Inlining Syntax Error Messages into Templates
By default, LINQ Reporting Engine throws an exception when encounters a template syntax error. Such an exception provides information on a reason of the error and specifies a tag or expression part where the error is encountered. In most cases, this information is enough to find a place in a template causing the error and fix it.
However, when dealing with complex templates containing a large number of tags, it becomes harder to find an exact place in a template causing an error. To make things easier, the engine supports the ReportBuildOptions.INLINE_ERROR_MESSAGES
option that enables inlining of a syntax error message into a template document at an exact position where the error occurs during runtime.
Note – A template syntax error message is written using a bold font to make it more apparent.
Consider the following template.
<<var [name]>>
By default, such a template causes the engine to throw an exception while building a report. However, when ReportBuildOptions.INLINE_ERROR_MESSAGES
is applied, no exception is thrown and the report looks as follows then.
<<var [name] Error! An assignment operator is expected. >>
Note – Only messages describing errors in template syntax can be inlined; messages describing errors encountered during expressions’ evaluation cannot.
When ReportBuildOptions.INLINE_ERROR_MESSAGES
is applied, a Boolean
value returned by a ReportingEngine.buildReport
overload indicates whether building of a report was finished successfully or was interrupted because of a template syntax error. This enables you to process reports which building succeeded or failed differently as shown in the following code snippet.
ReportingEngine engine = new ReportingEngine();
engine.setOptions(ReportBuildOptions.INLINE_ERROR_MESSAGES);
if (engine.buildReport(...))
{
// Do something with a successfully built report.
}
else
{
// Do something with a report containing a template syntax error.
}
Note – When ReportBuildOptions.INLINE_ERROR_MESSAGES
is not applied, ReportingEngine.buildReport
overloads return true
if there were no template syntax errors encountered or throw an exception otherwise.