for Sass, generate CSS + source map).

See also:

• Ability to include sourcemap with sass filter nanoc#1200

[denisdefreyne]

Idea: allow compiled content to have multiple “forks” (by default it only has one, e.g. :default). The #write call could then take a fork param, for selecting which fork to write:

compile '/**/*.scss' do
  filter :sass
  write ext: 'css'
  write ext: 'css.map', fork: 'sourcemap'
end

Same for #route presumably.

It needs more thought around how to run filter and layout on different forks. But maybe that’s not needed.

[opatry]

Hi @ddfreyne
I would be interested by this capability.

In my setup, I have several images put in content/.
From them I generate up to 4 representations of each.

• :excerpt repr + webp format
• :default repr + webp format
• :excerpt repr + original format
• :default repr + original format

I guess having a single filter letting me load the image once and output it in various formats could speed up things.
Currently, I'm using system(convert …), don't know if imagemagick can do several processing at once though.