Issue #86: Bug Fix: Ensure that context providers can exist without context data

hyde/model.py

@@ -95,13 +95,22 @@ class Context(object):
         context = {}
         try:
             context.update(ctx.data.__dict__)
-            for provider_name, resource_name in ctx.providers.__dict__.items():
-                res = File(Folder(sitepath).child(resource_name))
-                if res.exists:
-                    context[provider_name] = Expando(yaml.load(res.read_all()))
         except AttributeError:
             # No context data found
             pass
+
+        providers = {}
+        try:
+            providers.update(ctx.providers.__dict__)
+        except AttributeError:
+            # No providers found
+            pass
+
+        for provider_name, resource_name in providers.items():
+            res = File(Folder(sitepath).child(resource_name))
+            if res.exists:
+                context[provider_name] = Expando(yaml.load(res.read_all()))
+
         return context
 
 class Dependents(IterableUserDict):

hyde/tests/test_generate.py

@@ -162,6 +162,47 @@ main:
         assert "articles" in out
         assert "projects" in out
 
+    def test_context_providers_no_data(self):
+        site = Site(TEST_SITE, Config(TEST_SITE, config_dict={
+            "context": {
+                "providers": {
+                    "nav": "nav.yaml"
+                }
+            }
+        }))
+        nav = """
+main:
+    - home
+    - articles
+    - projects
+"""
+        text = """
+{% extends "base.html" %}
+
+{% block main %}
+    {{nav}}
+    {% for item in nav.main %}
+    {{item}}
+    {% endfor %}
+    abc = {{ abc }}
+    Hi!
+
+    I am a test template to make sure jinja2 generation works well with hyde.
+    {{resource.name}}
+{% endblock %}
+"""
+        File(TEST_SITE.child('nav.yaml')).write(nav)
+        site.load()
+        resource = site.content.resource_from_path(TEST_SITE.child('content/about.html'))
+        gen = Generator(site)
+        resource.source_file.write(text)
+        gen.generate_all()
+        target = File(site.config.deploy_root_path.child(resource.name))
+        out = target.read_all()
+        assert "home" in out
+        assert "articles" in out
+        assert "projects" in out
+
     def test_context_providers_equivalence(self):
         import yaml
         events = """