From 15852cd816aa0e9d8372003c183a87119ee2baf0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Carlos=20Andr=C3=A9s=20Rocha?= <rocha@edx.org>
Date: Mon, 12 Aug 2013 10:10:43 -0400
Subject: [PATCH] Modify export_to_xml to take an optional contentstore and
 work with xml courses

---
 .../contentstore/tests/test_contentstore.py   | 41 +++++++++++++++++++
 .../xmodule/modulestore/xml_exporter.py       | 22 ++++++----
 2 files changed, 55 insertions(+), 8 deletions(-)

diff --git a/cms/djangoapps/contentstore/tests/test_contentstore.py b/cms/djangoapps/contentstore/tests/test_contentstore.py
index 57e32429af..7f09e4dd60 100644
--- a/cms/djangoapps/contentstore/tests/test_contentstore.py
+++ b/cms/djangoapps/contentstore/tests/test_contentstore.py
@@ -1273,6 +1273,47 @@ class ContentStoreToyCourseTest(ModuleStoreTestCase):
         # export out to a tempdir
         export_to_xml(module_store, content_store, location, root_dir, 'test_export')
 
+    def test_export_course_without_content_store(self):
+        module_store = modulestore('direct')
+        content_store = contentstore()
+
+        # Create toy course
+
+        import_from_xml(module_store, 'common/test/data/', ['toy'])
+        location = CourseDescriptor.id_to_location('edX/toy/2012_Fall')
+
+        # Add a sequence
+
+        stub_location = Location(['i4x', 'edX', 'toy', 'sequential', 'vertical_sequential'])
+        sequential = module_store.get_item(stub_location)
+        module_store.update_children(sequential.location, sequential.children)
+
+        # Get course and export it without a content_store
+
+        course = module_store.get_item(location)
+        course.save()
+
+        root_dir = path(mkdtemp_clean())
+
+        print 'Exporting to tempdir = {0}'.format(root_dir)
+        export_to_xml(module_store, None, location, root_dir, 'test_export_no_content_store')
+
+        # Delete the course from module store and reimport it
+
+        delete_course(module_store, content_store, location, commit=True)
+
+        import_from_xml(
+            module_store, root_dir, ['test_export_no_content_store'],
+            draft_store=None,
+            static_content_store=None,
+            target_location_namespace=course.location
+        )
+
+        # Verify reimported course
+
+        items = module_store.get_items(stub_location)
+        self.assertEqual(len(items), 1)
+
 
 @override_settings(CONTENTSTORE=TEST_DATA_CONTENTSTORE, MODULESTORE=TEST_MODULESTORE)
 class ContentStoreTest(ModuleStoreTestCase):
diff --git a/common/lib/xmodule/xmodule/modulestore/xml_exporter.py b/common/lib/xmodule/xmodule/modulestore/xml_exporter.py
index a54d188b61..feb0a2ccfa 100644
--- a/common/lib/xmodule/xmodule/modulestore/xml_exporter.py
+++ b/common/lib/xmodule/xmodule/modulestore/xml_exporter.py
@@ -38,7 +38,7 @@ def export_to_xml(modulestore, contentstore, course_location, root_dir, course_d
     Export all modules from `modulestore` and content from `contentstore` as xml to `root_dir`.
 
     `modulestore`: A `ModuleStore` object that is the source of the modules to export
-    `contentstore`: A `ContentStore` object that is the source of the content to export
+    `contentstore`: A `ContentStore` object that is the source of the content to export, can be None
     `course_location`: The `Location` of the `CourseModuleDescriptor` to export
     `root_dir`: The directory to write the exported xml to
     `course_dir`: The name of the directory inside `root_dir` to write the course content to
@@ -46,7 +46,12 @@ def export_to_xml(modulestore, contentstore, course_location, root_dir, course_d
         alongside the public content in the course.
     """
 
-    course = modulestore.get_item(course_location)
+    # we use get_instance instead of get_item to support modulestores
+    # that can't guarantee that definitions are unique
+    course = modulestore.get_instance(
+        course_location.course_id,
+        course_location
+    )
 
     fs = OSFS(root_dir)
     export_fs = fs.makeopendir(course_dir)
@@ -55,13 +60,14 @@ def export_to_xml(modulestore, contentstore, course_location, root_dir, course_d
     with export_fs.open('course.xml', 'w') as course_xml:
         course_xml.write(xml)
 
-    policies_dir = export_fs.makeopendir('policies')
     # export the static assets
-    contentstore.export_all_for_course(
-        course_location,
-        root_dir + '/' + course_dir + '/static/',
-        root_dir + '/' + course_dir + '/policies/assets.json',
-    )
+    policies_dir = export_fs.makeopendir('policies')
+    if contentstore:
+        contentstore.export_all_for_course(
+            course_location,
+            root_dir + '/' + course_dir + '/static/',
+            root_dir + '/' + course_dir + '/policies/assets.json',
+        )
 
     # export the static tabs
     export_extra_content(export_fs, modulestore, course_location, 'static_tab', 'tabs', '.html')