Download and Install CodeIgniter 4
Download the latest version of CodeIgniter 4 and unzip source code to new folder named LearnCodeIgniter4WithRealApps
Cut index.php and htaccess files in public folder to root folder of project
Open index.php in root folder find to line 16 replace path to Paths.php file as below:
$pathsPath = realpath(FCPATH . '/app/Config/Paths.php');
Open App.php in app/Config folder find to line 39 remove index.php string in $indexPage variable as below:
public $indexPage = '';
Set BASE URL
Open App.php file in app/Config folder. Set value for $baseURL variable as below:
public $baseURL = 'http://localhost:8091/LearnCodeIgniter4WithRealApps/';
Create Custom Validation
Create new folder named Validation in app folder. In Validation folder create new PHP file named UsernameRules.php as below:
<?php
namespace App\Validation;
class UsernameRules
{
public function usernameValidation(string $str, string $fields, array $data)
{
if ($data['username'] == 'abc') {
return false;
} else {
return false;
}
}
}
Load Custom Validation
Open Validation.php file in app/Config folder and register custom validation as below:
<?php
use \App\Validation\UsernameRules;
public $ruleSets = [
//... other rules
UsernameRules::class // here we have registered
];
Create Controller
Create new PHP file named Account.php in app/Controllers folder as below:
<?php
namespace App\Controllers;
class Account extends BaseController
{
public function __construct()
{
helper(['url', 'form']);
}
public function index()
{
return view('account/index', [
'validation' => \Config\Services::validation()
]);
}
public function save()
{
$rules = [
'username' => 'trim|required|min_length[3]|max_length[12]|usernameValidation[username]',
'password' => 'trim|required|min_length[6]|max_length[20]|regex_match[/^((?=.*\\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[@#$%]).{6,20})$/]',
'repassword' => 'trim|required|min_length[3]|max_length[20]|matches[password]',
'age' => 'trim|required|integer|greater_than[18]|less_than[120]',
'email' => 'trim|required|valid_email',
'website' => 'trim|valid_url'
];
$errors = [
'username' => [
'usernameValidation' => 'Username already exists'
]
];
if (!$this->validate($rules, $errors)) {
return view('account/index', [
'validation' => \Config\Services::validation()
]);
} else {
$request = \Config\Services::request();
$data['account'] = $request->getPost();
return view('account/success', $data);
}
}
}
Create Views
Create new folder named account in app/Views folder. In this folder, create new PHP file named as below:
Index View
In account folder, create new PHP file named index.php as below:
<html>
<head>
<title>Codeigniter 4 Form Validation</title>
</head>
<body>
<h3>Register</h3>
<ul>
<?php foreach ($validation->getErrors() as $error) : ?>
<li><?= $error ?></li>
<?php endforeach ?>
</ul>
<form method="post" action="<?= site_url('account/save') ?>">
<table cellpadding="2" cellspacing="2">
<tr>
<td>Username</td>
<td>
<input type="text" name="username" value="<?= set_value('username'); ?>" />
</td>
<td><?= $validation->getError('username') ?></td>
</tr>
<tr>
<td>Password</td>
<td>
<input type="password" name="password" />
</td>
<td><?= $validation->getError('password') ?></td>
</tr>
<tr>
<td>Re-Password</td>
<td>
<input type="password" name="repassword" />
</td>
<td><?= $validation->getError('repassword') ?></td>
</tr>
<tr>
<td>Age</td>
<td>
<input type="text" name="age" />
</td>
<td><?= $validation->getError('age') ?></td>
</tr>
<tr>
<td>Email</td>
<td>
<input type="text" name="email" />
</td>
<td><?= $validation->getError('email') ?></td>
</tr>
<tr>
<td>Website</td>
<td>
<input type="text" name="website" />
</td>
<td><?= $validation->getError('website') ?></td>
</tr>
<tr>
<td> </td>
<td>
<input type="submit" value="Save" />
</td>
</tr>
</table>
</form>
</body>
</html>
Success View
In account folder, create new PHP file named success.php as below:
<html>
<head>
<title>Codeigniter 4 Form Validation</title>
</head>
<body>
<h3>Account Info</h3>
<table cellpadding="2" cellspacing="2" border="1">
<tr>
<td>Username</td>
<td><?= $account['username'] ?></td>
</tr>
<tr>
<td>Password</td>
<td><?= $account['password'] ?></td>
</tr>
<tr>
<td>Age</td>
<td><?= $account['age'] ?></td>
</tr>
<tr>
<td>Email</td>
<td><?= $account['email'] ?></td>
</tr>
<tr>
<td>Website</td>
<td><?= $account['website'] ?></td>
</tr>
</table>
</body>
</html>
Define Routes
Open Routes.php file in app/Config folder and define routes as below:
$routes->get('/', 'Account::index');
$routes->post('/account/save', 'Account::save');
Structure of CodeIgniter 4 Project
Run Application
Access index action in Account controller with following url: http://localhost:8091/LearnCodeIgniterWithRealApps/account/index
Output
Click Save button submit form to save action in Account controller with invalid data as below:
Click Save button submit form to save action in Account controller with valid data
Output
