From f82d61e6948ada7331b1787a17dd5d9a7d9e176c Mon Sep 17 00:00:00 2001
From: Thomas NOEL <tnoel@entrouvert.com>
Date: Wed, 5 Apr 2017 15:43:30 +0200
Subject: [PATCH] add error template on cell renderer (#15768)

---
 combo/data/models.py                               |  8 +++-
 .../templates/combo/cell-template-error.html       | 10 +++++
 tests/test_cells.py                                | 48 ++++++++++++++++++++++
 3 files changed, 65 insertions(+), 1 deletion(-)
 create mode 100644 combo/public/templates/combo/cell-template-error.html

diff --git a/combo/data/models.py b/combo/data/models.py
index 3382597..154d6fe 100644
--- a/combo/data/models.py
+++ b/combo/data/models.py
@@ -462,7 +462,13 @@ class CellBase(models.Model):
         if self.slug:
             template_names.append('combo/cells/%s/%s' % (self.slug, base_template_name))
         template_names.reverse()
-        tmpl = template.loader.select_template(template_names)
+        try:
+            tmpl = template.loader.select_template(template_names)
+        except (template.TemplateDoesNotExist, template.TemplateSyntaxError) as exception:
+            tmpl = template.loader.get_template('combo/cell-template-error.html')
+            context['exception'] = exception
+            context['exception_type'] = exception.__class__.__name__
+            context['template_names'] = template_names
         return tmpl.render(context)
 
     def modify_global_context(self, context, request=None):
diff --git a/combo/public/templates/combo/cell-template-error.html b/combo/public/templates/combo/cell-template-error.html
new file mode 100644
index 0000000..fbf074a
--- /dev/null
+++ b/combo/public/templates/combo/cell-template-error.html
@@ -0,0 +1,10 @@
+{% load i18n %}
+{% trans "template error:" %} {{ exception_type }}
+
+{% if debug %}
+<pre>
+{% trans "cell:" %} {{ cell }}
+{% trans "template names:" %} {{ template_names }}
+{% trans "exception message:" %} {{ exception }}
+</pre>
+{% endif %}
diff --git a/tests/test_cells.py b/tests/test_cells.py
index 3b15fd9..07edf97 100644
--- a/tests/test_cells.py
+++ b/tests/test_cells.py
@@ -10,6 +10,7 @@ from django.template import Context
 from django.test import override_settings
 from django.test.client import RequestFactory
 from django.contrib.auth.models import User
+from django.core.urlresolvers import reverse
 
 from combo.utils import NothingInCacheException
 
@@ -231,3 +232,50 @@ def test_config_json_cell():
             context = cell.get_cell_extra_context(Context({'request': request}))
             assert context['json'] == {'hello': 'world'}
             assert context['parameters'] == {'blah': 'plop'}
+
+def test_cell_template_error(app):
+    Page.objects.all().delete()
+    page = Page(title='example page', slug='example-page')
+    page.save()
+
+    with override_settings(JSON_CELL_TYPES={'foobar': {'name': 'Foobar', 'url': 'http://test/'},
+                                            'badsyntax': {'name': 'Error', 'url': 'http://test/'}},
+                           TEMPLATE_DIRS=['%s/templates-1' % os.path.abspath(os.path.dirname(__file__))]):
+        # missing template
+        cell = ConfigJsonCell()
+        cell.key = 'foobar'
+        cell.page = page
+        cell.order = 0
+        cell.save()
+
+        url = reverse('combo-public-ajax-page-cell', kwargs={'page_pk': page.id,
+                                                             'cell_reference': cell.get_reference()})
+        data = {'data': []}
+
+        with mock.patch('combo.utils.requests.get') as requests_get:
+            requests_get.return_value = mock.Mock(content=json.dumps(data), status_code=200)
+            with override_settings(DEBUG=False):
+                resp_body = app.get(url).body.strip()
+                assert resp_body == 'template error: TemplateDoesNotExist'
+            with override_settings(DEBUG=True):
+                resp_body = app.get(url).body.strip()
+                assert resp_body.startswith('template error: TemplateDoesNotExist')
+                assert 'cell: config json cell' in resp_body
+                assert 'template names: [' in resp_body
+                assert 'exception message: combo/json/foobar.html, combo/configjsoncell.html' in resp_body
+
+        # syntax error (see badsyntax.html)
+        cell.key = 'badsyntax'
+        cell.save()
+        with mock.patch('combo.utils.requests.get') as requests_get:
+            requests_get.return_value = mock.Mock(content=json.dumps(data), status_code=200)
+            with override_settings(DEBUG=False):
+                resp_body = app.get(url).body.strip()
+                assert resp_body == 'template error: TemplateSyntaxError'
+            with override_settings(DEBUG=True):
+                resp_body = app.get(url).body.strip()
+                assert resp_body.startswith('template error: TemplateSyntaxError')
+                assert 'cell: config json cell' in resp_body
+                assert 'template names: [' in resp_body
+                assert 'exception message: Invalid block tag' in resp_body
+                assert 'foo_boom_bar' in resp_body
-- 
2.11.0