Psycho-rebased branch 77-template-engine-header on top of master

diecutter · Apr 16, 2014 · 3b5752b · 3b5752b
2 parents dcacb19 + f060c7c
commit 3b5752b
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Showing 4 changed files with 93 additions and 14 deletions.
diff --git a/diecutter/service.py b/diecutter/service.py
@@ -13,6 +13,7 @@
 import diecutter
 import diecutter.validators
 import diecutter.utils
+from diecutter.settings import TEMPLATE_ENGINES_MAPPING
 from diecutter.writers import (zip_directory_response,
                                file_response,
                                targz_directory_response)
@@ -40,27 +41,39 @@ def get_resource(self, request):
         """Return the resource object (instance) matching request."""
         raise NotImplementedError()
 
+    def get_engine_factory(self, request, filename=False):
+        """ Returns the class of an engine """
+        param_name = 'diecutter{}filename_template_engine' if filename \
+                     else 'diecutter{}template_engine'
+
+        if param_name.format('_') in request.headers:
+            try:
+                engine_path = TEMPLATE_ENGINES_MAPPING[
+                    request.headers[param_name.format('_')]
+                ]
+            except KeyError:
+                raise HTTPNotAcceptable('Supported template engines: %s'
+                                        % ', '.join(sorted(
+                                            TEMPLATE_ENGINES_MAPPING.keys())))
+        else:
+            engine_path = request.registry.settings[param_name.format('.')]
+
+        config = Configurator(request.registry.settings)
+        engine_factory = config.maybe_dotted(engine_path)
+
+        return engine_factory
+
     def get_engine(self, request):
         """Return configured template engine to render templates."""
-        settings = request.registry.settings
-        config = Configurator(settings)
-        engine_factory_path = settings['diecutter.template_engine']
-        engine_factory = config.maybe_dotted(engine_factory_path)
-        engine = engine_factory()
-        return engine
+        return self.get_engine_factory(request)()
 
     def get_filename_engine(self, request):
         """Return configured template engine to render filenames.
 
         This is not used for dynamic trees.
 
         """
-        settings = request.registry.settings
-        config = Configurator(settings)
-        engine_factory_path = settings['diecutter.filename_template_engine']
-        engine_factory = config.maybe_dotted(engine_factory_path)
-        engine = engine_factory()
-        return engine
+        return self.get_engine_factory(request, filename=True)()
 
     def get_writers(self, request, resource, context):
         """Return iterable of writers."""

diff --git a/diecutter/settings.py b/diecutter/settings.py
@@ -1,8 +1,16 @@
 # -*- coding: utf-8 -*-
 """Parse settings, set defaults."""
 
+#: Mapping between engine name and engines.
+#: Used when getting the engine name from the user.
+TEMPLATE_ENGINES_MAPPING = {
+    'django': 'piecutter.engines.django:DjangoEngine',
+    'jinja2': 'piecutter.engines.jinja:Jinja2Engine',
+    'filename': 'piecutter.engines.filename:FilenameEngine',
+}
+
 #: Default values for settings.
-defaults = {
+DEFAULTS = {
     'diecutter.service': 'diecutter.local:LocalService',
     'diecutter.template_engine': 'piecutter.engines.jinja:Jinja2Engine',
     'diecutter.filename_template_engine': 'piecutter.engines.filename'
@@ -17,6 +25,6 @@ def normalize(settings={}):
 
     """
     normalized = settings.copy()
-    for key, value in defaults.items():
+    for key, value in DEFAULTS.items():
         normalized.setdefault(key, value)
     return normalized
diff --git a/diecutter/tests/engine_selector.py b/diecutter/tests/engine_selector.py
@@ -0,0 +1,37 @@
+# -*- coding: utf-8 -*-
+"""Tests around the functions to select templates."""
+import unittest
+try:
+    from unittest import mock
+except ImportError:
+    import mock
+
+from piecutter.engines.django import DjangoEngine
+from piecutter.engines.jinja import Jinja2Engine
+from pyramid.httpexceptions import HTTPNotAcceptable
+
+from diecutter.service import Service
+from diecutter.settings import DEFAULTS
+
+
+class EngineSelectorTestCase(unittest.TestCase):
+    """Tests around the functions to select templates."""
+    def setUp(self):
+        self.service = Service()
+
+    def test_engine_factory(self):
+        request = mock.Mock()
+        request.registry = mock.Mock()
+        request.registry.settings = DEFAULTS
+
+        request.headers = {}
+        self.assertEquals(self.service.get_engine_factory(request),
+                          Jinja2Engine)
+
+        request.headers = {"diecutter_template_engine": 'django'}
+        self.assertEquals(self.service.get_engine_factory(request),
+                          DjangoEngine)
+
+        request.headers = {"diecutter_template_engine": "<invalid>"}
+        self.assertRaises(HTTPNotAcceptable,
+                          self.service.get_engine_factory, request)
diff --git a/diecutter/tests/functional.py b/diecutter/tests/functional.py
@@ -120,6 +120,27 @@ def test_post_file(self):
         # Check content.
         self.assertEqual(response.body, "Hello world!")
 
+    def test_header_for_specific_template_engine(self):
+        """ Try to use the Django template engine by setting a header. """
+        content = "Hello {{ who }}!"
+        server_filename = os.path.join(self.template_dir.path, 'hello')
+        open(server_filename, 'w').write(content)
+        headers = {'diecutter_template_engine': 'django'}
+        # Perform request.
+        response = self.app.post('/hello', {'who': 'world'},
+                                 headers=headers, status=200)
+        # Check content.
+        self.assertEqual(response.body, "Hello world!")
+
+    def test_invalid_header_template_engine(self):
+        """ Try to us an invalid template engine by setting a header. """
+        content = "Hello {{ who }}!"
+        server_filename = os.path.join(self.template_dir.path, 'hello')
+        open(server_filename, 'w').write(content)
+        headers = {'diecutter_template_engine': 'invalid'}
+        # Perform request, and check if the status code is 406
+        self.app.post('/hello', {'who': 'world'}, headers=headers, status=406)
+
     def test_post_directory_targz(self):
         """POST context for directory returns TAR.GZ file content."""
         # Setup.