openedx · kenclary · Jul 20, 2023 · Jun 29, 2023 · bradenmacdonald · Jul 19, 2023
diff --git a/openedx/core/djangoapps/content_libraries/tests/base.py b/openedx/core/djangoapps/content_libraries/tests/base.py
@@ -49,6 +49,7 @@
 URL_BLOCK_RENDER_VIEW = '/api/xblock/v2/xblocks/{block_key}/view/{view_name}/'
 URL_BLOCK_GET_HANDLER_URL = '/api/xblock/v2/xblocks/{block_key}/handler_url/{handler_name}/'
 URL_BLOCK_METADATA_URL = '/api/xblock/v2/xblocks/{block_key}/'
+URL_BLOCK_FIELDS_URL = '/api/xblock/v2/xblocks/{block_key}/fields/'
 URL_BLOCK_XBLOCK_HANDLER = '/api/xblock/v2/xblocks/{block_key}/handler/{user_id}-{secure_token}/{handler_name}/'
 
 

diff --git a/openedx/core/djangoapps/content_libraries/tests/test_runtime.py b/openedx/core/djangoapps/content_libraries/tests/test_runtime.py
@@ -21,6 +21,7 @@
     URL_BLOCK_RENDER_VIEW,
     URL_BLOCK_GET_HANDLER_URL,
     URL_BLOCK_METADATA_URL,
+    URL_BLOCK_FIELDS_URL,
 )
 from openedx.core.djangoapps.content_libraries.tests.user_state_block import UserStateTestBlock
 from openedx.core.djangoapps.content_libraries.constants import COMPLEX, ALL_RIGHTS_RESERVED, CC_4_BY
@@ -42,6 +43,9 @@ def setUp(self):
         self.student_a = UserFactory.create(username="Alice", email="[email protected]", password="edx")
         self.student_b = UserFactory.create(username="Bob", email="[email protected]", password="edx")
 
+        # staff user
+        self.staff_user = UserFactory(password="edx", is_staff=True)
+
         # Create a collection using Blockstore API directly only because there
         # is not yet any Studio REST API for doing so:
         self.collection = blockstore_api.create_collection("Content Library Test Collection")
@@ -182,6 +186,43 @@ def test_xblock_metadata(self):
         assert metadata_view_result.data['student_view_data'] is None
         # Capa doesn't provide student_view_data
 
+    @skip_unless_cms  # modifying blocks only works properly in Studio
+    def test_xblock_fields(self):
+        """
+        Test the XBlock fields API
+        """
+        # act as staff:
+        client = APIClient()
+        client.login(username=self.staff_user.username, password='edx')
+
+        # create/save a block using the library APIs first
+        unit_block_key = library_api.create_library_block(self.library.key, "unit", "fields-u1").usage_key
+        block_key = library_api.create_library_block_child(unit_block_key, "html", "fields-p1").usage_key
+        new_olx = """
+        <html display_name="New Text Block">
+            <p>This is some <strong>HTML</strong>.</p>
+        </html>
+        """.strip()
+        library_api.set_library_block_olx(block_key, new_olx)
+        library_api.publish_changes(self.library.key)
+
+        # Check the GET API for the block:
+        fields_get_result = client.get(URL_BLOCK_FIELDS_URL.format(block_key=block_key))
+        assert fields_get_result.data['display_name'] == 'New Text Block'
+        assert fields_get_result.data['data'].strip() == '<p>This is some <strong>HTML</strong>.</p>'
+        assert fields_get_result.data['metadata']['display_name'] == 'New Text Block'
+
+        # Check the POST API for the block:
+        fields_post_result = client.post(URL_BLOCK_FIELDS_URL.format(block_key=block_key), data={
+            'data': '<p>test</p>',
+            'metadata': {
+                'display_name': 'New Display Name',
+            }
+        }, format='json')
+        block_saved = xblock_api.load_block(block_key, self.staff_user)
+        assert block_saved.data == '\n<p>test</p>\n'
+        assert xblock_api.get_block_display_name(block_saved) == 'New Display Name'
+
 
 @requires_blockstore
 class ContentLibraryRuntimeBServiceTest(ContentLibraryRuntimeTestMixin, TestCase):

diff --git a/openedx/core/djangoapps/xblock/rest_api/urls.py b/openedx/core/djangoapps/xblock/rest_api/urls.py
@@ -15,6 +15,8 @@
         path('xblocks/<str:usage_key_str>/', include([
             # get metadata about an XBlock:
             path('', views.block_metadata),
+            # get/post full json fields of an XBlock:
+            path('fields/', views.BlockFieldsView.as_view()),
             # render one of this XBlock's views (e.g. student_view)
             re_path(r'^view/(?P<view_name>[\w\-]+)/$', views.render_block_view),
             # get the URL needed to call this XBlock's handlers

diff --git a/openedx/core/djangoapps/xblock/rest_api/views.py b/openedx/core/djangoapps/xblock/rest_api/views.py
@@ -1,25 +1,28 @@
 """
 Views that implement a RESTful API for interacting with XBlocks.
-
-Note that these views are only for interacting with existing blocks. Other
-Studio APIs cover use cases like adding/deleting/editing blocks.
 """
 
+from common.djangoapps.util.json_request import JsonResponse
 from corsheaders.signals import check_request_enabled
 from django.contrib.auth import get_user_model
+from django.db.transaction import atomic
 from django.http import Http404
+from django.utils.translation import gettext as _
 from django.views.decorators.clickjacking import xframe_options_exempt
 from django.views.decorators.csrf import csrf_exempt
 from rest_framework import permissions
 from rest_framework.decorators import api_view, permission_classes  # lint-amnesty, pylint: disable=unused-import
 from rest_framework.exceptions import PermissionDenied, AuthenticationFailed, NotFound
 from rest_framework.response import Response
+from rest_framework.views import APIView
 from xblock.django.request import DjangoWebobRequest, webob_to_django_response
+from xblock.fields import Scope
 
 from opaque_keys import InvalidKeyError
 from opaque_keys.edx.keys import UsageKey
 from openedx.core.lib.api.view_utils import view_auth_classes
 from ..api import (
+    get_block_display_name,
     get_block_metadata,
     get_handler_url as _get_handler_url,
     load_block,
@@ -168,3 +171,86 @@ def cors_allow_xblock_handler(sender, request, **kwargs):  # lint-amnesty, pylin
 
 
 check_request_enabled.connect(cors_allow_xblock_handler)
+
+
+@view_auth_classes()
+class BlockFieldsView(APIView):
+    """
+    View to get/edit the field values of an XBlock as JSON (in the v2 runtime)
+
+    This class mimics the functionality of xblock_handler in block.py (for v1 xblocks), but for v2 xblocks.
+    However, it only implements the exact subset of functionality needed to support the v2 editors (from
+    the frontend-lib-content-components project). As such, it only supports GET and POST, and only the
+    POSTing of data/metadata fields.
+    """
-    View to get/edit the field values of an XBlock as JSON (in the v2 runtime)
-
-    This class mimics the functionality of xblock_handler in block.py (for v1 xblocks), but for v2 xblocks.
-    However, it only implements the exact subset of functionality needed to support the v2 editors (from
-    the frontend-lib-content-components project). As such, it only supports GET and POST, and only the
-    POSTing of data/metadata fields.
-    """
+    View for the field values of an XBlock, returned as JSON.
+
+    This class mimics the functionality of the v1 xblock_handler in block.py.
+    However, it only implements the exact subset of functionality needed to support xblock editing, for a single xblock which has no children blocks. As such, it only supports GET and POST.
+    """
-    View to get/edit the field values of an XBlock as JSON (in the v2 runtime)
-
-    This class mimics the functionality of xblock_handler in block.py (for v1 xblocks), but for v2 xblocks.
-    However, it only implements the exact subset of functionality needed to support the v2 editors (from
-    the frontend-lib-content-components project). As such, it only supports GET and POST, and only the
-    POSTing of data/metadata fields.
-    """
+    View for the field values of an XBlock, returned as JSON.
+
+    This class mimics the functionality of the v1 xblock_handler in block.py.
+    However, it only implements the exact subset of functionality needed to support xblock editing, for a single xblock which has no children blocks. As such, it only supports GET and POST.
+    """
+
+    @atomic
+    def get(self, request, usage_key_str):
+        """
+        retrieves the xblock, returning display_name, data, and metadata
+        """
+        try:
+            usage_key = UsageKey.from_string(usage_key_str)
+        except InvalidKeyError as e:
+            raise NotFound(invalid_not_found_fmt.format(usage_key=usage_key_str)) from e
+
+        block = load_block(usage_key, request.user)
+        block_dict = {
+            "display_name": get_block_display_name(block),  # potentially duplicated from metadata
+            "data": block.data,
+            "metadata": block.get_explicitly_set_fields_by_scope(Scope.settings),
+        }
+        return Response(block_dict)
+
+    @atomic
+    def post(self, request, usage_key_str):
+        """
+        edits the xblock, saving changes to data and metadata only (display_name included in metadata)
+        """
+        try:
+            usage_key = UsageKey.from_string(usage_key_str)
+        except InvalidKeyError as e:
+            raise NotFound(invalid_not_found_fmt.format(usage_key=usage_key_str)) from e
+
+        user = request.user
+        block = load_block(usage_key, user)
+        data = request.data.get("data")
+        metadata = request.data.get("metadata")
+
+        old_metadata = block.get_explicitly_set_fields_by_scope(Scope.settings)
+        old_content = block.get_explicitly_set_fields_by_scope(Scope.content)
+
+        block.data = data
+
+        # update existing metadata with submitted metadata (which can be partial)
+        # IMPORTANT NOTE: if the client passed 'null' (None) for a piece of metadata that means 'remove it'.
+        if metadata is not None:
+            for metadata_key, value in metadata.items():
+                field = block.fields[metadata_key]
+
+                if value is None:
+                    field.delete_from(block)
+                else:
+                    try:
+                        value = field.from_json(value)
+                    except ValueError as verr:
+                        reason = _("Invalid data")
+                        if str(verr):
+                            reason = _("Invalid data ({details})").format(
+                                details=str(verr)
+                            )
+                        return JsonResponse({"error": reason}, 400)
+
+                    field.write_to(block, value)
+
+        if callable(getattr(block, "editor_saved", None)):
+            block.editor_saved(user, old_metadata, old_content)
+
+        # Save after the callback so any changes made in the callback will get persisted.
+        block.save()
+
+        return Response({
+            "id": str(block.location),
+            "data": data,
+            "metadata": block.get_explicitly_set_fields_by_scope(Scope.settings),
+        })
diff --git a/openedx/core/djangoapps/xblock/runtime/blockstore_runtime.py b/openedx/core/djangoapps/xblock/runtime/blockstore_runtime.py
@@ -14,13 +14,13 @@
 from openedx.core.djangoapps.xblock.learning_context.manager import get_learning_context_impl
 from openedx.core.djangoapps.xblock.runtime.runtime import XBlockRuntime
 from openedx.core.djangoapps.xblock.runtime.olx_parsing import parse_xblock_include, BundleFormatException
-from openedx.core.djangoapps.xblock.runtime.serializer import serialize_xblock
 from openedx.core.djangolib.blockstore_cache import (
     BundleCache,
     get_bundle_file_data_with_cache,
     get_bundle_file_metadata_with_cache,
 )
 from openedx.core.lib import blockstore_api
+from openedx.core.lib.xblock_serializer.api import serialize_modulestore_block_for_blockstore
 
 log = logging.getLogger(__name__)
 
@@ -133,7 +133,9 @@ def save_block(self, block):
             if not learning_context.can_edit_block(self.user, block.scope_ids.usage_id):
                 log.warning("User %s does not have permission to edit %s", self.user.username, block.scope_ids.usage_id)
                 raise RuntimeError("You do not have permission to edit this XBlock")
-        olx_str, static_files = serialize_xblock(block)
+        serialized = serialize_modulestore_block_for_blockstore(block)
+        olx_str = serialized.olx_str
+        static_files = serialized.static_files
         # Write the OLX file to the bundle:
         draft_uuid = blockstore_api.get_or_create_bundle_draft(
             definition_key.bundle_uuid, definition_key.draft_name

diff --git a/openedx/core/djangoapps/xblock/runtime/serializer.py b/openedx/core/djangoapps/xblock/runtime/serializer.py
diff --git a/openedx/core/lib/xblock_serializer/utils.py b/openedx/core/lib/xblock_serializer/utils.py
@@ -45,7 +45,8 @@ def rewrite_absolute_static_urls(text, course_id):
         /static/SCI_1.2_Image_.png
     format for consistency and portability.
     """
-    assert isinstance(course_id, CourseKey)
+    if not course_id.is_course:
+        return text  # We can't rewrite URLs for libraries, which don't have "Files & Uploads".
     asset_full_url_re = r'https?://[^/]+/(?P<maybe_asset_key>[^\s\'"&]+)'
 
     def check_asset_key(match_obj):