######################################################################### 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.

Methods
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Attributes
[R] actions

List of actions attached to a task.

[RW] application

Application owning this task.

[R] comment

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

[R] full_comment

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

[R] locations

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).

[R] prerequisites

List of prerequisites for a task.

[R] scope

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

[W] sources

List of sources for task.

Class Public methods
new(task_name, app)

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

# File ../ruby/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
Instance Public methods
[](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.

# File ../ruby/lib/rake/task.rb, line 297
def [](task_name)
  Rake.application[task_name]
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.

# File ../ruby/lib/rake/task.rb, line 223
def add_description(description)
  return if ! description
  comment = description.strip
  add_comment(comment) if comment && ! comment.empty?
end
arg_names()

Name of arguments for this task.

# File ../ruby/lib/rake/task.rb, line 112
def arg_names
  @arg_names || []
end
clear()

Clear the existing prerequisites and actions of a rake task.

# File ../ruby/lib/rake/task.rb, line 123
def clear
  clear_prerequisites
  clear_actions
  self
end
clear_actions()

Clear the existing actions on a rake task.

# File ../ruby/lib/rake/task.rb, line 136
def clear_actions
  actions.clear
  self
end
clear_prerequisites()

Clear the existing prerequisites of a rake task.

# File ../ruby/lib/rake/task.rb, line 130
def clear_prerequisites
  prerequisites.clear
  self
end
comment=(description)

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

# File ../ruby/lib/rake/task.rb, line 230
def comment=(description)
  add_description(description)
end
create_rule(*args, &block)

Define a rule for synthesizing tasks.

# File ../ruby/lib/rake/task.rb, line 314
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.

# File ../ruby/lib/rake/task.rb, line 309
def define_task(*args, &block)
  Rake.application.define_task(self, *args, &block)
end
enhance(deps=nil, &block)

Enhance a task with prerequisites or actions. Returns self.

# File ../ruby/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)

Execute the actions associated with this task.

# File ../ruby/lib/rake/task.rb, line 190
def execute(args=nil)
  args ||= EMPTY_TASK_ARGS
  if application.options.dryrun
    $stderr.puts "** Execute (dry run) #{name}"
    return
  end
  if application.options.trace
    $stderr.puts "** 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()
# File ../ruby/lib/rake/task.rb, line 44
def inspect
  "<#{self.class} #{name} => [#{prerequisites.join(', ')}]>"
end
investigation()

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

# File ../ruby/lib/rake/task.rb, line 259
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)

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

# File ../ruby/lib/rake/task.rb, line 142
def invoke(*args)
  task_args = TaskArguments.new(arg_names, args)
  invoke_with_call_chain(task_args, InvocationChain::EMPTY)
end
name()

Name of the task, including any namespace qualifiers.

# File ../ruby/lib/rake/task.rb, line 93
def name
  @name.to_s
end
needed?()

Is this task needed?

# File ../ruby/lib/rake/task.rb, line 211
def needed?
  true
end
prerequisite_tasks()

List of prerequisite tasks

# File ../ruby/lib/rake/task.rb, line 55
def prerequisite_tasks
  prerequisites.collect { |pre| lookup_prerequisite(pre) }
end
reenable()

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

# File ../ruby/lib/rake/task.rb, line 118
def reenable
  @already_invoked = false
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.

# File ../ruby/lib/rake/task.rb, line 321
def scope_name(scope, task_name)
  (scope + [task_name]).join(':')
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.

# File ../ruby/lib/rake/task.rb, line 253
def set_arg_names(args)
  @arg_names = args.map { |a| a.to_sym }
end
source()

First source from a rule (nil if no sources)

# File ../ruby/lib/rake/task.rb, line 65
def source
  @sources.first if defined?(@sources)
end
sources()
# File ../ruby/lib/rake/task.rb, line 50
def sources
  @sources ||= []
end
task_defined?(task_name)

TRUE if the task name is already defined.

# File ../ruby/lib/rake/task.rb, line 302
def task_defined?(task_name)
  Rake.application.lookup(task_name) != nil
end
tasks()

List of all defined tasks.

# File ../ruby/lib/rake/task.rb, line 289
def tasks
  Rake.application.tasks
end
timestamp()

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

# File ../ruby/lib/rake/task.rb, line 217
def timestamp
  prerequisite_tasks.collect { |pre| pre.timestamp }.max || Time.now
end
to_s()

Return task name

# File ../ruby/lib/rake/task.rb, line 40
def to_s
  name
end
Instance Private methods
add_chain_to(exception, new_chain)
# File ../ruby/lib/rake/task.rb, line 166
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)

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

# File ../ruby/lib/rake/task.rb, line 236
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()

Format the trace flags for display.

# File ../ruby/lib/rake/task.rb, line 181
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)
# File ../ruby/lib/rake/task.rb, line 59
def lookup_prerequisite(prerequisite_name)
  application[prerequisite_name, @scope]
end