From d49b0d2f58f0b6146fb5987e723bb3db84577c19 Mon Sep 17 00:00:00 2001
From: Mads Jensen <mje@inducks.org>
Date: Sat, 24 Feb 2018 14:33:13 +0100
Subject: [PATCH] Use AppConfig.ready to check for sorl.thumbnail in images
 plugin.

---
 src/wiki/plugins/images/apps.py   |  6 ++++++
 src/wiki/plugins/images/checks.py | 13 +++++++++++++
 src/wiki/plugins/images/models.py |  6 ------
 3 files changed, 19 insertions(+), 6 deletions(-)
 create mode 100644 src/wiki/plugins/images/checks.py

diff --git a/src/wiki/plugins/images/apps.py b/src/wiki/plugins/images/apps.py
index cf4b4af6..c17597f4 100644
--- a/src/wiki/plugins/images/apps.py
+++ b/src/wiki/plugins/images/apps.py
@@ -1,8 +1,14 @@
 from django.apps import AppConfig
 from django.utils.translation import gettext_lazy as _
+from django.core.checks import register
+
+from . import checks
 
 
 class ImagesConfig(AppConfig):
     name = 'wiki.plugins.images'
     verbose_name = _("Wiki images")
     label = 'wiki_images'
+
+    def ready(self):
+        register(checks.check_for_required_installed_apps, checks.Tags.required_installed_apps)
diff --git a/src/wiki/plugins/images/checks.py b/src/wiki/plugins/images/checks.py
new file mode 100644
index 00000000..774eda17
--- /dev/null
+++ b/src/wiki/plugins/images/checks.py
@@ -0,0 +1,13 @@
+from django.apps import apps
+from django.core.checks import Error
+
+
+class Tags:
+    required_installed_apps = "required_installed_apps"
+
+
+def check_for_required_installed_apps(app_configs, **kwargs):
+    errors = []
+    if not apps.is_installed("sorl.thumbnail"):
+        errors.append(Error('needs sorl.thumbnail in INSTALLED_APPS', id='wiki_images.E001'))
+    return errors
diff --git a/src/wiki/plugins/images/models.py b/src/wiki/plugins/images/models.py
index 227adb6b..a594eb02 100644
--- a/src/wiki/plugins/images/models.py
+++ b/src/wiki/plugins/images/models.py
@@ -1,8 +1,6 @@
 import os.path
 
-from django.apps import apps
 from django.conf import settings as django_settings
-from django.core.exceptions import ImproperlyConfigured
 from django.db import models
 from django.db.models import signals
 from django.utils.translation import gettext, gettext_lazy as _
@@ -10,10 +8,6 @@ from wiki.models.pluginbase import RevisionPlugin, RevisionPluginRevision
 
 from . import settings
 
-if not apps.is_installed("sorl.thumbnail"):
-    raise ImproperlyConfigured(
-        'wiki.plugins.images: needs sorl.thumbnail in INSTALLED_APPS')
-
 
 def upload_path(instance, filename):
     # Has to match original extension filename
-- 
2.45.2