Add Draft module store that is used whenever any item is update in the CAS (but…

Add Draft module store that is used whenever any item is update in the CAS (but not during import, and not for templates)

cms/djangoapps/contentstore/management/commands/import.py

@@ -26,4 +26,4 @@ class Command(BaseCommand):
         print "Importing.  Data_dir={data}, course_dirs={courses}".format(
             data=data_dir,
             courses=course_dirs)
-        import_from_xml(modulestore(), data_dir, course_dirs, load_error_modules=False)
+        import_from_xml(modulestore('direct'), data_dir, course_dirs, load_error_modules=False)

cms/envs/dev.py

@@ -14,17 +14,23 @@ LOGGING = get_logger_config(ENV_ROOT / "log",
                             tracking_filename="tracking.log",
                             debug=True)
 
+modulestore_options = {
+    'default_class': 'xmodule.raw_module.RawDescriptor',
+    'host': 'localhost',
+    'db': 'xmodule',
+    'collection': 'modulestore',
+    'fs_root': GITHUB_REPO_ROOT,
+    'render_template': 'mitxmako.shortcuts.render_to_string',
+}
+
 MODULESTORE = {
     'default': {
+        'ENGINE': 'xmodule.modulestore.mongo.DraftMongoModuleStore',
+        'OPTIONS': modulestore_options
+    },
+    'direct': {
         'ENGINE': 'xmodule.modulestore.mongo.MongoModuleStore',
-        'OPTIONS': {
-            'default_class': 'xmodule.raw_module.RawDescriptor',
-            'host': 'localhost',
-            'db': 'xmodule',
-            'collection': 'modulestore',
-            'fs_root': GITHUB_REPO_ROOT,
-            'render_template': 'mitxmako.shortcuts.render_to_string',
-        }
+        'OPTIONS': modulestore_options
     }
 }
 

common/lib/xmodule/xmodule/modulestore/__init__.py

@@ -345,7 +345,9 @@ class ModuleStore(object):
         Returns a list containing the top level XModuleDescriptors of the courses
         in this modulestore.
         '''
-        raise NotImplementedError
+        # TODO (vshnayder): Why do I have to specify i4x here?
+        course_filter = Location("i4x", category="course")
+        return self.get_items(course_filter)
 
     def get_parent_locations(self, location):
         '''Find all locations that are the parents of this location.  Needed

common/lib/xmodule/xmodule/modulestore/draft.py

+
+from . import ModuleStoreBase, Location
+from .exceptions import ItemNotFoundError
+
+
+class DraftModuleStore(ModuleStoreBase):
+    """
+    This mixin modifies a modulestore to give it draft semantics.
+    That is, edits made to units are stored to locations that have the revision 'draft',
+    and when reads are made, they first read with revision 'draft', and then fall back
+    to the baseline revision only if 'draft' doesn't exist.
+
+    This module also includes functionality to promote 'draft' modules (and optionally
+    their children) to published modules.
+    """
+
+    def get_item(self, location, depth=0):
+        """
+        Returns an XModuleDescriptor instance for the item at location.
+        If location.revision is None, returns the item with the most
+        recent revision
+
+        If any segment of the location is None except revision, raises
+            xmodule.modulestore.exceptions.InsufficientSpecificationError
+
+        If no object is found at that location, raises
+            xmodule.modulestore.exceptions.ItemNotFoundError
+
+        location: Something that can be passed to Location
+
+        depth (int): An argument that some module stores may use to prefetch
+            descendents of the queried modules for more efficient results later
+            in the request. The depth is counted in the number of calls to
+            get_children() to cache. None indicates to cache all descendents
+        """
+        try:
+            return super(DraftModuleStore, self).get_item(Location(location)._replace(revision='draft'), depth)
+        except ItemNotFoundError:
+            return super(DraftModuleStore, self).get_item(location, depth)
+
+    def get_instance(self, course_id, location):
+        """
+        Get an instance of this location, with policy for course_id applied.
+        TODO (vshnayder): this may want to live outside the modulestore eventually
+        """
+        try:
+            return super(DraftModuleStore, self).get_instance(course_id, Location(location)._replace(revision='draft'))
+        except ItemNotFoundError:
+            return super(DraftModuleStore, self).get_instance(course_id, location)
+
+    def get_items(self, location, depth=0):
+        """
+        Returns a list of XModuleDescriptor instances for the items
+        that match location. Any element of location that is None is treated
+        as a wildcard that matches any value
+
+        location: Something that can be passed to Location
+
+        depth: An argument that some module stores may use to prefetch
+            descendents of the queried modules for more efficient results later
+            in the request. The depth is counted in the number of calls to
+            get_children() to cache. None indicates to cache all descendents
+        """
+        draft_loc = Location(location)._replace(revision='draft')
+        draft_items = super(DraftModuleStore, self).get_items(draft_loc, depth)
+        items = super(DraftModuleStore, self).get_items(location, depth)
+
+        draft_locs_found = set(item.location._replace(revision=None) for item in draft_items)
+        non_draft_items = [
+            item
+            for item in items
+            if (item.location.revision != 'draft'
+                and item.location._replace(revision=None) not in draft_locs_found)
+        ]
+        return draft_items + non_draft_items
+
+    def clone_item(self, source, location):
+        """
+        Clone a new item that is a copy of the item at the location `source`
+        and writes it to `location`
+        """
+        return super(DraftModuleStore, self).clone_item(source, Location(location)._replace(revision='draft'))
+
+    def update_item(self, location, data):
+        """
+        Set the data in the item specified by the location to
+        data
+
+        location: Something that can be passed to Location
+        data: A nested dictionary of problem data
+        """
+        return super(DraftModuleStore, self).update_item(Location(location)._replace(revision='draft'), data)
+
+    def update_children(self, location, children):
+        """
+        Set the children for the item specified by the location to
+        children
+
+        location: Something that can be passed to Location
+        children: A list of child item identifiers
+        """
+        return super(DraftModuleStore, self).update_children(Location(location)._replace(revision='draft'), children)
+
+    def update_metadata(self, location, metadata):
+        """
+        Set the metadata for the item specified by the location to
+        metadata
+
+        location: Something that can be passed to Location
+        metadata: A nested dictionary of module metadata
+        """
+        return super(DraftModuleStore, self).update_metadata(Location(location)._replace(revision='draft'), metadata)
+
+    def delete_item(self, location):
+        """
+        Delete an item from this modulestore
+
+        location: Something that can be passed to Location
+        """
+        return super(DraftModuleStore, self).delete_item(Location(location)._replace(revision='draft'))
+
+    def get_parent_locations(self, location):
+        '''Find all locations that are the parents of this location.  Needed
+        for path_to_location().
+
+        returns an iterable of things that can be passed to Location.
+        '''
+        return super(DraftModuleStore, self).get_parent_locations(Location(location)._replace(revision='draft'))

common/lib/xmodule/xmodule/modulestore/mongo.py

@@ -13,6 +13,7 @@ from xmodule.mako_module import MakoDescriptorSystem
 from xmodule.error_module import ErrorDescriptor
 
 from . import ModuleStoreBase, Location
+from .draft import DraftModuleStore
 from .exceptions import (ItemNotFoundError,
                          DuplicateItemError)
 
@@ -341,3 +342,8 @@ class MongoModuleStore(ModuleStoreBase):
         are loaded on demand, rather than up front
         """
         return {}
+
+
+# DraftModuleStore is first, because it needs to intercept calls to MongoModuleStore
+class DraftMongoModuleStore(DraftModuleStore, MongoModuleStore):
+    pass

common/lib/xmodule/xmodule/templates.py

@@ -75,6 +75,6 @@ def update_templates():
                 ), exc_info=True)
                 continue
 
-            modulestore().update_item(template_location, template.data)
-            modulestore().update_children(template_location, template.children)
-            modulestore().update_metadata(template_location, template.metadata)
+            modulestore('direct').update_item(template_location, template.data)
+            modulestore('direct').update_children(template_location, template.children)
+            modulestore('direct').update_metadata(template_location, template.metadata)