fnReturnCustError.pq

(IDCustErr as number)=> 
let
   //IDCustErr = 5, /* for debugging purposes */

  //  ============ START: Define your list of custom error records here ====================
  ListCustomErrors = {
        //Custom error #1: The only permissible tax rates are as follows 7% and 19% 
        [
            CustErrID = 1, 
            reason ="Illegal tax rate", 
            message = "The only allowed tax rates are 7% and 19%!", 
            detail = "Make sure in your data source, that only those 2 tax rates are included!", 
            InternalDescription = "When ever another tax rate comes up, throw this error record"
            ],

        //Custom error #2: 
        [
            CustErrID = 2, 
            reason ="Reason Error 2", 
            message = "Message Error 2", 
            detail = "Details Error 2", 
            InternalDescription = "INternal Description Error 2"
            ]

        /*
        Define as many other custom error records, as you want/ need here
        */

    },
  // ============ END: Define your list of custom error records here ====================
  
  //Convert the list into a table
  ListToTable = Table.FromList(ListCustomErrors, Splitter.SplitByNothing(), null, null, ExtraValues.Error),

  //Expand the table
  ExpandColumn = Table.ExpandRecordColumn(ListToTable, "Column1", {"CustErrID", "reason", "message", "detail", 
                    "InternalDescription"}, {"CustErrID", "reason", "message", "detail", "InternalDescription"}),

  //This step filters the table down to the record, which has the custom error ID that you passed to the function with 'IDCustErr'
  FilterForCustErrID = 
  try 
     //Try to call the CustErrID
      Table.SelectRows(ExpandColumn, each ([CustErrID] = IDCustErr)){0} 
  otherwise 
     //if the CustErrID doesn't exist, throw the following error
      error Error.Record( "Error ID not existing!", "The error ID doesn't exist! Use an existing one!"),

  //Throw the custom error
  Result = error Error.Record( FilterForCustErrID[reason], FilterForCustErrID[message], FilterForCustErrID[detail] )    
in  
  Result