Files
edx-platform/common/lib/xmodule/xmodule/videoalpha_module.py
Alexander Kryklia 495b5a366f Fix videoalpha import from xml
VideoAlphaDescriptor inherits from EmptyDataRawDescriptor.
EmptyDataRawDescriptor is used for modules which might not have any
XML data, but require XmlDescriptor's functionality for
export/import. Without it, VideoAlphaModule would cause a crash on
export if any modules had an empty `self.data` field.

Don't use default video if HTML5 sources are given.
2013-08-07 18:00:59 +03:00

368 lines
13 KiB
Python

# pylint: disable=W0223
"""VideoAlpha is ungraded Xmodule for support video content.
It's new improved video module, which support additional feature:
- Can play non-YouTube video sources via in-browser HTML5 video player.
- YouTube defaults to HTML5 mode from the start.
- Speed changes in both YouTube and non-YouTube videos happen via
in-browser HTML5 video method (when in HTML5 mode).
- Navigational subtitles can be disabled altogether via an attribute
in XML.
"""
import json
import logging
from lxml import etree
from pkg_resources import resource_string
from django.http import Http404
from django.conf import settings
from xmodule.x_module import XModule
from xmodule.editing_module import TabsEditingDescriptor
from xmodule.raw_module import EmptyDataRawDescriptor
from xmodule.modulestore.mongo import MongoModuleStore
from xmodule.modulestore.django import modulestore
from xmodule.contentstore.content import StaticContent
from xblock.core import Scope, String, Boolean, Float, List, Integer
import datetime
import time
log = logging.getLogger(__name__)
class VideoAlphaFields(object):
"""Fields for `VideoAlphaModule` and `VideoAlphaDescriptor`."""
display_name = String(
display_name="Display Name", help="Display name for this module.",
default="Video Alpha",
scope=Scope.settings
)
position = Integer(
help="Current position in the video",
scope=Scope.user_state,
default=0
)
show_captions = Boolean(
help="This controls whether or not captions are shown by default.",
display_name="Show Captions",
scope=Scope.settings,
default=True
)
# TODO: This should be moved to Scope.content, but this will
# require data migration to support the old video module.
youtube_id_1_0 = String(
help="This is the Youtube ID reference for the normal speed video.",
display_name="Youtube ID",
scope=Scope.settings,
default="OEoXaMPEzfM"
)
youtube_id_0_75 = String(
help="The Youtube ID for the .75x speed video.",
display_name="Youtube ID for .75x speed",
scope=Scope.settings,
default=""
)
youtube_id_1_25 = String(
help="The Youtube ID for the 1.25x speed video.",
display_name="Youtube ID for 1.25x speed",
scope=Scope.settings,
default=""
)
youtube_id_1_5 = String(
help="The Youtube ID for the 1.5x speed video.",
display_name="Youtube ID for 1.5x speed",
scope=Scope.settings,
default=""
)
start_time = Float(
help="Start time for the video.",
display_name="Start Time",
scope=Scope.settings,
default=0.0
)
end_time = Float(
help="End time for the video.",
display_name="End Time",
scope=Scope.settings,
default=0.0
)
source = String(
help="The external URL to download the video. This appears as a link beneath the video.",
display_name="Download Video",
scope=Scope.settings,
default=""
)
html5_sources = List(
help="A list of filenames to be used with HTML5 video. The first supported filetype will be displayed.",
display_name="Video Sources",
scope=Scope.settings,
default=[]
)
track = String(
help="The external URL to download the subtitle track. This appears as a link beneath the video.",
display_name="Download Track",
scope=Scope.settings,
default=""
)
sub = String(
help="The name of the subtitle track (for non-Youtube videos).",
display_name="HTML5 Subtitles",
scope=Scope.settings,
default=""
)
class VideoAlphaModule(VideoAlphaFields, XModule):
"""
XML source example:
<videoalpha show_captions="true"
youtube="0.75:jNCf2gIqpeE,1.0:ZwkTiUPN0mg,1.25:rsq9auxASqI,1.50:kMyNdzVHHgg"
url_name="lecture_21_3" display_name="S19V3: Vacancies"
>
<source src=".../mit-3091x/M-3091X-FA12-L21-3_100.mp4"/>
<source src=".../mit-3091x/M-3091X-FA12-L21-3_100.webm"/>
<source src=".../mit-3091x/M-3091X-FA12-L21-3_100.ogv"/>
</videoalpha>
"""
video_time = 0
icon_class = 'video'
js = {
'js': [
resource_string(__name__, 'js/src/videoalpha/01_initialize.js'),
resource_string(__name__, 'js/src/videoalpha/02_html5_video.js'),
resource_string(__name__, 'js/src/videoalpha/03_video_player.js'),
resource_string(__name__, 'js/src/videoalpha/04_video_control.js'),
resource_string(__name__, 'js/src/videoalpha/05_video_quality_control.js'),
resource_string(__name__, 'js/src/videoalpha/06_video_progress_slider.js'),
resource_string(__name__, 'js/src/videoalpha/07_video_volume_control.js'),
resource_string(__name__, 'js/src/videoalpha/08_video_speed_control.js'),
resource_string(__name__, 'js/src/videoalpha/09_video_caption.js'),
resource_string(__name__, 'js/src/videoalpha/10_main.js')
]
}
css = {'scss': [resource_string(__name__, 'css/videoalpha/display.scss')]}
js_module_name = "VideoAlpha"
def handle_ajax(self, dispatch, data):
"""This is not being called right now and we raise 404 error."""
log.debug(u"GET {0}".format(data))
log.debug(u"DISPATCH {0}".format(dispatch))
raise Http404()
def get_instance_state(self):
"""Return information about state (position)."""
return json.dumps({'position': self.position})
def get_html(self):
if isinstance(modulestore(), MongoModuleStore):
caption_asset_path = StaticContent.get_base_url_path_for_course_assets(self.location) + '/subs_'
else:
# VS[compat]
# cdodge: filesystem static content support.
caption_asset_path = "/static/subs/"
get_ext = lambda filename: filename.rpartition('.')[-1]
sources = {get_ext(src): src for src in self.html5_sources}
sources['main'] = self.source
return self.system.render_template('videoalpha.html', {
'youtube_streams': _create_youtube_string(self),
'id': self.location.html_id(),
'sub': self.sub,
'sources': sources,
'track': self.track,
'display_name': self.display_name_with_default,
# This won't work when we move to data that
# isn't on the filesystem
'data_dir': getattr(self, 'data_dir', None),
'caption_asset_path': caption_asset_path,
'show_captions': json.dumps(self.show_captions),
'start': self.start_time,
'end': self.end_time,
'autoplay': settings.MITX_FEATURES.get('AUTOPLAY_VIDEOS', True)
})
class VideoAlphaDescriptor(VideoAlphaFields, TabsEditingDescriptor, EmptyDataRawDescriptor):
"""Descriptor for `VideoAlphaModule`."""
module_class = VideoAlphaModule
tabs = [
# {
# 'name': "Subtitles",
# 'template': "videoalpha/subtitles.html",
# },
{
'name': "Settings",
'template': "tabs/metadata-edit-tab.html",
'current': True
}
]
def __init__(self, *args, **kwargs):
super(VideoAlphaDescriptor, self).__init__(*args, **kwargs)
# For backwards compatibility -- if we've got XML data, parse
# it out and set the metadata fields
if self.data:
model_data = VideoAlphaDescriptor._parse_video_xml(self.data)
self._model_data.update(model_data)
del self.data
@classmethod
def from_xml(cls, xml_data, system, org=None, course=None):
"""
Creates an instance of this descriptor from the supplied xml_data.
This may be overridden by subclasses
xml_data: A string of xml that will be translated into data and children for
this module
system: A DescriptorSystem for interacting with external resources
org and course are optional strings that will be used in the generated modules
url identifiers
"""
# Calling from_xml of XmlDescritor, to get right Location, when importing from XML
video = super(VideoAlphaDescriptor, cls).from_xml(xml_data, system, org, course)
return video
def export_to_xml(self, resource_fs):
"""
Returns an xml string representing this module.
"""
xml = etree.Element('videoalpha')
attrs = {
'display_name': self.display_name,
'show_captions': json.dumps(self.show_captions),
'youtube': _create_youtube_string(self),
'start_time': datetime.timedelta(seconds=self.start_time),
'end_time': datetime.timedelta(seconds=self.end_time),
'sub': self.sub
}
for key, value in attrs.items():
if value:
xml.set(key, str(value))
for source in self.html5_sources:
ele = etree.Element('source')
ele.set('src', source)
xml.append(ele)
if self.track:
ele = etree.Element('track')
ele.set('src', self.track)
xml.append(ele)
return etree.tostring(xml, pretty_print=True)
@staticmethod
def _parse_youtube(data):
"""
Parses a string of Youtube IDs such as "1.0:AXdE34_U,1.5:VO3SxfeD"
into a dictionary. Necessary for backwards compatibility with
XML-based courses.
"""
ret = {'0.75': '', '1.00': '', '1.25': '', '1.50': ''}
if data == '':
return ret
videos = data.split(',')
for video in videos:
pieces = video.split(':')
# HACK
# To elaborate somewhat: in many LMS tests, the keys for
# Youtube IDs are inconsistent. Sometimes a particular
# speed isn't present, and formatting is also inconsistent
# ('1.0' versus '1.00'). So it's necessary to either do
# something like this or update all the tests to work
# properly.
ret['%.2f' % float(pieces[0])] = pieces[1]
return ret
@staticmethod
def _parse_video_xml(xml_data):
"""
Parse video fields out of xml_data. The fields are set if they are
present in the XML.
"""
xml = etree.fromstring(xml_data)
model_data = {}
conversions = {
'show_captions': json.loads,
'start_time': VideoAlphaDescriptor._parse_time,
'end_time': VideoAlphaDescriptor._parse_time
}
# VideoModule and VideoAlphaModule use different names for
# these attributes -- need to convert between them
video_compat = {
'from': 'start_time',
'to': 'end_time'
}
sources = xml.findall('source')
if sources:
model_data['html5_sources'] = [ele.get('src') for ele in sources]
model_data['source'] = model_data['html5_sources'][0]
track = xml.find('track')
if track is not None:
model_data['track'] = track.get('src')
for attr, value in xml.items():
if attr in video_compat:
attr = video_compat[attr]
if attr == 'youtube':
speeds = VideoAlphaDescriptor._parse_youtube(value)
for speed, youtube_id in speeds.items():
# should have made these youtube_id_1_00 for
# cleanliness, but hindsight doesn't need glasses
normalized_speed = speed[:-1] if speed.endswith('0') else speed
# If the user has specified html5 sources, make sure we don't use the default video
if youtube_id != '' or 'html5_sources' in model_data:
model_data['youtube_id_{0}'.format(normalized_speed.replace('.', '_'))] = youtube_id
else:
# Convert XML attrs into Python values.
if attr in conversions:
value = conversions[attr](value)
model_data[attr] = value
return model_data
@staticmethod
def _parse_time(str_time):
"""Converts s in '12:34:45' format to seconds. If s is
None, returns empty string"""
if not str_time:
return ''
else:
obj_time = time.strptime(str_time, '%H:%M:%S')
return datetime.timedelta(
hours=obj_time.tm_hour,
minutes=obj_time.tm_min,
seconds=obj_time.tm_sec
).total_seconds()
def _create_youtube_string(module):
"""
Create a string of Youtube IDs from `module`'s metadata
attributes. Only writes a speed if an ID is present in the
module. Necessary for backwards compatibility with XML-based
courses.
"""
youtube_ids = [
module.youtube_id_0_75,
module.youtube_id_1_0,
module.youtube_id_1_25,
module.youtube_id_1_5
]
youtube_speeds = ['0.75', '1.00', '1.25', '1.50']
return ','.join([':'.join(pair)
for pair
in zip(youtube_speeds, youtube_ids)
if pair[1]])