Render Rule

public function onRenderCustomFieldRule(mixed $field, array &$data) : string

Fires before rendering a custom field.

Description

Trigger hook to allow external plugins to manipulate the data to display or the type of layout to render.

In case one of the attached plugins returned a non-empty string, then the field will use it as HTML in place of the default layout.

It is possible to access the rule of the field with $field->get('rule').

Parameters

$field

(VAPCustomField)  The custom field instance.

&$data

(array)  An associative array of display data.

Return Value

String. The new layout of the field. Do not return anything to keep using the layout defined by the field.

Example

The example below displays a dropdown of countries for those fields that picked our new "Country" rule.

/**
 * Trigger hook to allow external plugins to manipulate the data to
 * display or the type of layout to render. In case one of the attached
 * plugins returned a string, then the field will use it as HTML in
 * place of the default layout.
 *
 * @param   mixed   $field  The custom field instance.
 * @param   array   &$data  An array of display data.
 *
 * @return  string  The new layout of the field. Do not return anything
 *                  to keep using the layout defined by the field.
 */
public function onRenderCustomFieldRule($field, &$data)
{
    // make sure we are rendering a field with "country" rule
    if ($field->get('rule') !== 'country')
    {
        // different rule, do nothing
        return;
    }

    // get list of supported countries
    $countries = JHtml::_('vaphtml.countries.getlist', $order = 'country_name');

    // build options
    $options = JHtml::_('select.options', $countries, 'code2', 'name', $data['value']);

    // add a placeholder at the beginning
    $options = "<option></option>\n" . $options;

    // build dropdown HTML
    return sprintf(
        '<select name="%s" id="%s" class="%s">%s</select>',
        $data['name'],
        $data['id'],
        $data['class'],
        $options
    );
}

Example #2

The example below explains how to extend the form validation via javascript for a field assigned to a specific rule.

public function onRenderCustomFieldRule($field, &$data)
{
    // make sure we are rendering a field with "ticket" rule
    if ($field->get('rule') !== 'ticket')
    {
        // different rule, do nothing
        return;
    }

    $app = JFactory::getApplication();

    if ($app->isClient('site') !== true)
    {
        // ignore if we are not in the front-end
        return;
    }

    $app->getDocument()->addScriptDeclaration("(function($) {
    'use strict';

    onInstanceReady(() => {
        // wait until the custom fields validator is ready
        if (typeof vapCustomFieldsValidator === 'undefined') {
            return false;
        }

        return vapCustomFieldsValidator;
    }).then((form) => {
        // register a new validation callback at runtime
        form.addCallback(() => {
            // take our ticket field by ID
            const field = $('#{$data['id']}');

            // make sure the specified ticket is well-formed (to be adjusted according to your needs)
            if (field.val().match(/regex_goes_here/)) {
                // field valid, unset the invalid status previously set (if any)
                form.unsetInvalid(field);
                return true;
            }

            // field invalid
            form.setInvalid(field);
            // display further information to the user
            alert('The specified ticket does not seem to be valid.');
            return false;
        });
    });
})(jQuery);");
}

Changelog