Flash Remoting: The Definitive Guide

Catching Errors

Error handling is one of the most often overlooked parts of application development. How often have you been to a web page and seen a database error, JavaScript error, connection error, or page not found error? These are examples of errors that are not handled properly. It is up to you to decide how you want to recover from a particular error, but I will show you where the errors can occur in a Flash Remoting application and give you some basic strategies for developing your own error handling.

Error Types

Errors can occur in any aspect of your Flash movie or in the server-side code of a Flash Remoting application. Errors can be broken down into these basic types:

Syntax errors

Syntax errors are caused by malformed code (you typed something incorrectly, such as a misplaced comma or quote). If the syntax error is in the client-side code, Flash’s Output window generally displays the error when you attempt to compile your .swf file. Consult the online help, Chapter 15, or ActionScript for Flash MX: The Definitive Guide for the correct syntax for a given command. Although author-time syntax errors are usually easy to find and fix, those that occur because of user input are more difficult to detect. For example, a user entering a single quote into a form field might cause a syntax error in a SQL statement. Server-side syntax errors should be identified by the server-side development environment, although the exact process varies depending on the server technology in ...