Successfully read course children out of mongodb

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

@@ -6,11 +6,13 @@
 #import mitxmako.middleware
 #from courseware import content_parser
 #from django.contrib.auth.models import User
+import os.path
+from StringIO import StringIO
 from mako.template import Template
 from mako.lookup import TemplateLookup
 
 from django.core.management.base import BaseCommand
-from contentstore.models import create_item, update_item, update_children
+from keystore.django import keystore
 
 from lxml import etree
 
@@ -20,16 +22,15 @@ class Command(BaseCommand):
     def handle(self, *args, **options):
         print args
         data_dir = args[0]
-        course_file = 'course.xml'
  
         parser = etree.XMLParser(remove_comments = True)
 
         lookup = TemplateLookup(directories=[data_dir])
         template = lookup.get_template("course.xml")
         course_string = template.render(groups=[])
-        course = etree.XML(course_string, parser=parser)
+        course = etree.parse(StringIO(course_string), parser=parser)
 
-        elements = course.xpath("//*")
+        elements = list(course.iter())
 
         tag_to_category = {# Inside HTML ==> Skip these
             # Custom tags
@@ -39,11 +40,11 @@ class Command(BaseCommand):
             'image': 'Custom',
             'discuss': 'Custom',
             # Simple lists
-            'chapter': 'Sequence',
-            'course': 'Sequence',
-            'sequential': 'Sequence',
-            'vertical': 'Sequence',
-            'section': 'Sequence',
+            'chapter': 'Chapter',
+            'course': 'Course',
+            'sequential': 'LectureSequence',
+            'vertical': 'ProblemSet',
+            'section': 'Section',
             # True types
             'video': 'VideoSegment',
             'html': 'HTML',
@@ -114,7 +115,7 @@ class Command(BaseCommand):
             results[e.attrib['url']] = {'data':{'text':text}}
 
         def handle_problem(e):
-            data = open(data_dir+'problems/'+e.attrib['filename']+'.xml').read()
+            data = open(os.path.join(data_dir, 'problems', e.attrib['filename']+'.xml')).read()
             results[e.attrib['url']] = {'data':{'statement':data}}
 
         element_actions = {# Inside HTML ==> Skip these
@@ -149,10 +150,8 @@ class Command(BaseCommand):
 
         for k in results:
             print k
-            create_item(k, 'Piotr Mitros')
+            keystore.create_item(k, 'Piotr Mitros')
             if 'data' in results[k]:
-                update_item(k, results[k]['data'])
+                keystore.update_item(k, results[k]['data'])
             if 'children' in results[k]:
-                update_children(k, results[k]['children'])
-            
-
+                keystore.update_children(k, results[k]['children'])

cms/djangoapps/contentstore/views.py

 from mitxmako.shortcuts import render_to_response
-from keystore import Location
 from keystore.django import keystore
 from django.contrib.auth.decorators import login_required
 
 
 @login_required
 def calendar(request, org, course):
-    weeks = keystore.get_children_for_item(
-        Location(['i4x', org, course, 'Course', 'course'])
-    )
+    weeks = keystore.get_children_for_item(['i4x', org, course, 'Course', None])
     return render_to_response('calendar.html', {'weeks': weeks})
 
 

cms/lib/keystore/__init__.py

@@ -60,6 +60,40 @@ class KeyStore(object):
         with the specified location.
 
         If no object is found at that location, raises keystore.exceptions.ItemNotFoundError
+
+        Searches for all matches of a partially specifed location, but raises an
+        keystore.exceptions.InsufficientSpecificationError if more
+        than a single object matches the query.
+
+        location: Something that can be passed to Location
+        """
+        raise NotImplementedError
+
+    def create_item(self, location, editor):
+        """
+        Create an empty item at the specified location with the supplied editor
+
+        location: Something that can be passed to Location
+        """
+        raise NotImplementedError
+
+    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
+        """
+        raise NotImplementedError
+
+    def update_children(self, location, children):
+        """
+        Set the children for the item specified by the location to
+        data
+
+        location: Something that can be passed to Location
+        children: A list of child item identifiers
         """
         raise NotImplementedError
 

cms/lib/keystore/exceptions.py

@@ -5,3 +5,7 @@ Exceptions thrown by KeyStore objects
 
 class ItemNotFoundError(Exception):
     pass
+
+
+class InsufficientSpecificationError(Exception):
+    pass

cms/lib/keystore/mongo.py

 import pymongo
-from . import KeyStore
-from .exceptions import ItemNotFoundError
+from . import KeyStore, Location
+from .exceptions import ItemNotFoundError, InsufficientSpecificationError
 
 
 class MongoKeyStore(KeyStore):
@@ -12,15 +12,64 @@ class MongoKeyStore(KeyStore):
             host=host,
             port=port
         )[db][collection]
+        
+        # Force mongo to report errors, at the expense of performance
+        self.collection.safe = True
 
     def get_children_for_item(self, location):
-        item = self.collection.find_one(
-            {'location': location.dict()},
+        query = dict(
+            ('location.{key}'.format(key=key), val)
+            for (key, val)
+            in Location(location).dict().items()
+            if val is not None
+        )
+        items = self.collection.find(
+            query,
             fields={'children': True},
             sort=[('revision', pymongo.ASCENDING)],
+            limit=1,
         )
+        if items.count() > 1:
+            raise InsufficientSpecificationError(location)
+
+        if items.count() == 0:
+            raise ItemNotFoundError(location)
+
+        return items[0]['children']
+
+    def create_item(self, location, editor):
+        """
+        Create an empty item at the specified location with the supplied editor
+
+        location: Something that can be passed to Location
+        """
+        self.collection.insert({
+            'location': Location(location).dict(),
+            'editor': editor
+        })
 
-        if item is None:
-            raise ItemNotFoundError()
+    def update_item(self, location, data):
+        """
+        Set the data in the item specified by the location to
+        data
 
-        return item['children']
+        location: Something that can be passed to Location
+        data: A nested dictionary of problem data
+        """
+        self.collection.update(
+            {'location': Location(location).dict()},
+            {'$set': {'data': data}}
+        )
+
+    def update_children(self, location, children):
+        """
+        Set the children for the item specified by the location to
+        data
+
+        location: Something that can be passed to Location
+        children: A list of child item identifiers
+        """
+        self.collection.update(
+            {'location': Location(location).dict()},
+            {'$set': {'children': children}}
+        )