add a minimum size of image of members (150x150)

fet2020/members/models.py

@@ -1,4 +1,4 @@
-from django.core.validators import RegexValidator
+from django.core.validators import RegexValidator, ValidationError
 from django.db import models
 from django.db.models import Q
 from django.utils import timezone
@@ -114,6 +114,15 @@ class Member(models.Model):
         verbose_name = "Mitglied"
         verbose_name_plural = "Mitglieder"
 
+    def clean(self):
+        if self.image.height < 150 or self.image.width < 150:
+            raise ValidationError(
+                _('Das Bild ist zu klein. (Höhe: {}, Breite: {})').format(
+                    self.image.height,
+                    self.image.width
+                )
+            )
+
     def __str__(self):
         return self.firstname + " " + self.surname