Display an items count for the storages in admin

hardware_provisioning/admin.py

@@ -63,7 +63,7 @@ class LoanAdmin(admin.ModelAdmin):
 
 @admin.register(Storage)
 class StorageAdmin(admin.ModelAdmin):
-    list_display = ('name', 'truncated_notes')
+    list_display = ('name', 'truncated_notes', 'items_count')
 
     def truncated_notes(self, obj):
         if len(obj.notes) > 50:

hardware_provisioning/models.py

@@ -120,6 +120,10 @@ class Storage(models.Model):
     def __unicode__(self):
         return self.name
 
+    def items_count(self):
+        return self.items.count()
+    items_count.short_description = 'Nb. items stockés'
+
     class Meta:
         verbose_name = 'lieu de stockage'
         verbose_name_plural = 'lieux de stockage'