My first pass at populate the submission API.

apps/openassessment/peer/api.py

@@ -10,8 +10,14 @@ might be tricky with XML import based courses).
 
 """
 
+
 def create_evaluation(submission_id, score, rubric):
     pass
 
+
+def get_evaluations(submission_id):
+    pass
+
+
 def get_submission_to_evaluate(student_item, scorer_student_id):
     pass

apps/submissions/api.py

@@ -2,20 +2,61 @@
 Public interface for the submissions app.
 
 """
+from datetime import datetime
+
+from submissions.serializers import SubmissionSerializer
+from submissions.models import Submission, StudentItem, SubmissionStruct
+
 
 def create_submission(student_item, answer, submitted_at=None):
-    # score could be an optional param in the future.
-    pass
+    student_item = _get_student_item(student_item)
+    submitted_at = submitted_at if submitted_at else datetime.now()
+    if student_item:
+        submissions = Submission.objects.filter(student_item=student_item).order_by("submitted_at")[:0]
+        attempt_number = submissions[0].attempt_number if submissions else 1
+
+        submission = Submission.objects.create(
+            student_item=student_item,
+            submitted_at=submitted_at,
+            answer=answer,
+            attempt_number=attempt_number,
+        )
+        return SubmissionStruct(**SubmissionSerializer(submission).data)
+
 
 def get_submissions(student_item, limit=None):
-    pass
+    student_item = _get_student_item(student_item)
+    item_response = StudentItem.objects.get_or_create(
+        student_id=student_item.student_id,
+        course_id=student_item.course_id,
+        item_id=student_item.item_id,
+        item_type=student_item.item_type,
+    )
+
+    if limit:
+        submission_models = Submission.objects.filter(student_item=item_response[0])[:limit]
+    else:
+        submission_models = Submission.objects.filter(student_item=item_response[0])
+
+    return [SubmissionStruct(**SubmissionSerializer(submission).data) for submission in submission_models]
+
 
 def get_score(student_item):
     pass
 
+
 def get_scores(course_id, student_id, types=None):
     pass
 
+
 def set_score(student_item):
     pass
 
+
+def _get_student_item(student_item):
+    student_items = StudentItem.objects.filter(
+        item_id=student_item.item_id,
+        student_id=student_item.student_id,
+        course_id=student_item.course_id,
+    )
+    return student_items[0] if student_items else None
\ No newline at end of file

apps/submissions/models.py

@@ -5,8 +5,8 @@ workflows, ORA, etc. So the flow is this:
 Student submission:
 * XBlock creates a Submission
 * submissions app sends a general notification that a submission has happened
-* openresponse can listen for that signal if it wants, or query itself on demand
-* when openresponse is satistifed that it has collected enough information to
+* openassessment can listen for that signal if it wants, or query itself on demand
+* when openassessment is satisfied that it has collected enough information to
   score the student, it will push that score information back to this app.
 * when the LMS wants to know what raw scores a student has, it calls this app.
 
@@ -15,9 +15,13 @@ Things to consider probably aren't worth the extra effort/complexity in the MVP:
 * Version ID (this doesn't work until split-mongostore comes into being)
 
 """
+from collections import namedtuple
+
 from django.db import models
 from django.utils.timezone import now
 
+StudentItemStruct = namedtuple("StudentItemStruct", "student_id course_id item_id item_type")
+
 class StudentItem(models.Model):
     """Represents a single item for a single course for a single user.
 
@@ -42,11 +46,10 @@ class StudentItem(models.Model):
         unique_together = (
             # For integrity reasons, and looking up all of a student's items
             ("course_id", "student_id", "item_id"),
-
-            # Composite index for getting information across a course
-            ("course_id", "item_id"),
         )
 
+SubmissionStruct = namedtuple("SubmissionStruct", "student_item attempt_number submitted_at created_at answer")
+
 
 class Submission(models.Model):
     """A single response by a student for a given problem in a given course.

apps/submissions/serializers.py

+from rest_framework import serializers
+from submissions.models import StudentItem, Submission, Score
+
+
+class StudentItemSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = StudentItem
+        fields = ('student_id', 'course_id', 'item_id', 'item_type')
+
+
+class SubmissionSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Submission
+        fields = ('student_item', 'attempt_number', 'submitted_at', 'created_at', 'answer')
+
+
+class ScoreSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Score
+        fields = ('student_item', 'submission', 'points_earned', 'points_possible', 'created_at')

apps/submissions/tests/test_api.py

+from django.test import TestCase
+from submissions.models import StudentItem, StudentItemStruct
+from submissions.api import create_submission, get_submissions
+
+STUDENT_ITEM = StudentItemStruct(
+    student_id="Tim",
+    course_id="Demo_Course",
+    item_id="item_one",
+    item_type="Peer_Submission"
+)
+
+class TestApi(TestCase):
+
+    def setUp(self):
+        StudentItem.objects.create(
+            student_id=STUDENT_ITEM.student_id,
+            course_id=STUDENT_ITEM.course_id,
+            item_id=STUDENT_ITEM.item_id,
+            item_type=STUDENT_ITEM.student_id
+        )
+
+    def test_create_submission(self):
+        submission = create_submission(STUDENT_ITEM, "this is my answer!")
+        self._assert_submission(submission, "this is my answer!", 1, 1)
+
+    def test_get_submission(self):
+        create_submission(STUDENT_ITEM, "this is my answer!")
+        create_submission(STUDENT_ITEM, "this is my other answer!")
+        submissions = get_submissions(STUDENT_ITEM)
+
+        self._assert_submission(submissions[0], "this is my answer!", 1, 1)
+        self._assert_submission(submissions[1], "this is my other answer!", 1, 1)
+
+    def _assert_submission(self, submission, expected_answer, expected_item, expected_attempt):
+        self.assertIsNotNone(submission)
+        self.assertEqual(submission.answer, expected_answer)
+        self.assertEqual(submission.student_item, expected_item)
+        self.assertEqual(submission.attempt_number, expected_attempt)
\ No newline at end of file

requirements/base.txt

@@ -3,3 +3,4 @@
 
 # Third Party Requirements
 django==1.4.8
+djangorestframework==2.3.5