Course Content
Introduction to CodeIgniter 4
CodeIgniter is an Application Development Framework. CodeIgniter is a popular and powerful MVC (Model-View-Controller) framework that is used to develop web applications. It is a free and Open-source PHP framework.
MVC (Model-View-Controller)
MVC stands for Model-View-Controller. MVC is an application design model consisting of three interconnected parts. They include the model (data), the view (user interface), and the controller (processes that handle input).
The Session class allows you to maintain a user’s "state" and track their activity while they browse your site.
URI Routing
There is a one-to-one relationship between a URL string and its corresponding controller class/method.
Working with Database
Like any other framework, we need to interact with the database very often and CodeIgniter makes this job easy for us. It provides a rich set of functionalities to interact with the database.
PhpSpreadsheet is a PHP library for reading and writing spreadsheet files. Importing Excel and CSV into MySQL help to save the user time and avoid repetitive work.
CodeIgniter 4
About Lesson

A PHPMailer library is used to send an email using CodeIgniter. You can install the PHPMailer using Composer.

PHPMailer is a code library used to send emails safely and easily via PHP code from a web server. Sending emails directly via PHP code requires a high-level familiarity with SMTP standard protocol and related issues and vulnerabilities about Email injection for spamming.

Run the following command in the root directory of your project.


composer require phpmailer/phpmailer

1. Copy and Paste the following lines in app/Config/Routes.php

$routes->add('email/compose', 'Email::compose');
$routes->post('email/send-email', 'Email::send_email');

2. Create a compose.php file in the app/Views/ directory

<form action="<?php echo base_url('email/send-email') ?>" class="form-horizontal" 
id="add_email_form" autocomplete="off" method="post" accept-charset="utf-8">
    <div class="form-group">
        <label for="inputName" class="col-sm-2 control-label">Recipient Email</label>
        <div class="col-sm-10">
            <input type="hidden" name="id" value="9" id="id" />
            <input type="hidden" name="source_id" value="2" id="source_id" />
            <input type="text" name="email" value="" id="email" 
            placeholder="Recipient Email Address" class="form-control" required />
    <div class="form-group">
        <label for="inputName" class="col-sm-2 control-label">Subject</label>
        <div class="col-sm-10">
            <input type="text" name="subject" value="" id="subject" 
            placeholder="Subject" class="form-control" required />
    <div class="form-group">
        <label for="inputName" class="col-sm-2 control-label">Message</label>
        <div class="col-sm-10">
            <textarea class="form-control" name="message" id="message"></textarea>
    <div class="form-group">
        <div class="col-sm-offset-2 col-sm-10">
            <button type="submit" class="btn btn-info">Send Email</button>

3. Create a controller file Email.php in the app/Controllers/ directory.

namespace App\Controllers;

use App\Controllers\BaseController;
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;

class Email extends BaseController {
    public function __construct() {
    public function compose() {
        echo view('compose');
    public function send_email() {
        $email          = $this->request->getPost('email');
        $subject        = $this->request->getPost('subject');
        $message        = $this->request->getPost('message');
        $mail = new PHPMailer(true);  
        try {
            $mail->Host         = 'host'; //
            $mail->SMTPAuth     = true;     
            $mail->Username     = 'username';  
            $mail->Password     = 'password';
            $mail->SMTPSecure   = 'tls';  
            $mail->Port         = 587;  
            $mail->Subject      = $subject;
            $mail->Body         = $message;
            $mail->setFrom('username', 'display_name');
            if(!$mail->send()) {
                echo "Something went wrong. Please try again.";
            else {
                echo "Email sent successfully.";
        } catch (Exception $e) {
            echo "Something went wrong. Please try again.";