feat: CRUD API for Taxonomy Tags [FC-0036] (#96)

* Implements add, update, delete taxonomy tag api/rest + tests
* resyncs ObjectTags when tag added or updated.
* Updates Taxonomy Tags permissions to use Taxonomy permissions
* Bumps version to 0.2.6

openedx_learning/__init__.py

@@ -1,4 +1,4 @@
 """
 Open edX Learning ("Learning Core").
 """
-__version__ = "0.2.5"
+__version__ = "0.2.6"

openedx_tagging/core/tagging/api.py

@@ -135,6 +135,7 @@ def resync_object_tags(object_tags: QuerySet | None = None) -> int:
         if changed:
             object_tag.save()
             num_changed += 1
+
     return num_changed
 
 
@@ -315,3 +316,57 @@ def autocomplete_tags(
         # remove repeats
         .distinct()
     )
+
+
+def add_tag_to_taxonomy(
+    taxonomy: Taxonomy,
+    tag: str,
+    parent_tag_value: str | None = None,
+    external_id: str | None = None
+) -> Tag:
+    """
+    Adds a new Tag to provided Taxonomy. If a Tag already exists in the
+    Taxonomy, an exception is raised, otherwise the newly created
+    Tag is returned
+    """
+    taxonomy = taxonomy.cast()
+    new_tag = taxonomy.add_tag(tag, parent_tag_value, external_id)
+
+    # Resync all related ObjectTags after creating new Tag to
+    # to ensure any existing ObjectTags with the same value will
+    # be linked to the new Tag
+    object_tags = taxonomy.objecttag_set.all()
+    resync_object_tags(object_tags)
+
+    return new_tag
+
+
+def update_tag_in_taxonomy(taxonomy: Taxonomy, tag: str, new_value: str):
+    """
+    Update a Tag that belongs to a Taxonomy. The related ObjectTags are
+    updated accordingly.
+
+    Currently only supports updating the Tag value.
+    """
+    taxonomy = taxonomy.cast()
+    updated_tag = taxonomy.update_tag(tag, new_value)
+
+    # Resync all related ObjectTags to update to the new Tag value
+    object_tags = taxonomy.objecttag_set.all()
+    resync_object_tags(object_tags)
+
+    return updated_tag
+
+
+def delete_tags_from_taxonomy(
+    taxonomy: Taxonomy,
+    tags: list[str],
+    with_subtags: bool
+):
+    """
+    Delete Tags that belong to a Taxonomy. If any of the Tags have children and
+    the `with_subtags` is not set to `True` it will fail, otherwise
+    the sub-tags will be deleted as well.
+    """
+    taxonomy = taxonomy.cast()
+    taxonomy.delete_tags(tags, with_subtags)

openedx_tagging/core/tagging/models/base.py

@@ -342,6 +342,105 @@ def get_filtered_tags(
 
         return tag_set.order_by("value", "id")
 
+    def add_tag(
+        self,
+        tag_value: str,
+        parent_tag_value: str | None = None,
+        external_id: str | None = None
+    ) -> Tag:
+        """
+        Add new Tag to Taxonomy. If an existing Tag with the `tag_value` already
+        exists in the Taxonomy, an exception is raised, otherwise the newly
+        created Tag is returned
+        """
+        self.check_casted()
+
+        if self.allow_free_text:
+            raise ValueError(
+                "add_tag() doesn't work for free text taxonomies. They don't use Tag instances."
+            )
+
+        if self.system_defined:
+            raise ValueError(
+                "add_tag() doesn't work for system defined taxonomies. They cannot be modified."
+            )
+
+        if self.tag_set.filter(value__iexact=tag_value).exists():
+            raise ValueError(f"Tag with value '{tag_value}' already exists for taxonomy.")
+
+        parent = None
+        if parent_tag_value:
+            # Get parent tag from taxonomy, raises Tag.DoesNotExist if doesn't
+            # belong to taxonomy
+            parent = self.tag_set.get(value__iexact=parent_tag_value)
+
+        tag = Tag.objects.create(
+            taxonomy=self, value=tag_value, parent=parent, external_id=external_id
+        )
+
+        return tag
+
+    def update_tag(self, tag: str, new_value: str) -> Tag:
+        """
+        Update an existing Tag in Taxonomy and return it. Currently only
+        supports updating the Tag's value.
+        """
+        self.check_casted()
+
+        if self.allow_free_text:
+            raise ValueError(
+                "update_tag() doesn't work for free text taxonomies. They don't use Tag instances."
+            )
+
+        if self.system_defined:
+            raise ValueError(
+                "update_tag() doesn't work for system defined taxonomies. They cannot be modified."
+            )
+
+        # Update Tag instance with new value, raises Tag.DoesNotExist if
+        # tag doesn't belong to taxonomy
+        tag_to_update = self.tag_set.get(value__iexact=tag)
+        tag_to_update.value = new_value
+        tag_to_update.save()
+        return tag_to_update
+
+    def delete_tags(self, tags: List[str], with_subtags: bool = False):
+        """
+        Delete the Taxonomy Tags provided. If any of them have children and
+        the `with_subtags` is not set to `True` it will fail, otherwise
+        the sub-tags will be deleted as well.
+        """
+        self.check_casted()
+
+        if self.allow_free_text:
+            raise ValueError(
+                "delete_tags() doesn't work for free text taxonomies. They don't use Tag instances."
+            )
+
+        if self.system_defined:
+            raise ValueError(
+                "delete_tags() doesn't work for system defined taxonomies. They cannot be modified."
+            )
+
+        tags_to_delete = self.tag_set.filter(value__in=tags)
+
+        if tags_to_delete.count() != len(tags):
+            # If they do not match that means there is one or more Tag ID(s)
+            # provided that do not belong to this Taxonomy
+            raise ValueError("Invalid tag id provided or tag id does not belong to taxonomy")
+
+        # Check if any Tag contains subtags (children)
+        contains_children = tags_to_delete.filter(children__isnull=False).distinct().exists()
+
+        if contains_children and not with_subtags:
+            raise ValueError(
+                "Tag(s) contain children, `with_subtags` must be `True` for "
+                "all Tags and their subtags (children) to be deleted."
+            )
+
+        # Delete the Tags with their subtags if any
+        tags_to_delete.delete()
+
     def validate_value(self, value: str) -> bool:
         """
         Check if 'value' is part of this Taxonomy.

openedx_tagging/core/tagging/rest_api/v1/permissions.py

@@ -4,6 +4,8 @@
 import rules  # type: ignore[import]
 from rest_framework.permissions import DjangoObjectPermissions
 
+from ...models import Tag
+
 
 class TaxonomyObjectPermissions(DjangoObjectPermissions):
     """
@@ -35,22 +37,24 @@ class ObjectTagObjectPermissions(DjangoObjectPermissions):
     }
 
 
-class TagListPermissions(DjangoObjectPermissions):
+class TagObjectPermissions(DjangoObjectPermissions):
     """
-    Permissions for Tag object views.
+    Maps each REST API methods to its corresponding Tag permission.
     """
-    def has_permission(self, request, view):
-        """
-        Returns True if the user on the given request is allowed the given view.
-        """
-        if not request.user or (
-            not request.user.is_authenticated and self.authenticated_users_only
-        ):
-            return False
-        return True
+    perms_map = {
+        "GET": ["%(app_label)s.view_%(model_name)s"],
+        "OPTIONS": [],
+        "HEAD": ["%(app_label)s.view_%(model_name)s"],
+        "POST": ["%(app_label)s.add_%(model_name)s"],
+        "PUT": ["%(app_label)s.change_%(model_name)s"],
+        "PATCH": ["%(app_label)s.change_%(model_name)s"],
+        "DELETE": ["%(app_label)s.delete_%(model_name)s"],
+    }
 
+    # This is to handle the special case for GET list of Taxonomy Tags
     def has_object_permission(self, request, view, obj):
         """
         Returns True if the user on the given request is allowed the given view for the given object.
         """
+        obj = obj.taxonomy if isinstance(obj, Tag) else obj
         return rules.has_perm("oel_tagging.list_tag", request.user, obj)

openedx_tagging/core/tagging/rest_api/v1/serializers.py

@@ -1,7 +1,6 @@
 """
 API Serializers for taxonomies
 """
-
 from rest_framework import serializers
 from rest_framework.reverse import reverse
 
@@ -110,6 +109,7 @@ class Meta:
             "value",
             "taxonomy_id",
             "parent_id",
+            "external_id",
             "sub_tags_link",
             "children_count",
         )
@@ -120,11 +120,12 @@ def get_sub_tags_link(self, obj):
         """
         if obj.children.count():
             query_params = f"?parent_tag_id={obj.id}"
+            request = self.context.get("request")
+            url_namespace = request.resolver_match.namespace  # get the namespace, usually "oel_tagging"
             url = (
-                reverse("oel_tagging:taxonomy-tags", args=[str(obj.taxonomy_id)])
+                reverse(f"{url_namespace}:taxonomy-tags", args=[str(obj.taxonomy_id)])
                 + query_params
             )
-            request = self.context.get("request")
             return request.build_absolute_uri(url)
         return None
 
@@ -192,3 +193,33 @@ def get_children_count(self, obj):
         Returns the number of child tags of the given tag.
         """
         return len(obj.sub_tags)
+
+
+class TaxonomyTagCreateBodySerializer(serializers.Serializer):  # pylint: disable=abstract-method
+    """
+    Serializer of the body for the Taxonomy Tags CREATE request
+    """
+
+    tag = serializers.CharField(required=True)
+    parent_tag_value = serializers.CharField(required=False)
+    external_id = serializers.CharField(required=False)
+
+
+class TaxonomyTagUpdateBodySerializer(serializers.Serializer):  # pylint: disable=abstract-method
+    """
+    Serializer of the body for the Taxonomy Tags UPDATE request
+    """
+
+    tag = serializers.CharField(required=True)
+    updated_tag_value = serializers.CharField(required=True)
+
+
+class TaxonomyTagDeleteBodySerializer(serializers.Serializer):  # pylint: disable=abstract-method
+    """
+    Serializer of the body for the Taxonomy Tags DELETE request
+    """
+
+    tags = serializers.ListField(
+        child=serializers.CharField(), required=True
+    )
+    with_subtags = serializers.BooleanField(required=False)