public boolean isFunction ( final String variableExpression ) { if ( variableExpression == null || variableExpression . length ( ) == 0 ) { return false ; } for ( int i = 0 ; i < functionLibraries . size ( ) ; i ++ ) { FunctionLibrary lib = ( FunctionLibrary ) functionLibraries . get ( i ) ; if ( variableExpression . startsWith ( lib . getPrefix ( ) ) ) { return true ; } } return false ; }
Check if variable expression is a custom function . Expression has to start with one of the registered function library prefix .