PRACTICAL GUIDEUnder review
Validation and triggers in MVC models
Separates data validation from trigger-based filling.
Overview
A trigger derives a value but does not replace model validation. FWStruTrigger returns four elements: source field, target field, condition and execution for AddTrigger. This example uses fictional fields and no table lookup; both fields must exist. VldData checks model/submodels; CommitData requires successful validation and correctly configured persistence. Avoid duplicate side effects across UI and save events. (Sources: refs. 1–3.)
Commented example
// Fragment: oStruct contains character fields ED_ORIG and ED_DEST.
Local aTrigger := FWStruTrigger("ED_ORIG","ED_DEST","Upper(M->ED_ORIG)",.F.,"",0,"","","ED704")
// Fixed author-defined rule, not an external expression.
oStruct:AddTrigger(aTrigger[1],aTrigger[2],aTrigger[3],aTrigger[4])Expected result
Registers the trigger definition without activating a model or writing data. Under review: editorial example neither compiled nor run in Protheus. Check includes, release, RDD and context before testing.
- Test source/target, cycles and rejected validation. Textual rules are code, not free user input.
- Under review: editorial example neither compiled nor run in Protheus. Check includes, release, RDD and context before testing.
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