backoffice: fix form fields reorder (#45380)

tests/test_admin_pages.py

@@ -1992,6 +1992,36 @@ def test_form_limit_display_to_page(pub):
     assert '{{form_var_baz}}' in hidden_fields
 
 
+def test_form_fields_reorder(pub):
+    create_superuser(pub)
+    create_role()
+
+    FormDef.wipe()
+    formdef = FormDef()
+    formdef.name = 'form title'
+    formdef.fields = [
+        fields.PageField(id='0', label='1st page', type='page'),
+        fields.StringField(id='1', label='string', type='string'),
+        fields.PageField(id='2', label='2nd page', type='page'),
+        fields.StringField(id='3', label='string 2', type='string')
+    ]
+    formdef.store()
+
+    app = login(get_app(pub))
+    app.get('/backoffice/forms/%s/fields/update_order?order=0;3;1;2;' % formdef.id)
+    formdef = FormDef.get(formdef.id)
+    assert [x.id for x in formdef.fields] == ['0', '3', '1', '2']
+
+    # unknown id: ignored
+    app.get('/backoffice/forms/%s/fields/update_order?order=0;1;2;3;4;' % formdef.id)
+    formdef = FormDef.get(formdef.id)
+    assert [x.id for x in formdef.fields] == ['0', '1', '2', '3']
+    # missing id: do nothing
+    app.get('/backoffice/forms/%s/fields/update_order?order=0;3;1;' % formdef.id)
+    formdef = FormDef.get(formdef.id)
+    assert [x.id for x in formdef.fields] == ['0', '1', '2', '3']
+
+
 def test_form_legacy_int_id(pub):
     create_superuser(pub)
     create_role()

wcs/admin/fields.py

@@ -374,7 +374,14 @@ class FieldsDirectory(Directory):
     def update_order(self):
         request = get_request()
         new_order = request.form['order'].strip(';').split(';')
-        new_fields = [ [x for x in self.objectdef.fields if x.id == y][0] for y in new_order]
+        new_fields = []
+        for y in new_order:
+            for x in self.objectdef.fields:
+                if x.id == y:
+                    new_fields.append(x)
+                    break
+        if set(self.objectdef.fields) != set(new_fields):
+            return 'ko'
         self.objectdef.fields = new_fields
         self.objectdef.store()
         return 'ok'