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######################################################################### 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.
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 rake/task.rb, line 320 def [](task_name) Rake.application[task_name] end
Clear the task list. This cause rake to immediately forget all the tasks that have been assigned. (Normally used in the unit tests.)
# File rake/task.rb, line 307 def clear Rake.application.clear end
Define a rule for synthesizing tasks.
# File rake/task.rb, line 337 def create_rule(*args, &block) Rake.application.create_rule(*args, &block) 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 rake/task.rb, line 332 def define_task(*args, &block) Rake.application.define_task(self, *args, &block) end
Create a task named task_name
with no actions or
prerequisites. Use enhance
to add actions and prerequisites.
# File 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
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 rake/task.rb, line 344 def scope_name(scope, task_name) (scope + [task_name]).join(':') end
Add a description to the task. The description can consist of an option argument list (enclosed brackets) and an optional comment.
# File rake/task.rb, line 246 def add_description(description) return if ! description comment = description.strip add_comment(comment) if comment && ! comment.empty? end
Name of arguments for this task.
# File rake/task.rb, line 112 def arg_names @arg_names || [] end
Clear the existing prerequisites and actions of a rake task.
# File rake/task.rb, line 123 def clear clear_prerequisites clear_actions clear_comments self end
Clear the existing actions on a rake task.
# File rake/task.rb, line 137 def clear_actions actions.clear self end
Clear the existing comments on a rake task.
# File rake/task.rb, line 143 def clear_comments @full_comment = nil @comment = nil self end
Clear the existing prerequisites of a rake task.
# File rake/task.rb, line 131 def clear_prerequisites prerequisites.clear self end
Writing to the comment attribute is the same as adding a description.
# File rake/task.rb, line 253 def comment=(description) add_description(description) end
Enhance a task with prerequisites or actions. Returns self.
# File rake/task.rb, line 86 def enhance(deps=nil, &block) @prerequisites |= deps if deps @actions << block if block_given? self end
Execute the actions associated with this task.
# File rake/task.rb, line 213 def execute(args=nil) args ||= EMPTY_TASK_ARGS if application.options.dryrun application.trace "** Execute (dry run) #{name}" return end if application.options.trace application.trace "** 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
# File rake/task.rb, line 44 def inspect "<#{self.class} #{name} => [#{prerequisites.join(', ')}]>" end
Return a string describing the internal state of a task. Useful for debugging.
# File rake/task.rb, line 282 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 the task if it is needed. Prerequisites are invoked first.
# File rake/task.rb, line 150 def invoke(*args) task_args = TaskArguments.new(arg_names, args) invoke_with_call_chain(task_args, InvocationChain::EMPTY) end
Name of the task, including any namespace qualifiers.
# File rake/task.rb, line 93 def name @name.to_s end
Is this task needed?
# File rake/task.rb, line 234 def needed? true end
List of prerequisite tasks
# File rake/task.rb, line 55 def prerequisite_tasks prerequisites.collect { |pre| lookup_prerequisite(pre) } end
Reenable the task, allowing its tasks to be executed if the task is invoked again.
# File rake/task.rb, line 118 def reenable @already_invoked = false end
Set the names of the arguments for this task. args
should be
an array of symbols, one for each argument name.
# File rake/task.rb, line 276 def set_arg_names(args) @arg_names = args.map { |a| a.to_sym } end
First source from a rule (nil if no sources)
# File rake/task.rb, line 65 def source @sources.first if defined?(@sources) end
Comment for this task. Restricted to a single line of no more than 50 characters.