123456789_123456789_123456789_123456789_123456789_

Class: Rake::Task

Relationships & Source Files
Extension / Inclusion / Inheritance Descendants
Subclasses:
Inherits: Object
Defined in: lib/rake/task.rb

Overview

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.

Class Method Summary

Instance Attribute Summary

Instance Method Summary

Constructor Details

.new(task_name, app) ⇒ Task

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

[ GitHub ]

  
# File 'lib/rake/task.rb', line 99

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       = []
  @invocation_exception = nil
  @order_only_prerequisites = []
end

Class Method Details

.[](task_name)

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.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 404

def [](task_name)
  Rake.application[task_name]
end

.clear

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

[ GitHub ]

  
# File 'lib/rake/task.rb', line 391

def clear
  Rake.application.clear
end

.create_rule(*args, &block)

Define a rule for synthesizing tasks.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 421

def create_rule(*args, &block)
  Rake.application.create_rule(*args, &block)
end

.define_task(*args, &block)

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.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 416

def define_task(*args, &block)
  Rake.application.define_task(self, *args, &block)
end

.format_deps(deps)

Format dependencies parameter to pass to task.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 373

def self.format_deps(deps)
  deps = [deps] unless deps.respond_to?(:to_ary)
  deps.map { |d| Rake.from_pathname(d).to_s }
end

.scope_name(scope, task_name)

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.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 428

def scope_name(scope, task_name)
  scope.path_with_task_name(task_name)
end

.task_defined?(task_name) ⇒ Boolean

TRUE if the task name is already defined.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 409

def task_defined?(task_name)
  Rake.application.lookup(task_name) != nil
end

.tasks

List of all defined tasks.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 396

def tasks
  Rake.application.tasks
end

Instance Attribute Details

#actions (readonly)

List of actions attached to a task.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 24

attr_reader :actions

#already_invoked (readonly)

Has this task already been invoked? Already invoked tasks will be skipped unless you reenable them.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 39

attr_reader :already_invoked

#application (rw)

Application owning this task.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 27

attr_accessor :application

#comment (rw)

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

[ GitHub ]

  
# File 'lib/rake/task.rb', line 322

def comment
  transform_comments(" / ") { |c| first_sentence(c) }
end

#comment=(comment) (rw)

This method is for internal use only.
[ GitHub ]

  
# File 'lib/rake/task.rb', line 304

def comment=(comment) # :nodoc:
  add_comment(comment)
end

#locations (readonly)

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).

[ GitHub ]

  
# File 'lib/rake/task.rb', line 35

attr_reader :locations

#needed?Boolean (readonly)

Is this task needed?

[ GitHub ]

  
# File 'lib/rake/task.rb', line 286

def needed?
  true
end

#order_only_prerequisites (readonly)

List of order only prerequisites for a task.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 21

attr_reader :order_only_prerequisites

#prereqs (readonly)

Alias for #prerequisites.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 18

alias prereqs prerequisites

#prerequisites (readonly) Also known as: #prereqs

List of prerequisites for a task.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 17

attr_reader :prerequisites

#scope (readonly)

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

[ GitHub ]

  
# File 'lib/rake/task.rb', line 30

attr_reader :scope

#sources (rw)

[ GitHub ]

  
# File 'lib/rake/task.rb', line 52

def sources
  if defined?(@sources)
    @sources
  else
    prerequisites
  end
end

#sources=(value) (rw)

List of sources for task.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 51

attr_writer :sources

Instance Method Details

#add_chain_to(exception, new_chain) (private)

This method is for internal use only.
[ GitHub ]

  
# File 'lib/rake/task.rb', line 229

def add_chain_to(exception, new_chain) # :nodoc:
  exception.extend(InvocationExceptionMixin) unless
    exception.respond_to?(:chain)
  exception.chain = new_chain if exception.chain.nil?
end

#add_comment(comment) (private)

This method is for internal use only.
[ GitHub ]

  
# File 'lib/rake/task.rb', line 308

def add_comment(comment) # :nodoc:
  return if comment.nil?
  @comments << comment unless @comments.include?(comment)
end

#add_description(description)

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

[ GitHub ]

  
# File 'lib/rake/task.rb', line 298

def add_description(description)
  return unless description
  comment = description.strip
  add_comment(comment) if comment && !comment.empty?
end

#all_prerequisite_tasks

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

[ GitHub ]

  
# File 'lib/rake/task.rb', line 77

def all_prerequisite_tasks
  seen = {}
  collect_prerequisites(seen)
  seen.values
end

#arg_description

This method is for internal use only.

Argument description (nil if none).

[ GitHub ]

  
# File 'lib/rake/task.rb', line 136

def arg_description # :nodoc:
  @arg_names ? "[#{arg_names.join(',')}]" : nil
end

#arg_names

Name of arguments for this task.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 141

def arg_names
  @arg_names || []
end

#clear

Clear the existing prerequisites, actions, comments, and arguments of a rake task.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 153

def clear
  clear_prerequisites
  clear_actions
  clear_comments
  clear_args
  self
end

#clear_actions

Clear the existing actions on a rake task.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 168

def clear_actions
  actions.clear
  self
end

#clear_args

Clear the existing arguments on a rake task.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 180

def clear_args
  @arg_names = nil
  self
end

#clear_comments

Clear the existing comments on a rake task.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 174

def clear_comments
  @comments = []
  self
end

#clear_prerequisites

Clear the existing prerequisites of a rake task.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 162

def clear_prerequisites
  prerequisites.clear
  self
end

#collect_prerequisites(seen) (protected)

This method is for internal use only.
[ GitHub ]

  
# File 'lib/rake/task.rb', line 83

def collect_prerequisites(seen) # :nodoc:
  prerequisite_tasks.each do |pre|
    next if seen[pre.name]
    seen[pre.name] = pre
    pre.collect_prerequisites(seen)
  end
end

#enhance(deps = nil, &block)

Enhance a task with prerequisites or actions. Returns self.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 115

def enhance(deps=nil, &block)
  @prerequisites |= deps if deps
  @actions << block if block_given?
  self
end

#execute(args = nil)

Execute the actions associated with this task.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 270

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?
  if opts = Hash.try_convert(args) and !opts.empty?
    @actions.each { |act| act.call(self, args, **opts)}
  else
    @actions.each { |act| act.call(self, args)}
  end
end

#first_sentence(string) (private)

Get the first sentence in a string. The sentence is terminated by the first period, exclamation mark, or the end of the line. Decimal points do not count as periods.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 341

def first_sentence(string)
  string.split(/(?<=\w)(\.|!)[ \t]|(\.$|!)|\n/).first
end

#format_trace_flags (private)

Format the trace flags for display.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 261

def format_trace_flags
  flags = []
  flags << "first_time" unless @already_invoked
  flags << "not_needed" unless needed?
  flags.empty? ? "" : "(" + flags.join(", ") + ")"
end

#full_comment

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

[ GitHub ]

  
# File 'lib/rake/task.rb', line 316

def full_comment
  transform_comments("\n")
end

#inspect

This method is for internal use only.
[ GitHub ]

  
# File 'lib/rake/task.rb', line 46

def inspect # :nodoc:
  "<#{self.class} #{name} => [#{prerequisites.join(', ')}]>"
end

#investigation

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

[ GitHub ]

  
# File 'lib/rake/task.rb', line 354

def investigation
  result = "------------------------------\n".dup
  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(&:timestamp).max
  result <<  "latest-prerequisite time: #{latest_prereq}\n"
  result << "................................\n\n"
  return result
end

#invoke(*args)

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

[ GitHub ]

  
# File 'lib/rake/task.rb', line 186

def invoke(*args)
  task_args = TaskArguments.new(arg_names, args)
  invoke_with_call_chain(task_args, InvocationChain::EMPTY)
end

#invoke_prerequisites(task_args, invocation_chain)

This method is for internal use only.

Invoke all the prerequisites of a task.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 237

def invoke_prerequisites(task_args, invocation_chain) # :nodoc:
  if application.options.always_multitask
    invoke_prerequisites_concurrently(task_args, invocation_chain)
  else
    prerequisite_tasks.each { |p|
      prereq_args = task_args.new_scope(p.arg_names)
      p.invoke_with_call_chain(prereq_args, invocation_chain)
    }
  end
end

#invoke_prerequisites_concurrently(task_args, invocation_chain)

This method is for internal use only.

Invoke all the prerequisites of a task in parallel.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 249

def invoke_prerequisites_concurrently(task_args, invocation_chain)# :nodoc:
  futures = prerequisite_tasks.map do |p|
    prereq_args = task_args.new_scope(p.arg_names)
    application.thread_pool.future(p) do |r|
      r.invoke_with_call_chain(prereq_args, invocation_chain)
    end
  end
  # Iterate in reverse to improve performance related to thread waiting and switching
  futures.reverse_each(&:value)
end

#invoke_with_call_chain(task_args, invocation_chain) (protected)

Same as invoke, but explicitly pass a call chain to detect circular dependencies.

If multiple tasks depend on this one in parallel, they will all fail if the first execution of this task fails.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 197

def invoke_with_call_chain(task_args, invocation_chain)
  new_chain = Rake::InvocationChain.append(self, invocation_chain)
  @lock.synchronize do
    begin
      if application.options.trace
        application.trace "** Invoke #{name} #{format_trace_flags}"
      end

      if @already_invoked
        if @invocation_exception
          if application.options.trace
            application.trace "** Previous invocation of #{name} failed #{format_trace_flags}"
          end
          raise @invocation_exception
        else
          return
        end
      end

      @already_invoked = true

      invoke_prerequisites(task_args, new_chain)
      execute(task_args) if needed?
    rescue Exception => ex
      add_chain_to(ex, new_chain)
      @invocation_exception = ex
      raise ex
    end
  end
end

#lookup_prerequisite(prerequisite_name) (private)

This method is for internal use only.
[ GitHub ]

  
# File 'lib/rake/task.rb', line 65

def lookup_prerequisite(prerequisite_name) # :nodoc:
  scoped_prerequisite_task = application[prerequisite_name, @scope]
  if scoped_prerequisite_task == self
    unscoped_prerequisite_task = application[prerequisite_name]
  end
  unscoped_prerequisite_task || scoped_prerequisite_task
end

#name

Name of the task, including any namespace qualifiers.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 122

def name
  @name.to_s
end

#name_with_args

This method is for internal use only.

Name of task with argument list description.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 127

def name_with_args # :nodoc:
  if arg_description
    "#{name}#{arg_description}"
  else
    name
  end
end

#prerequisite_tasks

List of prerequisite tasks

[ GitHub ]

  
# File 'lib/rake/task.rb', line 61

def prerequisite_tasks
  (prerequisites + order_only_prerequisites).map { |pre| lookup_prerequisite(pre) }
end

#reenable

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

[ GitHub ]

  
# File 'lib/rake/task.rb', line 147

def reenable
  @already_invoked = false
  @invocation_exception = nil
end

#set_arg_names(args)

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

[ GitHub ]

  
# File 'lib/rake/task.rb', line 348

def set_arg_names(args)
  @arg_names = args.map(&:to_sym)
end

#source

First source from a rule (nil if no sources)

[ GitHub ]

  
# File 'lib/rake/task.rb', line 93

def source
  sources.first
end

#timestamp

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

[ GitHub ]

  
# File 'lib/rake/task.rb', line 292

def timestamp
  Time.now
end

#to_s

Return task name

[ GitHub ]

  
# File 'lib/rake/task.rb', line 42

def to_s
  name
end

#transform_comments(separator, &block) (private)

Transform the list of comments as specified by the block and join with the separator.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 328

def transform_comments(separator, &block)
  if @comments.empty?
    nil
  else
    block ||= lambda { |c| c }
    @comments.map(&block).join(separator)
  end
end

#|(deps)

Add order only dependencies.

[ GitHub ]

  
# File 'lib/rake/task.rb', line 379

def |(deps)
  @order_only_prerequisites |= Task.format_deps(deps) - @prerequisites
  self
end