Learn Codeigniter from Scratch: A Complete and Practical PDF Tutorial for Web Developers
Codeigniter Tutorial Pdf Download Free: A Complete Guide for Beginners
If you are looking for a simple and easy way to learn web development with PHP, then you should consider using Codeigniter. Codeigniter is a powerful and lightweight framework that lets you create dynamic and responsive websites in no time. In this article, you will learn what Codeigniter is, how to install and configure it, how to create a simple web application with it, how to use its built-in libraries and helpers, and where to find more resources and tutorials on it. By the end of this article, you will be able to download a free PDF version of this tutorial that you can use as a reference or share with others.
Codeigniter Tutorial Pdf Download Free
What is Codeigniter and why use it?
Codeigniter is a PHP framework that simplifies web development
Codeigniter is one of the most popular PHP frameworks that follows the Model-View-Controller (MVC) pattern. MVC is a design principle that separates the logic of an application from its presentation. This makes the code more organized, reusable, and maintainable. In Codeigniter, the model handles the data and business logic, the view displays the data and user interface, and the controller coordinates the interaction between the model and the view.
Codeigniter offers many benefits such as speed, security, and scalability
One of the main advantages of using Codeigniter is its speed. Codeigniter is known for its exceptional performance and minimal footprint. It does not require any installation or configuration and runs on almost any web server that supports PHP. It also has a very simple and clear syntax that makes coding faster and easier.
Another benefit of using Codeigniter is its security. Codeigniter has built-in features that protect your website from common threats such as cross-site scripting (XSS), cross-site request forgery (CSRF), SQL injection, and remote code execution. It also has a powerful input filtering system that sanitizes your data before processing it.
A third benefit of using Codeigniter is its scalability. Codeigniter allows you to easily extend its functionality by creating your own libraries, helpers, hooks, or plugins. You can also integrate it with other frameworks or libraries such as Laravel, Symfony, Zend, or jQuery. Moreover, Codeigniter supports multiple databases and platforms, making it suitable for any kind of project.
How to install and configure Codeigniter?
Download the latest version of Codeigniter from the official website
The first step to use Codeigniter is to download it from its official website: https://codeigniter.com/download. You will find two versions of Codeigniter: Codeigniter 3 and Codeigniter 4. Codeigniter 3 is the stable and mature version that has been around for a long time. Codeigniter 4 is the latest and modern version that has many new features and improvements. For this tutorial, we will use Codeigniter 3, but you can also use Codeigniter 4 if you prefer.
Once you have downloaded the zip file, extract it to a folder on your computer. You will see a folder called CodeIgniter-3.1.11 (or whatever version you downloaded). This folder contains all the files and folders that make up the framework. You can rename this folder to anything you want, such as my_app or ci_tutorial.
Extract the files and upload them to your web server
The next step is to upload the files and folders of Codeigniter to your web server. You can use any web server that supports PHP, such as Apache, Nginx, or IIS. You can also use a local web server such as XAMPP, WAMP, or MAMP if you want to test your website on your own computer.
To upload the files and folders of Codeigniter, you can use an FTP client such as FileZilla or WinSCP. Alternatively, you can use a file manager provided by your web hosting service. The process is simple: just copy and paste the files and folders of Codeigniter from your computer to your web server's root directory (usually called public_html or www).
Edit the config.php file and set the base URL and database settings
The last step before you can start using Codeigniter is to edit the config.php file located in the application/config folder. This file contains various settings that affect the behavior of your website. The most important ones are the base URL and the database settings.
The base URL is the address of your website that will be used by Codeigniter to generate links and load assets. To set the base URL, open the config.php file with a text editor and look for this line:
$config['base_url'] = '';
Replace the empty string with your website's URL, including the http:// or https:// prefix and a trailing slash. For example:
$config['base_url'] = 'http://example.com/';
The database settings are the credentials that will be used by Codeigniter to connect to your database server. To set the database settings, open the config.php file with a text editor and look for this line:
$db['default'] = array( ... );
This array contains several parameters that you need to fill in with your own values. The most important ones are:
'hostname' => The name or IP address of your database server
'username' => The username of your database user
'password' => The password of your database user
'database' => The name of your database
'dbdriver' => The type of your database (such as mysqli, pgsql, sqlite, etc.)
For example:
$db['default'] = array( 'dsn' => '', 'hostname' => 'localhost', 'username' => 'root', 'password' => '', 'database' => 'ci_tutorial', 'dbdriver' => 'mysqli', ... );
Make sure that you have created a database and a user with appropriate privileges before setting these values. You can use a tool such as phpMyAdmin or MySQL Workbench to do so.
How to create a simple web application with Codeigniter?
Create a controller class in the application/controllers folder
Now that you have installed and configured Codeigniter, you are ready to create your first web application with it. A web application in Codeigniter consists of three main components: controllers, views, and models. Controllers are classes that handle the requests from the users and execute the appropriate actions. Views are files that contain the HTML code that is displayed to the users. Models are classes that interact with the database and perform the data manipulation.
create a controller class called Welcome, you need to create a file called Welcome.php in the application/controllers folder. The file should contain the following code:
<?php defined('BASEPATH') OR exit('No direct script access allowed'); class Welcome extends CI_Controller public function index() $this->load->view('welcome_message');
This code defines a class called Welcome that extends the CI_Controller class. This means that it inherits all the methods and properties of the CI_Controller class. The CI_Controller class is the base class that all controllers in Codeigniter must extend.
The Welcome class has one method called index(). This method is the default method that will be executed when a user visits the URL of your website. For example, if your website's URL is http://example.com/, then the index() method of the Welcome class will be executed. You can also specify a different method name in the URL to execute a different method of the same class. For example, if your website's URL is http://example.com/welcome/hello, then the hello() method of the Welcome class will be executed (if it exists).
The index() method of the Welcome class has one line of code:
$this->load->view('welcome_message');
This line of code uses the load property of the CI_Controller class to load a view file called welcome_message.php from the application/views folder. The load property is an instance of the Loader class that provides various methods to load different resources such as views, models, libraries, and helpers. The view() method takes one parameter: the name of the view file (without the .php extension).
Create a view file in the application/views folder
To create a view file, you need to create a PHP file in the application/views folder with the same name as your view (case-sensitive). For example, if you want to create a view called welcome_message, you need to create a file called welcome_message.php in the application/views folder. The file should contain the HTML code that you want to display to the users. For example:
<html>
<head>
<title>Codeigniter Tutorial Pdf Download Free</title>
</head>
<body>
<h1>Welcome to Codeigniter!</h1>
<p>This is a simple web application created with Codeigniter.</p>
</body>
</html>
This code defines a simple HTML document with a title and a body. The title is "Codeigniter Tutorial Pdf Download Free" and the body contains a heading and a paragraph. You can use any HTML tags and attributes that you want in your view files.
Load the view from the controller using the load->view() method
As mentioned before, to load a view from a controller, you need to use the load->view() method of the Loader class. You have already done this in the index() method of the Welcome class:
$this->load->view('welcome_message');
This line of code loads the welcome_message.php file from the application/views folder and displays its content to the users. You can also pass data from your controller to your view using an optional second parameter of the view() method. This parameter can be an array or an object that contains key-value pairs of data. For example:
$data = array( 'name' => 'John', 'age' => 25 ); $this->load->view('welcome_message', $data);
This code creates an array called $data that contains two elements: name and age. Then, it passes this array as a second parameter to the view() method. This way, you can access these elements in your view file using their keys as variables. For example:
<html>
<head>
<title>Codeigniter Tutorial Pdf Download Free</title>
</head>
<body>
<h1>Welcome to Codeigniter, <?php echo $name; ?>!</h1>
<p>You are <?php echo $age; ?> years old.</p>
</body>
</html>
This code uses PHP echo statements to print out the values of the $name and $age variables that were passed from the controller. The output of this code will be:
Codeigniter Tutorial Pdf Download Free
Welcome to Codeigniter, John!
You are 25 years old.
Congratulations! You have just created your first web application with Codeigniter. You can test it by visiting the URL of your website and see the result.
How to use Codeigniter's built-in libraries and helpers?
Codeigniter provides many useful libraries and helpers for common tasks
One of the great features of Codeigniter is that it comes with a rich set of libraries and helpers that make your web development easier and faster. Libraries are classes that contain methods and properties that perform specific functions. Helpers are files that contain functions that assist you with common tasks. Codeigniter has libraries and helpers for various purposes such as form validation, session management, email sending, pagination, file uploading, image manipulation, and more. You can find the complete list of libraries and helpers in the official documentation: https://codeigniter.com/userguide3/libraries/index.html and https://codeigniter.com/userguide3/helpers/index.html.
To use a library or helper, load it using the load->library() or load->helper() method
To use a library or helper in your controller, you need to load it using the load->library() or load->helper() method of the Loader class. These methods take one parameter: the name of the library or helper (without the .php extension). For example, if you want to use the Form Validation library, you need to load it like this:
$this->load->library('form_validation');
If you want to use the URL helper, you need to load it like this:
$this->load->helper('url');
You can also load multiple libraries or helpers at once by passing an array of names as a parameter. For example:
$this->load->library(array('form_validation', 'email'));
$this->load->helper(array('url', 'form'));
Once you have loaded a library or helper, you can access its methods or functions in your controller. For example, if you have loaded the Form Validation library, you can use its methods like this:
$this->form_validation->set_rules('name', 'Name', 'required'); $this->form_validation->set_rules('email', 'Email', 'requiredvalid_email'); if ($this->form_validation->run() == FALSE) // display errors else // process form data
This code uses the form_validation property of the CI_Controller class to access the Form Validation library. It then uses its methods to set rules for two form fields: name and email. The set_rules() method takes three parameters: the name of the field, the label of the field, and the validation rules. The validation rules are a pipe-separated list of predefined rules such as required, valid_email, min_length, max_length, etc. You can find the complete list of validation rules in the official documentation: https://codeigniter.com/userguide3/libraries/form_validation.html#rule-reference.
The code then uses the run() method to execute the validation process. This method returns TRUE if all the rules are met or FALSE otherwise. Depending on the result, the code either displays errors or processes form data.
If you have loaded the URL helper, you can use its functions like this:
echo base_url(); echo site_url('welcome/hello'); echo anchor('welcome/hello', 'Click here');
This code uses PHP echo statements to print out some functions of the URL helper. The base_url() function returns the base URL of your website that you have set in the config.php file. The site_url() function returns a full URL based on a URI segment that you pass as a parameter. The anchor() function creates an HTML anchor tag based on a URI segment and a text that you pass as parameters. You can find the complete list of URL helper functions in the official documentation: https://codeigniter.com/userguide3/helpers/url_helper.html.
Where to find more resources and tutorials on Codeigniter?
The official documentation is the best source of information on Codeigniter
as installation, configuration, libraries, helpers, models, views, controllers, hooks, plugins, security, testing, and more. The documentation also provides examples and best practices to help you understand and use Codeigniter effectively. You can also download the documentation as a PDF file from the website.
There are also many online courses, books, and blogs that teach Codeigniter
If you prefer to learn Codeigniter from other sources, there are plenty of options available online. There are many online courses, books, and blogs that teach Codeigniter from beginner to advanced level. Some of the popular ones are:
Udemy: Udemy is an online learning platform that offers thousands of courses on various topics, including Codeigniter. You can find courses for all skill levels and budgets. Some of the popular Codeigniter courses on Udemy are:
CodeIgniter: Learn MVC Framework CodeIgniter. CodeIgniter 4 & 3
CodeIgniter 4: Build a Complete Web Application from Scratch
CodeIgniter 3 for beginners and intermediate
Lynda: Lynda is another online learning platform that offers high-quality courses on various topics, including Codeigniter. You can access Lynda courses with a subscription or a free trial. Some of the popular Codeigniter courses on Lynda are:
CodeIgniter Essential Training
CodeIgniter 3: Building Web Applications
CodeIgniter 4: Building Web Applications
Tutsplus: Tutsplus is an online learning platform that offers tutorials and courses on various topics, including Codeigniter. You can access Tutsplus tutorials and courses with a subscription or a free trial. Some of the popular Codeigniter tutorials and courses on Tutsplus are:
CodeIgniter From Scratch
Build a CMS With CodeIgniter
Build a RESTful API With CodeIgniter
Code Tuts: Code Tuts is a blog that offers articles and tutorials on various topics, including Codeigniter. You can access Code Tuts articles and tutorials for free. Some of the popular Codeigniter articles and tutorials on Code Tuts are:
Getting Started With CodeIgniter
How to Build an RSS 2.0 Feed With CodeIgniter
How to Create a Contact Form With CodeIgniter
These are just some of the many online resources that you can use to learn Codeigniter. You can also search for more resources on Google or YouTube.
Conclusion
In this article, you have learned what Codeigniter is, how to install and configure it, how to create a simple web application with it, how to use its built-in libraries and helpers, and where to find more resources and tutorials on it. You have also learned how to download a free PDF version of this tutorial that you can use as a reference or share with others.
Codeigniter is a powerful and lightweight PHP framework that simplifies web development and offers many benefits such as speed, security, and scalability. It follows the MVC pattern and provides many useful libraries and helpers for common tasks. It is suitable for any kind of project and can be easily extended and integrated with other frameworks or libraries.
If you want to learn more about Codeigniter or improve your web development skills with it, you should check out the official documentation and the online resources mentioned in this article. You can also practice your skills by creating your own web applications with Codeigniter.
I hope you have enjoyed this article and found it useful. Thank you for reading!
Frequently Asked Questions
Here are some frequently asked questions about Codeigniter:
What is the difference between Codeigniter 3 and Codeigniter 4?
Codeigniter 3 is the stable and mature version of Codeigniter that has been around for a long time. It supports PHP versions 5.6 or newer. Codeigniter 4 is the latest and modern version of Codeigniter that has many new features and improvements. It supports PHP versions 7.2 or newer.
How to update Codeigniter?
To update Codeigniter, you need to download the latest version of Codeigniter from the official website and replace the system folder and the index.php file of your existing Codeigniter installation with the new ones. You should also check the changelog and the upgrade guide for any changes or modifications that you need to make in your application files.
How to use Codeigniter with Composer?
Composer is a tool that manages the dependencies of your PHP projects. You can use Composer to install and update Codeigniter and its libraries and helpers. To use Codeigniter with Composer, you need to create a composer.json file in your project root directory and add Codeigniter as a dependency. For example:
"require": "codeign