feat: created custom django_cms serializer to be able to handle django cms filer images

Author: mihalikv

CHANGELOG.rst

@@ -2,6 +2,11 @@
 Changelog
 =========
 
+1.0.1 (2022-07-09)
+==================
+
+* Added support for custom serializer
+* Added serializer `django_cms` to be able to serializer `filer.Image`
 
 1.0.0 (2020-09-02)
 ==================

README.rst

@@ -8,10 +8,10 @@ django CMS Transfer
 and import plugin data from a page or a placeholder. It does not support foreign
 key relations and won't import/export related data, such as `media <https://github.com/django-cms/djangocms-transfer/issues/18>`_.
 
-.. note:: 
-        
+.. note::
+
         This project is endorsed by the `django CMS Association <https://www.django-cms.org/en/about-us/>`_.
-        That means that it is officially accepted by the dCA as being in line with our roadmap vision and development/plugin policy. 
+        That means that it is officially accepted by the dCA as being in line with our roadmap vision and development/plugin policy.
         Join us on `Slack <https://www.django-cms.org/slack/>`_.
 
 .. image:: preview.gif
@@ -23,8 +23,8 @@ Contribute to this project and win rewards
 
 Because this is a an open-source project, we welcome everyone to
 `get involved in the project <https://www.django-cms.org/en/contribute/>`_ and
-`receive a reward <https://www.django-cms.org/en/bounty-program/>`_ for their contribution. 
-Become part of a fantastic community and help us make django CMS the best CMS in the world.   
+`receive a reward <https://www.django-cms.org/en/bounty-program/>`_ for their contribution.
+Become part of a fantastic community and help us make django CMS the best CMS in the world.
 
 We'll be delighted to receive your
 feedback in the form of issues and pull requests. Before submitting your
@@ -44,6 +44,14 @@ file for additional dependencies:
 
 |python| |django| |djangocms|
 
+Custom serializer
+------------
+To be able to define custom behavior for various plugins, you can define a custom serializer as following::
+
+    SERIALIZATION_MODULES = {
+        "django_cms": "djangocms_transfer.serializers.django_cms",
+    }
+    DJANGO_CMS_TRANSFER_SERIALIZER = "django_cms"
 
 Installation
 ------------

djangocms_transfer/serializers/__init__.py

@@ -0,0 +1,77 @@
+import base64
+import io
+
+from django.core.files import File as DjangoFile
+from django.core.serializers import base
+from django.core.serializers.python import (
+    Serializer as PythonSerializer,
+    Deserializer as PythonDeserializer,
+    _get_model,
+)
+
+try:
+    from filer.fields.image import FilerImageField
+    from filer.models import Image
+
+    has_filer = True
+except ImportError:
+    has_filer = False
+
+
+class FilerImageFieldSerializer:
+    @classmethod
+    def serialize(cls, field_instance):
+        serializer = Serializer()
+        _image_plugin_data = serializer.serialize((field_instance,))[0]
+        _file_plugin_data = serializer.serialize(
+            (field_instance.file_ptr,), fields=["original_filename", "mime_type"]
+        )[0]
+        base64_image = base64.b64encode(field_instance.file.read())
+
+        _plugin_data = _image_plugin_data["fields"]
+        _plugin_data.update(_file_plugin_data["fields"])
+        _plugin_data["file_content"] = base64_image.decode()
+        return _plugin_data
+
+    @classmethod
+    def deserialize(cls, serialized_data):
+        base64_image = base64.b64decode(serialized_data.pop("file_content"))
+
+        filename = serialized_data["original_filename"]
+        file_obj = DjangoFile(io.BytesIO(base64_image), name=filename)
+        image = Image.objects.create(
+            **serialized_data,
+            file=file_obj,
+        )
+
+        return image.pk
+
+
+class Serializer(PythonSerializer):
+    def handle_fk_field(self, obj, field):
+        if has_filer and isinstance(field, FilerImageField):
+            field_instance = getattr(obj, field.name)
+            self._current[field.name] = FilerImageFieldSerializer.serialize(
+                field_instance
+            )
+        else:
+            super(Serializer, self).handle_fk_field(obj, field)
+
+
+def Deserializer(object_list, **options):
+    for d in object_list:
+        # Look up the model and starting build a dict of data for it.
+        try:
+            Model = _get_model(d["model"])
+        except base.DeserializationError:
+            if options["ignorenonexistent"]:
+                continue
+            else:
+                raise
+        for (field_name, field_value) in d["fields"].items():
+            field = Model._meta.get_field(field_name)
+            if has_filer and isinstance(field, FilerImageField):
+                value = FilerImageFieldSerializer.deserialize(field_value)
+                d["fields"][field_name] = value
+
+    yield from PythonDeserializer(object_list, **options)