Add __str__ method to have a better representation in admin interface

asset/models.py

@@ -24,6 +24,9 @@ class Asset(models.Model):
     def get_absolute_url(self):
         return reverse('asset:detail', kwargs={'pk': self.pk})
 
+    def __str__(self):
+        return self.named_id + ' (' + str(self.quantity) + '): ' + self.description
+
 
 class GtinProduct(models.Model):
     gtin = models.CharField(max_length=40, unique=True)
@@ -33,3 +36,6 @@ class GtinProduct(models.Model):
     brand = models.CharField(max_length=40, blank=True)
     created_ts = models.DateTimeField('datetime created', auto_now_add=True)
     changed_ts = models.DateTimeField('datetime updated', auto_now=True)
+
+    def __str__(self):
+        return self.gtin + ': ' + self.name

booker/models.py

@@ -16,3 +16,6 @@ class Scanner(models.Model):
     changed_ts = models.DateTimeField('datetime updated', auto_now=True)
     changed_by = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.SET(get_deleted_user),
                                    related_name='changed_scanners')
+
+    def __str__(self):
+        return self.named_id + ': ' + self.description + ' (' + str(self.last_online_ts) + ')'