Book Image

Digital Java EE 7 Web Application Development

By : Peter Pilgrim
Book Image

Digital Java EE 7 Web Application Development

By: Peter Pilgrim

Overview of this book

Digital Java EE 7 presents you with an opportunity to master writing great enterprise web software using the Java EE 7 platform with the modern approach to digital service standards. You will first learn about the lifecycle and phases of JavaServer Faces, become completely proficient with different validation models and schemes, and then find out exactly how to apply AJAX validations and requests. Next, you will touch base with JSF in order to understand how relevant CDI scopes work. Later, you’ll discover how to add finesse and pizzazz to your digital work in order to improve the design of your e-commerce application. Finally, you will deep dive into AngularJS development in order to keep pace with other popular choices, such as Backbone and Ember JS. By the end of this thorough guide, you’ll have polished your skills on the Digital Java EE 7 platform and be able to creat exiting web application.
Table of Contents (21 chapters)
Digital Java EE 7 Web Application Development
Credits
About the Author
Acknowledgment
About the Reviewers
www.PacktPub.com
Preface
Index

Expression language


The expression language version 3.0 is now a separate specification in Java EE 7. It allows the page author to reference the bean properties, invoke methods, and perform arithmetic operations in the page description language. Originally, EL was a part of the JavaServer Pages specification, and it also became useful for the JSF technology. There are two types of EL: immediate evaluation and deferred evaluation. JSP relied on the immediate form, whereas JSF—because of its lifecycle management of request and response—required a deferred form. EL 3.0 represents the final unification of these strategies.

EL is useful for the page authors so that the digital developer can reference the properties in the managed beans, CDI components, and reference methods in a controller. EL is also used to invoke methods in a controller. EL is used to retrieve values from the beans but it can also set values.

Immediate and deferred expressions

The syntax of an expression has two forms: ${expression...