Register helper example to make a dependant field required

pmpro-customizations-depends-required-example.php

<?php

 function my_pmprorh_init() {
	//don't break if Register Helper is not loaded
	if(!function_exists( 'pmprorh_add_registration_field' )) {
		return false;
	}
	
	//define the fields
	$fields = array();
    $fields[] = new PMProRH_Field(
        "profession", // input name, will also be used as meta key
        "select", // type of field
        array(
            "label" => "I am a…",
            "class" => "profession", // custom class
            "profile" => true, // show in user profile
            "required" => true, // make this field required
            "options" => array( // <option> elements for select field
                "" => "(Please Select an Option)", // blank option – cannot be selected if this field is required
                "physician" => "Physician",
                "nurse" => "Nurse",
                "healthcare" => "Other Healthcare Provider",
                "student" => "Student",
                "educator" => "Educator",
                "patient" => "Patient",
                "family" => "Family Member",
                "other" => "Other (Please Specify)"
            ),
        )
    );
    
    $fields[] = new PMProRH_Field(
    "other_profession",
    "text",
        array(
            "depends" => array( array( "id" => "profession", "value" => "other" )),
            "class" => "other-profession", // custom class
            "profile" => true, // show in user profile
          /* dependant will return required when required is set to true
           * for a workaround set the required attribute to false
           * enforcing it as required will be handled by a JQuery script
           * that we're adding to the footer
           */
            "required" => false, // make this field required
        )
    );
	//add the fields into a new checkout_boxes are of the checkout page
	foreach($fields as $field)
		pmprorh_add_registration_field(
			'checkout_boxes',				// location on checkout page
			$field						// PMProRH_Field object
		);
	//that's it. see the PMPro Register Helper readme for more information and examples.
}
add_action( 'init', 'my_pmprorh_init' );

/* Add JQuery function to page footer 
 * to make dependant field required when visiable
 */
function add_to_footer_profession_formfield_check() {
	global $pmpro_pages;
	// Only load script on checkout page.
	if ( is_page( $pmpro_pages['checkout'] ) ) {
	?>
	<script type="text/javascript">
			
			jQuery(document).ready(function(){
				// Hide fields by default that may depend on something.
				jQuery('#other_profession_div').hide();
				// Show fields.
				jQuery('#profession').change(function(){
                    var val = jQuery('#profession').val();
                    if ( val == 'other') {
                        jQuery('#other_profession_div').show();
							jQuery('#other_profession').prop('required', true).after(' *');; // make the input field required and add * after it.
                    } else {
                        jQuery('#other_profession_div').hide();
							jQuery('#other_profession').prop('required', false);
                    }
				});
			});
	</script>
	<?php
	}
}
add_action( 'wp_footer', 'add_to_footer_profession_formfield_check' );