Chapter 3. Understanding Basic Tag Logic The Core tag library of JSTL provides many rudimentary tags for performing basic flow control. Flow control refers to a program's ability to selectively execute portions of itself. Most programming languages achieve this flow control through if statements and other logical tags. A program's flow of execution can also be affected by errors. Error handling is an important part of any computer program. JSP provides tags that let you perform basic error handling. By making use of JSTL's built-in exception-handling capabilities, you can create programs that are capable of handling common runtime errors. In this chapter, we present a sample application that shows how to tie all these concepts together. A simple forms-based chat application will show you how to use scope and basic tag logic to allow two users to chat. Let's begin by examining JSTL's error-handling capabilities. |