From c084745290244584235ec2f8e5f366f5ea82f72c Mon Sep 17 00:00:00 2001
From: kimth <kimt@mit.edu>
Date: Mon, 20 Aug 2012 13:32:13 -0400
Subject: [PATCH] Textbook TOC from S3

---
 common/lib/xmodule/xmodule/course_module.py | 38 ++++++++++++++++++---
 lms/djangoapps/staticbook/views.py          |  4 +--
 2 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/common/lib/xmodule/xmodule/course_module.py b/common/lib/xmodule/xmodule/course_module.py
index 4729de905d..b647cf77ed 100644
--- a/common/lib/xmodule/xmodule/course_module.py
+++ b/common/lib/xmodule/xmodule/course_module.py
@@ -1,6 +1,7 @@
 from fs.errors import ResourceNotFoundError
 import time
 import logging
+import requests
 from lxml import etree
 
 from xmodule.util.decorators import lazyproperty
@@ -15,19 +16,48 @@ class CourseDescriptor(SequenceDescriptor):
     module_class = SequenceModule
 
     class Textbook:
-        def __init__(self, title, table_of_contents_url):
+        def __init__(self, title, book_url):
             self.title = title
-            self.table_of_contents_url = table_of_contents_url
+            self.book_url = book_url 
+            self.table_of_contents = self._get_toc_from_s3()
 
         @classmethod
         def from_xml_object(cls, xml_object):
-            return cls(xml_object.get('title'), xml_object.get('table_of_contents_url'))
+            return cls(xml_object.get('title'), xml_object.get('book_url'))
 
         @property
         def table_of_contents(self):
-            raw_table_of_contents = open(self.table_of_contents_url, 'r') # TODO: This will need to come from S3
+            '''
+            raw_table_of_contents = open(self.book_url, 'r') # TODO: This will need to come from S3
             table_of_contents = etree.parse(raw_table_of_contents).getroot()
             return table_of_contents
+            '''
+            return self.table_of_contents
+
+        def _get_toc_from_s3(self):
+            '''
+            Returns XML tree representation of the table of contents
+            '''
+            toc_url = self.book_url + 'toc.xml'
+
+            # Get the table of contents from S3
+            log.info("Retrieving textbook table of contents from %s" % toc_url)
+            try:
+                r = requests.get(toc_url)
+            except Exception as err:
+                msg = 'Error %s: Unable to retrieve textbook table of contents at %s' % (err, toc_url)
+                log.error(msg)
+                raise Exception(msg)
+
+            # TOC is XML. Parse it
+            try:
+                table_of_contents = etree.fromstring(r.text)
+            except Exception as err:
+                msg = 'Error %s: Unable to parse XML for textbook table of contents at %s' % (err, toc_url)
+                log.error(msg)
+                raise Exception(msg)
+
+            return table_of_contents
 
 
     def __init__(self, system, definition=None, **kwargs):
diff --git a/lms/djangoapps/staticbook/views.py b/lms/djangoapps/staticbook/views.py
index c43bed5ae6..d68117dd8a 100644
--- a/lms/djangoapps/staticbook/views.py
+++ b/lms/djangoapps/staticbook/views.py
@@ -14,10 +14,8 @@ def index(request, course_id, book_index, page=0):
     textbook = course.textbooks[int(book_index)]
     table_of_contents = textbook.table_of_contents
 
-    book_url = settings.BOOK_URL    
-
     return render_to_response('staticbook.html',
-                              {'page': int(page), 'course': course, 'book_url': book_url,
+                              {'page': int(page), 'course': course, 'book_url': textbook.book_url,
                                'table_of_contents': table_of_contents,
                                'staff_access': staff_access})