PRACTICAL GUIDEUnder review

Entry-point returns and validation

Matches return type and effect to the actual caller.

Entry-point returns and validationAdvPL

01 · OVERVIEW

Overview

Before choosing Return, inspect how the master consumes it: validation Boolean, button array, replacement text or ignored result. MVC BUTTONBAR uses an array while validation events use Booleans; this is not a universal rule for all entry points. Check transaction timing and repeated event delivery too. The exercise is a synthetic consumer accepting only Booleans, not an entry point or a universal .T. template. (Sources: refs. 1–2.)

03 · PRACTICAL EXAMPLE

Commented example

#Include "Protheus.ch"

User Function Ed626()
    Local xResponse := .T.
    Local lAccepted := .F.
    // Synthetic consumer: this exercise requires a Boolean.
    If ValType(xResponse) == "L"
        lAccepted := xResponse
    EndIf
    ConOut(lAccepted)
Return Nil

Expected result

Produces .T. for Boolean input. This particular consumer would reject strings and arrays. Under review: editorial example neither compiled nor run in Protheus. Check includes, release, RDD and context before testing.

BEST PRACTICES

Do not trigger irreversible integrations from validation that may run repeatedly.
Under review: editorial example neither compiled nor run in Protheus. Check includes, release, RDD and context before testing.

Entry-point returns and validation

Overview

Commented example

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