Files
edx-platform/openedx/core/lib/xblock_utils.py
Dmitry Viskov 209ddc700d Difficulty selectbox in Studio (based on new XBlockAside functionality). Include:
- adaptation asides to be imported from the XML
- updating SplitMongo to handle XBlockAsides (CRUD operations)
- updating Studio to handle XBlockAsides handler calls
- updating xblock/core.js to properly init XBlockAsides JavaScript
2016-03-02 03:37:13 +03:00

449 lines
18 KiB
Python

"""
Functions that can are used to modify XBlock fragments for use in the LMS and Studio
"""
import datetime
import json
import logging
import markupsafe
import re
import static_replace
import uuid
from lxml import html, etree
from contracts import contract
from django.conf import settings
from django.utils.timezone import UTC
from django.utils.html import escape
from django.contrib.auth.models import User
from edxmako.shortcuts import render_to_string
from xblock.core import XBlock
from xblock.exceptions import InvalidScopeError
from xblock.fragment import Fragment
from xmodule.seq_module import SequenceModule
from xmodule.vertical_block import VerticalBlock
from xmodule.x_module import shim_xmodule_js, XModuleDescriptor, XModule, PREVIEW_VIEWS, STUDIO_VIEW
from xmodule.modulestore import ModuleStoreEnum
from xmodule.modulestore.django import modulestore
log = logging.getLogger(__name__)
def wrap_fragment(fragment, new_content):
"""
Returns a new Fragment that has `new_content` and all
as its content, and all of the resources from fragment
"""
wrapper_frag = Fragment(content=new_content)
wrapper_frag.add_frag_resources(fragment)
return wrapper_frag
def request_token(request):
"""
Return a unique token for the supplied request.
This token will be the same for all calls to `request_token`
made on the same request object.
"""
# pylint: disable=protected-access
if not hasattr(request, '_xblock_token'):
request._xblock_token = uuid.uuid1().get_hex()
return request._xblock_token
def wrap_xblock(
runtime_class,
block,
view,
frag,
context, # pylint: disable=unused-argument
usage_id_serializer,
request_token, # pylint: disable=redefined-outer-name
display_name_only=False,
extra_data=None
):
"""
Wraps the results of rendering an XBlock view in a standard <section> with identifying
data so that the appropriate javascript module can be loaded onto it.
:param runtime_class: The name of the javascript runtime class to use to load this block
:param block: An XBlock (that may be an XModule or XModuleDescriptor)
:param view: The name of the view that rendered the fragment being wrapped
:param frag: The :class:`Fragment` to be wrapped
:param context: The context passed to the view being rendered
:param usage_id_serializer: A function to serialize the block's usage_id for use by the
front-end Javascript Runtime.
:param request_token: An identifier that is unique per-request, so that only xblocks
rendered as part of this request will have their javascript initialized.
:param display_name_only: If true, don't render the fragment content at all.
Instead, just render the `display_name` of `block`
:param extra_data: A dictionary with extra data values to be set on the wrapper
"""
if extra_data is None:
extra_data = {}
# If any mixins have been applied, then use the unmixed class
class_name = getattr(block, 'unmixed_class', block.__class__).__name__
data = {}
data.update(extra_data)
css_classes = [
'xblock',
'xblock-{}'.format(markupsafe.escape(view)),
'xblock-{}-{}'.format(
markupsafe.escape(view),
markupsafe.escape(block.scope_ids.block_type),
)
]
if isinstance(block, (XModule, XModuleDescriptor)):
if view in PREVIEW_VIEWS:
# The block is acting as an XModule
css_classes.append('xmodule_display')
elif view == STUDIO_VIEW:
# The block is acting as an XModuleDescriptor
css_classes.append('xmodule_edit')
if getattr(block, 'HIDDEN', False):
css_classes.append('is-hidden')
css_classes.append('xmodule_' + markupsafe.escape(class_name))
data['type'] = block.js_module_name
shim_xmodule_js(block, frag)
if frag.js_init_fn:
data['init'] = frag.js_init_fn
data['runtime-class'] = runtime_class
data['runtime-version'] = frag.js_init_version
data['block-type'] = block.scope_ids.block_type
data['usage-id'] = usage_id_serializer(block.scope_ids.usage_id)
data['request-token'] = request_token
if block.name:
data['name'] = block.name
template_context = {
'content': block.display_name if display_name_only else frag.content,
'classes': css_classes,
'display_name': block.display_name_with_default_escaped,
'data_attributes': u' '.join(u'data-{}="{}"'.format(markupsafe.escape(key), markupsafe.escape(value))
for key, value in data.iteritems()),
}
if hasattr(frag, 'json_init_args') and frag.json_init_args is not None:
# Replace / with \/ so that "</script>" in the data won't break things.
template_context['js_init_parameters'] = json.dumps(frag.json_init_args).replace("/", r"\/")
else:
template_context['js_init_parameters'] = ""
return wrap_fragment(frag, render_to_string('xblock_wrapper.html', template_context))
def wrap_xblock_aside(
runtime_class,
aside,
view,
frag,
context, # pylint: disable=unused-argument
usage_id_serializer,
request_token, # pylint: disable=redefined-outer-name
extra_data=None
):
"""
Wraps the results of rendering an XBlockAside view in a standard <section> with identifying
data so that the appropriate javascript module can be loaded onto it.
:param runtime_class: The name of the javascript runtime class to use to load this block
:param aside: An XBlockAside
:param view: The name of the view that rendered the fragment being wrapped
:param frag: The :class:`Fragment` to be wrapped
:param context: The context passed to the view being rendered
:param usage_id_serializer: A function to serialize the block's usage_id for use by the
front-end Javascript Runtime.
:param request_token: An identifier that is unique per-request, so that only xblocks
rendered as part of this request will have their javascript initialized.
:param extra_data: A dictionary with extra data values to be set on the wrapper
"""
if extra_data is None:
extra_data = {}
data = {}
data.update(extra_data)
css_classes = [
'xblock-{}'.format(markupsafe.escape(view)),
'xblock-{}-{}'.format(
markupsafe.escape(view),
markupsafe.escape(aside.scope_ids.block_type),
),
'xblock_asides-v1'
]
if frag.js_init_fn:
data['init'] = frag.js_init_fn
data['runtime-class'] = runtime_class
data['runtime-version'] = frag.js_init_version
data['block-type'] = aside.scope_ids.block_type
data['usage-id'] = usage_id_serializer(aside.scope_ids.usage_id)
data['request-token'] = request_token
template_context = {
'content': frag.content,
'classes': css_classes,
'data_attributes': u' '.join(u'data-{}="{}"'.format(markupsafe.escape(key), markupsafe.escape(value))
for key, value in data.iteritems()),
}
if hasattr(frag, 'json_init_args') and frag.json_init_args is not None:
# Replace / with \/ so that "</script>" in the data won't break things.
template_context['js_init_parameters'] = json.dumps(frag.json_init_args).replace("/", r"\/")
else:
template_context['js_init_parameters'] = ""
return wrap_fragment(frag, render_to_string('xblock_wrapper.html', template_context))
def replace_jump_to_id_urls(course_id, jump_to_id_base_url, block, view, frag, context): # pylint: disable=unused-argument
"""
This will replace a link between courseware in the format
/jump_to_id/<id> with a URL for a page that will correctly redirect
This is similar to replace_course_urls, but much more flexible and
durable for Studio authored courses. See more comments in static_replace.replace_jump_to_urls
course_id: The course_id in which this rewrite happens
jump_to_id_base_url:
A app-tier (e.g. LMS) absolute path to the base of the handler that will perform the
redirect. e.g. /courses/<org>/<course>/<run>/jump_to_id. NOTE the <id> will be appended to
the end of this URL at re-write time
output: a new :class:`~xblock.fragment.Fragment` that modifies `frag` with
content that has been update with /jump_to_id links replaced
"""
return wrap_fragment(frag, static_replace.replace_jump_to_id_urls(frag.content, course_id, jump_to_id_base_url))
def replace_course_urls(course_id, block, view, frag, context): # pylint: disable=unused-argument
"""
Updates the supplied module with a new get_html function that wraps
the old get_html function and substitutes urls of the form /course/...
with urls that are /courses/<course_id>/...
"""
return wrap_fragment(frag, static_replace.replace_course_urls(frag.content, course_id))
def replace_static_urls(data_dir, block, view, frag, context, course_id=None, static_asset_path=''): # pylint: disable=unused-argument
"""
Updates the supplied module with a new get_html function that wraps
the old get_html function and substitutes urls of the form /static/...
with urls that are /static/<prefix>/...
"""
return wrap_fragment(frag, static_replace.replace_static_urls(
frag.content,
data_dir,
course_id,
static_asset_path=static_asset_path
))
def grade_histogram(module_id):
'''
Print out a histogram of grades on a given problem in staff member debug info.
Warning: If a student has just looked at an xmodule and not attempted
it, their grade is None. Since there will always be at least one such student
this function almost always returns [].
'''
from django.db import connection
cursor = connection.cursor()
query = """\
SELECT courseware_studentmodule.grade,
COUNT(courseware_studentmodule.student_id)
FROM courseware_studentmodule
WHERE courseware_studentmodule.module_id=%s
GROUP BY courseware_studentmodule.grade"""
# Passing module_id this way prevents sql-injection.
cursor.execute(query, [module_id.to_deprecated_string()])
grades = list(cursor.fetchall())
grades.sort(key=lambda x: x[0]) # Add ORDER BY to sql query?
if len(grades) >= 1 and grades[0][0] is None:
return []
return grades
def sanitize_html_id(html_id):
"""
Template uses element_id in js function names, so can't allow dashes and colons.
"""
sanitized_html_id = re.sub(r'[:-]', '_', html_id)
return sanitized_html_id
@contract(user=User, has_instructor_access=bool, block=XBlock, view=basestring, frag=Fragment, context="dict|None")
def add_staff_markup(user, has_instructor_access, disable_staff_debug_info, block, view, frag, context): # pylint: disable=unused-argument
"""
Updates the supplied module with a new get_html function that wraps
the output of the old get_html function with additional information
for admin users only, including a histogram of student answers, the
definition of the xmodule, and a link to view the module in Studio
if it is a Studio edited, mongo stored course.
Does nothing if module is a SequenceModule.
"""
# TODO: make this more general, eg use an XModule attribute instead
if isinstance(block, VerticalBlock) and (not context or not context.get('child_of_vertical', False)):
# check that the course is a mongo backed Studio course before doing work
is_mongo_course = modulestore().get_modulestore_type(block.location.course_key) != ModuleStoreEnum.Type.xml
is_studio_course = block.course_edit_method == "Studio"
if is_studio_course and is_mongo_course:
# build edit link to unit in CMS. Can't use reverse here as lms doesn't load cms's urls.py
edit_link = "//" + settings.CMS_BASE + '/container/' + unicode(block.location)
# return edit link in rendered HTML for display
return wrap_fragment(
frag,
render_to_string(
"edit_unit_link.html",
{'frag_content': frag.content, 'edit_link': edit_link}
)
)
else:
return frag
if isinstance(block, SequenceModule) or getattr(block, 'HIDDEN', False):
return frag
block_id = block.location
if block.has_score and settings.FEATURES.get('DISPLAY_HISTOGRAMS_TO_STAFF'):
histogram = grade_histogram(block_id)
render_histogram = len(histogram) > 0
else:
histogram = None
render_histogram = False
if settings.FEATURES.get('ENABLE_LMS_MIGRATION') and hasattr(block.runtime, 'filestore'):
[filepath, filename] = getattr(block, 'xml_attributes', {}).get('filename', ['', None])
osfs = block.runtime.filestore
if filename is not None and osfs.exists(filename):
# if original, unmangled filename exists then use it (github
# doesn't like symlinks)
filepath = filename
data_dir = block.static_asset_path or osfs.root_path.rsplit('/')[-1]
giturl = block.giturl or 'https://github.com/MITx'
edit_link = "%s/%s/tree/master/%s" % (giturl, data_dir, filepath)
else:
edit_link = False
# Need to define all the variables that are about to be used
giturl = ""
data_dir = ""
source_file = block.source_file # source used to generate the problem XML, eg latex or word
# Useful to indicate to staff if problem has been released or not.
# TODO (ichuang): use _has_access_descriptor.can_load in lms.courseware.access,
# instead of now>mstart comparison here.
now = datetime.datetime.now(UTC())
is_released = "unknown"
mstart = block.start
if mstart is not None:
is_released = "<font color='red'>Yes!</font>" if (now > mstart) else "<font color='green'>Not yet</font>"
field_contents = []
for name, field in block.fields.items():
try:
field_contents.append((name, field.read_from(block)))
except InvalidScopeError:
log.warning("Unable to read field in Staff Debug information", exc_info=True)
field_contents.append((name, "WARNING: Unable to read field"))
staff_context = {
'fields': field_contents,
'xml_attributes': getattr(block, 'xml_attributes', {}),
'tags': block._class_tags, # pylint: disable=protected-access
'location': block.location,
'xqa_key': block.xqa_key,
'source_file': source_file,
'source_url': '%s/%s/tree/master/%s' % (giturl, data_dir, source_file),
'category': str(block.__class__.__name__),
'element_id': sanitize_html_id(block.location.html_id()),
'edit_link': edit_link,
'user': user,
'xqa_server': settings.FEATURES.get('XQA_SERVER', "http://your_xqa_server.com"),
'histogram': json.dumps(histogram),
'render_histogram': render_histogram,
'block_content': frag.content,
'is_released': is_released,
'has_instructor_access': has_instructor_access,
'disable_staff_debug_info': disable_staff_debug_info,
}
return wrap_fragment(frag, render_to_string("staff_problem_info.html", staff_context))
def get_course_update_items(course_updates, provided_index=0):
"""
Returns list of course_updates data dictionaries either from new format if available or
from old. This function don't modify old data to new data (in db), instead returns data
in common old dictionary format.
New Format: {"items" : [{"id": computed_id, "date": date, "content": html-string}],
"data": "<ol>[<li><h2>date</h2>content</li>]</ol>"}
Old Format: {"data": "<ol>[<li><h2>date</h2>content</li>]</ol>"}
"""
def _course_info_content(html_parsed):
"""
Constructs the HTML for the course info update, not including the header.
"""
if len(html_parsed) == 1:
# could enforce that update[0].tag == 'h2'
content = html_parsed[0].tail
else:
content = html_parsed[0].tail if html_parsed[0].tail is not None else ""
content += "\n".join([html.tostring(ele) for ele in html_parsed[1:]])
return content
if course_updates and getattr(course_updates, "items", None):
if provided_index and 0 < provided_index <= len(course_updates.items):
return course_updates.items[provided_index - 1]
else:
# return list in reversed order (old format: [4,3,2,1]) for compatibility
return list(reversed(course_updates.items))
course_update_items = []
if course_updates:
# old method to get course updates
# purely to handle free formed updates not done via editor. Actually kills them, but at least doesn't break.
try:
course_html_parsed = html.fromstring(course_updates.data)
except (etree.XMLSyntaxError, etree.ParserError):
log.error("Cannot parse: " + course_updates.data)
escaped = escape(course_updates.data)
course_html_parsed = html.fromstring("<ol><li>" + escaped + "</li></ol>")
# confirm that root is <ol>, iterate over <li>, pull out <h2> subs and then rest of val
if course_html_parsed.tag == 'ol':
# 0 is the newest
for index, update in enumerate(course_html_parsed):
if len(update) > 0:
content = _course_info_content(update)
# make the id on the client be 1..len w/ 1 being the oldest and len being the newest
computed_id = len(course_html_parsed) - index
payload = {
"id": computed_id,
"date": update.findtext("h2"),
"content": content
}
if provided_index == 0:
course_update_items.append(payload)
elif provided_index == computed_id:
return payload
return course_update_items