Make the form compatible with Bootstrap server side validation tools

src/api/app/views/webui/projects/label_templates/_form.html.haml

@@ -4,9 +4,9 @@
       = form.label(:name, 'Name:', class: 'form-label')
       = form.text_field(:name, class: classes_with_validation(label_template, :name))
       - label_template.errors.where(:name).each do |error|
-        .error-message= error.message.capitalize
+        .invalid-feedback= error.message.capitalize
     .mb-3#color
       = form.label(:color, 'Color:', class: 'form-label')
       = form.color_field(:color, class: classes_with_validation(label_template, :color))
       - label_template.errors.where(:color).each do |error|
-        .error-message= error.message.capitalize
+        .invalid-feedback= error.message.capitalize

src/api/config/initializers/field_with_errors.rb

@@ -0,0 +1,8 @@
+# Rails form helpers wrap controls with a .field_with_errors class that prevents the validation styles from bootstrap to work.
+# This snippet replaces the wrapping with that class with an injection of .is-invalid class, which is bootstrap compatible.
+ActionView::Base.field_error_proc = proc do |html|
+  frag = Nokogiri::HTML5::DocumentFragment.parse(html)
+  klass = frag.children[0].attributes['class']
+  frag.children[0].attributes['class'].value = [klass, 'is-invalid'].join(' ')
+  frag.to_html.html_safe # rubocop:disable Rails/OutputSafety The input is code from our views, so it's safe to disable this
+end