from __future__ import absolute_import
import logging
from django.conf import settings
from django.contrib.auth.decorators import login_required
from django.core.exceptions import PermissionDenied
from django.http import Http404, HttpResponseBadRequest
from django.utils.translation import ugettext as _
from django.views.decorators.http import require_GET
from opaque_keys import InvalidKeyError
from opaque_keys.edx.asides import AsideUsageKeyV1, AsideUsageKeyV2
from opaque_keys.edx.keys import UsageKey
from xblock.core import XBlock
from xblock.django.request import django_to_webob_request, webob_to_django_response
from xblock.exceptions import NoSuchHandlerError
from xblock.plugin import PluginMissingError
from xblock.runtime import Mixologist
from contentstore.utils import get_lms_link_for_item, get_xblock_aside_instance, reverse_course_url
from contentstore.views.helpers import get_parent_xblock, is_unit, xblock_type_display_name
from contentstore.views.item import StudioEditModuleRuntime, add_container_page_publishing_info, create_xblock_info
from edxmako.shortcuts import render_to_response
from student.auth import has_course_author_access
from xblock_django.api import authorable_xblocks, disabled_xblocks
from xblock_django.models import XBlockStudioConfigurationFlag
from xmodule.modulestore.django import modulestore
from xmodule.modulestore.exceptions import ItemNotFoundError
__all__ = [
'container_handler',
'component_handler'
]
log = logging.getLogger(__name__)
# NOTE: This list is disjoint from ADVANCED_COMPONENT_TYPES
COMPONENT_TYPES = ['discussion', 'html', 'problem', 'video']
ADVANCED_COMPONENT_TYPES = sorted(set(name for name, class_ in XBlock.load_classes()) - set(COMPONENT_TYPES))
ADVANCED_PROBLEM_TYPES = settings.ADVANCED_PROBLEM_TYPES
CONTAINER_TEMPLATES = [
"basic-modal", "modal-button", "edit-xblock-modal",
"editor-mode-button", "upload-dialog",
"add-xblock-component", "add-xblock-component-button", "add-xblock-component-menu",
"add-xblock-component-support-legend", "add-xblock-component-support-level", "add-xblock-component-menu-problem",
"xblock-string-field-editor", "xblock-access-editor", "publish-xblock", "publish-history",
"unit-outline", "container-message", "container-access", "license-selector",
]
def _advanced_component_types(show_unsupported):
"""
Return advanced component types which can be created.
Args:
show_unsupported: if True, unsupported XBlocks may be included in the return value
Returns:
A dict of authorable XBlock types and their support levels (see XBlockStudioConfiguration). For example:
{
"done": "us", # unsupported
"discussion: "fs" # fully supported
}
Note that the support level will be "True" for all XBlocks if XBlockStudioConfigurationFlag
is not enabled.
"""
enabled_block_types = _filter_disabled_blocks(ADVANCED_COMPONENT_TYPES)
if XBlockStudioConfigurationFlag.is_enabled():
authorable_blocks = authorable_xblocks(allow_unsupported=show_unsupported)
filtered_blocks = {}
for block in authorable_blocks:
if block.name in enabled_block_types:
filtered_blocks[block.name] = block.support_level
return filtered_blocks
else:
all_blocks = {}
for block_name in enabled_block_types:
all_blocks[block_name] = True
return all_blocks
def _load_mixed_class(category):
"""
Load an XBlock by category name, and apply all defined mixins
"""
component_class = XBlock.load_class(category, select=settings.XBLOCK_SELECT_FUNCTION)
mixologist = Mixologist(settings.XBLOCK_MIXINS)
return mixologist.mix(component_class)
@require_GET
@login_required
def container_handler(request, usage_key_string):
"""
The restful handler for container xblock requests.
GET
html: returns the HTML page for editing a container
json: not currently supported
"""
if 'text/html' in request.META.get('HTTP_ACCEPT', 'text/html'):
try:
usage_key = UsageKey.from_string(usage_key_string)
except InvalidKeyError: # Raise Http404 on invalid 'usage_key_string'
raise Http404
with modulestore().bulk_operations(usage_key.course_key):
try:
course, xblock, lms_link, preview_lms_link = _get_item_in_course(request, usage_key)
except ItemNotFoundError:
return HttpResponseBadRequest()
component_templates = get_component_templates(course)
ancestor_xblocks = []
parent = get_parent_xblock(xblock)
action = request.GET.get('action', 'view')
is_unit_page = is_unit(xblock)
unit = xblock if is_unit_page else None
while parent and parent.category != 'course':
if unit is None and is_unit(parent):
unit = parent
ancestor_xblocks.append(parent)
parent = get_parent_xblock(parent)
ancestor_xblocks.reverse()
assert unit is not None, "Could not determine unit page"
subsection = get_parent_xblock(unit)
assert subsection is not None, "Could not determine parent subsection from unit " + unicode(unit.location)
section = get_parent_xblock(subsection)
assert section is not None, "Could not determine ancestor section from unit " + unicode(unit.location)
# Fetch the XBlock info for use by the container page. Note that it includes information
# about the block's ancestors and siblings for use by the Unit Outline.
xblock_info = create_xblock_info(xblock, include_ancestor_info=is_unit_page)
if is_unit_page:
add_container_page_publishing_info(xblock, xblock_info)
# need to figure out where this item is in the list of children as the
# preview will need this
index = 1
for child in subsection.get_children():
if child.location == unit.location:
break
index += 1
return render_to_response('container.html', {
'context_course': course, # Needed only for display of menus at top of page.
'action': action,
'xblock': xblock,
'xblock_locator': xblock.location,
'unit': unit,
'is_unit_page': is_unit_page,
'subsection': subsection,
'section': section,
'new_unit_category': 'vertical',
'outline_url': '{url}?format=concise'.format(url=reverse_course_url('course_handler', course.id)),
'ancestor_xblocks': ancestor_xblocks,
'component_templates': component_templates,
'xblock_info': xblock_info,
'draft_preview_link': preview_lms_link,
'published_preview_link': lms_link,
'templates': CONTAINER_TEMPLATES
})
else:
return HttpResponseBadRequest("Only supports HTML requests")
def get_component_templates(courselike, library=False):
"""
Returns the applicable component templates that can be used by the specified course or library.
"""
def create_template_dict(name, category, support_level, boilerplate_name=None, tab="common", hinted=False):
"""
Creates a component template dict.
Parameters
display_name: the user-visible name of the component
category: the type of component (problem, html, etc.)
support_level: the support level of this component
boilerplate_name: name of boilerplate for filling in default values. May be None.
hinted: True if hinted problem else False
tab: common(default)/advanced, which tab it goes in
"""
return {
"display_name": name,
"category": category,
"boilerplate_name": boilerplate_name,
"hinted": hinted,
"tab": tab,
"support_level": support_level
}
def component_support_level(editable_types, name, template=None):
"""
Returns the support level for the given xblock name/template combination.
Args:
editable_types: a QuerySet of xblocks with their support levels
name: the name of the xblock
template: optional template for the xblock
Returns:
If XBlockStudioConfigurationFlag is enabled, returns the support level
(see XBlockStudioConfiguration) or False if this xblock name/template combination
has no Studio support at all. If XBlockStudioConfigurationFlag is disabled,
simply returns True.
"""
# If the Studio support feature is disabled, return True for all.
if not XBlockStudioConfigurationFlag.is_enabled():
return True
if template is None:
template = ""
extension_index = template.rfind(".yaml")
if extension_index >= 0:
template = template[0:extension_index]
for block in editable_types:
if block.name == name and block.template == template:
return block.support_level
return False
def create_support_legend_dict():
"""
Returns a dict of settings information for the display of the support level legend.
"""
return {
"show_legend": XBlockStudioConfigurationFlag.is_enabled(),
"allow_unsupported_xblocks": allow_unsupported,
"documentation_label": _("{platform_name} Support Levels:").format(platform_name=settings.PLATFORM_NAME)
}
component_display_names = {
'discussion': _("Discussion"),
'html': _("HTML"),
'problem': _("Problem"),
'video': _("Video")
}
component_templates = []
categories = set()
# The component_templates array is in the order of "advanced" (if present), followed
# by the components in the order listed in COMPONENT_TYPES.
component_types = COMPONENT_TYPES[:]
# Libraries do not support discussions
if library:
component_types = [component for component in component_types if component != 'discussion']
component_types = _filter_disabled_blocks(component_types)
# Content Libraries currently don't allow opting in to unsupported xblocks/problem types.
allow_unsupported = getattr(courselike, "allow_unsupported_xblocks", False)
for category in component_types:
authorable_variations = authorable_xblocks(allow_unsupported=allow_unsupported, name=category)
support_level_without_template = component_support_level(authorable_variations, category)
templates_for_category = []
component_class = _load_mixed_class(category)
if support_level_without_template:
# add the default template with localized display name
# TODO: Once mixins are defined per-application, rather than per-runtime,
# this should use a cms mixed-in class. (cpennington)
display_name = xblock_type_display_name(category, _('Blank')) # this is the Blank Advanced problem
templates_for_category.append(
create_template_dict(display_name, category, support_level_without_template, None, 'advanced')
)
categories.add(category)
# add boilerplates
if hasattr(component_class, 'templates'):
for template in component_class.templates():
filter_templates = getattr(component_class, 'filter_templates', None)
if not filter_templates or filter_templates(template, courselike):
template_id = template.get('template_id')
support_level_with_template = component_support_level(
authorable_variations, category, template_id
)
if support_level_with_template:
# Tab can be 'common' 'advanced'
# Default setting is common/advanced depending on the presence of markdown
tab = 'common'
if template['metadata'].get('markdown') is None:
tab = 'advanced'
hinted = template.get('hinted', False)
templates_for_category.append(
create_template_dict(
_(template['metadata'].get('display_name')), # pylint: disable=translation-of-non-string
category,
support_level_with_template,
template_id,
tab,
hinted,
)
)
# Add any advanced problem types. Note that these are different xblocks being stored as Advanced Problems,
# currently not supported in libraries .
if category == 'problem' and not library:
disabled_block_names = [block.name for block in disabled_xblocks()]
advanced_problem_types = [advanced_problem_type for advanced_problem_type in ADVANCED_PROBLEM_TYPES
if advanced_problem_type['component'] not in disabled_block_names]
for advanced_problem_type in advanced_problem_types:
component = advanced_problem_type['component']
boilerplate_name = advanced_problem_type['boilerplate_name']
authorable_advanced_component_variations = authorable_xblocks(
allow_unsupported=allow_unsupported, name=component
)
advanced_component_support_level = component_support_level(
authorable_advanced_component_variations, component, boilerplate_name
)
if advanced_component_support_level:
try:
component_display_name = xblock_type_display_name(component)
except PluginMissingError:
log.warning('Unable to load xblock type %s to read display_name', component, exc_info=True)
else:
templates_for_category.append(
create_template_dict(
component_display_name,
component,
advanced_component_support_level,
boilerplate_name,
'advanced'
)
)
categories.add(component)
component_templates.append({
"type": category,
"templates": templates_for_category,
"display_name": component_display_names[category],
"support_legend": create_support_legend_dict()
})
# Libraries do not support advanced components at this time.
if library:
return component_templates
# Check if there are any advanced modules specified in the course policy.
# These modules should be specified as a list of strings, where the strings
# are the names of the modules in ADVANCED_COMPONENT_TYPES that should be
# enabled for the course.
course_advanced_keys = courselike.advanced_modules
advanced_component_templates = {
"type": "advanced",
"templates": [],
"display_name": _("Advanced"),
"support_legend": create_support_legend_dict()
}
advanced_component_types = _advanced_component_types(allow_unsupported)
# Set component types according to course policy file
if isinstance(course_advanced_keys, list):
for category in course_advanced_keys:
if category in advanced_component_types.keys() and category not in categories:
# boilerplates not supported for advanced components
try:
component_display_name = xblock_type_display_name(category, default_display_name=category)
advanced_component_templates['templates'].append(
create_template_dict(
component_display_name,
category,
advanced_component_types[category]
)
)
categories.add(category)
except PluginMissingError:
# dhm: I got this once but it can happen any time the
# course author configures an advanced component which does
# not exist on the server. This code here merely
# prevents any authors from trying to instantiate the
# non-existent component type by not showing it in the menu
log.warning(
"Advanced component %s does not exist. It will not be added to the Studio new component menu.",
category
)
else:
log.error(
"Improper format for course advanced keys! %s",
course_advanced_keys
)
if len(advanced_component_templates['templates']) > 0:
component_templates.insert(0, advanced_component_templates)
return component_templates
def _filter_disabled_blocks(all_blocks):
"""
Filter out disabled xblocks from the provided list of xblock names.
"""
disabled_block_names = [block.name for block in disabled_xblocks()]
return [block_name for block_name in all_blocks if block_name not in disabled_block_names]
@login_required
def _get_item_in_course(request, usage_key):
"""
Helper method for getting the old location, containing course,
item, lms_link, and preview_lms_link for a given locator.
Verifies that the caller has permission to access this item.
"""
# usage_key's course_key may have an empty run property
usage_key = usage_key.replace(course_key=modulestore().fill_in_run(usage_key.course_key))
course_key = usage_key.course_key
if not has_course_author_access(request.user, course_key):
raise PermissionDenied()
course = modulestore().get_course(course_key)
item = modulestore().get_item(usage_key, depth=1)
lms_link = get_lms_link_for_item(item.location)
preview_lms_link = get_lms_link_for_item(item.location, preview=True)
return course, item, lms_link, preview_lms_link
@login_required
def component_handler(request, usage_key_string, handler, suffix=''):
"""
Dispatch an AJAX action to an xblock
Args:
usage_id: The usage-id of the block to dispatch to
handler (str): The handler to execute
suffix (str): The remainder of the url to be passed to the handler
Returns:
:class:`django.http.HttpResponse`: The response from the handler, converted to a
django response
"""
usage_key = UsageKey.from_string(usage_key_string)
# Let the module handle the AJAX
req = django_to_webob_request(request)
asides = []
try:
if isinstance(usage_key, (AsideUsageKeyV1, AsideUsageKeyV2)):
descriptor = modulestore().get_item(usage_key.usage_key)
aside_instance = get_xblock_aside_instance(usage_key)
asides = [aside_instance] if aside_instance else []
resp = aside_instance.handle(handler, req, suffix)
else:
descriptor = modulestore().get_item(usage_key)
descriptor.xmodule_runtime = StudioEditModuleRuntime(request.user)
resp = descriptor.handle(handler, req, suffix)
except NoSuchHandlerError:
log.info("XBlock %s attempted to access missing handler %r", descriptor, handler, exc_info=True)
raise Http404
# unintentional update to handle any side effects of handle call
# could potentially be updating actual course data or simply caching its values
modulestore().update_item(descriptor, request.user.id, asides=asides)
return webob_to_django_response(resp)