From 068e97f43f8d4d59441ba05315e768a3526f6bfe Mon Sep 17 00:00:00 2001
From: Matthias Kestenholz <mk@feinheit.ch>
Date: Fri, 7 Jun 2024 09:38:18 +0200
Subject: [PATCH] Add an unregister method to renderers

---
 CHANGELOG.rst                         |  4 ++
 feincms3/renderer.py                  | 17 ++++++
 tests/testapp/test_region_renderer.py | 76 +++++++++++++++++++++++++++
 3 files changed, 97 insertions(+)

diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index abbb9d1..6e1aad6 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -6,6 +6,10 @@ Change log
 Next version
 ~~~~~~~~~~~~
 
+- Added ``RegionRenderer.copy()`` and ``RegionRenderer.unregister`` methods to
+  allow modifying existing renderers without having to reach into internal
+  attributes.
+
 
 5.1 (2024-06-06)
 ~~~~~~~~~~~~~~~~
diff --git a/feincms3/renderer.py b/feincms3/renderer.py
index ce4081c..40ee11f 100644
--- a/feincms3/renderer.py
+++ b/feincms3/renderer.py
@@ -108,6 +108,23 @@ def copy(self):
         obj._marks = dict(self._marks)
         return obj
 
+    def unregister(self, *plugins, keep=()):
+        if bool(plugins) == bool(keep):
+            raise ImproperlyConfigured(
+                "Only ever provide either a list of plugins or a list of plugins to keep."
+            )
+
+        test = (
+            (lambda cls: not issubclass(cls, plugins))
+            if plugins
+            else (lambda cls: issubclass(cls, tuple(keep)))
+        )
+
+        self._fetch = [p for p in self._fetch if test(p)]
+        self._renderers = {p: r for p, r in self._renderers.items() if test(p)}
+        self._subregions = {p: s for p, s in self._subregions.items() if test(p)}
+        self._marks = {p: m for p, m in self._marks.items() if test(p)}
+
     def register(
         self,
         plugin,
diff --git a/tests/testapp/test_region_renderer.py b/tests/testapp/test_region_renderer.py
index 67e0e3a..671a41a 100644
--- a/tests/testapp/test_region_renderer.py
+++ b/tests/testapp/test_region_renderer.py
@@ -147,3 +147,79 @@ def test_invalid_renderer(self):
             ImproperlyConfigured, r"has less than the two required arguments"
         ):
             r.register(1, lambda plugin: "")
+
+    def test_register_unregister(self):
+        richtext_renderer = template_renderer("renderer/richtext.html")
+        html_renderer = template_renderer("renderer/html.html")
+
+        renderer = RegionRenderer()
+        renderer.register(RichText, richtext_renderer)
+        renderer.register(HTML, html_renderer)
+
+        r2 = renderer.copy()
+        r2.unregister(RichText)
+
+        r3 = renderer.copy()
+        r3.unregister(keep=[HTML])
+
+        self.assertEqual(renderer._fetch, [RichText, HTML])
+        self.assertEqual(
+            renderer._renderers,
+            {
+                RichText: richtext_renderer,
+                HTML: html_renderer,
+            },
+        )
+        self.assertEqual(
+            renderer._subregions,
+            {RichText: "default", HTML: "default"},
+        )
+        self.assertEqual(
+            renderer._subregions,
+            {RichText: "default", HTML: "default"},
+        )
+        self.assertEqual(
+            renderer._marks,
+            {RichText: {"default"}, HTML: {"default"}},
+        )
+
+        self.assertEqual(
+            r2._renderers,
+            {
+                HTML: html_renderer,
+            },
+        )
+        self.assertEqual(
+            r2._subregions,
+            {HTML: "default"},
+        )
+        self.assertEqual(
+            r2._subregions,
+            {HTML: "default"},
+        )
+        self.assertEqual(
+            r2._marks,
+            {HTML: {"default"}},
+        )
+
+        self.assertEqual(
+            r3._renderers,
+            {
+                HTML: html_renderer,
+            },
+        )
+        self.assertEqual(
+            r3._subregions,
+            {HTML: "default"},
+        )
+        self.assertEqual(
+            r3._subregions,
+            {HTML: "default"},
+        )
+        self.assertEqual(
+            r3._marks,
+            {HTML: {"default"}},
+        )
+
+        with self.assertRaises(ImproperlyConfigured):
+            renderer.unregister(HTML, keep=[RichText])