Handle frontmatter in the blog extension.

handroll/extensions/blog.py

@@ -1,7 +1,37 @@
 # Copyright (c) 2015, Matt Layman
 
+from handroll.exceptions import AbortError
 from handroll.extensions.base import Extension
+from handroll.i18n import _
+
+
+class BlogPost(object):
+
+    def __init__(self, **kwargs):
+        self.source_file = kwargs['source_file']
 
 
 class BlogExtension(Extension):
     """Track files marked as blog entries and generate a feed."""
+
+    handle_frontmatter_loaded = True
+    handle_post_composition = True
+
+    def __init__(self, config):
+        super(BlogExtension, self).__init__(config)
+        self.posts = []
+
+    def on_frontmatter_loaded(self, source_file, frontmatter):
+        """Scan for blog posts.
+
+        If a post is found, record it.
+        """
+        is_post = frontmatter.get('blog', False)
+        if type(is_post) != bool:
+            raise AbortError(
+                _('Invalid blog frontmatter (expects True or False): '
+                  '{blog_value}').format(blog_value=is_post))
+        if is_post:
+            self.posts.append(BlogPost(
+                source_file=source_file,
+            ))

handroll/tests/test_extensions.py

@@ -4,6 +4,7 @@
 
 from handroll import signals
 from handroll.configuration import Configuration
+from handroll.exceptions import AbortError
 from handroll.extensions.base import Extension
 from handroll.extensions.blog import BlogExtension
 from handroll.extensions.loader import ExtensionLoader
@@ -12,6 +13,11 @@
 
 class TestExtensionLoader(TestCase):
 
+    def tearDown(self):
+        # Clean up any attached extension instance.
+        signals.frontmatter_loaded.receivers.clear()
+        signals.post_composition.receivers.clear()
+
     def test_loads_available_extensions(self):
         loader = ExtensionLoader()
         loader.load()
@@ -60,3 +66,36 @@ class PostComposer(Extension):
         self.assertRaises(
             NotImplementedError, signals.post_composition.send, director)
         signals.post_composition.receivers.clear()
+
+
+class TestBlogExtension(TestCase):
+
+    def tearDown(self):
+        # Clean up any attached extension instance.
+        signals.frontmatter_loaded.receivers.clear()
+        signals.post_composition.receivers.clear()
+
+    def test_handles_frontmatter_loaded(self):
+        extension = BlogExtension(None)
+        self.assertTrue(extension.handle_frontmatter_loaded)
+
+    def test_handles_post_composition(self):
+        extension = BlogExtension(None)
+        self.assertTrue(extension.handle_post_composition)
+
+    def test_registers_blog_post(self):
+        extension = BlogExtension(None)
+        extension.on_frontmatter_loaded('thundercats.md', {'blog': True})
+        post = extension.posts[0]
+        self.assertEqual('thundercats.md', post.source_file)
+
+    def test_ignores_non_blog_post(self):
+        extension = BlogExtension(None)
+        extension.on_frontmatter_loaded('exosquad.md', {})
+        self.assertEqual(0, len(extension.posts))
+
+    def test_blog_must_be_boolean(self):
+        extension = BlogExtension(None)
+        self.assertRaises(
+            AbortError, extension.on_frontmatter_loaded, 'animaniacs.md',
+            {'blog': 'crazy'})