Compiler logging

Flex provides you with control over the output of warning and debug messages for the application and component compilers. When you compile, you can enable the message output to help you to locate and fix problems in your application.

For the command-line compiler, the settings that you use to control messages are defined in the flex-config.xml file or as command-line compiler options.

You have a high level of control over what compiler messages are displayed. For example, you can enable or disable messages such as binding-related warnings in the flex-config.xml file by using the show-binding-warnings option. The following example disables these messages in the flex-config.xml file:

<show-binding-warnings>false</show-binding-warnings>

You can also set this option on the command line.

For Flash Builder, you set error and warning options in the Compiler Properties dialog box. To open the Compiler Properties dialog box, select Project > Properties > Flex Compiler. You can enable or disable warnings in this dialog box. In addition, you can enter more specific options such as show-binding-warnings in the Additional Compiler Arguments field.

If you enable compiler messages, they are written to the console window (or System.out) by default.

Also in Flash Builder is a separate Eclipse Error Log file. This file stores messages from the Eclipse environment. The default location of this log file on Windows XP is c:\Documents and Settings\user_name\workspace\.metadata\.log. For MacOS and Linux, the default location is also in the workspace directory, but files and directories that begin with a dot are hidden by default. As a result, you must make those files visible before you can view the log file.

For more information on the compiler logging settings, see Viewing warnings and errors.