Team trigrams and names are unique

apps/participation/forms.py

@@ -17,11 +17,22 @@ class TeamForm(forms.ModelForm):
     """
     Form to create a team, with the name and the trigram,...
     """
+    def clean_name(self):
+        if "name" in self.cleaned_data:
+            name = self.cleaned_data["name"].upper()
+            if not self.instance.pk and Team.objects.filter(name=name).exists():
+                raise ValidationError(_("This name is already used."))
+            return name
+
     def clean_trigram(self):
-        trigram = self.cleaned_data["trigram"].upper()
-        if not re.match("[A-Z]{3}", trigram):
-            raise ValidationError(_("The trigram must be composed of three uppercase letters."))
-        return trigram
+        if "trigram" in self.cleaned_data:
+            trigram = self.cleaned_data["trigram"].upper()
+            if not re.match("[A-Z]{3}", trigram):
+                raise ValidationError(_("The trigram must be composed of three uppercase letters."))
+
+            if not self.instance.pk and Team.objects.filter(trigram=trigram).exists():
+                raise ValidationError(_("This trigram is already used."))
+            return trigram
 
     class Meta:
         model = Team