From: Martin Honermeyer <maze@...>
Date: 2005-09-02T23:42:06+09:00
Subject: Rake: multiple prerequisites in rule?

Hello,

I am using Kwartz as a templating engine for my Rails project. Kwartz
compiles an .rhtml (ERB) file from an .html and a .plogic file. 

I tried writing a Rake task which should automagically recompile each
template upon changing either the .html or the .plogic file. I've come up
with the following:

desc "Make ERB templates from Kwartz html and plogic files"
SRC = FileList['app/views/**/*.html']
OBJ = SRC.ext('rhtml')
task :templates => [OBJ]

rule '.rhtml' => ['.html'] do |t|
  sh "kwartz -Rails -e -p #{t.source.ext('plogic')} --extract=content
#{t.source} > #{t.name}"
end


This works. The problem is that the .rhtml is only regenerated when
the .html changes. I tried adding the .plogic file as another prerequisite:

rule '.rhtml' => ['.html', '.plogic'] do |t|

That makes Rake say

Too many dependents specified in rule .rhtml: [".html", ".plogic"]


Apparently, it's not possible to have multiple prerequisites for a rule.
Does anyone have a hint on this?



Cheers,
Martin