Files
edx-platform/cms/djangoapps/contentstore/course_info_model.py
2012-11-30 10:41:10 -05:00

148 lines
6.5 KiB
Python

from xmodule.modulestore.exceptions import ItemNotFoundError
from xmodule.modulestore import Location
from xmodule.modulestore.django import modulestore
from lxml import etree
import re
from django.http import HttpResponseBadRequest
## TODO store as array of { date, content } and override course_info_module.definition_from_xml
## This should be in a class which inherits from XmlDescriptor
def get_course_updates(location):
"""
Retrieve the relevant course_info updates and unpack into the model which the client expects:
[{id : location.url() + idx to make unique, date : string, content : html string}]
"""
try:
course_updates = modulestore('direct').get_item(location)
except ItemNotFoundError:
template = Location(['i4x', 'edx', "templates", 'course_info', "Empty"])
course_updates = modulestore('direct').clone_item(template, Location(location))
# current db rep: {"_id" : locationjson, "definition" : { "data" : "<ol>[<li><h2>date</h2>content</li>]</ol>"} "metadata" : ignored}
location_base = course_updates.location.url()
# purely to handle free formed updates not done via editor. Actually kills them, but at least doesn't break.
try:
course_html_parsed = etree.fromstring(course_updates.definition['data'], etree.XMLParser(remove_blank_text=True))
except etree.XMLSyntaxError:
course_html_parsed = etree.fromstring("<ol></ol>")
# Confirm that root is <ol>, iterate over <li>, pull out <h2> subs and then rest of val
course_upd_collection = []
if course_html_parsed.tag == 'ol':
# 0 is the oldest so that new ones get unique idx
for idx, update in enumerate(course_html_parsed.iter("li")):
if (len(update) == 0):
continue
elif (len(update) == 1):
content = update.find("h2").tail
else:
content = etree.tostring(update[1])
course_upd_collection.append({"id" : location_base + "/" + str(idx),
"date" : update.findtext("h2"),
"content" : content})
# return newest to oldest
course_upd_collection.reverse()
return course_upd_collection
def update_course_updates(location, update, passed_id=None):
"""
Either add or update the given course update. It will add it if the passed_id is absent or None. It will update it if
it has an passed_id which has a valid value. Until updates have distinct values, the passed_id is the location url + an index
into the html structure.
"""
try:
course_updates = modulestore('direct').get_item(location)
except ItemNotFoundError:
return HttpResponseBadRequest
# purely to handle free formed updates not done via editor. Actually kills them, but at least doesn't break.
try:
course_html_parsed = etree.fromstring(course_updates.definition['data'], etree.XMLParser(remove_blank_text=True))
except etree.XMLSyntaxError:
course_html_parsed = etree.fromstring("<ol></ol>")
try:
new_html_parsed = etree.fromstring(update['content'], etree.XMLParser(remove_blank_text=True))
except etree.XMLSyntaxError:
new_html_parsed = None
# Confirm that root is <ol>, iterate over <li>, pull out <h2> subs and then rest of val
if course_html_parsed.tag == 'ol':
# ??? Should this use the id in the json or in the url or does it matter?
if passed_id:
element = course_html_parsed.findall("li")[get_idx(passed_id)]
element[0].text = update['date']
if (len(element) == 1):
if new_html_parsed is not None:
element[0].tail = None
element.append(new_html_parsed)
else:
element[0].tail = update['content']
else:
if new_html_parsed is not None:
element[1] = new_html_parsed
else:
element.pop(1)
element[0].tail = update['content']
else:
idx = len(course_html_parsed.findall("li"))
passed_id = course_updates.location.url() + "/" + str(idx)
element = etree.SubElement(course_html_parsed, "li")
date_element = etree.SubElement(element, "h2")
date_element.text = update['date']
if new_html_parsed is not None:
element.append(new_html_parsed)
else:
date_element.tail = update['content']
# update db record
course_updates.definition['data'] = etree.tostring(course_html_parsed)
modulestore('direct').update_item(location, course_updates.definition['data'])
return {"id" : passed_id,
"date" : update['date'],
"content" :update['content']}
def delete_course_update(location, update, passed_id):
"""
Delete the given course_info update from the db.
Returns the resulting course_updates b/c their ids change.
"""
if not passed_id:
return HttpResponseBadRequest
try:
course_updates = modulestore('direct').get_item(location)
except ItemNotFoundError:
return HttpResponseBadRequest
# TODO use delete_blank_text parser throughout and cache as a static var in a class
# purely to handle free formed updates not done via editor. Actually kills them, but at least doesn't break.
try:
course_html_parsed = etree.fromstring(course_updates.definition['data'], etree.XMLParser(remove_blank_text=True))
except etree.XMLSyntaxError:
course_html_parsed = etree.fromstring("<ol></ol>")
if course_html_parsed.tag == 'ol':
# ??? Should this use the id in the json or in the url or does it matter?
element_to_delete = course_html_parsed.xpath('/ol/li[position()=' + str(get_idx(passed_id) + 1) + "]")
if element_to_delete:
course_html_parsed.remove(element_to_delete[0])
# update db record
course_updates.definition['data'] = etree.tostring(course_html_parsed)
store = modulestore('direct')
store.update_item(location, course_updates.definition['data'])
return get_course_updates(location)
def get_idx(passed_id):
"""
From the url w/ idx appended, get the idx.
"""
# TODO compile this regex into a class static and reuse for each call
idx_matcher = re.search(r'.*/(\d)+$', passed_id)
if idx_matcher:
return int(idx_matcher.group(1))