From fe54b085c6cc1651bd35f829de4e186d918dd4e3 Mon Sep 17 00:00:00 2001
From: Usman Khalid <2200617@gmail.com>
Date: Wed, 1 Jul 2015 20:55:59 +0500
Subject: [PATCH] Added ability to disable xblock types in LMS.

TNL-2305
---
 cms/envs/common.py                            |  2 +
 common/djangoapps/xblock_django/admin.py      |  9 +++
 .../xblock_django/migrations/0001_initial.py  | 74 +++++++++++++++++++
 .../xblock_django/migrations/__init__.py      |  0
 common/djangoapps/xblock_django/models.py     | 39 ++++++++++
 common/lib/xmodule/xmodule/hidden_module.py   |  3 +
 .../xmodule/xmodule/modulestore/__init__.py   |  3 +-
 .../lib/xmodule/xmodule/modulestore/django.py | 11 +++
 .../xmodule/xmodule/modulestore/mongo/base.py |  1 +
 .../xmodule/modulestore/split_mongo/split.py  |  1 +
 common/lib/xmodule/xmodule/x_module.py        | 14 +++-
 .../courseware/tests/test_module_render.py    | 23 ++++++
 lms/envs/common.py                            |  5 ++
 .../sass/course/courseware/_courseware.scss   | 18 +++--
 openedx/core/lib/xblock_utils.py              |  5 +-
 15 files changed, 199 insertions(+), 9 deletions(-)
 create mode 100644 common/djangoapps/xblock_django/admin.py
 create mode 100644 common/djangoapps/xblock_django/migrations/0001_initial.py
 create mode 100644 common/djangoapps/xblock_django/migrations/__init__.py
 create mode 100644 common/djangoapps/xblock_django/models.py

diff --git a/cms/envs/common.py b/cms/envs/common.py
index d9b7725859..c4d0026368 100644
--- a/cms/envs/common.py
+++ b/cms/envs/common.py
@@ -795,6 +795,8 @@ INSTALLED_APPS = (
     # Import/Export API
     'rest_framework',
     'openedx.core.djangoapps.import_export',
+
+    'xblock_django',
 )
 
 
diff --git a/common/djangoapps/xblock_django/admin.py b/common/djangoapps/xblock_django/admin.py
new file mode 100644
index 0000000000..8114460671
--- /dev/null
+++ b/common/djangoapps/xblock_django/admin.py
@@ -0,0 +1,9 @@
+"""
+Django admin dashboard configuration.
+"""
+
+from django.contrib import admin
+from config_models.admin import ConfigurationModelAdmin
+from xblock_django.models import XBlockDisableConfig
+
+admin.site.register(XBlockDisableConfig, ConfigurationModelAdmin)
diff --git a/common/djangoapps/xblock_django/migrations/0001_initial.py b/common/djangoapps/xblock_django/migrations/0001_initial.py
new file mode 100644
index 0000000000..68485f0196
--- /dev/null
+++ b/common/djangoapps/xblock_django/migrations/0001_initial.py
@@ -0,0 +1,74 @@
+# -*- coding: utf-8 -*-
+from south.utils import datetime_utils as datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Adding model 'XBlockDisableConfig'
+        db.create_table('xblock_django_xblockdisableconfig', (
+            ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
+            ('change_date', self.gf('django.db.models.fields.DateTimeField')(auto_now_add=True, blank=True)),
+            ('changed_by', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['auth.User'], null=True, on_delete=models.PROTECT)),
+            ('enabled', self.gf('django.db.models.fields.BooleanField')(default=False)),
+            ('disabled_blocks', self.gf('django.db.models.fields.TextField')(default='', blank=True)),
+        ))
+        db.send_create_signal('xblock_django', ['XBlockDisableConfig'])
+
+
+    def backwards(self, orm):
+        # Deleting model 'XBlockDisableConfig'
+        db.delete_table('xblock_django_xblockdisableconfig')
+
+
+    models = {
+        'auth.group': {
+            'Meta': {'object_name': 'Group'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '80'}),
+            'permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'})
+        },
+        'auth.permission': {
+            'Meta': {'ordering': "('content_type__app_label', 'content_type__model', 'codename')", 'unique_together': "(('content_type', 'codename'),)", 'object_name': 'Permission'},
+            'codename': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['contenttypes.ContentType']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        },
+        'auth.user': {
+            'Meta': {'object_name': 'User'},
+            'date_joined': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'email': ('django.db.models.fields.EmailField', [], {'max_length': '75', 'blank': 'True'}),
+            'first_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'groups': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Group']", 'symmetrical': 'False', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'is_active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'is_staff': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'is_superuser': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'last_login': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'last_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'password': ('django.db.models.fields.CharField', [], {'max_length': '128'}),
+            'user_permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'}),
+            'username': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '30'})
+        },
+        'contenttypes.contenttype': {
+            'Meta': {'ordering': "('name',)", 'unique_together': "(('app_label', 'model'),)", 'object_name': 'ContentType', 'db_table': "'django_content_type'"},
+            'app_label': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'model': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '100'})
+        },
+        'xblock_django.xblockdisableconfig': {
+            'Meta': {'ordering': "('-change_date',)", 'object_name': 'XBlockDisableConfig'},
+            'change_date': ('django.db.models.fields.DateTimeField', [], {'auto_now_add': 'True', 'blank': 'True'}),
+            'changed_by': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['auth.User']", 'null': 'True', 'on_delete': 'models.PROTECT'}),
+            'disabled_blocks': ('django.db.models.fields.TextField', [], {'default': "''", 'blank': 'True'}),
+            'enabled': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'})
+        }
+    }
+
+    complete_apps = ['xblock_django']
\ No newline at end of file
diff --git a/common/djangoapps/xblock_django/migrations/__init__.py b/common/djangoapps/xblock_django/migrations/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/common/djangoapps/xblock_django/models.py b/common/djangoapps/xblock_django/models.py
new file mode 100644
index 0000000000..863be4a3a7
--- /dev/null
+++ b/common/djangoapps/xblock_django/models.py
@@ -0,0 +1,39 @@
+"""
+Models.
+"""
+from django.utils.translation import ugettext_lazy as _
+
+from django.db.models import TextField
+
+from config_models.models import ConfigurationModel
+
+
+class XBlockDisableConfig(ConfigurationModel):
+    """
+    Configuration for disabling XBlocks.
+    """
+
+    disabled_blocks = TextField(
+        default='', blank=True,
+        help_text=_('Space-separated list of XBlocks which should not render.')
+    )
+
+    @classmethod
+    def is_block_type_disabled(cls, block_type):
+        """ Return True if block_type is disabled. """
+
+        config = cls.current()
+        if not config.enabled:
+            return False
+
+        return block_type in config.disabled_blocks.split()  # pylint: disable=no-member
+
+    @classmethod
+    def disabled_block_types(cls):
+        """ Return list of disabled xblock types. """
+
+        config = cls.current()
+        if not config.enabled:
+            return ()
+
+        return config.disabled_blocks.split()  # pylint: disable=no-member
diff --git a/common/lib/xmodule/xmodule/hidden_module.py b/common/lib/xmodule/xmodule/hidden_module.py
index 50a72af786..ebce62ee49 100644
--- a/common/lib/xmodule/xmodule/hidden_module.py
+++ b/common/lib/xmodule/xmodule/hidden_module.py
@@ -3,6 +3,9 @@ from xmodule.raw_module import RawDescriptor
 
 
 class HiddenModule(XModule):
+
+    HIDDEN = True
+
     def get_html(self):
         if self.system.user_is_staff:
             return u"ERROR: This module is unknown--students will not see it at all"
diff --git a/common/lib/xmodule/xmodule/modulestore/__init__.py b/common/lib/xmodule/xmodule/modulestore/__init__.py
index 9d997cc2a5..c511aa9b32 100644
--- a/common/lib/xmodule/xmodule/modulestore/__init__.py
+++ b/common/lib/xmodule/xmodule/modulestore/__init__.py
@@ -1122,7 +1122,7 @@ class ModuleStoreReadBase(BulkOperationsMixin, ModuleStoreRead):
         contentstore=None,
         doc_store_config=None,  # ignore if passed up
         metadata_inheritance_cache_subsystem=None, request_cache=None,
-        xblock_mixins=(), xblock_select=None,
+        xblock_mixins=(), xblock_select=None, disabled_xblock_types=(),  # pylint: disable=bad-continuation
         # temporary parms to enable backward compatibility. remove once all envs migrated
         db=None, collection=None, host=None, port=None, tz_aware=True, user=None, password=None,
         # allow lower level init args to pass harmlessly
@@ -1139,6 +1139,7 @@ class ModuleStoreReadBase(BulkOperationsMixin, ModuleStoreRead):
         self.request_cache = request_cache
         self.xblock_mixins = xblock_mixins
         self.xblock_select = xblock_select
+        self.disabled_xblock_types = disabled_xblock_types
         self.contentstore = contentstore
 
     def get_course_errors(self, course_key):
diff --git a/common/lib/xmodule/xmodule/modulestore/django.py b/common/lib/xmodule/xmodule/modulestore/django.py
index e851f43c71..8c631a75ae 100644
--- a/common/lib/xmodule/xmodule/modulestore/django.py
+++ b/common/lib/xmodule/xmodule/modulestore/django.py
@@ -46,6 +46,11 @@ try:
 except ImportError:
     HAS_USER_SERVICE = False
 
+try:
+    from xblock_django.models import XBlockDisableConfig
+except ImportError:
+    XBlockDisableConfig = None
+
 log = logging.getLogger(__name__)
 ASSET_IGNORE_REGEX = getattr(settings, "ASSET_IGNORE_REGEX", r"(^\._.*$)|(^\.DS_Store$)|(^.*~$)")
 
@@ -161,12 +166,18 @@ def create_modulestore_instance(
     if 'read_preference' in doc_store_config:
         doc_store_config['read_preference'] = getattr(ReadPreference, doc_store_config['read_preference'])
 
+    if XBlockDisableConfig and settings.FEATURES.get('ENABLE_DISABLING_XBLOCK_TYPES', False):
+        disabled_xblock_types = XBlockDisableConfig.disabled_block_types()
+    else:
+        disabled_xblock_types = ()
+
     return class_(
         contentstore=content_store,
         metadata_inheritance_cache_subsystem=metadata_inheritance_cache,
         request_cache=request_cache,
         xblock_mixins=getattr(settings, 'XBLOCK_MIXINS', ()),
         xblock_select=getattr(settings, 'XBLOCK_SELECT_FUNCTION', None),
+        disabled_xblock_types=disabled_xblock_types,
         doc_store_config=doc_store_config,
         i18n_service=i18n_service or ModuleI18nService(),
         fs_service=fs_service or xblock.reference.plugins.FSService(),
diff --git a/common/lib/xmodule/xmodule/modulestore/mongo/base.py b/common/lib/xmodule/xmodule/modulestore/mongo/base.py
index d7ef5d542b..898db379c0 100644
--- a/common/lib/xmodule/xmodule/modulestore/mongo/base.py
+++ b/common/lib/xmodule/xmodule/modulestore/mongo/base.py
@@ -937,6 +937,7 @@ class MongoModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase, Mongo
                 cached_metadata=cached_metadata,
                 mixins=self.xblock_mixins,
                 select=self.xblock_select,
+                disabled_xblock_types=self.disabled_xblock_types,
                 services=services,
             )
         else:
diff --git a/common/lib/xmodule/xmodule/modulestore/split_mongo/split.py b/common/lib/xmodule/xmodule/modulestore/split_mongo/split.py
index b8e425eb27..64ccfb824a 100644
--- a/common/lib/xmodule/xmodule/modulestore/split_mongo/split.py
+++ b/common/lib/xmodule/xmodule/modulestore/split_mongo/split.py
@@ -3099,6 +3099,7 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
             render_template=self.render_template,
             mixins=self.xblock_mixins,
             select=self.xblock_select,
+            disabled_xblock_types=self.disabled_xblock_types,
             services=self.services,
         )
 
diff --git a/common/lib/xmodule/xmodule/x_module.py b/common/lib/xmodule/xmodule/x_module.py
index 4cb4ccfd40..0280655965 100644
--- a/common/lib/xmodule/xmodule/x_module.py
+++ b/common/lib/xmodule/xmodule/x_module.py
@@ -1298,9 +1298,9 @@ class DescriptorSystem(MetricsMixin, ConfigurableFragmentWrapper, Runtime):  # p
     """
     Base class for :class:`Runtime`s to be used with :class:`XModuleDescriptor`s
     """
-
+    # pylint: disable=bad-continuation
     def __init__(
-        self, load_item, resources_fs, error_tracker, get_policy=None, **kwargs
+        self, load_item, resources_fs, error_tracker, get_policy=None, disabled_xblock_types=(), **kwargs
     ):
         """
         load_item: Takes a Location and returns an XModuleDescriptor
@@ -1358,10 +1358,20 @@ class DescriptorSystem(MetricsMixin, ConfigurableFragmentWrapper, Runtime):  # p
         else:
             self.get_policy = lambda u: {}
 
+        self.disabled_xblock_types = disabled_xblock_types
+
     def get_block(self, usage_id, for_parent=None):
         """See documentation for `xblock.runtime:Runtime.get_block`"""
         return self.load_item(usage_id, for_parent=for_parent)
 
+    def load_block_type(self, block_type):
+        """
+        Returns a subclass of :class:`.XBlock` that corresponds to the specified `block_type`.
+        """
+        if block_type in self.disabled_xblock_types:
+            return self.default_class
+        return super(DescriptorSystem, self).load_block_type(block_type)
+
     def get_field_provenance(self, xblock, field):
         """
         For the given xblock, return a dict for the field's current state:
diff --git a/lms/djangoapps/courseware/tests/test_module_render.py b/lms/djangoapps/courseware/tests/test_module_render.py
index 3459f4eb46..ba9331fa6b 100644
--- a/lms/djangoapps/courseware/tests/test_module_render.py
+++ b/lms/djangoapps/courseware/tests/test_module_render.py
@@ -1687,3 +1687,26 @@ class TestFilteredChildren(ModuleStoreTestCase):
         Used to assert that sets of children are equivalent.
         """
         self.assertEquals(set(child_usage_ids), set(child.scope_ids.usage_id for child in block.get_children()))
+
+
+@attr('shard_1')
+@ddt.ddt
+class TestDisabledXBlockTypes(ModuleStoreTestCase):
+    """
+    Tests that verify disabled XBlock types are not loaded.
+    """
+    # pylint: disable=attribute-defined-outside-init, no-member
+    def setUp(self):
+        super(TestDisabledXBlockTypes, self).setUp()
+
+        for store in self.store.modulestores:
+            store.disabled_xblock_types = ('combinedopenended', 'peergrading', 'video')
+
+    @ddt.data(ModuleStoreEnum.Type.mongo, ModuleStoreEnum.Type.split)
+    def test_get_item(self, default_ms):
+        with self.store.default_store(default_ms):
+            course = CourseFactory()
+            for block_type in ('peergrading', 'combinedopenended', 'video'):
+                item = ItemFactory(category=block_type, parent=course)
+                item = self.store.get_item(item.scope_ids.usage_id)
+                self.assertEqual(item.__class__.__name__, 'RawDescriptorWithMixins')
diff --git a/lms/envs/common.py b/lms/envs/common.py
index a26aa80ba0..38f3e1e5c6 100644
--- a/lms/envs/common.py
+++ b/lms/envs/common.py
@@ -413,6 +413,9 @@ FEATURES = {
 
     # Full Course/Library Import/Export API
     'ENABLE_IMPORT_EXPORT_LMS': False,
+
+    # The block types to disable need to be specified in "x block disable config" in django admin.
+    'ENABLE_DISABLING_XBLOCK_TYPES': True,
 }
 
 # Ignore static asset files on import which match this pattern
@@ -1929,6 +1932,8 @@ INSTALLED_APPS = (
 
     # Import/Export API
     'openedx.core.djangoapps.import_export',
+
+    'xblock_django',
 )
 
 ######################### CSRF #########################################
diff --git a/lms/static/sass/course/courseware/_courseware.scss b/lms/static/sass/course/courseware/_courseware.scss
index 9548715201..d43a0597c1 100644
--- a/lms/static/sass/course/courseware/_courseware.scss
+++ b/lms/static/sass/course/courseware/_courseware.scss
@@ -142,11 +142,6 @@ div.course-wrapper {
       list-style: none;
 
       > div {
-        @extend .clearfix;
-        border-bottom: 1px solid #ddd;
-        margin-bottom: ($baseline*0.75);
-        padding: 0 0 15px;
-
         .collapsible {
           header {
             margin-bottom: 0;
@@ -212,6 +207,19 @@ div.course-wrapper {
           }
         }
       }
+
+      .vert > .xblock-student_view {
+        @extend .clearfix;
+        border-bottom: 1px solid #ddd;
+        margin-bottom: ($baseline*0.75);
+        padding: 0 0 15px;
+      }
+
+      .vert > .xblock-student_view.is-hidden {
+          display: none;
+          border-bottom: 0px;
+          margin-bottom: 0px;
+      }
     }
 
     section.xblock-student_view-wrapper div.vert-mod > div {
diff --git a/openedx/core/lib/xblock_utils.py b/openedx/core/lib/xblock_utils.py
index bc105af8c4..3431a8e15d 100644
--- a/openedx/core/lib/xblock_utils.py
+++ b/openedx/core/lib/xblock_utils.py
@@ -106,6 +106,9 @@ def wrap_xblock(
             # The block is acting as an XModuleDescriptor
             css_classes.append('xmodule_edit')
 
+        if getattr(block, 'HIDDEN', False):
+            css_classes.append('is-hidden')
+
         css_classes.append('xmodule_' + markupsafe.escape(class_name))
         data['type'] = block.js_module_name
         shim_xmodule_js(block, frag)
@@ -240,7 +243,7 @@ def add_staff_markup(user, has_instructor_access, disable_staff_debug_info, bloc
         else:
             return frag
 
-    if isinstance(block, SequenceModule):
+    if isinstance(block, SequenceModule) or getattr(block, 'HIDDEN', False):
         return frag
 
     block_id = block.location