What this book covers

Chapter 1, Ecosystem Overview, gives a gentle introduction to the current state of the PHP ecosystem. It looks into the latest features of PHP 7, some of which open a door to the new concepts of use in modular development. Furthermore, this chapter glosses over the popular PHP frameworks.

Chapter 2, GoF Design Patterns, describes recurring solutions to common problems in software design. Practical PHP examples are given for each of the following patterns: creation pattern types, structural patterns, and behavioral patterns.

Chapter 3, SOLID Design Principles, dives into the five basic principles of object-oriented programming and design under the acronym SOLID (single responsibility, open-closed, Liskov substitution, Interface Segregation, and dependency inversion).It gives practical examples and explains the importance of these principles in modular development.

Chapter 4, Requirement Specification for a Modular Web Shop App, guides a reader through the process of defining overall application requirements. It starts by defining actual application feature requirements and progresses all the way to the technology stack selection.

Chapter 5, Symfony at a Glance, gives a high-level overview of Symfony as a framework, a set of tools, and a development methodology. It focuses on the building blocks that we will need to build our modular application.

Chapter 6, Building the Core Module, guides you through setting up a core module based on the Symfony bundle. The core module is then used to set the structure and dependencies for other modules to use.

Chapter 7, Building the Catalog Module, guides us through building a self-sufficient module that matches the web shop catalog-only feature set. It shows us how to set up entities relevant to the module functionality and how to manage those entities and their interactions using the existing framework.

Chapter 8, Building the Customer Module, guides us through building a self-sufficient module that matches the web shop customer-related feature set. It shows us how to set up entities relevant to the module's functionality and how to manage those entities and their interactions using the existing framework. It further shows us how to create a register and login systems.

Chapter 9, Building the Payment Module, guides us through building a self-sufficient module that matches the web shop payment-related feature set. It shows us how to integrate with a third-party payment provider. It further shows us how to expose a payment provider as service for other modules to use.

Chapter 10, Building the Shipment Module, guides us through building a self-sufficient module that matches the web shop shipment-related feature set. It shows us how to define several flat methods that yield different shipment pricing based on various cart product attributes. It further shows us how to expose a shipment method as service for other modules to use.

Chapter 11, Building the Sales Module, guides us through building a self-sufficient module that matches the web shop sales-only feature set. It shows us how to set up cart, cart item, order, and order item entities relevant to the module functionality and how to manage those entities and their interactions using the existing framework.

Chapter 12, Integrating and Distributing Modules, integrates all the modules built in the preceding chapters into a single functioning application. Moving on, it guides us through the modern PHP module distribution techniques. These include Git and Composer, which in turn indirectly include GitHub and Packagist.