FUNCTIONUnder review

FieldPut

FieldPut( nPos, xValue ) --> xRet

Assigns a typed value to a locked record field.

FieldPutAdvPL

01 · OVERVIEW

Overview

FieldPut requires a type-compatible value and record lock like direct assignment. It returns the assigned value rather than complete business success. The GitHub source modifies SA1 field five without testing RecLock; this adaptation uses only an owned table, finds the named field, checks type/length and writes only after acquiring the lock. It does not replace complete routine validation and error handling. EDTRB is an already-open owned test alias; ED_COD, when used, is a length-10 character field in the teaching schema. (TOTVS, n.d., ref. 1)

02 · SYNTAX

Syntax

FieldPut( nPos, xValue ) --> xRet

Parameters

nPos

NumericRequired

Valid field position.

xValue

AnyRequired

Type- and length-compatible value.

Return value

Assigned value; Nil for an invalid field number.

03 · PRACTICAL EXAMPLE

Commented example

#Include "Protheus.ch"

User Function Ed385()
    Local nPosition
    Local aStructure
    Local cValue := "SAMPLE"
    If Select("EDTRB") > 0
        nPosition := EDTRB->(FieldPos("ED_COD"))
        If nPosition > 0 .And. !EDTRB->(Eof())
            aStructure := EDTRB->(DBStruct())
            If aStructure[nPosition,2] == "C" .And. aStructure[nPosition,3] >= Len(cValue)
                // Write only to the locked test record.
                If RecLock("EDTRB", .F.)
                    EDTRB->(FieldPut(nPosition, cValue))
                    EDTRB->(MsUnlock())
                EndIf
            EndIf
        EndIf
    EndIf
Return Nil

Expected result

Assigns fictional text only when requirements are met; no Protheus persistence test performed. Under review: editorial example neither compiled nor run in Protheus. Check includes, release, RDD and context before testing.

BEST PRACTICES

Use only an owned test table with known schema. Qualify the alias, check record position and manage context changes under the caller contract.
Under review: editorial example neither compiled nor run in Protheus. Check includes, release, RDD and context before testing.