Tech Tip: Extracting a Field comment from the property

PRODUCT: 4D | VERSION: 16 | PLATFORM: Mac & Win

Published On: December 28, 2018

In the structure editor, there is an area in the field properties of a table to insert comments:

The following utility method can extract the comments of a field programatically:

//---------------------------------------------------------------------------------
// Name: EXTRACT_FIELD_COMMENT
// Description: Method will extract the Comment property of a Field
//
// Parameters:
// $1 (POINTER) - Pointer to the field
//
// Output:
// $0 (TEXT) - Text of the Comment
// --------------------------------------------------------------------------------
C_POINTER($1;$ptrField)
C_LONGINT($pos;$pos2;$pos3)
C_TEXT($0;$vTStruc;$comment;$fieldNum;$search1;$search2;$search3)

$ptrField:=$1

$fieldNum:=String(Field($ptrField))
$search1:="id=\""+$fieldNum+"\">"
$search2:=""
$search3:=""

EXPORT STRUCTURE($vTStruc)

$pos:=Position($search1;$vTStruc) // search for ID
$pos2:=Position($search2;$vTStruc;$pos)
$pos3:=Position($search3;$vTStruc;$pos2+Length($search2))
$comment:=Substring($vTStruc;$pos2+Length($search2);$pos3-$pos2-Length($search2))

$0:=$comment

Here is an example to extract the field "firstName" comments:

C_TEXT($comment)

$comment:=EXTRACT_FIELD_COMMENT (->[Table_1]firstName)
// Comments for firstName field