Module: Capistrano::Configuration::Callbacks

Included in:
Capistrano::Configuration
Defined in:
lib/capistrano/configuration/callbacks.rb

Instance Attribute Summary (collapse)

Class Method Summary (collapse)

Instance Method Summary (collapse)

Instance Attribute Details

- (Object) callbacks (readonly)

The hash of callbacks that have been registered for this configuration



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# File 'lib/capistrano/configuration/callbacks.rb', line 14

def callbacks
  @callbacks
end

Class Method Details

+ (Object) included(base)

:nodoc:



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# File 'lib/capistrano/configuration/callbacks.rb', line 6

def self.included(base) #:nodoc:
  %w(initialize invoke_task_directly).each do |method|
    base.send :alias_method, "#{method}_without_callbacks", method
    base.send :alias_method, method, "#{method}_with_callbacks"
  end
end

Instance Method Details

- (Object) after(task_name, *args, &block)

Defines a callback to be invoked after the given task. You must specify the fully-qualified task name, both for the primary task, and for the task(s) to be executed after. Alternatively, you can pass a block to be executed after the given task.

after "deploy:update_code", :log_difference
after :deploy, "custom:announce"
after :deploy, :this, "then:this", "and:then:this"
after :some_task do
  puts "an anonymous hook!"
end

This just provides a convenient interface to the more general #on method.



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# File 'lib/capistrano/configuration/callbacks.rb', line 64

def after(task_name, *args, &block)
  options = args.last.is_a?(Hash) ? args.pop : {}
  args << options.merge(:only => task_name)
  on :after, *args, &block
end

- (Object) before(task_name, *args, &block)

Defines a callback to be invoked before the given task. You must specify the fully-qualified task name, both for the primary task, and for the task(s) to be executed before. Alternatively, you can pass a block to be executed before the given task.

before "deploy:update_code", :record_difference
before :deploy, "custom:log_deploy"
before :deploy, :this, "then:this", "and:then:this"
before :some_task do
  puts "an anonymous hook!"
end

This just provides a convenient interface to the more general #on method.



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# File 'lib/capistrano/configuration/callbacks.rb', line 45

def before(task_name, *args, &block)
  options = args.last.is_a?(Hash) ? args.pop : {}
  args << options.merge(:only => task_name)
  on :before, *args, &block
end

- (Object) filter_deprecated_tasks(names)

Filters the given task name or names and attempts to replace deprecated tasks with their equivalents.



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# File 'lib/capistrano/configuration/callbacks.rb', line 118

def filter_deprecated_tasks(names)
  deprecation_msg = "[Deprecation Warning] This API has changed, please hook `deploy:create_symlink` instead of" \
    " `deploy:symlink`."

  if names == "deploy:symlink"
    warn deprecation_msg
    names = "deploy:create_symlink"
  elsif names.is_a?(Array) && names.include?("deploy:symlink")
    warn deprecation_msg
    names = names.map { |name| name == "deploy:symlink" ? "deploy:create_symlink" : name }
  end

  names
end

- (Object) initialize_with_callbacks(*args)

:nodoc:



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# File 'lib/capistrano/configuration/callbacks.rb', line 16

def initialize_with_callbacks(*args) #:nodoc:
  initialize_without_callbacks(*args)
  @callbacks = {}
end

- (Object) invoke_task_directly_with_callbacks(task)

:nodoc:



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# File 'lib/capistrano/configuration/callbacks.rb', line 21

def invoke_task_directly_with_callbacks(task) #:nodoc:

  trigger :before, task

  result = invoke_task_directly_without_callbacks(task)

  trigger :after, task

  return result
end

- (Object) on(event, *args, &block)

Defines one or more callbacks to be invoked in response to some event. Capistrano currently understands the following events:

  • :before, triggered before a task is invoked

  • :after, triggered after a task is invoked

  • :start, triggered before a top-level task is invoked via the command-line

  • :finish, triggered when a top-level task completes

  • :load, triggered after all recipes have loaded

  • :exit, triggered after all tasks have completed

Specify the (fully-qualified) task names that you want invoked in response to the event. Alternatively, you can specify a block to invoke when the event is triggered. You can also pass a hash of options as the last parameter, which may include either of two keys:

  • :only, should specify an array of task names. Restricts this callback so that it will only fire when the event applies to those tasks.

  • :except, should specify an array of task names. Restricts this callback so that it will never fire when the event applies to those tasks.

Usage:

on :before, "some:hook", "another:hook", :only => "deploy:update"
on :after, "some:hook", :except => "deploy:create_symlink"
on :before, "global:hook"
on :after, :only => :deploy do
  puts "after deploy here"
end


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# File 'lib/capistrano/configuration/callbacks.rb', line 98

def on(event, *args, &block)
  options = args.last.is_a?(Hash) ? args.pop : {}
  callbacks[event] ||= []

  if args.empty? && block.nil?
    raise ArgumentError, "please specify either a task name or a block to invoke"
  elsif args.any? && block
    raise ArgumentError, "please specify only a task name or a block, but not both"
  elsif block
    callbacks[event] << ProcCallback.new(block, options)
  else
    args = filter_deprecated_tasks(args)
    options[:only] = filter_deprecated_tasks(options[:only])
    options[:except] = filter_deprecated_tasks(options[:except])

    callbacks[event].concat(args.map { |name| TaskCallback.new(self, name, options) })
  end
end

- (Object) trigger(event, task = nil)

Trigger the named event for the named task. All associated callbacks will be fired, in the order they were defined.



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# File 'lib/capistrano/configuration/callbacks.rb', line 135

def trigger(event, task=nil)
  pending = Array(callbacks[event]).select { |c| c.applies_to?(task) }
  if pending.any?
    msg = "triggering #{event} callbacks"
    msg << " for `#{task.fully_qualified_name}'" if task
    logger.trace(msg)
    pending.each { |callback| callback.call }
  end
end