Add RasterFile model and use it as Foreing Key to RasterDataset (#5)

* Add RasterFile model and use it as Foreing Key to RasterDataset

* Improve validation and tests

Author: willemarcel

.gitignore

@@ -54,6 +54,7 @@ coverage.xml
 *.log
 .static_storage/
 .media/
+.media/raster/*
 local_settings.py
 
 # Flask stuff:

vbos/datasets/admin.py

@@ -10,6 +10,7 @@
 
 from .models import (
     RasterDataset,
+    RasterFile,
     TabularDataset,
     TabularItem,
     VectorDataset,
@@ -18,9 +19,14 @@
 from .forms import CSVUploadForm, GeoJSONUploadForm
 
 
+@admin.register(RasterFile)
+class RasterFileAdmin(admin.ModelAdmin):
+    list_display = ["id", "name", "created", "file"]
+
+
 @admin.register(RasterDataset)
 class RasterDatasetAdmin(admin.ModelAdmin):
-    list_display = ["id", "name", "created", "updated", "file_path"]
+    list_display = ["id", "name", "created", "updated", "file"]
 
 
 @admin.register(VectorDataset)

vbos/datasets/migrations/0003_rasterdataset.py

@@ -0,0 +1,61 @@
+# Generated by Django 5.2.5 on 2025-09-03 16:50
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("datasets", "0002_tabulardataset_tabularitem"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="RasterFile",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("name", models.CharField(max_length=155)),
+                ("created", models.DateTimeField(auto_now_add=True)),
+                ("file", models.FileField(upload_to="raster/")),
+            ],
+            options={
+                "ordering": ["id"],
+            },
+        ),
+        migrations.CreateModel(
+            name="RasterDataset",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("name", models.CharField(max_length=155)),
+                ("created", models.DateTimeField(auto_now_add=True)),
+                ("updated", models.DateTimeField(auto_now=True)),
+                (
+                    "file",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.PROTECT,
+                        to="datasets.rasterfile",
+                    ),
+                ),
+            ],
+            options={
+                "ordering": ["id"],
+            },
+        ),
+    ]

vbos/datasets/migrations/0003_rasterfile_rasterdataset.py

@@ -1,11 +1,45 @@
 from django.contrib.gis.db import models
+from django.core.validators import FileExtensionValidator
+from django.db.models.fields.files import default_storage
+from django.db.models.signals import pre_delete
+from django.dispatch import receiver
+
+
+class RasterFile(models.Model):
+    name = models.CharField(max_length=155)
+    created = models.DateTimeField(auto_now_add=True)
+    file = models.FileField(
+        upload_to="raster/",
+        validators=[
+            FileExtensionValidator(
+                allowed_extensions=["tiff", "tif", "geotiff", "gtiff"]
+            )
+        ],
+    )
+
+    def __str__(self):
+        return self.name
+
+    class Meta:
+        ordering = ["id"]
+
+
+@receiver(pre_delete, sender=RasterFile)
+def delete_raster_file(sender, instance, **kwargs):
+    """
+    Delete the file from storage when a RasterFile instance is deleted
+    """
+    if instance.file:
+        # Using default_storage for better compatibility with different storage backends
+        if default_storage.exists(instance.file.name):
+            default_storage.delete(instance.file.name)
 
 
 class RasterDataset(models.Model):
     name = models.CharField(max_length=155)
     created = models.DateTimeField(auto_now_add=True)
     updated = models.DateTimeField(auto_now=True)
-    file_path = models.CharField(max_length=2000, null=False, blank=False)
+    file = models.ForeignKey(RasterFile, on_delete=models.PROTECT)
 
     def __str__(self):
         return self.name

vbos/datasets/models.py

@@ -11,9 +11,11 @@
 
 
 class RasterDatasetSerializer(serializers.ModelSerializer):
+    file = serializers.ReadOnlyField(source="file.file.url")
+
     class Meta:
         model = RasterDataset
-        fields = "__all__"
+        fields = ["id", "name", "created", "updated", "file"]
 
 
 class VectorDatasetSerializer(serializers.ModelSerializer):

vbos/datasets/serializers.py

@@ -0,0 +1,10 @@
+{% extends "admin/change_list.html" %}
+{% load admin_urls %}
+{% block object-tools-items %}
+{{ block.super }}
+<li>
+    <a href="{% url opts|admin_urlname:'import_file' %}" class="addlink">
+        Import File
+    </a>
+</li>
+{% endblock %}

vbos/datasets/test/change_list.html

@@ -0,0 +1,44 @@
+from django.db.models.deletion import ProtectedError
+from django.test import TestCase
+from django.core.files.uploadedfile import SimpleUploadedFile
+from django.core.exceptions import ValidationError
+
+from vbos.datasets.models import RasterDataset, RasterFile
+from genericpath import exists
+
+
+class TestRasterModels(TestCase):
+    def setUp(self):
+        self.valid_file = SimpleUploadedFile(
+            "rainfall.tif", b"file_content", content_type="image/tiff"
+        )
+        self.r_1 = RasterFile.objects.create(name="Rainfall COG", file=self.valid_file)
+        self.r_2 = RasterFile.objects.create(
+            name="Coastline COG", file="raster/coastline.tiff"
+        )
+        self.dataset = RasterDataset.objects.create(name="Rainfall", file=self.r_1)
+
+    def test_deletion(self):
+        # RasterFile can't be deleted if it's associates with a dataset
+        with self.assertRaises(ProtectedError):
+            self.r_1.delete()
+        # modify dataset
+        self.dataset.file = self.r_2
+        self.dataset.save()
+        # delete file
+        self.r_1.delete()
+        self.assertEqual(RasterFile.objects.count(), 1)
+        # delete dataset
+        self.dataset.delete()
+        self.assertEqual(RasterDataset.objects.count(), 0)
+        # delete remaining file
+        self.r_2.delete()
+        self.assertEqual(RasterFile.objects.count(), 0)
+
+        # test file extension validation
+        invalid_file = SimpleUploadedFile(
+            "test.jpg", b"file_content", content_type="image/jpeg"
+        )
+        raster = RasterFile(name="Test", file=invalid_file)
+        with self.assertRaises(ValidationError):
+            raster.full_clean()

vbos/datasets/test/test_raster_models.py

@@ -2,16 +2,20 @@
 from rest_framework.test import APITestCase
 from django.urls import reverse
 
-from ..models import RasterDataset
+from ..models import RasterDataset, RasterFile
 
 
 class TestRasterDatasetListDetailViews(APITestCase):
     def setUp(self):
-        self.dataset_1 = RasterDataset.objects.create(
-            name="Rainfall", file_path="cogs/rainfall.tiff"
+        self.r_1 = RasterFile.objects.create(
+            name="Rainfall COG", file="raster/rainfall.tiff"
         )
+        self.r_2 = RasterFile.objects.create(
+            name="Coastline COG", file="raster/coastline.tiff"
+        )
+        self.dataset_1 = RasterDataset.objects.create(name="Rainfall", file=self.r_1)
         self.dataset_2 = RasterDataset.objects.create(
-            name="Coastline changes", file_path="cogs/coastlines.tiff"
+            name="Coastline changes", file=self.r_2
         )
         self.url = reverse("datasets:raster-list")
 
@@ -27,6 +31,6 @@ def test_raster_datasets_detail(self):
         req = self.client.get(url)
         assert req.status_code == status.HTTP_200_OK
         assert req.data.get("name") == "Rainfall"
-        assert req.data.get("file_path") == "cogs/rainfall.tiff"
+        assert req.data.get("file") == "/media/raster/rainfall.tiff"
         assert req.data.get("created")
         assert req.data.get("updated")