Class | Rake::Task |
In: |
lib/rake.rb
|
Parent: | Object |
######################################################################### 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.
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. |
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. |
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.rb, line 638 638: def [](task_name) 639: Rake.application[task_name] 640: end
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.rb, line 650 650: def define_task(*args, &block) 651: Rake.application.define_task(self, *args, &block) 652: end
Create a task named task_name with no actions or prerequisites. Use enhance to add actions and prerequisites.
# File lib/rake.rb, line 447 447: def initialize(task_name, app) 448: @name = task_name.to_s 449: @prerequisites = FileList[] 450: @actions = [] 451: @already_invoked = false 452: @full_comment = nil 453: @comment = nil 454: @lock = Mutex.new 455: @application = app 456: @scope = app.current_scope 457: @arg_names = nil 458: end
Add a description to the task. The description can consist of an option argument list (enclosed brackets) and an optional comment.
# File lib/rake.rb, line 564 564: def add_description(description) 565: return if ! description 566: comment = description.strip 567: add_comment(comment) if comment && ! comment.empty? 568: end
Name of arguments for this task.
# File lib/rake.rb, line 487 487: def arg_names 488: @arg_names || [] 489: end
Writing to the comment attribute is the same as adding a description.
# File lib/rake.rb, line 571 571: def comment=(description) 572: add_description(description) 573: end
Enhance a task with prerequisites or actions. Returns self.
# File lib/rake.rb, line 461 461: def enhance(deps=nil, &block) 462: @prerequisites |= deps if deps 463: @actions << block if block_given? 464: self 465: end
Execute the actions associated with this task.
# File lib/rake.rb, line 532 532: def execute(args) 533: if application.options.dryrun 534: puts "** Execute (dry run) #{name}" 535: return 536: end 537: if application.options.trace 538: puts "** Execute #{name}" 539: end 540: application.enhance_with_matching_rule(name) if @actions.empty? 541: @actions.each do |act| 542: case act.arity 543: when 1 544: act.call(self) 545: else 546: act.call(self, args) 547: end 548: end 549: end
# File lib/rake.rb, line 430 430: def inspect 431: "<#{self.class} #{name} => [#{prerequisites.join(', ')}]>" 432: end
Return a string describing the internal state of a task. Useful for debugging.
# File lib/rake.rb, line 600 600: def investigation 601: result = "------------------------------\n" 602: result << "Investigating #{name}\n" 603: result << "class: #{self.class}\n" 604: result << "task needed: #{needed?}\n" 605: result << "timestamp: #{timestamp}\n" 606: result << "pre-requisites: \n" 607: prereqs = @prerequisites.collect {|name| application[name]} 608: prereqs.sort! {|a,b| a.timestamp <=> b.timestamp} 609: prereqs.each do |p| 610: result << "--#{p.name} (#{p.timestamp})\n" 611: end 612: latest_prereq = @prerequisites.collect{|n| application[n].timestamp}.max 613: result << "latest-prerequisite time: #{latest_prereq}\n" 614: result << "................................\n\n" 615: return result 616: end
Invoke the task if it is needed. Prerequites are invoked first.
# File lib/rake.rb, line 492 492: def invoke(*args) 493: task_args = TaskArguments.new(arg_names, args) 494: invoke_with_call_chain(task_args, InvocationChain::EMPTY) 495: end
Invoke all the prerequisites of a task.
# File lib/rake.rb, line 514 514: def invoke_prerequisites(task_args, invocation_chain) 515: @prerequisites.each { |n| 516: prereq = application[n, @scope] 517: prereq_args = task_args.new_scope(prereq.arg_names) 518: prereq.invoke_with_call_chain(prereq_args, invocation_chain) 519: } 520: end
Name of the task, including any namespace qualifiers.
# File lib/rake.rb, line 468 468: def name 469: @name.to_s 470: end
Same as invoke, but explicitly pass a call chain to detect circular dependencies.
# File lib/rake.rb, line 499 499: def invoke_with_call_chain(task_args, invocation_chain) 500: new_chain = InvocationChain.append(self, invocation_chain) 501: @lock.synchronize do 502: if application.options.trace 503: puts "** Invoke #{name} #{format_trace_flags}" 504: end 505: return if @already_invoked 506: @already_invoked = true 507: invoke_prerequisites(task_args, new_chain) 508: execute(task_args) if needed? 509: end 510: end