vagrant/lib/vagrant/action/hook.rb

108 lines
3.1 KiB
Ruby

module Vagrant
module Action
# This class manages hooks into existing {Builder} stacks, and lets you
# add and remove middleware classes. This is the primary method by which
# plugins can hook into built-in middleware stacks.
class Hook
# This is a hash of the middleware to prepend to a certain
# other middleware.
#
# @return [Hash<Class, Array<Class>>]
attr_reader :before_hooks
# This is a hash of the middleware to append to a certain other
# middleware.
#
# @return [Hash<Class, Array<Class>>]
attr_reader :after_hooks
# This is a list of the hooks to just prepend to the beginning
#
# @return [Array<Class>]
attr_reader :prepend_hooks
# This is a list of the hooks to just append to the end
#
# @return [Array<Class>]
attr_reader :append_hooks
def initialize
@before_hooks = Hash.new { |h, k| h[k] = [] }
@after_hooks = Hash.new { |h, k| h[k] = [] }
@prepend_hooks = []
@append_hooks = []
end
# Add a middleware before an existing middleware.
#
# @param [Class] existing The existing middleware.
# @param [Class] new The new middleware.
def before(existing, new, *args, &block)
@before_hooks[existing] << [new, args, block]
end
# Add a middleware after an existing middleware.
#
# @param [Class] existing The existing middleware.
# @param [Class] new The new middleware.
def after(existing, new, *args, &block)
@after_hooks[existing] << [new, args, block]
end
# Append a middleware to the end of the stack. Note that if the
# middleware sequence ends early, then the new middleware won't
# be run.
#
# @param [Class] new The middleware to append.
def append(new, *args, &block)
@append_hooks << [new, args, block]
end
# Prepend a middleware to the beginning of the stack.
#
# @param [Class] new The new middleware to prepend.
def prepend(new, *args, &block)
@prepend_hooks << [new, args, block]
end
# This applies the given hook to a builder. This should not be
# called directly.
#
# @param [Builder] builder
def apply(builder, options=nil)
options ||= {}
if !options[:no_prepend_or_append]
# Prepends first
@prepend_hooks.each do |klass, args, block|
builder.insert(0, klass, *args, &block)
end
# Appends
@append_hooks.each do |klass, args, block|
builder.use(klass, *args, &block)
end
end
# Before hooks
@before_hooks.each do |key, list|
next if !builder.index(key)
list.each do |klass, args, block|
builder.insert_before(key, klass, *args, &block)
end
end
# After hooks
@after_hooks.each do |key, list|
next if !builder.index(key)
list.each do |klass, args, block|
builder.insert_after(key, klass, *args, &block)
end
end
end
end
end
end