"""
Serializer for video outline
"""
from rest_framework.reverse import reverse
from xmodule.modulestore.mongo.base import BLOCK_TYPES_WITH_CHILDREN
from xmodule.modulestore.django import modulestore
from courseware.access import has_access
from courseware.courses import get_course_by_id
from courseware.model_data import FieldDataCache
from courseware.module_render import get_module_for_descriptor
from util.module_utils import get_dynamic_descriptor_children
from edxval.api import (
get_video_info_for_course_and_profiles, ValInternalError
)
class BlockOutline(object):
"""
Serializes course videos, pulling data from VAL and the video modules.
"""
def __init__(self, course_id, start_block, block_types, request, video_profiles):
"""Create a BlockOutline using `start_block` as a starting point."""
self.start_block = start_block
self.block_types = block_types
self.course_id = course_id
self.request = request # needed for making full URLS
self.local_cache = {}
try:
self.local_cache['course_videos'] = get_video_info_for_course_and_profiles(
unicode(course_id), video_profiles
)
except ValInternalError: # pragma: nocover
self.local_cache['course_videos'] = {}
def __iter__(self):
def parent_or_requested_block_type(usage_key):
"""
Returns whether the usage_key's block_type is one of self.block_types or a parent type.
"""
return (
usage_key.block_type in self.block_types or
usage_key.block_type in BLOCK_TYPES_WITH_CHILDREN
)
def create_module(descriptor):
"""
Factory method for creating and binding a module for the given descriptor.
"""
field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
self.course_id, self.request.user, descriptor, depth=0,
)
course = get_course_by_id(self.course_id)
return get_module_for_descriptor(
self.request.user, self.request, descriptor, field_data_cache, self.course_id, course=course
)
with modulestore().bulk_operations(self.course_id):
child_to_parent = {}
stack = [self.start_block]
while stack:
curr_block = stack.pop()
if curr_block.hide_from_toc:
# For now, if the 'hide_from_toc' setting is set on the block, do not traverse down
# the hierarchy. The reason being is that these blocks may not have human-readable names
# to display on the mobile clients.
# Eventually, we'll need to figure out how we want these blocks to be displayed on the
# mobile clients. As they are still accessible in the browser, just not navigatable
# from the table-of-contents.
continue
if curr_block.location.block_type in self.block_types:
if not has_access(self.request.user, 'load', curr_block, course_key=self.course_id):
continue
summary_fn = self.block_types[curr_block.category]
block_path = list(path(curr_block, child_to_parent, self.start_block))
unit_url, section_url = find_urls(self.course_id, curr_block, child_to_parent, self.request)
yield {
"path": block_path,
"named_path": [b["name"] for b in block_path],
"unit_url": unit_url,
"section_url": section_url,
"summary": summary_fn(self.course_id, curr_block, self.request, self.local_cache)
}
if curr_block.has_children:
children = get_dynamic_descriptor_children(
curr_block,
self.request.user.id,
create_module,
usage_key_filter=parent_or_requested_block_type
)
for block in reversed(children):
stack.append(block)
child_to_parent[block] = curr_block
def path(block, child_to_parent, start_block):
"""path for block"""
block_path = []
while block in child_to_parent:
block = child_to_parent[block]
if block is not start_block:
block_path.append({
# to be consistent with other edx-platform clients, return the defaulted display name
'name': block.display_name_with_default_escaped,
'category': block.category,
'id': unicode(block.location)
})
return reversed(block_path)
def find_urls(course_id, block, child_to_parent, request):
"""
Find the section and unit urls for a block.
Returns:
unit_url, section_url:
unit_url (str): The url of a unit
section_url (str): The url of a section
"""
block_path = []
while block in child_to_parent:
block = child_to_parent[block]
block_path.append(block)
block_list = list(reversed(block_path))
block_count = len(block_list)
chapter_id = block_list[1].location.block_id if block_count > 1 else None
section = block_list[2] if block_count > 2 else None
position = None
if block_count > 3:
position = 1
for block in section.children:
if block.name == block_list[3].url_name:
break
position += 1
kwargs = {'course_id': unicode(course_id)}
if chapter_id is None:
course_url = reverse("courseware", kwargs=kwargs, request=request)
return course_url, course_url
kwargs['chapter'] = chapter_id
if section is None:
chapter_url = reverse("courseware_chapter", kwargs=kwargs, request=request)
return chapter_url, chapter_url
kwargs['section'] = section.url_name
section_url = reverse("courseware_section", kwargs=kwargs, request=request)
if position is None:
return section_url, section_url
kwargs['position'] = position
unit_url = reverse("courseware_position", kwargs=kwargs, request=request)
return unit_url, section_url
def video_summary(video_profiles, course_id, video_descriptor, request, local_cache):
"""
returns summary dict for the given video module
"""
always_available_data = {
"name": video_descriptor.display_name,
"category": video_descriptor.category,
"id": unicode(video_descriptor.scope_ids.usage_id),
"only_on_web": video_descriptor.only_on_web,
}
if video_descriptor.only_on_web:
ret = {
"video_url": None,
"video_thumbnail_url": None,
"duration": 0,
"size": 0,
"transcripts": {},
"language": None,
}
ret.update(always_available_data)
return ret
# Get encoded videos
video_data = local_cache['course_videos'].get(video_descriptor.edx_video_id, {})
# Get highest priority video to populate backwards compatible field
default_encoded_video = {}
if video_data:
for profile in video_profiles:
default_encoded_video = video_data['profiles'].get(profile, {})
if default_encoded_video:
break
if default_encoded_video:
video_url = default_encoded_video['url']
# Then fall back to VideoDescriptor fields for video URLs
elif video_descriptor.html5_sources:
video_url = video_descriptor.html5_sources[0]
else:
video_url = video_descriptor.source
# Get duration/size, else default
duration = video_data.get('duration', None)
size = default_encoded_video.get('file_size', 0)
# Transcripts...
transcripts_info = video_descriptor.get_transcripts_info()
transcript_langs = video_descriptor.available_translations(transcripts_info, verify_assets=False)
transcripts = {
lang: reverse(
'video-transcripts-detail',
kwargs={
'course_id': unicode(course_id),
'block_id': video_descriptor.scope_ids.usage_id.block_id,
'lang': lang
},
request=request,
)
for lang in transcript_langs
}
ret = {
"video_url": video_url,
"video_thumbnail_url": None,
"duration": duration,
"size": size,
"transcripts": transcripts,
"language": video_descriptor.get_default_transcript_language(transcripts_info),
"encoded_videos": video_data.get('profiles')
}
ret.update(always_available_data)
return ret