Hook up link to create modules from templates

common/lib/xmodule/xmodule/html_module.py

@@ -6,7 +6,7 @@ import sys
 from lxml import etree
 from path import path
 
-from .x_module import XModule
+from .x_module import XModule, Template
 from .xml_module import XmlDescriptor, name_to_pathname
 from .editing_module import EditingDescriptor
 from .stringify import stringify_children
@@ -34,6 +34,10 @@ class HtmlDescriptor(XmlDescriptor, EditingDescriptor):
     module_class = HtmlModule
     filename_extension = "xml"
 
+    templates = [
+        Template('Empty', '', [])
+    ]
+
     # VS[compat] TODO (cpennington): Delete this method once all fall 2012 course
     # are being edited in the cms
     @classmethod

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

@@ -297,8 +297,11 @@ class ModuleStore(object):
         """
         raise NotImplementedError
 
-    # TODO (cpennington): Replace with clone_item
-    def create_item(self, location, editor):
+    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`
+        """
         raise NotImplementedError
 
     def update_item(self, location, data):

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

@@ -237,20 +237,16 @@ class MongoModuleStore(ModuleStoreBase):
 
         return self._load_items(list(items), depth)
 
-    # TODO (cpennington): This needs to be replaced by clone_item as soon as we allow
-    # creation of items from the cms
-    def create_item(self, location):
+    def clone_item(self, source, location):
         """
-        Create an empty item at the specified location.
-
-        If that location already exists, raises a DuplicateItemError
-
-        location: Something that can be passed to Location
+        Clone a new item that is a copy of the item at the location `source`
+        and writes it to `location`
         """
         try:
-            self.collection.insert({
-                '_id': Location(location).dict(),
-            })
+            source_item = self.collection.find_one(location_to_query(source))
+            source_item['_id'] = Location(location).dict()
+            self.collection.insert(source_item)
+            return self._load_items([source_item])[0]
         except pymongo.errors.DuplicateKeyError:
             raise DuplicateItemError(location)
 

common/lib/xmodule/xmodule/modulestore/xml.py

@@ -471,10 +471,6 @@ class XMLModuleStore(ModuleStoreBase):
         """
         return dict( (k, self.errored_courses[k].errors) for k in self.errored_courses)
 
-    def create_item(self, location):
-        raise NotImplementedError("XMLModuleStores are read-only")
-
-
     def update_item(self, location, data):
         """
         Set the data in the item specified by the location to

common/lib/xmodule/xmodule/modulestore/xml_importer.py

@@ -24,13 +24,6 @@ def import_from_xml(store, data_dir, course_dirs=None,
     for course_id in module_store.modules.keys():
         for module in module_store.modules[course_id].itervalues():
 
-            # TODO (cpennington): This forces import to overrite the same items.
-            # This should in the future create new revisions of the items on import
-            try:
-                store.create_item(module.location)
-            except DuplicateItemError:
-                log.exception('Item already exists at %s' % module.location.url())
-                pass
             if 'data' in module.definition:
                 store.update_item(module.location, module.definition['data'])
             if 'children' in module.definition:

common/lib/xmodule/xmodule/templates.py

@@ -0,0 +1,30 @@
+from collections import defaultdict
+from .x_module import XModuleDescriptor
+from .modulestore import Location
+from .modulestore.django import modulestore
+
+
+def all_templates():
+    """
+    Returns all templates for enabled modules, grouped by descriptor type
+    """
+
+    templates = defaultdict(list)
+    for category, descriptor in XModuleDescriptor.load_classes():
+        templates[category] = descriptor.templates
+
+    return templates
+
+
+def update_templates():
+    """
+    Updates the set of templates in the modulestore with all templates currently
+    available from the installed plugins
+    """
+
+    for category, templates in all_templates().items():
+        for template in templates:
+            template_location = Location('i4x', 'edx', 'templates', category, Location.clean_for_url_name(template.name))
+            modulestore().update_item(template_location, template.data)
+            modulestore().update_children(template_location, template.children)
+            modulestore().update_metadata(template_location, {'display_name': template.name})

common/lib/xmodule/xmodule/x_module.py

@@ -7,6 +7,7 @@ from functools import partial
 from lxml import etree
 from lxml.etree import XMLSyntaxError
 from pprint import pprint
+from collections import namedtuple
 
 from xmodule.errortracker import exc_info_to_str
 from xmodule.modulestore import Location
@@ -71,7 +72,11 @@ class Plugin(object):
 
     @classmethod
     def load_classes(cls):
-        return [class_.load()
+        """
+        Returns a list of containing the identifiers and their corresponding classes for all
+        of the available instances of this plugin
+        """
+        return [(class_.name, class_.load())
                 for class_
                 in pkg_resources.iter_entry_points(cls.entry_point)]
 
@@ -321,6 +326,9 @@ def policy_key(location):
     return '{cat}/{name}'.format(cat=location.category, name=location.name)
 
 
+Template = namedtuple("Template", "name data children")
+
+
 class XModuleDescriptor(Plugin, HTMLSnippet):
     """
     An XModuleDescriptor is a specification for an element of a course. This
@@ -361,6 +369,11 @@ class XModuleDescriptor(Plugin, HTMLSnippet):
     equality_attributes = ('definition', 'metadata', 'location',
                            'shared_state_key', '_inherited_metadata')
 
+    # A list of Template objects that describe possible templates that can be used
+    # to create a module of this type.
+    # If no templates are provided, there will be no way to create a module of this type
+    templates = []
+
     # ============================= STRUCTURAL MANIPULATION ===================
     def __init__(self,
                  system,