OFBiz was created in May 2001 by David E Jones and Andy Zeneski after they discovered that the problems they had tried to solve independently were similar and that existing solutions at the time were not sufficient. They realized that these problems could be solved using an Open Source model.

During the course of the next 5 years the OFBiz community grew and as such the number of organizations adopting OFBiz as their ERP system rose, and in January 2006 the project was accepted by the Apache Incubator Project Management Committee (PMC).

In December 2006 the Board of Directors voted to make Apache OFBiz a top-level project. Today OFBiz remains a highly active, community driven, not for profit project enjoying a growing membership and a wider adoption.

The examples and tutorials featured within this book aim to, by the end of our journey, come together to produce a working web-based application. Various approaches will be explored during this project. Different combinations of techniques will be tried and evaluated, so we can learn when best to use them.

We will find that OFBiz is more than just a framework or toolkit. A good portion of OFBiz is comprised of ready-made functions and structures that easily lend themselves to being building blocks for ERP software, the application components. Whilst it is possible to use only the OFBiz framework to build a complete ERP application, it will be at least several magnitudes faster to build on top of these ready-made application components. We will study some of these applications while doing our project, which will also lead to a better understanding of some tried and tested best practices.

Chapter 1, using a Windows machine, guides us through downloading and installing the necessary software we need to obtain and run the OFBiz framework. We are shown how to create an Eclipse project and once running we are shown a few of the components as we place an order on the applications customer facing website and fulfill the order using the back office's Order Manager component.

In Chapter 2 we learn the structure of OFBiz. We are introduced to the concepts of the framework, applications, and hot-deploy directories. We perform our first customization on an existing OFBiz component and finally create the structure of our own bespoke application.

In Chapter 3 we take a look at how the output to the screen is constructed using the screen widgets. We start by creating a simple screen in our learning component, showing a basic output. By the end of the chapter we have learned how to create complex screens, made up of different sections.

In Chapter 4 we study form widgets. We learn how they are used within screen widgets and can save us development time and effort by quickly producing XHTML forms so we can input information to the application.

In Chapter 5 we complete our investigation into the presentation layer of OFBiz by learning how to use Menu-Widgets to navigate around our component. We also take more of a look at how FreeMarker can help us display more complicated screens.

In Chapter 6 we re-visit the Control, learning more about how OFBiz makes use of the Front Controller pattern to configure the flow through our component in just one place. We learn how OFBiz handles different types of requests and we are introduced to the concept of security. By the end of the chapter, we have added "log in" functionality to our bespoke application and have seen how easy it is to force a request to be "secure".

In Chapter 7 we move on to the concepts of the Entity Engine and learn how OFBiz employs the use of the Delegation Pattern to give us easy access to methods to persist data. We learn how OFBiz creates the database structure, adding fields, tables, constraints and indexes from definitions in XML files. We see how, by using View Entities, we can perform joins across tables allowing us to create complex queries. We are also introduced to the Webtools administration component of OFBiz and discover how to access the raw data through these screens.

In Chapter 8 we are led through a series of examples designed to showcase data lookup and persistence techniques. We learn how to use the GenericDelegator's methods to lookup and manipulate the underlying data. We discover how using the Entity Engine Cache can massively improve performance by cutting down the number of database queries and learn how complex queries can be created on the fly by using Dynamic View Entity. Finally we learn how to use the EntityListIterator to efficiently paginate through large record sets.

In Chapter 9 we take a closer look at Java events by learning a number of techniques vital to programming the flow of the application. We also take a look at how we can assign users permissions and how these permissions are checked within the Java methods.

In Chapter 10 we next see another type of event and a very important one—the services. We learn about the advantages of the Service Engine and how it works, learning how to define and write services in Java. We learn the difference between invoking these services synchronously and asynchronously and how services can be scheduled using the Job Scheduler. Finally we learn how to trigger these services using ECAs (Event Condition Actions).

In Chapter 11 we move on to study complex permissions, learning how to assign users granular permissions, and how simply these permissions can be checked from our services. We learn by example how to restrict users from viewing or inputting data depending on access rights whilst building up our bespoke application.

In Chapter 12 we learn about the OFBiz Mini-Language. We see how we can write simple services and events in Minilang, and we learn when it should be ideally used. We see its versatility and see how widespread its concepts are used throughout the framework.

In Chapter 13 we come towards the end of learning about the framework, we see how easy it is to change the look and feel of the component and study the structure of the existing screens. The chapter moves on to some more advanced FreeMarker techniques that are commonly used throughout all of the components. Finally using the production of a PDF as an example we see how to output different formats.

In Chapter 14 we learn some real world developing techniques, including how to debug through the different parts and languages found within the framework. We see how to connect a remote debugger to the application and step through the Java code line by line using the Eclipse IDE. We next learn the concepts behind getting the latest bug fixes and features and merging these into our project using Windows tools enabling us to successfully work with the latest and greatest version on OFBiz. Finally we see learn how to run OFBiz behind the Apache HTTP Server allowing us to create a scalable architecture.

Full download and installation instructions for all software and applications required to obtain and run OFBiz can be found in Chapter 1. These included:

At the time of writing, the latest stable version of OFBiz is 4.0. We will be working with that version, and not with the trunk version. In OFBiz speak (version control speak, rather), such a stable version is termed a "release branch"; the single trunk that forges ahead 24/7 is simply called the "trunk". Each stable branch can still move forward, due to the application of bug fixes. Hence, even release branches do go through revisions.

The trunk is the "latest, greatest and riskiest" state of OFBiz, where new features are added frequently, possibly along with new bugs. Such frequent addition of features do not allow for adequate testing. Before the dust can settle after a new addition by one contributor, more additions may come in from other contributors around the world. Scary as that sounds, this rapid and globally collaborative environment gives the OFBiz framework the fantastic advantage of being improved at a breakneck pace.

On the other hand, release branches like OFBiz 4.0 have had a "feature-freeze", and are invested with testing efforts focused on removing bugs and enhancing stability rather than adding new and untested features. Release branches are ideal for deployment in production environments (for real business use) where stability and ease of maintenance and support are vital.

Working with the trunk presents a moving target, a challenge that is best taken when we have some decent competency with the OFBiz framework as well as familiarity with recent OFBiz trends and changes.

This book may refer to existing code and also to line numbers within files. Bug fixes may therefore have an effect on these line numbers. Since they are only bug fixes, the line numbers should not drastically alter and a simple "Find" in the file will point you in the right direction.

The official policy on the frequency of releases (creation of new release branches) is published once per year, as defined in the Apache OFBiz Release Plan - General Release Policies http://docs.ofbiz.org/display/OFBADMIN/Release+Plan#ReleasePlan-GeneralReleasePolicies.

This book is intended for people wishing to understand and begin to customize the OFBiz framework. A basic level of Java is required and some understanding of Object Oriented Design (OOD) concepts would be beneficial. A basic grasp of Simple Query Language (SQL), although not strictly necessary, is certainly helpful to quickly understand some of the concepts in OFBiz.

Some fundamental skill with XML syntax is required, but only as far as is required to create well-formed XML documents.

The book will offer more hand-holding to MS Windows users. Users of other Operating Systems, such as Linux, should naturally be more adept at grasping the concepts laid out using Windows-specific examples and translating those examples into their respective OS's dialects.

In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text are shown as follows: " The <include-form> element includes a form named FirstForm residing in a file LearningForms.xml."

A block of code will be set as follows:

<request-map uri="OneForm">
<response name="success" type="view" value="OneFormScreen"/>
</request-map>

When we wish to draw your attention to a particular part of a code block, the relevant lines or items will be made bold:

server="default-server"
location="webapp/partymgr"
base-permission="OFBTOOLS,PARTYMGR"
mount-point="/partymgr"/>

New terms and important words are introduced in a bold-type font. Words that you see on the screen, in menus or dialog boxes for example, appear in our text like this: " We see two fields First Name and Last Name, and one Submit button.".

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