Merging Common Cartridge Export (LTI 1.1) into develop/nutmeg.master.

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

@@ -0,0 +1,124 @@
+"""
+A Django command that exports a course to a tar.gz file using IMSCC protocol
+
+At present, it differs from Studio exports in several ways:
+
+* It does not include static content.
+* It only supports the export of courses.  It does not export libraries.
+"""
+
+import os
+import re
+import shutil
+import tarfile
+from tempfile import mkdtemp, mktemp
+from textwrap import dedent
+
+from django.core.management.base import BaseCommand, CommandError
+from opaque_keys import InvalidKeyError
+from opaque_keys.edx.keys import CourseKey
+from path import Path as path
+
+from xmodule.modulestore.django import modulestore
+from xmodule.modulestore.imscc_exporter import export_course_to_imscc
+
+class Command(BaseCommand):
+    """
+    Export a course to IMSCC. The output is compressed as a tar.gz file.
+    """
+    help = dedent(__doc__).strip()
+
+    def add_arguments(self, parser):
+        parser.add_argument('course_id',  nargs="+") #nargs = "+" allows parsing of unlimited course ids
+        parser.add_argument('--output')
+        parser.add_argument(
+            '--external-tool-only',
+            action = 'store_true',
+            help = 'Export Common Cartridge file using only external tools and no assignment types')
+
+    def handle(self, *args, **options):
+        external_tool_only = options.get('external_tool_only', False)
+        course_ids = options['course_id']
+
+        # stores all the different course keys based on the inputted course ids
+        course_keys = []
+        for course_id in course_ids:
+            try:
+                course_keys.append(CourseKey.from_string(course_id))
+            except InvalidKeyError:
+                raise CommandError("Unparsable course_id")  # lint-amnesty, pylint: disable=raise-missing-from
+            except IndexError:
+                raise CommandError("Insufficient arguments")  # lint-amnesty, pylint: disable=raise-missing-from
+
+        filename = options['output']
+        pipe_results = False
+
+        if filename is None:
+            filename = mktemp()
+            pipe_results = True
+
+        export_course_to_tarfile(course_keys, filename, external_tool_only)
+
+        results = self._get_results(filename) if pipe_results else b''
+
+        # results is of type bytes, so we must write the underlying buffer directly.
+        self.stdout.buffer.write(results)
+
+    def _get_results(self, filename):
+        """
+        Load results from file.
+
+        Returns:
+            bytes: bytestring of file contents.
+        """
+        with open(filename, 'rb') as f:
+            results = f.read()
+            os.remove(filename)
+        return results
+
+
+def export_course_to_tarfile(course_keys, filename, external_tool_only):
+    """Exports a course into a tar.gz file"""
+    tmp_dir = mkdtemp()
+    try:
+        course_dir = export_course_to_directory(course_keys, tmp_dir, external_tool_only)
+        compress_directory(course_dir, filename)
+    finally:
+        shutil.rmtree(tmp_dir, ignore_errors=True)
+
+
+def export_course_to_directory(course_keys, root_dir, external_tool_only):
+    """Export course into a directory"""
+    # attempt to get all the courses based on the course_keys
+    store = modulestore()
+    courses = []
+    for course_key in course_keys:
+        course = store.get_course(course_key)
+        if course is None:
+            raise CommandError("Invalid course_id")
+        courses.append(course)
+
+    course_ids = []
+    for course in courses:
+        course_ids.append(course.id)
+    # The safest characters are A-Z, a-z, 0-9, <underscore>, <period> and <hyphen>.
+    # We represent the first four with \w.
+    # TODO: Once we support courses with unicode characters, we will need to revisit this.
+    replacement_char = '-'
+    course_dir = replacement_char.join([courses[0].id.org, courses[0].id.course, courses[0].id.run])
+    course_dir = re.sub(r'[^\w\.\-]', replacement_char, course_dir)
+
+    if len(courses) > 1:
+        course_dir = "MULTI-COURSE-EXPORT"
+    export_course_to_imscc(store, None, course_ids, root_dir, course_dir, external_tool_only)
+
+    export_dir = path(root_dir) / course_dir
+    return export_dir
+
+
+def compress_directory(directory, filename):
+    """Compress a directory into a tar.gz file"""
+    mode = 'w:gz'
+    name = path(directory).name
+    with tarfile.open(filename, mode) as tar_file:
+        tar_file.add(directory, arcname=name)