class Rake::Task
######################################################################### 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.
Attributes
List of actions attached to a task.
Application owning this task.
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).
List of prerequisites for a task.
Array of nested namespaces names used for task lookup by this task.
List of sources for task.
Public Class 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 lib/rake/task.rb, line 347 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 lib/rake/task.rb, line 334 def clear Rake.application.clear end
Define a rule for synthesizing tasks.
# File lib/rake/task.rb, line 364 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 lib/rake/task.rb, line 359 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 lib/rake/task.rb, line 82 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
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 lib/rake/task.rb, line 371 def scope_name(scope, task_name) # (scope + [task_name]).join(':') scope.path_with_task_name(task_name) end
TRUE if the task name is already defined.
# File lib/rake/task.rb, line 352 def task_defined?(task_name) Rake.application.lookup(task_name) != nil end
List of all defined tasks.
# File lib/rake/task.rb, line 339 def tasks Rake.application.tasks end
Public Instance Methods
Add a description to the task. The description can consist of an option argument list (enclosed brackets) and an optional comment.
# File lib/rake/task.rb, line 254 def add_description(description) return unless description comment = description.strip add_comment(comment) if comment && ! comment.empty? end
List of all unique prerequisite tasks including prerequisite tasks' prerequisites. Includes self when cyclic dependencies are found.
# File lib/rake/task.rb, line 60 def all_prerequisite_tasks seen = {} collect_prerequisites(seen) seen.values end
Name of arguments for this task.
# File lib/rake/task.rb, line 122 def arg_names @arg_names || [] end
Clear the existing prerequisites and actions of a rake task.
# File lib/rake/task.rb, line 133 def clear clear_prerequisites clear_actions clear_comments self end
Clear the existing actions on a rake task.
# File lib/rake/task.rb, line 147 def clear_actions actions.clear self end
Clear the existing comments on a rake task.
# File lib/rake/task.rb, line 153 def clear_comments @comments = [] self end
Clear the existing prerequisites of a rake task.
# File lib/rake/task.rb, line 141 def clear_prerequisites prerequisites.clear self end
First line (or sentence) of all comments. Multiple comments are separated by a “/”.
# File lib/rake/task.rb, line 277 def comment transform_comments(" / ") { |c| first_sentence(c) } end
# File lib/rake/task.rb, line 260 def comment=(comment) add_comment(comment) end
Enhance a task with prerequisites or actions. Returns self.
# File lib/rake/task.rb, line 96 def enhance(deps=nil, &block) @prerequisites |= deps if deps @actions << block if block_given? self end
Execute the actions associated with this task.
# File lib/rake/task.rb, line 223 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 collection of comments. Multiple comments are separated by newlines.
# File lib/rake/task.rb, line 271 def full_comment transform_comments("\n") end
# File lib/rake/task.rb, line 37 def inspect "<#{self.class} #{name} => [#{prerequisites.join(', ')}]>" end
Return a string describing the internal state of a task. Useful for debugging.
# File lib/rake/task.rb, line 309 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 the task if it is needed. Prerequisites are invoked first.
# File lib/rake/task.rb, line 159 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 lib/rake/task.rb, line 103 def name @name.to_s end
Is this task needed?
# File lib/rake/task.rb, line 242 def needed? true end
List of prerequisite tasks
# File lib/rake/task.rb, line 48 def prerequisite_tasks prerequisites.map { |pre| lookup_prerequisite(pre) } end
Reenable the task, allowing its tasks to be executed if the task is invoked again.
# File lib/rake/task.rb, line 128 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 lib/rake/task.rb, line 303 def set_arg_names(args) @arg_names = args.map { |a| a.to_sym } end
First source from a rule (nil if no sources)
# File lib/rake/task.rb, line 76 def source @sources.first if defined?(@sources) end
# File lib/rake/task.rb, line 43 def sources @sources ||= [] end
Timestamp for this task. Basic tasks return the current time for their time stamp. Other tasks can be more sophisticated.
# File lib/rake/task.rb, line 248 def timestamp Time.now end
Return task name
# File lib/rake/task.rb, line 33 def to_s name end
Protected Instance Methods
# File lib/rake/task.rb, line 66 def collect_prerequisites(seen) prerequisite_tasks.each do |pre| next if seen[pre.name] seen[pre.name] = pre pre.collect_prerequisites(seen) end end
Private Instance Methods
# File lib/rake/task.rb, line 183 def add_chain_to(exception, new_chain) exception.extend(InvocationExceptionMixin) unless exception.respond_to?(:chain) exception.chain = new_chain if exception.chain.nil? end
# File lib/rake/task.rb, line 264 def add_comment(comment) @comments << comment unless @comments.include?(comment) end
Get the first sentence in a string. The sentence is terminated by the first period or the end of the line. Decimal points do not count as periods.
# File lib/rake/task.rb, line 296 def first_sentence(string) string.split(/\.[ \t]|\.$|\n/).first end
Format the trace flags for display.
# File lib/rake/task.rb, line 214 def format_trace_flags flags = [] flags << "first_time" unless @already_invoked flags << "not_needed" unless needed? flags.empty? ? "" : "(" + flags.join(", ") + ")" end
# File lib/rake/task.rb, line 52 def lookup_prerequisite(prerequisite_name) application[prerequisite_name, @scope] end
Transform the list of comments as specified by the block and join with the separator.
# File lib/rake/task.rb, line 283 def transform_comments(separator, &block) if @comments.empty? nil else block ||= lambda { |c| c } @comments.map(&block).join(separator) end end