A practical book about Grails 3 full stack framework! 

We try to describe here how a complete greenfield application can be implemented with Grails 3 in a fast way using profiles and plugins - and we do this in the sample application that accompanies this book. You can find news about this book on its presentation site located here: www.grailsthreebook.com. This book is not a replacement of the [Grails 3 Reference Documentation](http://docs.grails.org/latest) which is a complete description of [Grails 3](https://grails.org), made by the creators of the framework.

The source code used in this book is part of this sample application which is a free project hosted on GitHub on this location: https://github.com/colaru/mvp-application. If a source code fragment is included in this book, then it is taken from this project. We use BDD or other specification by example techniques for describing the sample application specification - the leaving documentation for the project can be found here: http://serenity.itjobsboard.eu. The application code is tested in a TDD style using automated unit, integration and functional tests. 

The sample application is based on a multi project Gradle build so the application can be automatically built using Gradle - the build tool used by Grails 3. The web application is available here: https://www.itjobsboard.eu. The admin application is available online here: https://admin.itjobsboard.eu. The deployment is done automatically to AWS cloud in a Continuous Deployment style using Jenkins. 

We use links to various external resources in this book (you will see them in the page’s footers), because this book is intended to be in electronic format from the beginning. The reader can use these links for consulting external references in an easy way.

The book has two parts. 

First part - Grails 3 Essentials

An introduction to application development with Grails 3; we describe the main application that will be implemented in the second part of the book

**Chapter 1** is an introduction to the framework. You will find here some history of the framework and a lot of links to the Grails resources; it is presenting the classical three layered architecture for a web application provided by Grails 3

**Chapter 2** describes how to start your work with Grails 3 framework and how to install all the tools for a free working environment - free as much as possible because you have to pay some money for the best tools on the market

**Chapter 3** presents the project we want to implement as an example; it is presenting also the way we choose to work on implementing the sample application, based on BDD, TDD, CI and CD; it shows how the main application is split into multiple parts based on Grails 3 profiles

Second part - Practical example with Grails 3

A practical implementation of a greenfield application with Grails 3; the application is composed of multiple parts corresponding to various Grails 3 profiles

**Chapter 4** describes the implementation of the application admin portal that will be used in Intranet by the site administrators, based on a classical Grails 3 Web Profile

**Chapter 5** describes the implementation of the application site exposed to the Internet to the customers, that is based on Grails 3 Angular Profile 

**Chapter 6** describes a REST web API exposed with Grails 3 Rest Profile and consumed by a mobile hybrid application created with Ionic 2 (can be published in Google Play, Apple Store, and Windows Store)

**Chapter 7** describes a Microservice developed with Grails 3 Rest API Profile