class Rake::Task

######################################################################### A Task is the basic unit of work in a Rakefile. Tasks have associated actions (possibly more than one) and a list of prerequisites. When invoked, a task will first ensure that all of its prerequisites have an opportunity to run and then it will execute its own actions.

Tasks are not usually created directly using the new method, but rather use the file and task convenience methods.

Attributes

actions[R]

List of actions attached to a task.

application[RW]

Application owning this task.

locations[R]

File/Line locations of each of the task definitions for this task (only valid if the task was defined with the detect location option set).

prerequisites[R]

List of prerequisites for a task.

scope[R]

Array of nested namespaces names used for task lookup by this task.

sources[W]

List of sources for task.

Public Class Methods

[](task_name) click to toggle source

Return a task with the given name. If the task is not currently known, try to synthesize one from the defined rules. If no rules are found, but an existing file matches the task name, assume it is a file task with no dependencies or actions.

# File lib/rake/task.rb, line 347
def [](task_name)
  Rake.application[task_name]
end
clear() click to toggle source

Clear the task list. This cause rake to immediately forget all the tasks that have been assigned. (Normally used in the unit tests.)

# File lib/rake/task.rb, line 334
def clear
  Rake.application.clear
end
create_rule(*args, &block) click to toggle source

Define a rule for synthesizing tasks.

# File lib/rake/task.rb, line 364
def create_rule(*args, &block)
  Rake.application.create_rule(*args, &block)
end
define_task(*args, &block) click to toggle source

Define a task given args and an option block. If a rule with the given name already exists, the prerequisites and actions are added to the existing task. Returns the defined task.

# File lib/rake/task.rb, line 359
def define_task(*args, &block)
  Rake.application.define_task(self, *args, &block)
end
new(task_name, app) click to toggle source

Create a task named task_name with no actions or prerequisites. Use enhance to add actions and prerequisites.

# File lib/rake/task.rb, line 82
def initialize(task_name, app)
  @name            = task_name.to_s
  @prerequisites   = []
  @actions         = []
  @already_invoked = false
  @comments        = []
  @lock            = Monitor.new
  @application     = app
  @scope           = app.current_scope
  @arg_names       = nil
  @locations       = []
end
scope_name(scope, task_name) click to toggle source

Apply the scope to the task name according to the rules for this kind of task. Generic tasks will accept the scope as part of the name.

# File lib/rake/task.rb, line 371
      def scope_name(scope, task_name)
#        (scope + [task_name]).join(':')
        scope.path_with_task_name(task_name)
      end
task_defined?(task_name) click to toggle source

TRUE if the task name is already defined.

# File lib/rake/task.rb, line 352
def task_defined?(task_name)
  Rake.application.lookup(task_name) != nil
end
tasks() click to toggle source

List of all defined tasks.

# File lib/rake/task.rb, line 339
def tasks
  Rake.application.tasks
end

Public Instance Methods

add_description(description) click to toggle source

Add a description to the task. The description can consist of an option argument list (enclosed brackets) and an optional comment.

# File lib/rake/task.rb, line 254
def add_description(description)
  return unless description
  comment = description.strip
  add_comment(comment) if comment && ! comment.empty?
end
all_prerequisite_tasks() click to toggle source

List of all unique prerequisite tasks including prerequisite tasks' prerequisites. Includes self when cyclic dependencies are found.

# File lib/rake/task.rb, line 60
def all_prerequisite_tasks
  seen = {}
  collect_prerequisites(seen)
  seen.values
end
arg_names() click to toggle source

Name of arguments for this task.

# File lib/rake/task.rb, line 122
def arg_names
  @arg_names || []
end
clear() click to toggle source

Clear the existing prerequisites and actions of a rake task.

# File lib/rake/task.rb, line 133
def clear
  clear_prerequisites
  clear_actions
  clear_comments
  self
end
clear_actions() click to toggle source

Clear the existing actions on a rake task.

# File lib/rake/task.rb, line 147
def clear_actions
  actions.clear
  self
end
clear_comments() click to toggle source

Clear the existing comments on a rake task.

# File lib/rake/task.rb, line 153
def clear_comments
  @comments = []
  self
end
clear_prerequisites() click to toggle source

Clear the existing prerequisites of a rake task.

# File lib/rake/task.rb, line 141
def clear_prerequisites
  prerequisites.clear
  self
end
comment() click to toggle source

First line (or sentence) of all comments. Multiple comments are separated by a “/”.

# File lib/rake/task.rb, line 277
def comment
  transform_comments(" / ") { |c| first_sentence(c) }
end
comment=(comment) click to toggle source
# File lib/rake/task.rb, line 260
def comment=(comment)
  add_comment(comment)
end
enhance(deps=nil, &block) click to toggle source

Enhance a task with prerequisites or actions. Returns self.

# File lib/rake/task.rb, line 96
def enhance(deps=nil, &block)
  @prerequisites |= deps if deps
  @actions << block if block_given?
  self
end
execute(args=nil) click to toggle source

Execute the actions associated with this task.

# File lib/rake/task.rb, line 223
def execute(args=nil)
  args ||= EMPTY_TASK_ARGS
  if application.options.dryrun
    application.trace "** Execute (dry run) #{name}"
    return
  end
  application.trace "** Execute #{name}" if application.options.trace
  application.enhance_with_matching_rule(name) if @actions.empty?
  @actions.each do |act|
    case act.arity
    when 1
      act.call(self)
    else
      act.call(self, args)
    end
  end
end
full_comment() click to toggle source

Full collection of comments. Multiple comments are separated by newlines.

# File lib/rake/task.rb, line 271
def full_comment
  transform_comments("\n")
end
inspect() click to toggle source
# File lib/rake/task.rb, line 37
def inspect
  "<#{self.class} #{name} => [#{prerequisites.join(', ')}]>"
end
investigation() click to toggle source

Return a string describing the internal state of a task. Useful for debugging.

# File lib/rake/task.rb, line 309
def investigation
  result = "------------------------------\n"
  result << "Investigating #{name}\n"
  result << "class: #{self.class}\n"
  result <<  "task needed: #{needed?}\n"
  result <<  "timestamp: #{timestamp}\n"
  result << "pre-requisites: \n"
  prereqs = prerequisite_tasks
  prereqs.sort! { |a, b| a.timestamp <=> b.timestamp }
  prereqs.each do |p|
    result << "--#{p.name} (#{p.timestamp})\n"
  end
  latest_prereq = prerequisite_tasks.map { |pre| pre.timestamp }.max
  result <<  "latest-prerequisite time: #{latest_prereq}\n"
  result << "................................\n\n"
  return result
end
invoke(*args) click to toggle source

Invoke the task if it is needed. Prerequisites are invoked first.

# File lib/rake/task.rb, line 159
def invoke(*args)
  task_args = TaskArguments.new(arg_names, args)
  invoke_with_call_chain(task_args, InvocationChain::EMPTY)
end
name() click to toggle source

Name of the task, including any namespace qualifiers.

# File lib/rake/task.rb, line 103
def name
  @name.to_s
end
needed?() click to toggle source

Is this task needed?

# File lib/rake/task.rb, line 242
def needed?
  true
end
prerequisite_tasks() click to toggle source

List of prerequisite tasks

# File lib/rake/task.rb, line 48
def prerequisite_tasks
  prerequisites.map { |pre| lookup_prerequisite(pre) }
end
reenable() click to toggle source

Reenable the task, allowing its tasks to be executed if the task is invoked again.

# File lib/rake/task.rb, line 128
def reenable
  @already_invoked = false
end
set_arg_names(args) click to toggle source

Set the names of the arguments for this task. args should be an array of symbols, one for each argument name.

# File lib/rake/task.rb, line 303
def set_arg_names(args)
  @arg_names = args.map { |a| a.to_sym }
end
source() click to toggle source

First source from a rule (nil if no sources)

# File lib/rake/task.rb, line 76
def source
  @sources.first if defined?(@sources)
end
sources() click to toggle source
# File lib/rake/task.rb, line 43
def sources
  @sources ||= []
end
timestamp() click to toggle source

Timestamp for this task. Basic tasks return the current time for their time stamp. Other tasks can be more sophisticated.

# File lib/rake/task.rb, line 248
def timestamp
  Time.now
end
to_s() click to toggle source

Return task name

# File lib/rake/task.rb, line 33
def to_s
  name
end

Protected Instance Methods

collect_prerequisites(seen) click to toggle source
# File lib/rake/task.rb, line 66
def collect_prerequisites(seen)
  prerequisite_tasks.each do |pre|
    next if seen[pre.name]
    seen[pre.name] = pre
    pre.collect_prerequisites(seen)
  end
end