fix: add migration to remove old ckeditor table (#61)

Co-authored-by: Fabian Braun <fsbraun@gmx.de>

Author: earthcomfy

README.rst

@@ -59,13 +59,17 @@ Upgrading from djangocms-text-ckeditor
 --------------------------------------
 
 djangocms-text's migrations automatically migrate existing text plugins
-from djangocms-text-ckeditor. All you have to do is:
+from djangocms-text-ckeditor, and clean up old tables. All you have to do is:
 
 * uninstall ``djangocms-text-ckeditor``
 * remove ``djangocms_text_ckeditor`` from ``INSTALLED_APPS``
 * add ``djangocms_text`` to ``INSTALLED_APPS`` (see above)
 * run ``python -m manage migrate djangocms_text``
 
+**Attention**: The migration command also deletes djangocms-text-ckeditor's 
+tables from the database (to avoid referential integrity issues). To be on
+the safe side, make a backup of its content.
+
 When transitioning from CKEditor4 to Tiptap as the rich text editor in your
 project, consider the following points:
 

djangocms_text/cms_plugins.py

@@ -581,7 +581,6 @@ def get_messages(self, request):
     @lru_cache
     def get_child_plugin_candidates(cls, *args, **kwargs):
         """
-
         This method is a class method that returns a list of child plugin candidates for a given slot and page.
 
         Parameters:

djangocms_text/migrations/0004_remove_old_ckeditor_table.py

@@ -0,0 +1,23 @@
+from django.db import migrations
+
+
+def drop_table_if_exists(apps, schema_editor):
+    table_name = "djangocms_text_ckeditor_text"
+    if table_name in schema_editor.connection.introspection.table_names():
+        if schema_editor.connection.vendor == "postgresql":
+            schema_editor.execute("DROP TABLE IF EXISTS djangocms_text_ckeditor_text CASCADE;")
+        else:
+            schema_editor.execute("DROP TABLE IF EXISTS djangocms_text_ckeditor_text;")
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("djangocms_text", "0003_auto_20240702_1409"),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            code=drop_table_if_exists,
+            reverse_code=migrations.RunPython.noop,
+        ),
+    ]