Fix course download to support Python 2 and 3

4 files changed, 29 insertions, 22 deletions

diff --git a/yaksh/file_utils.py b/yaksh/file_utils.py
index 6b0340f..af0ee1e 100644
--- a/yaksh/file_utils.py
+++ b/yaksh/file_utils.py
@@ -80,8 +80,11 @@ def write_static_files_to_zip(zipfile, course_name, current_dir):
         folder_path = os.sep.join((current_dir, "static", "yaksh", folder))
         for file in static_files[folder]:
             file_path = os.sep.join((folder_path, file))
-            zipfile.write(file_path, os.sep.join((course_name, "static",
-                                                  folder, file)))
+            with open(file_path, "rb") as f:
+                zipfile.writestr(
+                    os.sep.join((course_name, "static", folder, file)),
+                    f.read()
+                    )
 
 
 def write_templates_to_zip(zipfile, template_path, data, filename, filepath):
@@ -91,4 +94,4 @@ def write_templates_to_zip(zipfile, template_path, data, filename, filepath):
         context = Context(data)
         render = template.render(context)
         zipfile.writestr(os.sep.join((filepath, "{0}.html".format(filename))),
-                         render)
+                         str(render))
diff --git a/yaksh/models.py b/yaksh/models.py
index b97859d..34aee25 100644
--- a/yaksh/models.py
+++ b/yaksh/models.py
@@ -210,12 +210,12 @@ class Lesson(models.Model):
         if self.video_file:
             video_file = os.sep.join((sub_folder_name, os.path.basename(
                         self.video_file.name)))
-            zip_file.write(self.video_file.path, video_file)
+            zip_file.writestr(video_file, self.video_file.read())
         for lesson_file in lesson_files:
             if os.path.exists(lesson_file.file.path):
                 filename = os.sep.join((sub_folder_name, os.path.basename(
                     lesson_file.file.name)))
-                zip_file.write(lesson_file.file.path, filename)
+                zip_file.writestr(filename, lesson_file.file.read())
         unit_file_path = os.sep.join((
             path, "templates", "yaksh", "unit.html"
             ))
@@ -228,7 +228,7 @@ class Lesson(models.Model):
 #############################################################################
 class LessonFile(models.Model):
     lesson = models.ForeignKey(Lesson, related_name="lesson")
-    file = models.FileField(upload_to=get_file_dir)
+    file = models.FileField(upload_to=get_file_dir, default=None)
 
     def remove(self):
         if os.path.exists(self.file.path):
@@ -882,16 +882,19 @@ class Course(models.Model):
     def is_student(self, user):
         return user in self.students.all()
 
-    def create_zip(self, zip_file, path):
-        course_name = self.name.replace(" ", "_")
-        modules = self.get_learning_modules()
-        file_path = os.sep.join((path, "templates", "yaksh", "index.html"))
-        write_static_files_to_zip(zip_file, course_name, path)
-        course_data = {"course": self, "modules": modules}
-        write_templates_to_zip(zip_file, file_path, course_data,
-                               "index", course_name)
-        for module in modules:
-            module._add_module_to_zip(self, zip_file, path)
+    def create_zip(self, path):
+        zip_file_name = string_io()
+        with zipfile.ZipFile(zip_file_name, "a") as zip_file:
+            course_name = self.name.replace(" ", "_")
+            modules = self.get_learning_modules()
+            file_path = os.sep.join((path, "templates", "yaksh", "index.html"))
+            write_static_files_to_zip(zip_file, course_name, path)
+            course_data = {"course": self, "modules": modules}
+            write_templates_to_zip(zip_file, file_path, course_data,
+                                   "index", course_name)
+            for module in modules:
+                module._add_module_to_zip(self, zip_file, path)
+        return zip_file_name
 
     def has_lessons(self):
         modules = self.get_learning_modules()
diff --git a/yaksh/test_views.py b/yaksh/test_views.py
index 41f0401..c1511c0 100644
--- a/yaksh/test_views.py
+++ b/yaksh/test_views.py
@@ -1743,6 +1743,10 @@ class TestCourses(TestCase):
         self.lesson = Lesson.objects.create(
             name="demo lesson", description="test description",
             creator=self.user1)
+        lesson_file = SimpleUploadedFile("file1.mp4", b"Test")
+        django_file = File(lesson_file)
+        self.lesson.video_file.save(lesson_file.name, django_file,
+                                    save=True)
 
         self.lesson_unit = LearningUnit.objects.create(
             order=1, type="lesson", lesson=self.lesson)
diff --git a/yaksh/views.py b/yaksh/views.py
index c5c5be1..f159411 100644
--- a/yaksh/views.py
+++ b/yaksh/views.py
@@ -2830,16 +2830,13 @@ def download_course(request, course_id):
     if not course.has_lessons():
         raise Http404("{0} course does not have any lessons".format(
             course.name))
-    file_name = string_io()
     current_dir = os.path.dirname(__file__)
     course_name = course.name.replace(" ", "_")
-    zip_file = zipfile.ZipFile(file_name, "w")
-    course.create_zip(zip_file, current_dir)
-    zip_file.close()
-    file_name.seek(0)
+    zip_file = course.create_zip(current_dir)
+    zip_file.seek(0)
     response = HttpResponse(content_type='application/zip')
     response['Content-Disposition'] = 'attachment; filename={0}.zip'.format(
                                             course_name
                                             )
-    response.write(file_name.read())
+    response.write(zip_file.read())
     return response