add signals to delete files (#243)

* add signals to delete files

* fix flake8 error

Author: HuxleyBerry

client/src/views/EmailVerificationView.vue

@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { defineProps, onMounted, ref } from 'vue'
+import { onMounted, ref } from 'vue'
 import { useMessageStore } from '@/stores/message'
 import { useRouter } from 'vue-router'
 import { useUserStore } from '@/stores/user'

client/src/views/ForgotPasswordView.vue

@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { defineProps, onMounted, ref } from 'vue'
+import { onMounted, ref } from 'vue'
 import { useMessageStore } from '@/stores/message'
 import { useUserStore } from '@/stores/user'
 import { useModalStore } from '@/stores/modal'

server/bingo/apps.py

@@ -4,3 +4,6 @@
 class BingoConfig(AppConfig):
     default_auto_field = "django.db.models.BigAutoField"
     name = "bingo"
+
+    def ready(self):
+        import bingo.signals  # noqa

server/bingo/signals.py

@@ -0,0 +1,38 @@
+from .models import TileInteraction
+import os
+from django.dispatch import receiver
+from django.db.models.signals import post_delete, pre_save
+
+# modified from https://stackoverflow.com/a/16041527
+
+
+@receiver(post_delete, sender=TileInteraction)
+def auto_delete_file_on_delete(sender, instance, **kwargs):
+    """
+    Deletes file from filesystem
+    when corresponding `TileInteraction` object is deleted.
+    """
+    if instance.image:
+        if os.path.isfile(instance.image.path):
+            os.remove(instance.image.path)
+
+
+@receiver(pre_save, sender=TileInteraction)
+def auto_delete_file_on_change(sender, instance, **kwargs):
+    """
+    Deletes old file from filesystem
+    when corresponding `TileInteraction` object is updated
+    with new file.
+    """
+    if not instance.pk:
+        return False
+
+    try:
+        old_image = TileInteraction.objects.get(pk=instance.pk).image
+    except TileInteraction.DoesNotExist:
+        return False
+
+    new_image = instance.image
+    if old_image and not old_image == new_image:
+        if os.path.isfile(old_image.path):
+            os.remove(old_image.path)