===FailOnError===

The **FailOnError** function of the [[mplreport]] class will gracefully fail the report with a "This Report Is Unavailable" message and some explanatory text if one or more errors have been returned as part of a data request, such as //FetchHistory// or //GetEvents//.

==Parameters==

^Parameter^Type^Default^Meaning^
|description|str|None|An optional string value that describes the type of data being requested|

==Results===

The final report will say 'xxx Data Unavailable: <driver error messages here>', where 'xxx' is the description.

The description is most often used when a report contains multiple queries (such as one for time-series data and one for events) to differentiate which type of source was unavailable.

But it also makes error messages more human-readable, even when used in reports with only a single request.

==Return==

No Return Value. This function calls **sys.exit()** to terminate the script.

==Usage==

If the data is required to generate your report, we suggest calling this function immediately after any call to [[GetEvents]] or [[FetchHistory]].