feat!: collapse extraneous XBlock mixins

CHANGELOG.rst

@@ -2,11 +2,62 @@
 Change history for XBlock
 =========================
 
-These are notable changes in XBlock.
-
 Unreleased
 ----------
 
+
+3.0.0 - 2024-03-18
+------------------
+
+Various extraneous classes have been removed from the XBlock API, simplifying its implementation
+and making debugging of XBlock instances easier. We believe that most, if not all, XBlock API users
+will be unaffected by this change. Some improvements have also been made to the reference documentation.
+
+Specific changes:
+
+* **Removed:** 
+
+  * ``xblock.XBlockMixin`` (still available as ``xblock.core.XBlockMixin``)
+  * ``xblock.core.SharedBlockBase`` (replaced with ``xblock.core.Blocklike``)
+  * ``xblock.internal.Nameable``
+  * ``xblock.internal.NamedAttributesMetaclass``
+  * ``xblock.django.request.HeadersDict``
+  * ``xblock.fields.XBlockMixin`` (still available as ``xblock.core.XBlockMixin``)
+  * ``xblock.mixins.RuntimeServicesMixin``
+  * ``xblock.mixins.ScopedStorageMixin``
+  * ``xblock.mixins.IndexInfoMixin``
+  * ``xblock.mixins.XmlSerializationMixin``
+  * ``xblock.mixins.HandlersMixin``
+  * ``xblock.mixins.ChildrenModelMetaclass``
+  * ``xblock.mixins.HierarchyMixin``
+  * ``xblock.mixins.ViewsMixin``
+
+* **Added:**
+
+  * ``xblock.core.Blocklike``, the new common ancestor of ``XBlock`` and ``XBlockAside``, and ``XBlockMixin``,
+    replacing ``xblock.core.SharedBlockBase``.
+
+  * New attributes on ``xblock.core.XBlockAside``, each behaving the same as their ``XBlock`` counterpart:
+
+    * ``usage_key``
+    * ``context_key``
+    * ``index_dictionary``
+
+  * Various new attributes on ``xblock.core.XBlockMixin``, encompassing the functionality of these former classes:
+
+    * ``xblock.mixins.IndexInfoMixin``
+    * ``xblock.mixins.XmlSerializationMixin``
+    * ``xblock.mixins.HandlersMixin``
+
+* **Docs**
+
+  * Various docstrings have been improved, some of which are published in the docs.
+  * XBlockAside will now be represented in the API docs, right below XBlock on the "XBlock API" page.
+  * XBlockMixin has been removed from the docs. 
+    It was only ever documented under the "Fields API" page (which didn't make any sense),
+    and it was barely even documented there. We considered adding it back to the "XBlock API" page,
+    but as noted in the class's new docstring, we do not want to encourage any new use of XBlockMixin.
+
 2.0.0 - 2024-02-26
 ------------------
 

docs/conf.py

@@ -128,6 +128,7 @@
     ('py:class', 'aside'),
     ('py:class', 'aside_fn'),
     ('py:class', 'webob.Request'),
+    ('py:class', 'webob.Response'),
 ]
 
 suppress_warnings = [

xblock/__init__.py

@@ -2,29 +2,4 @@
 XBlock Courseware Components
 """
 
-# For backwards compatibility, provide the XBlockMixin in xblock.fields
-# without causing a circular import
-import codecs
-import os
-import warnings
-
-import xblock.core
-import xblock.fields
-
-
-class XBlockMixin(xblock.core.XBlockMixin):
-    """
-    A wrapper around xblock.core.XBlockMixin that provides backwards compatibility for the old location.
-
-    Deprecated.
-    """
-    def __init__(self, *args, **kwargs):
-        warnings.warn("Please use xblock.core.XBlockMixin", DeprecationWarning, stacklevel=2)
-        super().__init__(*args, **kwargs)
-
-
-# For backwards compatibility, provide the XBlockMixin in xblock.fields
-# without causing a circular import
-xblock.fields.XBlockMixin = XBlockMixin
-
-__version__ = '2.0.0'
+__version__ = '3.0.0'