From 11094f9e62e08227bb45c351ad9f1a6cc6c828c3 Mon Sep 17 00:00:00 2001
From: Krzysztof Wawer <krzysztof.wawer@gmail.com>
Date: Mon, 13 Apr 2015 21:24:27 +0200
Subject: [PATCH] added json extension

---
 README.md             | 23 +++++++++++++++++++++++
 lib/hobbit/contrib.rb |  1 +
 lib/hobbit/json.rb    | 32 ++++++++++++++++++++++++++++++++
 test/json_test.rb     | 20 ++++++++++++++++++++
 4 files changed, 76 insertions(+)
 create mode 100644 lib/hobbit/json.rb
 create mode 100644 test/json_test.rb

diff --git a/README.md b/README.md
index 1b954a6..c92fc7e 100644
--- a/README.md
+++ b/README.md
@@ -28,6 +28,7 @@ $ gem install hobbit-contrib
 
 * [mote](https://github.com/soveran/mote) if you want to use `Hobbit::Mote`.
 * [tilt](https://github.com/rtomayko/tilt) if you want to use `Hobbit::Render`.
+* [multi_json](https://github.com/intridea/multi_json) if you want to use `Hobbit::JSON`.
 
 ## Usage
 
@@ -149,6 +150,28 @@ run App.new
 **Note**: It is recommended to include `Hobbit::Filter` before
 `Hobbit::ErrorHandling` if you want to use both extensions.
 
+### Hobbit::JSON
+
+This extension provides helper method which convert object to json and set json header.
+To use this extension just include the module:
+
+```ruby
+require 'hobbit'
+require 'hobbit/contrib'
+
+class App < Hobbit::Base
+  include Hobbit::JSON
+
+  get '/' do
+    json({'hello' => 'world'})
+  end
+end
+```
+
+#### Available methods
+
+* `json`: Sets json header and convert object to json.
+
 ### Hobbit::Mote
 
 This module provides rendering to your hobbit application using [mote](https://github.com/soveran/mote).
diff --git a/lib/hobbit/contrib.rb b/lib/hobbit/contrib.rb
index 8b2a18d..2a41bb1 100644
--- a/lib/hobbit/contrib.rb
+++ b/lib/hobbit/contrib.rb
@@ -1,6 +1,7 @@
 require 'hobbit/contrib/version'
 require 'hobbit/environment'
 require 'hobbit/error_handling'
+require 'hobbit/json'
 require 'hobbit/filter'
 begin
   require 'hobbit/mote'
diff --git a/lib/hobbit/json.rb b/lib/hobbit/json.rb
new file mode 100644
index 0000000..b26d08d
--- /dev/null
+++ b/lib/hobbit/json.rb
@@ -0,0 +1,32 @@
+require 'multi_json'
+
+module Hobbit
+  module JSON
+    def json(object)
+      response.headers['Content-Type'] = resolve_content_type
+      resolve_encoder_action(object, resolve_encoder)
+    end
+
+    private
+
+    def resolve_content_type
+      'application/json'
+    end
+
+    def resolve_encoder_action(object, encoder)
+      [:encode, :generate].each do |method|
+        return encoder.send(method, object) if encoder.respond_to? method
+      end
+
+      if encoder.is_a? Symbol
+        object.__send__(encoder)
+      else
+        fail "#{encoder} does not respond to #generate nor #encode"
+      end
+    end
+
+    def resolve_encoder
+      ::MultiJson
+    end
+  end
+end
diff --git a/test/json_test.rb b/test/json_test.rb
new file mode 100644
index 0000000..297060a
--- /dev/null
+++ b/test/json_test.rb
@@ -0,0 +1,20 @@
+require 'helper'
+
+scope Hobbit::Render do
+  setup do
+    mock_app do
+      include Hobbit::JSON
+
+      get('/') { json({'hello' => 'world'}) }
+    end
+  end
+
+  scope '#json' do
+    test 'returns json response' do
+      get '/'
+      assert last_response.ok?
+      assert last_response.headers['Content-Type'] == 'application/json'
+      assert JSON.parse(last_response.body) == {'hello' => 'world'}
+    end
+  end
+end