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Class: Rake::Task

Relationships & Source Files
Extension / Inclusion / Inheritance Descendants
Subclasses:
FileCreationTask, FileTask, MultiTask
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 94



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


  







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.


  



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# File 'lib/rake/task.rb', line 360



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.)


  



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# File 'lib/rake/task.rb', line 347



def clear
  Rake.application.clear
end


  








  

    .create_rule(*args, &block)  
  



  

    

Define a rule for synthesizing tasks.


  



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# File 'lib/rake/task.rb', line 377



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.


  



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# File 'lib/rake/task.rb', line 372



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


  



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# File 'lib/rake/task.rb', line 384



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.


  





  


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# File 'lib/rake/task.rb', line 365



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 352



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 19



attr_reader :actions


  








  

    #already_invoked   (readonly)
  



  

    

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


  



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# File 'lib/rake/task.rb', line 34



attr_reader :already_invoked


  








  

    #application   (rw)
  



  

    

Application owning this task.


  



  [ GitHub ]


  

  


# File 'lib/rake/task.rb', line 22



attr_accessor :application


  








  

    #comment   (rw)
  



  

    

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


  



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# File 'lib/rake/task.rb', line 290



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


  



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



attr_reader :locations


  








  

    #needed?  ⇒ Boolean  (readonly)
  



  

    

Is this task needed?


  





  


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# File 'lib/rake/task.rb', line 254



def needed?
  true
end


  








  

    #prerequisites   (readonly)
  



  

    

List of prerequisites for a task.


  



  [ GitHub ]


  

  


# File 'lib/rake/task.rb', line 16



attr_reader :prerequisites


  








  

    #scope   (readonly)
  



  

    

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


  



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# File 'lib/rake/task.rb', line 25



attr_reader :scope


  








  

    #sources   (rw)
  

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# File 'lib/rake/task.rb', line 47



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 46



attr_writer :sources


  







Instance Method Details



  

    #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 266



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 72



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


  








  

    #arg_names  
  



  

    

Name of arguments for this task.


  



  [ GitHub ]


  

  


# File 'lib/rake/task.rb', line 134



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 145



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 160



def clear_actions
  actions.clear
  self
end


  








  

    #clear_args  
  



  

    

Clear the existing arguments on a rake task.


  



  [ GitHub ]


  

  


# File 'lib/rake/task.rb', line 172



def clear_args
  @arg_names = nil
  self
end


  








  

    #clear_comments  
  



  

    

Clear the existing comments on a rake task.


  



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# File 'lib/rake/task.rb', line 166



def clear_comments
  @comments = []
  self
end


  








  

    #clear_prerequisites  
  



  

    

Clear the existing prerequisites of a rake task.


  



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# File 'lib/rake/task.rb', line 154



def clear_prerequisites
  prerequisites.clear
  self
end


  








  

    #enhance(deps = nil, &block)  
  



  

    

Enhance a task with prerequisites or actions.  Returns self.


  



  [ GitHub ]


  

  


# File 'lib/rake/task.rb', line 108



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 242



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 { |act| act.call(self, args) }
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 309



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


  








  

    #format_trace_flags   (private)
  



  

    

Format the trace flags for display.


  



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# File 'lib/rake/task.rb', line 233



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.


  



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# File 'lib/rake/task.rb', line 284



def full_comment
  transform_comments("\n")
end


  








  

    #investigation  
  



  

    

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


  



  [ GitHub ]


  

  


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



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(&: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.


  



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# File 'lib/rake/task.rb', line 178



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.


  



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



def name
  @name.to_s
end


  








  

    #prerequisite_tasks  
  



  

    

List of prerequisite tasks


  



  [ GitHub ]


  

  


# File 'lib/rake/task.rb', line 56



def prerequisite_tasks
  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 140



def reenable
  @already_invoked = false
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.


  



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



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


  








  

    #source  
  



  

    

First source from a rule (nil if no sources)


  



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# File 'lib/rake/task.rb', line 88



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 260



def timestamp
  Time.now
end


  








  

    #to_s  
  



  

    

Return task name


  



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# File 'lib/rake/task.rb', line 37



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 296



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