Modifying RakeFile to allow varied targets - ruby

Question

I am working on an HTML5/JavaScript app with Ruby packaging to be used on multiple platforms including a dash display unit on a car. The code base is the same across platforms except for a single wrapper file that houses all of the API-specific calls for a single platform: i.e. "sdk.web.js" or "sdk.car.js".
I'm hoping to modify the current PackageTask to allow an input for a target platform. Depending on the target, I want the corresponding wrapper file to be renamed to "sdk.js" and included in the package, disregarding the rest to keep the zip archive as small as possible.
From terminal, I want to say something like:
rake target "web"
which would put together a package including "sdk.web.js" renamed "sdk.js". Anyone know if this is possible, and how I would modify my existing RakeFile (below) in order to accomplish this?
require 'fileutils'
require 'rake/packagetask'
VERSION = ""
task :default => [:package]
def parse_version(filename)
f = File.open(filename, "rb")
contents = f.read
m = contents.match('var version = "([0-9.]+)";')
if m
return m[1]
else
return nil
end
end
desc "Package up the app into a zip file"
Rake::PackageTask.new("myApp") do |p|
p.version = parse_version("js/application.js")
p.need_zip = true
p.package_files = FileList["*", "**/*"]
p.package_files.exclude(".git", "pkg/*", "Rakefile", ".rvmrc", "Gemfile", "Gemfile.lock", ".project", ".settings", ".gitignore", "data/store/*", "docs", "docs/*")
end

Answer 1

In general, you can pass arguments to rake tasks. See for instance this page.
However, you don't have access to the package task from PackageTask. A solution would be to define your own packaging task which would add the right js script and then invoke package manually. For instance (untested):
Rake::PackageTask.new("myApp") do |p|
[snip]
p.package_files << "sdk.js"
end
task 'custom_packaging', :sdk do |t, args|
# Copy the right file to sdk.js
FileUtils.cp_f "sdk.#{args[:sdk]}.js", "sdk.js"
Rake::Task["package"].invoke
end