module Evoke

Adds a code block that will be called before the task is invoked.

@param [Proc] &block The code to execute before the task is invoked. @example Loading the Rails environment before running any Evoke tasks.

# File: evoke.rb - In the Rails application's root path

Evoke.before_task {|task, *args|
  require File.expand_path("../config/environment.rb", __FILE__)
}

# File lib/evoke.rb, line 62
def before_task(&block)
  @before_hooks ||= []
  @before_hooks << block if block_given?
end

Finds a task with the supplied name.

@param [String] name The underscored name of the task. @return [Evoke::Task] The task or nil if not found. @example Find a task that has the class name ‘Example::HelloWorld`.

Evoke.find_task('example/hello_world') # => Example::HelloWorld

# File lib/evoke.rb, line 24
def find_task(name)
  tasks.find { |task| task.to_s == name.camelize }
end

Creates an instance of a task, validates the amount of arguments supplied matches the task’s invoke method, executes the before_task callbacks, and invokes the task.

@param [Class] task The Evoke::Task class to invoke. @param [Array] *arguments The arguments to invoke the task with.

# File lib/evoke.rb, line 73
def invoke(task, *arguments)
  task.validate_arguments(arguments)
  task = task.new
  Evoke.call_before_hooks(task, *arguments)
  task.invoke(*arguments)
end

Loads all the Evoke tasks in the supplied path.

@example Loading tasks in the local “lib/tasks” folder.

Evoke.load_tasks("lib/tasks")

@example Loading tasks with an absolute path name.

path = File.expand_path("../lib/evoke", __FILE__)
Evoke.load_tasks(path, false)

@param [String] path The root path that contains the tasks. @param [Boolean] relative Path is relative to working directory (default). @return [Array] The files that were loaded.

# File lib/evoke.rb, line 42
def load_tasks(path, relative=true)
  if relative
    path = File.join(Dir.pwd, path)
    path = File.expand_path(path)
  end

  Dir[File.join(path, '**', '*_task.rb')].each { |f| load f }
end

Gets all the classes that descend from Evoke::Task.

@return [Array] The task classes.

# File lib/evoke.rb, line 12
def tasks
  ObjectSpace.each_object(Class).select { |klass| klass < Evoke::Task }
end

Executes the before callbacks.

@param [Evoke::Task] task The task instance that is being invoked. @param [Array] args The arguments that are being passed to the task.

# File lib/evoke.rb, line 86
def call_before_hooks(task, *args)
  Array(@before_hooks).each { |hook| hook.call(task, *args) }
end