Customized field constructor with constraints

Question

I have written my own field constructor like the following:

@(elements: helper.FieldElements)

@*****************************************************
* Generate input according to Twitter Bootsrap rules *
******************************************************@
<div class="control-group @if(elements.hasErrors) {error}">
    <label class="control-label" for="@elements.id">@elements.label @if(elements.field.constraints.map(c => c._1).contains("constraint.required")) {*}</label>
    <div class="controls">
        @elements.input
        <span class="help-inline">@elements.errors(elements.lang).mkString(", ")</span>
        <span class="help-block">@elements.infos(elements.lang).mkString(", ")</span>
    </div>
</div>

The idea is to add a star symbol * after the label of the required elements.

It works fine with fields that have the nonEmptyText mapping in the form definition but my main concern is to do the same with the required email fields: may the field be defined as email or optional(email) in the form, the same constraint constraint.email is used.

So how can I find the difference in my field constructor and add the star only to the required email fields?

Answer 1

Specifically for email:

You can define your email address in the Form mapping like so:

import play.api.data.Forms.email
import play.api.data.validation.Constraints.nonEmpty

"email" -> email.verifying(nonEmpty)

This will add the constraint you expect: "constraint.required"