Merge pull request #7 from MikaTech-dev/feat/serializers

Feat/serializers

Author: MikaTech-dev

.pylintrc

@@ -7,4 +7,5 @@ disable=missing-module-docstring,
         missing-class-docstring,
         missing-function-docstring,
         too-few-public-methods,
-        invalid-name
+        invalid-name,
+        imported-auth-user

api/migrations/0002_alter_question_correct_answers.py

@@ -0,0 +1,18 @@
+# Generated by Django 6.0 on 2026-01-02 20:47
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='question',
+            name='correct_answers',
+            field=models.JSONField(default=dict, help_text="e.g. {'answer': 'B'}"),
+        ),
+    ]

api/models.py

@@ -1,10 +1,11 @@
 from django.db import models
-from django.contrib.auth.models import User 
-from django.utils import timezone
+
+# Create your models here.
+from django.contrib.auth.models import User  # Inbuilt auth User model
 
 class Exam(models.Model):
     title = models.CharField(max_length=255)
-    duration = models.DurationField() 
+    duration = models.DurationField()
     course_name = models.CharField(max_length=255)
     metadata = models.TextField(blank=True)
     created_at = models.DateTimeField(auto_now_add=True)
@@ -13,18 +14,23 @@ def __str__(self):
         return self.title
 
 class Question(models.Model):
+    # Defining enums/choices
     QUESTION_TYPES = [
         ('MCQ', 'Multiple Choice'),
         ('SA', 'Short Answer'),
     ]
 
-    exam = models.ForeignKey(Exam, related_name='questions', on_delete=models.CASCADE)
+    exam: Exam = models.ForeignKey(Exam, related_name='questions', on_delete=models.CASCADE)
     question_text = models.TextField()
-    question_type = models.CharField(max_length=3, choices=QUESTION_TYPES, default='MCQ')
+    question_type = models.CharField(
+        max_length=3, choices=QUESTION_TYPES,
+          default='MCQ'
+          )   # using choices
 
-    options = models.JSONField(default=dict, blank=True, help_text="For MCQs: {'options': ['A', 'B', 'C']}")
-    correct_answers = models.JSONField(help_text="e.g. {'answer': 'B'}")
-    
+    # Flexible storage for options (e.g. ["A", "B", "C"]) and correct answers
+    options = models.JSONField(
+        default=dict, blank=True, help_text="For MCQs: {'options': ['A', 'B', 'C']}")
+    correct_answers = models.JSONField(default=dict, help_text="e.g. {'answer': 'B'}")
     order = models.PositiveSmallIntegerField(default=1)
 
     class Meta:
@@ -39,10 +45,12 @@ class Submission(models.Model):
         ('graded', 'Graded'),
     ]
 
+    # Link the submission to the inbuilt User model via FK
     student = models.ForeignKey(User, on_delete=models.CASCADE)
     exam = models.ForeignKey(Exam, on_delete=models.CASCADE)
     submitted_at = models.DateTimeField(auto_now_add=True)
 
+    # Allow score and feedback to be blank (nullable) initially until graded
     total_score = models.DecimalField(max_digits=5, decimal_places=2, null=True, blank=True)
     feedback = models.TextField(blank=True)
     status = models.CharField(max_length=10, choices=STATUS_CHOICES, default='pending')
@@ -55,6 +63,7 @@ class Answer(models.Model):
     question = models.ForeignKey(Question, on_delete=models.CASCADE)
     student_answer = models.JSONField()
 
+    # Optional: store individual score per question if needed later
     is_correct = models.BooleanField(default=False, blank=True)
 
     def __str__(self):

api/serializers.py

@@ -0,0 +1,59 @@
+from rest_framework import serializers
+from django.contrib.auth.models import User
+from .models import Exam, Question, Submission, Answer
+
+class UserSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = User
+        fields = ['id', 'username', 'email']
+
+class QuestionSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Question
+        fields = ['id', 'question_text', 'question_type', 'options', 'order']
+
+class ExamSerializer(serializers.ModelSerializer):
+    #  Embedding qustions inside the exam details
+    questions = QuestionSerializer(many=True, read_only=True)
+
+    class Meta:
+        model = Exam
+        fields = ['id', 'title', 'duration', 'course_name', 'metadata', 'questions', 'created_at']
+
+class AnswerSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Answer
+        fields = ['question', 'student_answer', 'is_correct']
+        read_only_fields = ['is_correct']
+
+class SubmissionSerializer(serializers.ModelSerializer):
+    answers = AnswerSerializer(many=True)
+    student = UserSerializer(read_only=True)
+
+    class Meta:
+        model = Submission
+        fields = [
+            'id', 
+            'student', 
+            'exam', 
+            'submitted_at', 
+            'total_score', 
+            'feedback', 
+            'status', 
+            'answers'
+            ]
+        # These fields will br created/filled by the grading.service(TBD), not by the student
+        read_only_fields = ['total_score', 'feedback', 'status', 'submitted_at']
+    def create(self, validated_data):
+        """
+        Handles creating the Submission AND the nested Answers in one go.
+        """
+        answers_data = validated_data.pop('answers')
+        # Creating the Submission instance
+        submission = Submission.objects.create(**validated_data)
+
+        # Creating the Answers instance
+        for answer_data in answers_data:
+            Answer.objects.create(submission=submission, **answer_data)
+
+        return submission

api/views.py

@@ -1,3 +1,30 @@
-from django.shortcuts import render
+# from django.shortcuts import render
 
 # Create your views here.
+from rest_framework import viewsets, permissions
+from .models import Exam, Submission
+from .serializers import ExamSerializer, SubmissionSerializer
+
+class ExamViewSet(viewsets.ReadOnlyModelViewSet):
+    """
+    API endpoint that allows exams to be viewed or listed.
+    READ-ONLY: Users (Students) cannot create or modify exams here.
+    """
+    queryset = Exam.objects.all()
+    serializer_class = ExamSerializer
+    permission_classes = [permissions.IsAuthenticated]
+
+class SubmissionViewSet(viewsets.ModelViewSet):
+    """
+    API endpoint for students to submit exams and view their submission history.
+    """
+    serializer_class = SubmissionSerializer
+    permission_classes = [permissions.IsAuthenticated]
+
+    def get_queryset(self):
+        # Ensuring users only have access to their own submission
+        return Submission.objects.filter(student=self.request.user)
+
+    def perform_create(self, serializer):
+        # link submission to the actual user 
+        serializer.save(student=self.request.user)