Add command to dump the structure of a course as a JSON

lms/djangoapps/courseware/management/commands/dump_course_structure.py

+"""
+A Django command that dumps the structure of a course as a JSON object.
+
+The resulting JSON object has one entry for each module in the course:
+
+{
+  "$module_url": {
+    "category": "$module_category",
+    "children": [$module_children_urls... ],
+    "metadata": {$module_metadata}
+  },
+
+  "$module_url": ....
+  ...
+}
+
+"""
+
+import json
+from optparse import make_option
+from textwrap import dedent
+
+from django.core.management.base import BaseCommand, CommandError
+
+from xmodule.modulestore.django import modulestore
+from xmodule.modulestore.inheritance import own_metadata
+
+
+FILTER_LIST = ['xml_attributes', 'checklists']
+
+
+class Command(BaseCommand):
+    """
+    Write out to stdout a structural and metadata information for a
+    course as a JSON object
+    """
+    args = "<course_id>"
+    help = dedent(__doc__).strip()
+    option_list = BaseCommand.option_list + (
+        make_option('--modulestore',
+                    action='store',
+                    default='default',
+                    help='Name of the modulestore'),
+    )
+
+    def handle(self, *args, **options):
+        if len(args) != 1:
+            raise CommandError("course_id not specified")
+
+        # Get the modulestore
+
+        try:
+            name = options['modulestore']
+            store = modulestore(name)
+        except KeyError:
+            raise CommandError("Unknown modulestore {}".format(name))
+
+        # Get the course data
+
+        course_id = args[0]
+        course = store.get_course(course_id)
+        if course is None:
+            raise CommandError("Invalid course_id")
+
+        # Convert course data to dictionary and dump it as JSON to stdout
+
+        info = dump_module(course)
+
+        return json.dumps(info, indent=2, sort_keys=True)
+
+
+def dump_module(module, destination=None):
+    """
+    Add the module and all its children to the destination dictionary in
+    as a flat structure.
+    """
+
+    destination = destination if destination else {}
+
+    items = own_metadata(module).iteritems()
+    filtered_metadata = {k: v for k, v in items if k not in FILTER_LIST}
+
+    destination[module.location.url()] = {
+        'category': module.location.category,
+        'children': module.children if hasattr(module, 'children') else [],
+        'metadata': filtered_metadata
+    }
+
+    for child in module.get_children():
+        dump_module(child, destination)
+
+    return destination

lms/djangoapps/courseware/tests/test_commands.py

 """Tests for Django management commands"""
 
+import json
 from StringIO import StringIO
 
 from django.core.management import call_command
@@ -43,3 +44,30 @@ class CommandsTestCase(CommandTestCase):
         output = self.call_command('dump_course_ids', **kwargs)
         dumped_courses = output.strip().split('\n')
         self.assertEqual(self.loaded_courses, dumped_courses)
+
+    def test_dump_course_structure(self):
+
+        args = ['edX/simple/2012_Fall']
+        kwargs = {'modulestore': 'default'}
+        output = self.call_command('dump_course_structure', *args, **kwargs)
+
+        dump = json.loads(output)
+
+        # Check a few elements in the course dump
+
+        parent_id = 'i4x://edX/simple/chapter/Overview'
+        self.assertEqual(dump[parent_id]['category'], 'chapter')
+        self.assertEqual(len(dump[parent_id]['children']), 3)
+
+        child_id = dump[parent_id]['children'][1]
+        self.assertEqual(dump[child_id]['category'], 'videosequence')
+        self.assertEqual(len(dump[child_id]['children']), 2)
+
+        video_id = 'i4x://edX/simple/video/Welcome'
+        self.assertEqual(dump[video_id]['category'], 'video')
+        self.assertEqual(len(dump[video_id]['metadata']), 4)
+        self.assertIn('youtube_id_1_0', dump[video_id]['metadata'])
+
+        # Check if there is the right number of elements
+
+        self.assertEqual(len(dump), 16)