As you develop UJML code, it is often necessary to track down and remove errors in your code (also known as 'bugs'). The UJML Application Debugger is a useful resource toward that end. Errors typically fall into one of the following categories:

Poorly-formed XML does not follow the conventions of XML. This typically happens because an opening or closing element tag is omitted, or the tags are unbalanced. The debugger identifies these errors in the UJML Source pane.

Invalid UJML is well-formed XML that does not follow the UJML DTD. This typically happens because an element tag is omitted or misspelled, or because a required attribute is omitted, or some similar error. The debugger identifies these errors in the UJML Source pane.

Compile-time errors occur because the UJML file, while valid, is not logically consistent with the UJML language. This can happen when, for example, the number of parameters in a function call do not match the function definition, or when an integer variable is assigned a boolean result. The debugger identifies these errors in the UJML Source pane.

Load-time errors occur when a partition is loaded that does not match the requirements of the application or partition that is loading the file. This can happen when, for example, the type or size of an imported variable does not match its definition in the original file. The debugger identifies these errors in the Messages pane.

Run-time errors occur when the player encounters an executable statement that cannot be processed. In some cases, such as when an array reference is greater than the defined array size, the error appears in the Messages pane. In other cases, such as a divide by zero error, the player is unable to catch the error and it will appear as a Java exception in the Messages pane.

If an application uses JSP to generate UJML, it is possible to have errors in the Java code. Java errors will appear in the logs directory of your Tomcat installation. 

It is also possible that you have uncovered a bug in the UIE Player, Server, or Debugger. If you are having trouble with these pieces (or if you have other feedback or feature requests) please contact us at sdk@uievolution.com.