Class | Rack::Builder |
In: |
lib/rack/builder.rb
|
Parent: | Object |
Rack::Builder implements a small DSL to iteratively construct Rack applications.
Example:
app = Rack::Builder.new { use Rack::CommonLogger use Rack::ShowExceptions map "/lobster" do use Rack::Lint run Rack::Lobster.new end }
Or
app = Rack::Builder.app do use Rack::CommonLogger lambda { |env| [200, {'Content-Type' => 'text/plain'}, 'OK'] } end
use adds a middleware to the stack, run dispatches to an application. You can use map to construct a Rack::URLMap in a convenient way.
# File lib/rack/builder.rb, line 27 27: def initialize(&block) 28: @ins = [] 29: instance_eval(&block) if block_given? 30: end
# File lib/rack/builder.rb, line 48 48: def map(path, &block) 49: if @ins.last.kind_of? Hash 50: @ins.last[path] = self.class.new(&block).to_app 51: else 52: @ins << {} 53: map(path, &block) 54: end 55: end
# File lib/rack/builder.rb, line 44 44: def run(app) 45: @ins << app #lambda { |nothing| app } 46: end
# File lib/rack/builder.rb, line 57 57: def to_app 58: @ins[-1] = Rack::URLMap.new(@ins.last) if Hash === @ins.last 59: inner_app = @ins.last 60: @ins[0...-1].reverse.inject(inner_app) { |a, e| e.call(a) } 61: end