Transform Map - reject all records in import if one recored is rejected

[russellprice]

Hi

Is there a way I can do a pre-check of data from source table before it transforms? then if it finds a record that it will reject due to a choice field being invalid it rejects the whole inport so that the correction can be made and the spreadsheet imported again with corrections?

Or is there a way to do on-the-fly corrections as and when it finds invalid choices?

any advise would be appreciated.

[russellprice]

Sorry, can you expand on this please? This sounds like exactly what I need but Im very new to scripting so any examples you can provide would be appreciated