dokan-forminator-validation.php

<?php


add_action('wp_footer','custom_js_form_validation');

function custom_js_form_validation(){
?>

	<script>
    jQuery( document ).ready(function($) {

      $(".store-name-forminator input").on('blur', function (e) {

        var _field = $(this);
        var _field_val = _field.val();

        $.ajax({
          url : '<?php echo admin_url( 'admin-ajax.php' ); ?>',
          type: "POST",
            data: {'action': 'check_store_availability_forminator', store: _field_val},
            dataType: "json",
            success: function(response) {
              console.log(response.status);
              if(response.status == 'unavailable'){
                $('.custom-validation-store').remove();
                $('.store-name-forminator input').parent().parent().append('<label class="forminator-label--validation custom-validation-store">Store is not available.</label>');
              }else{
                $('.custom-validation-store').remove();
                $('.store-name-forminator input').parent().parent().append('<label class="forminator-label--validation custom-validation-store">Store is available.</label>');
              }
            }
          });
        });
      });
    </script>
<?php
}

add_action('wp_ajax_nopriv_check_store_availability_forminator', 'check_store_availability_forminator');
add_action('wp_ajax_check_store_availability_forminator', 'check_store_availability_forminator');

function check_store_availability_forminator() {
    $response = array();
    $store = sanitize_text_field( $_POST['store'] );

    $stores = get_user_by('slug', $store);

    if( $stores ){
          $response['status'] = 'unavailable';
          $response['text'] = __('Custom text that can be used later');
    }else{
          $response['status'] = 'available';
          $response['text'] = __('Custom text that can be used later');
    }
    echo json_encode($response);
    die();
}