Skip to main content

Map expressions and validation

Direct field mappings should remain the default. Add script only where the transformation needs conditional, calculated or record-lifecycle behaviour.

Script locations​

Map items persist formulas for On Start Map, Before Map, On Map, After Map, After Detail Map, Linked Data and On End Map, plus a Map-level Global Script. Field and view items also retain compile status and editor position.

Execution creates/synchronises data sources, runs start/view/field events, maps primary keys, processes linked data and finishes end events. The exact available fields/locals depend on the event scope; do not copy an expression between scopes without recompiling and testing it.

Rules​

  • Use Help > Code Library for the functions in the installed Velox version.
  • Keep business rules deterministic and state their inputs, output type, null behaviour and failure result.
  • Use Scriptlets for genuinely shared code and Variable Groups for governed shared values.
  • Do not place credentials in script text or ordinary variables.
  • Validate text before constructing SQL, paths, commands or external requests.
  • Treat a successful compile as syntax/type evidence, not as proof of business correctness.

Test matrix​

Compile every event, then test zero/one/many records, every conditional branch, null/empty values, minimum/maximum numbers/dates/text, master/detail repetitions, invalid input and a forced destination failure. Compare record counts and persisted output with the source contract. If a formula intentionally skips or changes a record, make that result visible in logs or reconciliation evidence.

See scripting concepts and Map runtime.