Class: Vagrant::Action::Builder
- Inherits:
-
Object
- Object
- Vagrant::Action::Builder
- Defined in:
- lib/vagrant/action/builder.rb
Overview
Action builder which provides a nice DSL for building up
a middleware sequence for Vagrant actions. This code is based
heavily off of Rack::Builder
and ActionDispatch::MiddlewareStack
in Rack and Rails, respectively.
Usage
Building an action sequence is very easy:
app = Vagrant::Action::Builder.new do
use MiddlewareA
use MiddlewareB
end
Vagrant::Action.run(app)
Instance Method Summary collapse
-
#call(env) ⇒ Object
Runs the builder stack with the given environment.
-
#delete(index) ⇒ Object
Deletes the given middleware object or index.
-
#flatten ⇒ Object
Returns a mergeable version of the builder.
-
#index(object) ⇒ Integer
Returns the numeric index for the given middleware object.
-
#initialize(&block) ⇒ Builder
constructor
Initializes the builder.
-
#insert(index, middleware, *args, &block) ⇒ Object
(also: #insert_before)
Inserts a middleware at the given index or directly before the given middleware object.
-
#insert_after(index, middleware, *args, &block) ⇒ Object
Inserts a middleware after the given index or middleware object.
-
#stack ⇒ Array
Returns the current stack of middlewares.
-
#swap(index, middleware, *args, &block) ⇒ Object
Swaps out the given middlware object or index with the new middleware.
-
#to_app(env) ⇒ Object
Converts the builder stack to a runnable action sequence.
-
#use(middleware, *args, &block) ⇒ Object
Adds a middleware class to the middleware stack.
Constructor Details
#initialize(&block) ⇒ Builder
Initializes the builder. An optional block can be passed which will be evaluated in the context of the instance.
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# File 'lib/vagrant/action/builder.rb', line 22 def initialize(&block) instance_eval(&block) if block_given? end |
Instance Method Details
#call(env) ⇒ Object
Runs the builder stack with the given environment.
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# File 'lib/vagrant/action/builder.rb', line 119 def call(env) to_app(env).call(env) end |
#delete(index) ⇒ Object
Deletes the given middleware object or index
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# File 'lib/vagrant/action/builder.rb', line 91 def delete(index) index = self.index(index) unless index.is_a?(Integer) stack.delete_at(index) end |
#flatten ⇒ Object
Returns a mergeable version of the builder. If use
is called with
the return value of this method, then the stack will merge, instead
of being treated as a separate single middleware.
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# File 'lib/vagrant/action/builder.rb', line 37 def flatten lambda do |env| self.call(env) end end |
#index(object) ⇒ Integer
Returns the numeric index for the given middleware object.
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# File 'lib/vagrant/action/builder.rb', line 100 def index(object) stack.each_with_index do |item, i| return i if item[0] == object end nil end |
#insert(index, middleware, *args, &block) ⇒ Object Also known as: insert_before
Inserts a middleware at the given index or directly before the given middleware object.
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# File 'lib/vagrant/action/builder.rb', line 64 def insert(index, middleware, *args, &block) index = self.index(index) unless index.is_a?(Integer) stack.insert(index, [middleware, args, block]) end |
#insert_after(index, middleware, *args, &block) ⇒ Object
Inserts a middleware after the given index or middleware object.
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# File 'lib/vagrant/action/builder.rb', line 72 def insert_after(index, middleware, *args, &block) index = self.index(index) unless index.is_a?(Integer) raise "no such middleware to insert after: #{index.inspect}" unless index insert(index + 1, middleware, *args, &block) end |
#stack ⇒ Array
Returns the current stack of middlewares. You probably won't need to use this directly, and it's recommended that you don't.
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# File 'lib/vagrant/action/builder.rb', line 30 def stack @stack ||= [] end |
#swap(index, middleware, *args, &block) ⇒ Object
Swaps out the given middlware object or index with the new middleware.
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# File 'lib/vagrant/action/builder.rb', line 80 def swap(index, middleware, *args, &block) if index.is_a?(Integer) delete(index) insert(index, middleware, *args, &block) else insert_before(index, middleware, *args, &block) delete(index) end end |
#to_app(env) ⇒ Object
Converts the builder stack to a runnable action sequence.
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# File 'lib/vagrant/action/builder.rb', line 112 def to_app(env) # Wrap the middleware stack with the Warden to provide a consistent # and predictable behavior upon exceptions. Warden.new(stack.dup, env) end |
#use(middleware, *args, &block) ⇒ Object
Adds a middleware class to the middleware stack. Any additional args and a block, if given, are saved and passed to the initializer of the middleware.
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# File 'lib/vagrant/action/builder.rb', line 48 def use(middleware, *args, &block) if middleware.kind_of?(Builder) # Prepend with a environment setter if args are given self.use(Env::Set, *args, &block) if !args.empty? && args.first.is_a?(Hash) # Merge in the other builder's stack into our own self.stack.concat(middleware.stack) else self.stack << [middleware, args, block] end self end |