Files
edx-platform/common/lib/xmodule/xmodule/templates.py
2013-05-14 09:37:13 -04:00

110 lines
4.2 KiB
Python

"""
This module handles loading xmodule templates from disk into the modulestore.
These templates are used by the CMS to provide baseline content that
can be cloned when adding new modules to a course.
`Template`s are defined in x_module. They contain 3 attributes:
metadata: A dictionary with the template metadata. This should contain
any values for fields
* with scope Scope.settings
* that have values different than the field defaults
* and that are to be editable in Studio
data: A JSON value that defines the template content. This should be a dictionary
containing values for fields
* with scope Scope.content
* that have values different than the field defaults
* and that are to be editable in Studio
or, if the module uses a single Scope.content String field named `data`, this
should be a string containing the contents of that field
children: A list of Location urls that define the template children
Templates are defined on XModuleDescriptor types, in the template attribute.
"""
import logging
from fs.memoryfs import MemoryFS
from collections import defaultdict
from .x_module import XModuleDescriptor
from .mako_module import MakoDescriptorSystem
from .modulestore import Location
log = logging.getLogger(__name__)
def all_templates():
"""
Returns all templates for enabled modules, grouped by descriptor type
"""
templates = defaultdict(list)
for category, descriptor in XModuleDescriptor.load_classes():
templates[category] = descriptor.templates()
return templates
class TemplateTestSystem(MakoDescriptorSystem):
"""
This system exists to help verify that XModuleDescriptors can be instantiated
from their defined templates before we load the templates into the modulestore.
"""
def __init__(self):
super(TemplateTestSystem, self).__init__(
lambda *a, **k: None,
MemoryFS(),
lambda msg: None,
render_template=lambda *a, **k: None,
)
def update_templates(modulestore):
"""
Updates the set of templates in the modulestore with all templates currently
available from the installed plugins
"""
# cdodge: build up a list of all existing templates. This will be used to determine which
# templates have been removed from disk - and thus we need to remove from the DB
templates_to_delete = modulestore.get_items(['i4x', 'edx', 'templates', None, None, None])
for category, templates in all_templates().items():
for template in templates:
if 'display_name' not in template.metadata:
log.warning('No display_name specified in template {0}, skipping'.format(template))
continue
template_location = Location('i4x', 'edx', 'templates', category, Location.clean_for_url_name(template.metadata['display_name']))
try:
json_data = {
'definition': {
'data': template.data,
'children': template.children
},
'metadata': template.metadata
}
json_data['location'] = template_location.dict()
XModuleDescriptor.load_from_json(json_data, TemplateTestSystem())
except:
log.warning('Unable to instantiate {cat} from template {template}, skipping'.format(
cat=category,
template=template
), exc_info=True)
continue
modulestore.update_item(template_location, template.data)
modulestore.update_children(template_location, template.children)
modulestore.update_metadata(template_location, template.metadata)
# remove template from list of templates to delete
templates_to_delete = [t for t in templates_to_delete if t.location != template_location]
# now remove all templates which appear to have removed from disk
if len(templates_to_delete) > 0:
logging.debug('deleting dangling templates = {0}'.format(templates_to_delete))
for template in templates_to_delete:
modulestore.delete_item(template.location)