TNL-1907 Implement Course Team Membership API

lms/djangoapps/teams/api_urls.py

@@ -7,7 +7,9 @@ from .views import (
     TeamsListView,
     TeamsDetailView,
     TopicDetailView,
-    TopicListView
+    TopicListView,
+    MembershipListView,
+    MembershipDetailView
 )
 
 TEAM_ID_PATTERN = r'(?P<team_id>[a-z\d_-]+)'
@@ -35,5 +37,15 @@ urlpatterns = patterns(
         r'^v0/topics/' + TOPIC_ID_PATTERN + ',' + settings.COURSE_ID_PATTERN + '$',
         TopicDetailView.as_view(),
         name="topics_detail"
+    ),
+    url(
+        r'^v0/team_membership$',
+        MembershipListView.as_view(),
+        name="team_membership_list"
+    ),
+    url(
+        r'^v0/team_membership/' + TEAM_ID_PATTERN + ',' + USERNAME_PATTERN + '$',
+        MembershipDetailView.as_view(),
+        name="team_membership_detail"
     )
 )

lms/djangoapps/teams/errors.py

+"""Errors thrown in the Team API"""
+
+
+class TeamAPIRequestError(Exception):
+    """There was a problem with a request to the Team API."""
+    pass
+
+
+class NotEnrolledInCourseForTeam(TeamAPIRequestError):
+    """User is not enrolled in the course for the team they are trying to join."""
+    pass
+
+
+class AlreadyOnTeamInCourse(TeamAPIRequestError):
+    """User is already a member of another team in the same course."""
+    pass

lms/djangoapps/teams/models.py

@@ -7,7 +7,8 @@ from django_countries.fields import CountryField
 
 from xmodule_django.models import CourseKeyField
 from util.model_utils import generate_unique_readable_id
-from student.models import LanguageField
+from student.models import LanguageField, CourseEnrollment
+from .errors import AlreadyOnTeamInCourse, NotEnrolledInCourseForTeam
 
 
 class CourseTeam(models.Model):
@@ -62,7 +63,11 @@ class CourseTeam(models.Model):
 
     def add_user(self, user):
         """Adds the given user to the CourseTeam."""
-        CourseTeamMembership.objects.get_or_create(
+        if not CourseEnrollment.is_enrolled(user, self.course_id):
+            raise NotEnrolledInCourseForTeam
+        if CourseTeamMembership.objects.filter(user=user, team__course_id=self.course_id).exists():
+            raise AlreadyOnTeamInCourse
+        return CourseTeamMembership.objects.create(
             user=user,
             team=self
         )

openedx/core/lib/api/view_utils.py

@@ -70,6 +70,16 @@ class DeveloperErrorViewMixin(object):
             raise
 
 
+class ExpandableFieldViewMixin(object):
+    """A view mixin to add expansion information to the serializer context for later use by an ExpandableField."""
+
+    def get_serializer_context(self):
+        """Adds expand information from query parameters to the serializer context to support expandable fields."""
+        result = super(ExpandableFieldViewMixin, self).get_serializer_context()
+        result['expand'] = [x for x in self.request.QUERY_PARAMS.get('expand', '').split(',') if x]
+        return result
+
+
 def view_course_access(depth=0, access_action='load', check_for_milestones=False):
     """
     Method decorator for an API endpoint that verifies the user has access to the course.
@@ -142,6 +152,21 @@ def add_serializer_errors(serializer, data, field_errors):
     return field_errors
 
 
+def build_api_error(message, **kwargs):
+    """Build an error dict corresponding to edX API conventions.
+
+    Args:
+        message (string): The string to use for developer and user messages.
+            The user message will be translated, but for this to work message
+            must have already been scraped. ugettext_noop is useful for this.
+        **kwargs: format parameters for message
+    """
+    return {
+        'developer_message': message.format(**kwargs),
+        'user_message': _(message).format(**kwargs),  # pylint: disable=translation-of-non-string
+    }
+
+
 class RetrievePatchAPIView(RetrieveModelMixin, UpdateModelMixin, GenericAPIView):
     """Concrete view for retrieving and updating a model instance.