Book Image

Learning PHP 7

By : Antonio L Zapata (GBP)
Book Image

Learning PHP 7

By: Antonio L Zapata (GBP)

Overview of this book

PHP is a great language for building web applications. It is essentially a server-side scripting language that is also used for general purpose programming. PHP 7 is the latest version with a host of new features, and it provides major backwards-compatibility breaks. This book begins with the fundamentals of PHP programming by covering the basic concepts such as variables, functions, class, and objects. You will set up PHP server on your machine and learn to read and write procedural PHP code. After getting an understanding of OOP as a paradigm, you will execute MySQL queries on your database. Moving on, you will find out how to use MVC to create applications from scratch and add tests. Then, you will build REST APIs and perform behavioral tests on your applications. By the end of the book, you will have the skills required to read and write files, debug, test, and work with MySQL.
Table of Contents (17 chapters)
Learning PHP 7
About the Author
About the Reviewer

Dependency injection

At the end of the chapter, we will cover one of the most interesting and controversial of the topics that come with, not only the MVC pattern, but OOP in general: dependency injection. We will show you why it is so important, and how to implement a solution that suits our specific application, even though there are quite a few different implementations that can cover different necessities.

Why is dependency injection necessary?

We still need to cover the way to unit test your code, hence you have not experienced it by yourself yet. But one of the signs of a potential source of problems is when you use the new statement in your code to create an instance of a class that does not belong to your code base—also known as a dependency. Using new to create a domain object like Book or Sale is fine. Using it to instantiate models is also acceptable. But manually instantiating, which something else, such as the template engine, the database connection, or the logger, is something...