Change the required Asterix to an (optional) label on non required fields

[andybroomfield]

This is to fit with the GDS pattern (old link).

[ekes]

In an ideal world it feels like you could swap * when there is a required class for (optional) when there is :not('required') class. Or add (optional) when $element['required'] === FALSE in a similar moment that the class is added.

The CSS targets .form-item__label.form-required::after, .fieldset__label.form-required::after to add the *.

In hook_preprocess form_element_label and fieldset, required is set to true, false and null. You can't add (optional) to everything that is false, because individual radio and checkbox labels would all get it. But with a bit of logic it feels like it should be do-able. Something like always add to legend title in fieldset if required is false; add to element title in form_element_label if required is false and type is not radios, checkboxes (and maybe some other things). checkbox preprocess variables gives no context that it is being rendered in checkboxes. The preprocess for the label is also called before any fieldset. Finally, adding (optional) onto other form field elements (search textfield for example) might be undesirable.

What will give enough context is adding an #after_build callback to appropriate element types in hook_element_info_alter(). The $element array passed to the callback includes information about parents, so if it's desired to mark solitary elements (optional) they can be differentiated from elements with parents. The callback also gets a FormStateInterface so can check the form object to see that it is a Webform. Changing the #title in the array based on the value of #required does make changes on the form.
I've tested all this, and will make a MR, the task will be listing all element types that want to have (optional) added to them if they are not required.

[ekes]

1.x...feature/102-optional initial commit to show working.

Needs expanded list of element types.
And a switch to turn on/off (preferably off for existing installs I'd think).
Needs some state related js to trigger a redraw of the label on fieldsets (checkboxes etc.)