Step 3 Adding a helper file

Introduction

In this step we add a helper file to the module. Helper files are used in Joomla to hold complex logic, so that the main module code is kept simple.

In this case we use a helper file to find the username of the currently logged on user, and then output "Hello <username>". If the user isn't logged on then we output "Hello Guest".

The source code is available at mod_hello step 3.

Helper File

Following the Joomla convention, we call our helper class HelloHelper, and store it in src/Helper/HelloHelper.php. This then means that our namespace and class definitions must be

namespace My\Module\Hello\Site\Helper;

class HelloHelper { ... }

In the helper file we obtain the username of the logged-on user; here's the full code of the helper class:

mod_hello/src/Helper/HelloHelper.php

<?php

namespace My\Module\Hello\Site\Helper;

\defined('_JEXEC') or die;

use Joomla\CMS\Factory;

class HelloHelper
{
    public static function getLoggedonUsername(string $default)
    {
        $user = Factory::getApplication()->getIdentity();
        if ($user->id !== 0)  // found a logged-on user
        {
            return $user->username;
        }
        else
        {
            return $default;
        }
    }
}

Dispatcher

There are 2 ways we can get access to our HelloHelper class. In this step we'll access it directly using Namespacing. When we later look at Dependency Injection we'll change the code to use the alternative method of getting it instantiated via a HelperFactory class.

mod_hello/src/Dispatcher/Dispatcher.php

<?php

namespace My\Module\Hello\Site\Dispatcher;

\defined('_JEXEC') or die;

use Joomla\CMS\Dispatcher\DispatcherInterface;
use Joomla\CMS\Helper\ModuleHelper;
use My\Module\Hello\Site\Helper\HelloHelper;

class Dispatcher implements DispatcherInterface
{
    public function dispatch()
    {
        $username = HelloHelper::getLoggedonUsername('Guest');

        $hello = "Hello {$username}";

        require ModuleHelper::getLayoutPath('mod_hello');
    }
}

Manifest File update

We've already included the /src directory in our list of files which Joomla should process, so we just specify the updated version number.

mod_hello/mod_hello.xml

<?xml version="1.0" encoding="UTF-8"?>
<extension type="module" client="site" method="upgrade">
    <name>Joomla module tutorial</name>
    <version>1.0.3</version>
    <author>me</author>
    <creationDate>today</creationDate>
    <description>Code used in the Joomla module tutorial</description>
    <namespace path="src">My\Module\Hello</namespace>
    <files>
        <folder module="mod_hello">services</folder>
        <folder>src</folder>
        <folder>tmpl</folder>
    </files>
</extension>

Installation

Once again, zip up your mod_hello directory and install the upgraded module on Joomla.

When you navigate to a site page you should now see

• "Hello <your username>" displayed by the module when you're logged in
• "Hello Guest" when you're not logged in