Add new format json

docs/options.rst

@@ -151,6 +151,14 @@ Using the ``--html`` option, ``Glue`` will also generate a test html per sprite
 
     $ glue source output --html
 
+--json
+-----------
+Using the ``--json`` option, ``Glue`` will generate both a sprite image and a json metadata file.
+
+.. code-block:: bash
+
+    $ glue source output --json
+
 
 -l --less
 ---------

glue/formats/__init__.py

@@ -2,8 +2,10 @@
 from .cocos2d import Cocos2dFormat
 from .img import ImageFormat
 from .html import HtmlFormat
+from .json_format import JSONFormat
 
 formats = {'css': CssFormat,
            'cocos2d': Cocos2dFormat,
            'img': ImageFormat,
-           'html': HtmlFormat}
+           'html': HtmlFormat,
+           'json': JSONFormat}

glue/formats/json_format.py

@@ -0,0 +1,36 @@
+import os
+import json
+import codecs
+
+from base import BaseTextFormat
+
+
+class JSONFormat(BaseTextFormat):
+
+    extension = 'json'
+
+    @classmethod
+    def populate_argument_parser(cls, parser):
+        group = parser.add_argument_group("JSON format options")
+
+        group.add_argument("--json",
+                           dest="json_dir",
+                           nargs='?',
+                           const=True,
+                           default=os.environ.get('GLUE_JSON', False),
+                           metavar='DIR',
+                           help="Generate JSON files and optionally where")
+
+    def needs_rebuild(self):
+        if os.path.exists(self.output_path()):
+            try:
+                with codecs.open('output/simple.css', 'r', 'utf-8-sig') as f:
+                    data = json.loads(f.read())
+                assert data['hash'] == self.sprite.hash
+                return False
+            except Exception:
+                pass
+        return True
+
+    def render(self, *args, **kwargs):
+        return json.dumps(self.get_context())

tests.py

@@ -1,5 +1,6 @@
 import os
 import sys
+import json
 import codecs
 import shutil
 import unittest
@@ -927,6 +928,17 @@ def test_html(self):
         self.assertExists("output/simple.css")
         self.assertExists("output/simple.html")
 
+    def test_json(self):
+        self.create_image("simple/red.png", RED)
+        self.create_image("simple/blue.png", BLUE)
+        code = self.call("glue simple output --json")
+        self.assertEqual(code, 0)
+
+        self.assertExists("output/simple.png")
+        self.assertExists("output/simple.json")
+        with codecs.open('output/simple.json', 'r', 'utf-8-sig') as f:
+            json.loads(f.read())
+
     def test_img(self):
         self.create_image("simple/red.png", RED)
         self.create_image("simple/blue.png", BLUE)