class ActionDispatch::Reloader
ActionDispatch::Reloader provides prepare and cleanup callbacks, intended to assist with code reloading during development.
Prepare callbacks are run before each request, and cleanup callbacks after each request. In this respect they are analogs of ActionDispatch::Callback's before and after callbacks. However, cleanup callbacks are not called until the request is fully complete – that is, after close has been called on the response body. This is important for streaming responses such as the following:
self.response_body = lambda { |response, output| # code here which refers to application models }
Cleanup callbacks will not be called until after the response_body lambda is evaluated, ensuring that it can refer to application models and other classes before they are unloaded.
By default, ActionDispatch::Reloader is
included in the middleware stack only in the development environment;
specifically, when config.cache_classes
is false. Callbacks may be registered even when it is not
included in the middleware stack, but are executed only when
ActionDispatch::Reloader.prepare!
or
ActionDispatch::Reloader.cleanup!
are called manually.
Public Class Methods
Execute all cleanup callbacks.
# File lib/action_dispatch/middleware/reloader.rb, line 59 def self.cleanup! new(nil).cleanup! end
# File lib/action_dispatch/middleware/reloader.rb, line 63 def initialize(app, condition=nil) @app = app @condition = condition || lambda { true } @validated = true end
Execute all prepare callbacks.
# File lib/action_dispatch/middleware/reloader.rb, line 54 def self.prepare! new(nil).prepare! end
Add a cleanup callback. Cleanup callbacks are run after each request is complete (after close is called on the response body).
# File lib/action_dispatch/middleware/reloader.rb, line 46 def self.to_cleanup(*args, &block) unless block_given? warn "to_cleanup without a block is deprecated. Please use a block" end set_callback(:cleanup, *args, &block) end
Add a prepare callback. Prepare callbacks are run before each request, prior to ActionDispatch::Callback's before callbacks.
# File lib/action_dispatch/middleware/reloader.rb, line 37 def self.to_prepare(*args, &block) unless block_given? warn "to_prepare without a block is deprecated. Please use a block" end set_callback(:prepare, *args, &block) end
Public Instance Methods
# File lib/action_dispatch/middleware/reloader.rb, line 69 def call(env) @validated = @condition.call prepare! response = @app.call(env) response[2] = ::Rack::BodyProxy.new(response[2]) { cleanup! } response rescue Exception cleanup! raise end