Make rake task from gem available everywhere?

问题:

So I'm writing a small gem and I have a '/tasks' dir in it with some specific rake tasks. How do I make those tasks available automatically everywhere, where the gem is required? For example I wish I could run 'rake mygemrake:task' inside my rails root dir after I have the gem installed.

回答1:

For Rails3 applications, you might want to look into making a Railtie for your gem.

You can do so with:

lib/your_gem/railtie.rb

require 'your_gem'
require 'rails'
module YourGem
  class Railtie < Rails::Railtie
    rake_tasks do
      require 'path/to/rake.task'
    end
  end
end

lib/your_gem.rb

module YourGem
  require "lib/your_gem/railtie" if defined?(Rails)
end

Though, I had my share of difficulties with requiring the rake.task file in my railtie.rb. I opted to just define my measley one or two tasks within the rake_tasks block.

回答2:

Check out the rdoctask in rake for an example of how to define a task provided by a gem. The task is defined in ruby instead of the rake build language and can be required like so:

require 'rake'             # the gem
require 'rake/rdoctask'    # the task

回答3:

You have to import those tasks in application's Rakefile. This is how it looks in mine (I am using bundler08 to manage my gems):

%w(gem1 gem2 gem3).each do |g|
  Dir[File.dirname(__FILE__) + "/vendor/bundler_gems/**/#{g}*/tasks/*.rake"].each do |f|
    import f
  end
end

回答4:

You can write normal rake tasks for a gem and load them like this:

require 'rake'
load 'path/to/your/tasks.rake'

Also, take a look at thor vs. rake.

回答5:

That's what Sake is for. Datamapper and Merb have been using Sake with success.