Validate Field Data - Server Side

Beside client side validation, from version 3.5.0 of Events Booking, you can also validate custom fields data using server side validation (using PHP code). You can use both built-in validators and implement custom validators yourself. To use server side validation, you can edit the custom field, enter the rules you want to use into Server Validation Rules

Built-in validators

We use Valitron Validation library - the most awesome validation engine ever created for PHP for validating custom fields data in Events Booking. See https://github.com/vlucas/valitron#built-in-validation-rules for list of supported validators you can use.

The syntax which you can enter into Server Validation Rules is rule1|rule2:param1,param2. Basically:

• You can add many rules you want to validate data for the filed. Each rule must be separated by | character
• You can add parameters to rule by adding : character after rule name, list of parameters separated by comma

Examples:

• min:10: will force the field to be a a number greater than or equal 10
• max:10: will force the field to be a a number smaller than or equal 10
• length:10: will force the field to be a string with exactly 10 characters
• lengthMin:10: will force the field to be a string has at least 10 characters
• lengthMax:10: will force the field to be a string has maximum 10 characters
• lengthBetween:5,15: will force the field to be a string with minimum 5 characters and maximum 15 characters

Build custom validators

Sometime, you will need to build custom validator to validate the custom field data using the logic you want. To do that:

1. Create a field validator.php and upload it to components/com_eventbooking/helper folder on your site
2. Edit that file, add the code like below to the file:

<?php
/**
 * @package            Joomla
 * @subpackage         Event Booking
 * @author             Tuan Pham Ngoc
 * @copyright          Copyright (C) 2010 - 2018 Ossolution Team
 * @license            GNU/GPL, see LICENSE.php
 */

defined('_JEXEC') or die;

Valitron\Validator::addRule('my_custom_rule', function($field, $value, array $params, array $fields) {
    if (strlen($value) != 9)
    {
            return false;
    }

    return true;
}, 'The field must has exactly 9 characters');

Valitron\Validator::addRule('my_custom_rule2', function($field, $value, array $params, array $fields) {
    if ($value != 9)
    {
            return false;
    }

    return true;
}, 'The field must has value = 9');

Each rule contains a block of code like that with the following parameters:

• $field: Name of the field which the rule is applied
• $value: Value of that field
• $params: Array of parameters which users passed to the rule when setup the server validation rules
• $fields: Array contains data of other fields in the form

See https://github.com/vlucas/valitron#adding-custom-validation-rules for more detailed instructions from the original library

4. To use this custom rule, you just need to edit the field and enter my_custom_rule into Server Validation Rules setting of the field. Now, when the form is submitted, the system will use the code in your my_custom_rule to validate data of that field.

Custom error message

When data for a field is not valid, the system will show an error message to registrants so that they will know about the error and correct it. Yoi should setup a clear error message for the field in Validation error message setting like [FIELD_NAME] must be a string with maximum 20 characters..., [FIELD_NAME] must be a integer number between 10 and 20....