Merge pull request #10878 from mitocw/refactor/aq/move_code_from_view

CCX app refactoring. Moved some code to utils.py from views.py

lms/djangoapps/ccx/utils.py

@@ -3,14 +3,43 @@ CCX Enrollment operations for use by Coach APIs.
 
 Does not include any access control, be sure to check access before calling.
 """
+import datetime
 import logging
+import pytz
 
-from lms.djangoapps.ccx.models import CustomCourseForEdX
+from contextlib import contextmanager
+
+from django.contrib.auth.models import User
+from django.core.exceptions import ValidationError
+from django.utils.translation import ugettext as _
+from django.core.validators import validate_email
+from openedx.core.djangoapps.content.course_overviews.models import CourseOverview
 
+from courseware.courses import get_course_by_id
+from courseware.model_data import FieldDataCache
+from courseware.module_render import get_module_for_descriptor
+from instructor.enrollment import (
+    enroll_email,
+    unenroll_email,
+)
+from instructor.access import allow_access
+from instructor.views.tools import get_student_from_identifier
+from student.models import CourseEnrollment
+from student.roles import CourseCcxCoachRole
+
+from lms.djangoapps.ccx.models import CustomCourseForEdX
+from lms.djangoapps.ccx.overrides import get_override_for_ccx
 
 log = logging.getLogger("edx.ccx")
 
 
+class CCXUserValidationException(Exception):
+    """
+    Custom Exception for validation of users in CCX
+    """
+    pass
+
+
 def get_ccx_from_ccx_locator(course_id):
     """ helper function to allow querying ccx fields from templates """
     ccx_id = getattr(course_id, 'ccx', None)
@@ -24,3 +53,206 @@ def get_ccx_from_ccx_locator(course_id):
         )
         return None
     return ccx[0]
+
+
+def get_date(ccx, node, date_type=None, parent_node=None):
+    """
+    This returns override or master date for section, subsection or a unit.
+
+    :param ccx: ccx instance
+    :param node: chapter, subsection or unit
+    :param date_type: start or due
+    :param parent_node: parent of node
+    :return: start or due date
+    """
+    date = get_override_for_ccx(ccx, node, date_type, None)
+    if date_type == "start":
+        master_date = node.start
+    else:
+        master_date = node.due
+
+    if date is not None:
+        # Setting override date [start or due]
+        date = date.strftime('%Y-%m-%d %H:%M')
+    elif not parent_node and master_date is not None:
+        # Setting date from master course
+        date = master_date.strftime('%Y-%m-%d %H:%M')
+    elif parent_node is not None:
+        # Set parent date (vertical has same dates as subsections)
+        date = get_date(ccx, node=parent_node, date_type=date_type)
+
+    return date
+
+
+def validate_date(year, month, day, hour, minute):
+    """
+    avoid corrupting db if bad dates come in
+    """
+    valid = True
+    if year < 0:
+        valid = False
+    if month < 1 or month > 12:
+        valid = False
+    if day < 1 or day > 31:
+        valid = False
+    if hour < 0 or hour > 23:
+        valid = False
+    if minute < 0 or minute > 59:
+        valid = False
+    return valid
+
+
+def parse_date(datestring):
+    """
+    Generate a UTC datetime.datetime object from a string of the form
+    'YYYY-MM-DD HH:MM'.  If string is empty or `None`, returns `None`.
+    """
+    if datestring:
+        date, time = datestring.split(' ')
+        year, month, day = map(int, date.split('-'))
+        hour, minute = map(int, time.split(':'))
+        if validate_date(year, month, day, hour, minute):
+            return datetime.datetime(
+                year, month, day, hour, minute, tzinfo=pytz.UTC)
+
+    return None
+
+
+def get_ccx_for_coach(course, coach):
+    """
+    Looks to see if user is coach of a CCX for this course.  Returns the CCX or
+    None.
+    """
+    ccxs = CustomCourseForEdX.objects.filter(
+        course_id=course.id,
+        coach=coach
+    )
+    # XXX: In the future, it would be nice to support more than one ccx per
+    # coach per course.  This is a place where that might happen.
+    if ccxs.exists():
+        return ccxs[0]
+    return None
+
+
+def get_valid_student_email(identifier):
+    """
+    Helper function to get an user email from an identifier and validate it.
+
+    In the UI a Coach can enroll users using both an email and an username.
+    This function takes care of:
+    - in case the identifier is an username, extracting the user object from
+        the DB and then the associated email
+    - validating the email
+
+    Arguments:
+        identifier (str): Username or email of the user to enroll
+
+    Returns:
+        str: A validated email for the user to enroll
+
+    Raises:
+        CCXUserValidationException: if the username is not found or the email
+            is not valid.
+    """
+    user = email = None
+    try:
+        user = get_student_from_identifier(identifier)
+    except User.DoesNotExist:
+        email = identifier
+    else:
+        email = user.email
+    try:
+        validate_email(email)
+    except ValidationError:
+        raise CCXUserValidationException('Could not find a user with name or email "{0}" '.format(identifier))
+    return email
+
+
+def ccx_students_enrolling_center(action, identifiers, email_students, course_key, email_params):
+    """
+    Function to enroll/add or unenroll/revoke students.
+
+    This function exists for backwards compatibility: in CCX there are
+    two different views to manage students that used to implement
+    a different logic. Now the logic has been reconciled at the point that
+    this function can be used by both.
+    The two different views can be merged after some UI refactoring.
+
+    Arguments:
+        action (str): type of action to perform (add, Enroll, revoke, Unenroll)
+        identifiers (list): list of students username/email
+        email_students (bool): Flag to send an email to students
+        course_key (CCXLocator): a CCX course key
+        email_params (dict): dictionary of settings for the email to be sent
+
+    Returns:
+        list: list of error
+    """
+    errors = []
+
+    if action == 'Enroll' or action == 'add':
+        ccx_course_overview = CourseOverview.get_from_id(course_key)
+        for identifier in identifiers:
+            if CourseEnrollment.objects.is_course_full(ccx_course_overview):
+                error = _('The course is full: the limit is {max_student_enrollments_allowed}').format(
+                    max_student_enrollments_allowed=ccx_course_overview.max_student_enrollments_allowed)
+                log.info("%s", error)
+                errors.append(error)
+                break
+            try:
+                email = get_valid_student_email(identifier)
+            except CCXUserValidationException as exp:
+                log.info("%s", exp)
+                errors.append("{0}".format(exp))
+                continue
+            enroll_email(course_key, email, auto_enroll=True, email_students=email_students, email_params=email_params)
+    elif action == 'Unenroll' or action == 'revoke':
+        for identifier in identifiers:
+            try:
+                email = get_valid_student_email(identifier)
+            except CCXUserValidationException as exp:
+                log.info("%s", exp)
+                errors.append("{0}".format(exp))
+                continue
+            unenroll_email(course_key, email, email_students=email_students, email_params=email_params)
+    return errors
+
+
+def prep_course_for_grading(course, request):
+    """Set up course module for overrides to function properly"""
+    field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
+        course.id, request.user, course, depth=2)
+    course = get_module_for_descriptor(
+        request.user, request, course, field_data_cache, course.id, course=course
+    )
+
+    course._field_data_cache = {}  # pylint: disable=protected-access
+    course.set_grading_policy(course.grading_policy)
+
+
+@contextmanager
+def ccx_course(ccx_locator):
+    """Create a context in which the course identified by course_locator exists
+    """
+    course = get_course_by_id(ccx_locator)
+    yield course
+
+
+def assign_coach_role_to_ccx(ccx_locator, user, master_course_id):
+    """
+    Check if user has ccx_coach role on master course then assign him coach role on ccx only
+    if role is not already assigned. Because of this coach can open dashboard from master course
+    as well as ccx.
+    :param ccx_locator: CCX key
+    :param user: User to whom we want to assign role.
+    :param master_course_id: Master course key
+    """
+    coach_role_on_master_course = CourseCcxCoachRole(master_course_id)
+    # check if user has coach role on master course
+    if coach_role_on_master_course.has_user(user):
+        # Check if user has coach role on ccx.
+        role = CourseCcxCoachRole(ccx_locator)
+        if not role.has_user(user):
+            # assign user role coach on ccx
+            with ccx_course(ccx_locator) as course:
+                allow_access(course, user, "ccx_coach", send_email=False)