A CodeIgniter Tutorial


Before learning to use CodeIgniter, we should review some basic PHP knowledge. First, we’ll discuss MVC architecture and how to build an application. We’ll also look at Object-Oriented programming (OOP) and the Doctrine ORM. Finally, the Form validation library is also discussed.

PHP MVC framework

CodeIgniter is one of the most popular MVC frameworks for PHP. Many developers prefer it over other frameworks because of its lightweight code, simple documentation, and ease of use. This framework is easy to learn and debug and has an international community of developers. In addition, it has many features and is fast.

It has a simple setup and a comprehensive tutorial. You can start with its First Application tutorial, which builds a simple CMS with CRUD functions. The tutorial assumes a basic understanding of PHP and the concepts behind frameworks. You should have some experience with a framework before attempting to build your first application.

CodeIgniter tutorials are also available on Udemy. The PHP MVC framework Course by Edwin Diaz is an excellent place to start learning this framework. There are more than 2,700 students enrolled and 1,296 student reviews on Udemy.

Object-Oriented Programming

Object-Oriented programming (OOP) is a programming paradigm that forces developers to think about the structure and logic of the application before writing a line of code. Object-oriented programming helps developers keep code organized and coherent, making adding new functionality and features more accessible.

Object-Oriented programming uses classes and objects to define the structure of a program. A class encapsulates a piece of code, including data, logic, and behavior. A thing is an instance of a class, and it is the class’s responsibility to define the object. For example, PHP declares types using the class keyword, followed by the class’s name and curly braces. A class is a data structure that a programmer defines. An object is an instance of a data structure defined by a type.

Classes are the most fundamental concept in Object-Oriented programming. These concepts are taught in textbooks and online resources. An object is a single instance of a class that has specific properties and behavior. These properties are called member variables and are available to external applications through a member function.

Doctrine ORM

This CodeIgniter tutorial will use the Doctrine ORM framework to access and manage data. This framework is a PHP extension and can be installed on a Codeigniter server. Using this framework, you can access data on a database from your website.

Doctrine is a PHP library for database interaction. It focuses on Object Relational Mapping (ORM) and Database Abstraction Layer (DBAL) techniques. It works by translating a logical representation of objects into database form while preserving the properties and relationships of entities. You can use Doctrine in conjunction with other frameworks or independently.

Form validation library usage

The Form validation library in CodeIgniter is used to validate inputs on your form. The library has several functions to help you validate inputs. For example, you can set font size and style for a text field. The script will display a FALSE message if the input value is incorrect. In addition, you can use the set_message() function to set global or custom error messages.

The form validation library has built-in rules allowing you to make your form fields valid or invalid. The law creates a field required, while the others make it optional. These rules also enable you to use your validation methods.

Rendering views with simple PHP functions

A simple PHP function can be used to render a view in a web application. The idea can be either HTML or PHP code. You can pass parameters to the view file using a key name. In this way, the view can be loaded from the URL.

The View class collects the parameters of the view and processes them until they are rendered. To correctly render a statement, the names of the parameters must be unique. The escaping of parameter values depends on the config setting. It can be helpful to display the contents of a database, but this can pose a security risk. Therefore, it’s recommended to validate the contents of a database before using this function.

PHP does not support Unicode at low levels, but there are workarounds. For example, you can use mb_* functions to ensure that Unicode strings do not get garbled. But note that not all string functions have an mb_* counterpart. In addition, you should also explicitly define the encoding of any PHP script. This will save you from headaches later.