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.

comment[R]

Comment for this task. Restricted to a single line of no more than 50 characters.

full_comment[R]

Full text of the (possibly multi-line) comment.

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 320
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 307
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 337
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 332
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 71
def initialize(task_name, app)
  @name = task_name.to_s
  @prerequisites = []
  @actions = []
  @already_invoked = false
  @full_comment = nil
  @comment = nil
  @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 344
def scope_name(scope, task_name)
  (scope + [task_name]).join(':')
end

task_defined?(task_name) click to toggle source

TRUE if the task name is already defined.

# File lib/rake/task.rb, line 325
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 312
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 246
def add_description(description)
  return if ! description
  comment = description.strip
  add_comment(comment) if comment && ! comment.empty?
end

arg_names() click to toggle source

Name of arguments for this task.

# File lib/rake/task.rb, line 112
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 123
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 137
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 143
def clear_comments
  @full_comment = nil
  @comment = nil
  self
end

clear_prerequisites() click to toggle source

Clear the existing prerequisites of a rake task.

# File lib/rake/task.rb, line 131
def clear_prerequisites
  prerequisites.clear
  self
end

comment=(description) click to toggle source

Writing to the comment attribute is the same as adding a description.

# File lib/rake/task.rb, line 253
def comment=(description)
  add_description(description)
end

enhance(deps=nil, &block) click to toggle source

Enhance a task with prerequisites or actions. Returns self.

# File lib/rake/task.rb, line 86
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 213
def execute(args=nil)
  args ||= EMPTY_TASK_ARGS
  if application.options.dryrun
    application.trace "** Execute (dry run) #{name}"
    return
  end
  if application.options.trace
    application.trace "** Execute #{name}"
  end
  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

inspect() click to toggle source

# File lib/rake/task.rb, line 44
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 282
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.collect { |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 150
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 93
def name
  @name.to_s
end

needed?() click to toggle source

Is this task needed?

# File lib/rake/task.rb, line 234
def needed?
  true
end

prerequisite_tasks() click to toggle source

List of prerequisite tasks

# File lib/rake/task.rb, line 55
def prerequisite_tasks
  prerequisites.collect { |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 118
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 276
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 65
def source
  @sources.first if defined?(@sources)
end

sources() click to toggle source

# File lib/rake/task.rb, line 50
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 240
def timestamp
  prerequisite_tasks.collect { |pre| pre.timestamp }.max || Time.now
end

to_s() click to toggle source

Return task name

# File lib/rake/task.rb, line 40
def to_s
  name
end

Private Instance Methods

add_chain_to(exception, new_chain) click to toggle source

# File lib/rake/task.rb, line 174
def add_chain_to(exception, new_chain)
  exception.extend(InvocationExceptionMixin) unless exception.respond_to?(:chain)
  exception.chain = new_chain if exception.chain.nil?
end

add_comment(comment) click to toggle source

Add a comment to the task. If a comment already exists, separate the new comment with “ / ”.

# File lib/rake/task.rb, line 259
def add_comment(comment)
  if @full_comment
    @full_comment << " / "
  else
    @full_comment = ''
  end
  @full_comment << comment
  if @full_comment =~ /\A([^.]+?\.)( |$)/
    @comment = $1
  else
    @comment = @full_comment
  end
end

format_trace_flags() click to toggle source

Format the trace flags for display.

# File lib/rake/task.rb, line 204
def format_trace_flags
  flags = []
  flags << "first_time" unless @already_invoked
  flags << "not_needed" unless needed?
  flags.empty? ? "" : "(" + flags.join(", ") + ")"
end

lookup_prerequisite(prerequisite_name) click to toggle source

# File lib/rake/task.rb, line 59
def lookup_prerequisite(prerequisite_name)
  application[prerequisite_name, @scope]
end