Here's one example. There are probably other ways and v4 development team members might be able to suggest more appropriate approaches. But this works.
This example is done using a fresh install of v4.
The only default value changed is that $baseURL in /application/Config/App.php is set with the testing server's URL.
No items are removed or added to the file /application/Config/Routes.php
Here's a very simple "library"
/application/Libraries/Test.php
PHP Code:
<?php namespace App\Libraries;
class Test
{
protected $message;
public function __construct()
{
$this->message = 'Greetings from the class <em>Test</em>.';
}
public function getMessage()
{
return $this->message;
}
}
We will create an instance of this class and use the class method getMessge() in the controller Base
/application/Controllers/Base.php
PHP Code:
<?php namespace App\Controllers;
class Base extends \CodeIgniter\Controller
{
/**
* @var \App\Libraries\Test instance of Test class
*/
protected $testLib;
public function __construct(...$params)
{
parent::__construct(...$params);
//create instance of "Test" class assign it to the controller's property
$this->testLib = new \App\Libraries\Test();
}
public function index()
{
$data['title'] = 'Testing 1,2,3'; //Browser tab text
// Use the "Test" class
$data['message'] = $this->testLib->getMessage();
//show the view file
echo view('test_message', $data);
}
}
The above controller can be used to extend other controllers and the property $testLib can be accessed in child classes using
$this->testLib.
The "view" is a hacked... er, revised version of welcome_message.php that comes with a clean install.
/applications/Views/test_message.php
Code:
<!doctype html>
<html>
<head>
<title><?= $title; ?></title>
<link rel="shortcut icon" type="image/png" href="/favicon.ico"/>
</head>
<body>
<style {csp-style-nonce}>
div.logo {
height: 200px;
width: 155px;
display: inline-block;
opacity: 0.08;
position: absolute;
top: 2rem;
left: 50%;
margin-left: -73px;
}
body {
height: 100%;
background: #fafafa;
font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
color: #777;
font-weight: 300;
}
h1 {
font-weight: lighter;
letter-spacing: 0.8;
font-size: 3rem;
margin-top: 145px;
margin-bottom: 0;
color: #222;
}
.wrap {
max-width: 1024px;
margin: 5rem auto;
padding: 2rem;
background: #fff;
text-align: center;
border: 1px solid #efefef;
border-radius: 0.5rem;
position: relative;
}
.version {
margin-top: 0;
color: #999;
}
.guide {
margin-top: 3rem;
text-align: left;
}
.msg{
font-weight: bold;
}
pre {
white-space: normal;
margin-top: 1.5rem;
}
code {
background: #fafafa;
border: 1px solid #efefef;
padding: 0.5rem 1rem;
border-radius: 5px;
display: block;
}
p {
margin-top: 1.5rem;
}
.footer {
margin-top: 2rem;
border-top: 1px solid #efefef;
padding: 1em 2em 0 2em;
font-size: 85%;
color: #999;
}
a:active,
a:link,
a:visited {
color: #dd4814;
}
</style>
<div class="wrap">
<h1>Welcome to CodeIgniter</h1>
<p class="version">version <?= CodeIgniter\CodeIgniter::CI_VERSION ?></p>
<div class="logo">
<svg version="1.0" xmlns="http://www.w3.org/2000/svg"
width="155.000000px" height="200.000000px" viewBox="0 0 155.000000 200.000000"
preserveAspectRatio="xMidYMid meet">
<g transform="translate(0.000000,200.000000) scale(0.100000,-0.100000)" fill="#000000" stroke="none">
<path d="M737 1963 c22 -79 -7 -185 -78 -290 -18 -26 -107 -122 -197 -213
-239 -240 -336 -371 -403 -544 -79 -206 -78 -408 5 -582 64 -134 212 -264 361
-314 l60 -20 -30 22 c-210 152 -229 387 -48 588 25 27 48 50 51 50 4 0 7 -27
7 -61 0 -57 2 -62 37 -95 30 -27 46 -34 78 -34 56 0 99 24 116 65 29 69 16
120 -50 205 -105 134 -117 233 -43 347 l31 48 7 -47 c13 -82 58 -129 250 -258
209 -141 306 -261 328 -405 11 -72 -1 -161 -31 -218 -27 -53 -112 -143 -165
-174 -24 -14 -43 -26 -43 -28 0 -2 24 4 53 14 241 83 427 271 482 486 19 76
19 202 -1 285 -35 152 -146 305 -299 412 l-70 49 -6 -33 c-8 -48 -26 -76 -59
-93 -45 -23 -103 -19 -138 10 -67 57 -78 146 -37 305 30 116 32 206 5 291 -27
89 -104 206 -162 247 -17 13 -18 12 -11 -15z"/>
</g>
</svg>
</div>
<div class="guide">
<p>This example demonstrates one way to utilize a custom class
(a.k.a. library) in a CodeIgniter version 4.0-dev controller.</p>
<p>The following message was provided by the custom class:
<span class="msg"><?= $message; ?></span></p>
<p>The custom class used is found at:</p>
<pre><code>application/Libraries/Test.php</code></pre>
<p>If you would like to edit the view file you'll find it located at:</p>
<pre><code>application/Views/test_message.php</code></pre>
<p>The controller file for this page is found at:</p>
<pre><code>application/Controllers/Base.php</code></pre>
</div>
<div class="footer">
Page rendered in {elapsed_time} seconds. Environment: <?= ENVIRONMENT ?>
</div>
</div>
</body>
</html>
Direct your browser to
http://yoursite.com/base to see if all the pieces fit together and produce the expected output.
