Extend overhangio scorm xblock with custom storage

GN-1174

nau_openedx_extensions/custom_registration_form/context_extender.py

@@ -9,9 +9,9 @@
 from django.core.exceptions import ObjectDoesNotExist
 from django.db import models
 from django.utils.translation import ugettext as _
-from openedx.core.djangoapps.site_configuration import helpers as configuration_helpers  # pylint: disable=import-error
 
 from nau_openedx_extensions.custom_registration_form.models import NauUserExtendedModel
+from nau_openedx_extensions.edxapp_wrapper import site_configuration_helpers as configuration_helpers
 
 log = logging.getLogger(__name__)
 

nau_openedx_extensions/scorm/storage.py

@@ -0,0 +1,89 @@
+"""
+NAU additional configuration of Overhangio scorm xblock for openedx.
+https://github.com/overhangio/openedx-scorm-xblock
+
+On NAU we store the static assets on a S3 bucket.
+By default the Django storage is configured so the user connects and get the files from the
+S3 server / domain.
+But, to make the SCORM score work, we need that the SCORM files need to be delivered on the
+same domain.
+This fixes:
+```
+Error: Unable to aquire LMS API
+```
+
+JS console error:
+```
+Uncaught DOMException: Blocked a frame with origin "https://<bucket_domain>" from accessing a cross-origin frame
+```
+"""
+from django.conf import settings
+from django.utils.module_loading import import_string
+
+from nau_openedx_extensions.edxapp_wrapper import site_configuration_helpers as configuration_helpers
+
+
+def scorm_xblock_storage(xblock):  # pylint: disable=unused-argument
+    """
+    Custom SCORM storage configuration.
+    So S3 storage to save the bucket
+    """
+    return get_scorm_storage() if hasattr(settings, 'NAU_SCORM_XBLOCK_STORAGE') else None
+
+
+def get_scorm_storage():
+    """
+    Return the configured django storage backend for SCORM xblock.
+    It requires the `NAU_SCORM_XBLOCK_STORAGE` setting and inside it uses additional settings:
+    - `STORAGE_CLASS` - the class of the Django storage to use
+    - `STORAGE_KWARGS` - the additional kwargs for the Django storage
+    The location can be changed by directly changing the location inside the xblock.
+
+    ```python
+    XBLOCK_SETTINGS["ScormXBlock"] = {
+        "LOCATION": "alternatevalue",
+    }
+    ```
+
+    It automatically creates and adds the `custom_domain` on the kwargs of the storage.
+    ```yaml
+    NAU_SCORM_XBLOCK_STORAGE:
+        STORAGE_CLASS: storages.backends.s3boto3.S3Boto3Storage
+        STORAGE_KWARGS:
+            default_acl: public-read
+            querystring_expire: 86400
+            access_key: XXXX
+            secret_key: YYYY
+            bucket: ZZZZ
+    ```
+    """
+    if hasattr(settings, 'NAU_SCORM_XBLOCK_STORAGE'):
+        storage_kwargs = get_storage_kwargs()
+        return get_storage_class(
+            settings.NAU_SCORM_XBLOCK_STORAGE.get('STORAGE_CLASS'),
+        )(**storage_kwargs)
+
+    # during edx-platform loading this method gets called but settings are not ready yet
+    # so in that case we will return default(FileSystemStorage) storage class instance
+    return get_storage_class()()
+
+
+def get_storage_kwargs():
+    """
+    Build Django storage class additional kwargs with a dynamic `custom_domain` parameter
+    that depends on the current in use LMS URL.
+    """
+
+    if settings.SERVICE_VARIANT == "lms":
+        domain = configuration_helpers.get_value('LMS_BASE', settings.LMS_BASE)
+    else:
+        domain = configuration_helpers.get_value('CMS_BASE', settings.CMS_BASE)
+    storage_kwargs_settings = settings.NAU_SCORM_XBLOCK_STORAGE.get('STORAGE_KWARGS', {})
+    return {**storage_kwargs_settings, **{'custom_domain': domain}}
+
+
+def get_storage_class(import_path=None):
+    """
+    Get the Django storage class to be used by custom SCORM storage.
+    """
+    return import_string(import_path or settings.DEFAULT_FILE_STORAGE)

nau_openedx_extensions/settings/production.py

@@ -76,3 +76,11 @@ def plugin_settings(settings):
     settings.SCORMXBLOCK_ASYNC_THRESHOLD = getattr(settings, "ENV_TOKENS", {}).get(
         "SCORMXBLOCK_ASYNC_THRESHOLD", settings.SCORMXBLOCK_ASYNC_THRESHOLD
     )
+
+    settings.NAU_SCORM_XBLOCK_STORAGE = getattr(settings, "ENV_TOKENS", {}).get(
+        "NAU_SCORM_XBLOCK_STORAGE", None
+    )
+    from nau_openedx_extensions.scorm.storage import scorm_xblock_storage  # pylint: disable=import-outside-toplevel
+    settings.XBLOCK_SETTINGS["ScormXBlock"] = {
+        "STORAGE_FUNC": scorm_xblock_storage,
+    }

nau_openedx_extensions/tests/test_scorm.py

@@ -0,0 +1,43 @@
+"""
+Tests that check the extended settings for overhangio SCORM xblock.
+"""
+from django.test import TestCase
+from django.test.utils import override_settings
+
+from nau_openedx_extensions.scorm.storage import get_storage_kwargs, scorm_xblock_storage
+
+
+class SCORMXblockTest(TestCase):
+    """
+    Tests that check the extended settings for overhangio SCORM xblock.
+    """
+
+    def test_scorm_storage_no_scorm_storage_setting(self):
+        """
+        Test if `NAU_SCORM_XBLOCK_STORAGE` is not defined then we shouldn't create a custom storage for the
+        SCORM Xblock.
+        """
+        self.assertIsNone(scorm_xblock_storage(None))
+
+    @override_settings(LMS_BASE='lms.example.com', SERVICE_VARIANT="lms", NAU_SCORM_XBLOCK_STORAGE={
+        'STORAGE_CLASS': 'storages.backends.s3boto3.S3Boto3Storage',
+        'STORAGE_KWARGS': {
+            'default_acl': 'public-read',
+            'querystring_expire': 86400
+        }
+    })
+    def test_scorm_storage_custom_storage_with_kwargs_service_variant_lms(self):
+        """
+        Test if NAU_SCORM_XBLOCK_STORAGE setting is defined we should have a custom storage.
+        """
+        self.assertEqual(get_storage_kwargs().get('custom_domain'), 'lms.example.com')
+
+    @override_settings(CMS_BASE='studio.example.com', SERVICE_VARIANT="cms", NAU_SCORM_XBLOCK_STORAGE={
+        'STORAGE_CLASS': 'storages.backends.s3boto3.S3Boto3Storage',
+    })
+    def test_scorm_storage_custom_storage_with_kwargs_service_variant_studio(self):
+        """
+        Test if NAU_SCORM_XBLOCK_STORAGE setting is defined, and we are running the studio instead
+        of lms, then we should return the studio domain on the custom domain.
+        """
+        self.assertEqual(get_storage_kwargs().get('custom_domain'), 'studio.example.com')