Catch exceptions at Rack level. closes #183

lib/middleman.rb

@@ -64,6 +64,9 @@ module Middleman
   
     # Pass custom options to views
     autoload :Routing,        "middleman/core_extensions/routing"
+    
+    # Catch and show exceptions at the Rack level
+    autoload :ShowExceptions, "middleman/core_extensions/show_exceptions"
   end
 
   module Extensions

lib/middleman/base.rb

@@ -59,7 +59,17 @@ class Middleman::Base
     # @return [Rack::Builder]
     def to_rack_app(&block)
       inner_app = inst(&block)
+      
+      (@middleware || []).each do |m|
+        app.use(m[0], *m[1], &m[2])
+      end
+      
       app.map("/") { run inner_app }
+      
+      (@mappings || []).each do |m|
+        app.map(m[0], &m[1])
+      end
+      
       app
     end
     
@@ -82,14 +92,16 @@ class Middleman::Base
     #
     # @param [Class] Middleware
     def use(middleware, *args, &block)
-      app.use(middleware, *args, &block)
+      @middleware ||= []
+      @middleware << [middleware, args, block]
     end
     
     # Add Rack App mapped to specific path
     #
     # @param [String] Path to map
     def map(map, &block)
-      app.map(map, &block)
+      @mappings ||= []
+      @mappings << [map, block]
     end
     
     # Mix-in helper methods. Accepts either a list of Modules
@@ -168,6 +180,10 @@ class Middleman::Base
   # @return [String]
   set :http_prefix, "/"
 
+  # Whether to catch and display exceptions
+  # @return [Boolean]
+  set :show_exceptions, true
+
   # Automatically loaded extensions
   # @return [Array<Symbol>]
   set :default_extensions, [
@@ -182,6 +198,9 @@ class Middleman::Base
   # Activate custom features and extensions
   include Middleman::CoreExtensions::Extensions
   
+  # Handle exceptions
+  register Middleman::CoreExtensions::ShowExceptions
+    
   # Add Builder Callbacks
   register Middleman::CoreExtensions::Builder
   

lib/middleman/core_extensions/show_exceptions.rb

@@ -0,0 +1,16 @@
+require 'rack/showexceptions'
+
+module Middleman::CoreExtensions::ShowExceptions
+  class << self
+    def registered(app)
+      app.after_configuration do
+        if show_exceptions
+          use ::Middleman::CoreExtensions::ShowExceptions::Middleware
+        end
+      end
+    end
+  end
+  
+  class Middleware < ::Rack::ShowExceptions
+  end
+end