Resolve "Validate data against json schema"

Closes #17 (closed)

uhepp_org/uhepp_api/serializers.py

+import json
+import os
 from django.contrib.auth.models import User
 from django.db.models import Q
 from django.urls import reverse
 from rest_framework import serializers
+import jsonschema
 from uhepp_vault.models import PUBLIC_LEVEL, INTERNAL_LEVEL, PUBLIC_LEVEL, \
                                VISIBILITY_LEVELS, Plot, Collection
 from .masks import filter_collections
@@ -70,6 +73,24 @@ class PlotSerializer(serializers.HyperlinkedModelSerializer):
         'collection-detail',
         queryset=Collection.objects
     )
+
+    def validate_uhepp(self, value):
+        """Check if the JSON data conforms to the uhepp schema"""
+        try:
+            schema_path = os.path.join(
+                os.path.dirname(__file__),
+                "uhepp.schema.json"
+            )
+
+            with open(schema_path) as schema_file:
+                schema = json.load(schema_file)
+
+            jsonschema.validate(value, schema=schema)
+        except Exception as e:
+            raise serializers.ValidationError("JSON schema validation error: %s" % e)
+
+        return value
+
     class Meta:
         model = Plot
         fields = ["uuid", "collection", "url", "uhepp"]