Book Image

Apex Design Patterns

By : Anshul Verma, Jitendra Zaa
Book Image

Apex Design Patterns

By: Anshul Verma, Jitendra Zaa

Overview of this book

Apex is an on-demand programming language providing a complete set of features for building business applications – including data models and objects to manage data. Apex being a proprietor programming language from Salesforce to be worked with multi tenant environment is a lot different than traditional OOPs languages like Java and C#. It acts as a workflow engine for managing collaboration of the data between users, a user interface model to handle forms and other interactions, and a SOAP API for programmatic access and integration. Apex Design Patterns gives you an insight to several problematic situations that can arise while developing on Force.com platform and the usage of Design patterns to solve them. Packed with real life examples, it gives you a walkthrough from learning design patterns that Apex can offer us, to implementing the appropriate ones in your own application. Furthermore, we learn about the creational patterns that deal with object creation mechanism and structural patterns that helps to identify the relationship between entities. Also, the behavioural and concurrency patterns are put forward explaining the communication between objects and multi-threaded programming paradigm respectively. We later on, deal with the issues regarding structuring of classes, instantiating or how to give a dynamic behaviour at a runtime, with the help of anti-patterns. We learn the basic OOPs principal in polymorphic and modular way to enhance its capability. Also, best practices of writing Apex code are explained to differentiate between the implementation of appropriate patterns. This book will also explain some unique patterns that could be applied to get around governor limits. By the end of this book, you will be a maestro in developing your applications on Force.com for Salesforce
Table of Contents (12 chapters)
Apex Design Patterns
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface

The adapter pattern


The name adapter is derived from the real world, wherein we have various adapters being used in electrical and mechanical domains. While building an application, we often come across scenarios where we have to integrate with other applications/code, which are incompatible. Often, this results in lots of changes being made to either the base code or third-party code. But, in real-world scenarios, there can be various reasons wherein changes cannot be made to either the base code or third-party code or even both.

Note

The adapter design pattern enables two incompatible classes to interact with each other, without those classes knowing about each other's implementation.

Universal Call Center is expanding and wants to enable its customers to pay via credit cards for their services. Assume that there is a third-party library available named PaymentForYou, which helps processing payments using PayPal. So, developers created a class that will send the payment processing request...