protected override void BeginProcessing() { base.BeginProcessing(); if (!VariableName.StartsWith(":")) { var exceptionToThrow = new ArgumentException(ErrorStrings.ParameterMissingColon); var errorExecuting = new ErrorRecord(exceptionToThrow, ErrorStrings.ParameterMissingColon, ErrorCategory.InvalidData, exceptionToThrow.Source); ThrowTerminatingError(errorExecuting); } if (!Regex.IsMatch(VariableName.TrimStart(':'), ResourceStrings.RegexParameterValidation)) { var exceptionToThrow = new ArgumentException(ErrorStrings.ParameterNonAlphaNumeric); var errorExecuting = new ErrorRecord(exceptionToThrow, ErrorStrings.ParameterNonAlphaNumeric, ErrorCategory.InvalidData, exceptionToThrow.Source); ThrowTerminatingError(errorExecuting); } }