Class: Rake::Task

Inherits:
Object
  • Object
show all
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.

Direct Known Subclasses

FileTask, MultiTask

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(task_name, app) ⇒ Task

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



86
87
88
89
90
91
92
93
94
95
96
97
 
# File 'lib/rake/task.rb', line 86

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

Instance Attribute Details

#actions ⇒ Object (readonly)

List of actions attached to a task.



19
20
21
 
# File 'lib/rake/task.rb', line 19

def actions
  @actions
end

#application ⇒ Object

Application owning this task.



22
23
24
 
# File 'lib/rake/task.rb', line 22

def application
  @application
end

#locations ⇒ Object (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).



30
31
32
 
# File 'lib/rake/task.rb', line 30

def locations
  @locations
end

#prerequisites ⇒ Object (readonly)

List of prerequisites for a task.



16
17
18
 
# File 'lib/rake/task.rb', line 16

def prerequisites
  @prerequisites
end

#scope ⇒ Object (readonly)

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



25
26
27
 
# File 'lib/rake/task.rb', line 25

def scope
  @scope
end

#sources ⇒ Object 



43
44
45
46
47
48
49
 
# File 'lib/rake/task.rb', line 43

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

Class Method Details

.[](task_name) ⇒ Object

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.



352
353
354
 
# File 'lib/rake/task.rb', line 352

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

.clear ⇒ Object

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



339
340
341
 
# File 'lib/rake/task.rb', line 339

def clear
  Rake.application.clear
end

.create_rule(*args, &block) ⇒ Object

Define a rule for synthesizing tasks.



369
370
371
 
# File 'lib/rake/task.rb', line 369

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

.define_task(*args, &block) ⇒ Object

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.



364
365
366
 
# File 'lib/rake/task.rb', line 364

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

.scope_name(scope, task_name) ⇒ Object

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.



376
377
378
379
 
# File 'lib/rake/task.rb', line 376

def scope_name(scope, task_name)
#        (scope + [task_name]).join(':')
  scope.path_with_task_name(task_name)
end

.task_defined?(task_name) ⇒ Boolean

TRUE if the task name is already defined.

Returns:

  • (Boolean) 


357
358
359
 
# File 'lib/rake/task.rb', line 357

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

.tasks ⇒ Object

List of all defined tasks.



344
345
346
 
# File 'lib/rake/task.rb', line 344

def tasks
  Rake.application.tasks
end

Instance Method Details

#add_description(description) ⇒ Object

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



258
259
260
261
262
 
# File 'lib/rake/task.rb', line 258

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

#all_prerequisite_tasks ⇒ Object

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



64
65
66
67
68
 
# File 'lib/rake/task.rb', line 64

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

#arg_description ⇒ Object

Argument description (nil if none).



121
122
123
 
# File 'lib/rake/task.rb', line 121

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

#arg_names ⇒ Object

Name of arguments for this task.



126
127
128
 
# File 'lib/rake/task.rb', line 126

def arg_names
  @arg_names || []
end

#clear ⇒ Object

Clear the existing prerequisites and actions of a rake task.



137
138
139
140
141
142
 
# File 'lib/rake/task.rb', line 137

def clear
  clear_prerequisites
  clear_actions
  clear_comments
  self
end

#clear_actions ⇒ Object

Clear the existing actions on a rake task.



151
152
153
154
 
# File 'lib/rake/task.rb', line 151

def clear_actions
  actions.clear
  self
end

#clear_comments ⇒ Object

Clear the existing comments on a rake task.



157
158
159
160
 
# File 'lib/rake/task.rb', line 157

def clear_comments
  @comments = []
  self
end

#clear_prerequisites ⇒ Object

Clear the existing prerequisites of a rake task.



145
146
147
148
 
# File 'lib/rake/task.rb', line 145

def clear_prerequisites
  prerequisites.clear
  self
end

#comment ⇒ Object

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



282
283
284
 
# File 'lib/rake/task.rb', line 282

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

#comment=(comment) ⇒ Object

:nodoc:



264
265
266
 
# File 'lib/rake/task.rb', line 264

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

#enhance(deps = nil, &block) ⇒ Object

Enhance a task with prerequisites or actions. Returns self.



100
101
102
103
104
 
# File 'lib/rake/task.rb', line 100

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

#execute(args = nil) ⇒ Object

Execute the actions associated with this task.



227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
 
# File 'lib/rake/task.rb', line 227

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 ⇒ Object

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



276
277
278
 
# File 'lib/rake/task.rb', line 276

def full_comment
  transform_comments("\n")
end

#inspect ⇒ Object

:nodoc:



37
38
39
 
# File 'lib/rake/task.rb', line 37

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

#investigation ⇒ Object

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



314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
 
# File 'lib/rake/task.rb', line 314

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) ⇒ Object

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



163
164
165
166
 
# File 'lib/rake/task.rb', line 163

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) ⇒ Object

Invoke all the prerequisites of a task.



195
196
197
198
199
200
201
202
203
204
 
# File 'lib/rake/task.rb', line 195

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) ⇒ Object

Invoke all the prerequisites of a task in parallel.



207
208
209
210
211
212
213
214
215
 
# File 'lib/rake/task.rb', line 207

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
  futures.each { |f| f.value }
end

#name ⇒ Object

Name of the task, including any namespace qualifiers.



107
108
109
 
# File 'lib/rake/task.rb', line 107

def name
  @name.to_s
end

#name_with_args ⇒ Object

Name of task with argument list description.



112
113
114
115
116
117
118
 
# File 'lib/rake/task.rb', line 112

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

#needed? ⇒ Boolean

Is this task needed?

Returns:

  • (Boolean) 


246
247
248
 
# File 'lib/rake/task.rb', line 246

def needed?
  true
end

#prerequisite_tasks ⇒ Object

List of prerequisite tasks



52
53
54
 
# File 'lib/rake/task.rb', line 52

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

#reenable ⇒ Object

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



132
133
134
 
# File 'lib/rake/task.rb', line 132

def reenable
  @already_invoked = false
end

#set_arg_names(args) ⇒ Object

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



308
309
310
 
# File 'lib/rake/task.rb', line 308

def set_arg_names(args)
  @arg_names = args.map { |a| a.to_sym }
end

#source ⇒ Object

First source from a rule (nil if no sources)



80
81
82
 
# File 'lib/rake/task.rb', line 80

def source
  sources.first
end

#timestamp ⇒ Object

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



252
253
254
 
# File 'lib/rake/task.rb', line 252

def timestamp
  Time.now
end

#to_s ⇒ Object

Return task name



33
34
35
 
# File 'lib/rake/task.rb', line 33

def to_s
  name
end