Allow loading template from iterable

flask/templating.py

@@ -109,17 +109,19 @@ def _render(template, context, app):
     return rv
 
 
-def render_template(template_name, **context):
+def render_template(template_name_or_list, **context):
     """Renders a template from the template folder with the given
     context.
 
-    :param template_name: the name of the template to be rendered
+    :param template_name_or_list: the name of the template to be
+                                  rendered, or an iterable with template names
+                                  the first one existing will be rendered
     :param context: the variables that should be available in the
                     context of the template.
     """
     ctx = _request_ctx_stack.top
     ctx.app.update_template_context(context)
-    return _render(ctx.app.jinja_env.get_template(template_name),
+    return _render(ctx.app.jinja_env.get_or_select_template(template_name_or_list),
                    context, ctx.app)
 
 

flask/testsuite/templating.py

@@ -178,6 +178,25 @@ class TemplatingTestCase(FlaskTestCase):
         self.assert_equal(rv.data, 'Hello Custom World!')
 
 
+    def test_iterable_loader(self):
+        app = flask.Flask(__name__)
+        @app.context_processor
+        def context_processor():
+            return {'whiskey': 'Jameson'}
+        @app.route('/')
+        def index():
+            return flask.render_template(
+                ['no_template.xml', # should skip this one
+                'simple_template.html', # should render this
+                'context_template.html'],
+                value=23)
+
+        rv = app.test_client().get('/')
+        self.assert_equal(rv.data, '<h1>Jameson</h1>')
+
+
+
+
 def suite():
     suite = unittest.TestSuite()
     suite.addTest(unittest.makeSuite(TemplatingTestCase))