Re: Replacing Bower with "guix environment"

[Christopher Allan Webber <cwebber@dustycloud.org>]

David Thompson writes:

> Ludovic Courtès <ludo@gnu.org> writes:
>
>> Christopher Allan Webber <cwebber@dustycloud.org> skribis:
>>
>>>  - The "hip new way" of doing things is to use Bower.  Bower is a
>>>    package manager, but it's made specifically for static assets served
>>>    to the user, such as css files, fonts, javascript like jquery, etc.
>>>    Bower also puts these in an extlib/ or whatever, but it puts them in
>>>    that place *for* you.
>>
>> Interesting.
>>
>> (Thinking out lout.)
>>
>> Just like ‘guix system vm’ returns a script that runs QEMU with the
>> right arguments, one could imagine generating a script that copies
>> dependencies in the right place maybe?
>>
>>   (define (make-installer assets)
>>     (gexp->script "copy-assets"
>>                   #~(begin
>>                       (for-each copy-file '#$@assets)
>>                       ...)))
>>
>> (This could/should be turned into a package object so that adding it as
>> an input would drop it in $PATH.)

The idea has me really excited.  But how do I make this happen, so that
copy-assets appears in $PATH?  I am trying to do something with
"guix environment" that does this, but I'm pretty confused as to how it
could be done.

How would you turn a gexp into a package object?  Would it just be a lot
of package object stuff stubbed out?

>> The developer would have to explicitly run that script to have the files
>> copied under extlib/.
>
> That is a really neat use of gexps, and I guess running the script
> manually would be akin to running 'bower install', so that should work.
>
> I envision the package recipe below, is this approximately what you were
> describing?
>
>     (package
>       (name "mediagoblin")
>       (version "0.8.0")
>       ...
>       (inputs
>        `(("python" ,python)
>          ("assets" ,(web-assets jquery
>                                 videojs
>                                 bootstrap))))
>       ...)

Does web-assets generate that package object I assume?

I tried looking for examples of other package definitions that include
derivations from gexps, and couldn't find anything clear...

It also isn't clear to me: is it okay for (inputs) to include things
that aren't packages?

I'd really like to explore this, though!