Defaults

The DATAdesign engine allows you to use defaults for bufferids, indexids and fieldids. There is however no guarantee that any default is actually valid.


Default buffer

You can always set or get the bufferid of the default buffer. Reading is done like this (but you don't know if that buffer still exists) :

Sbasic
    id= bufferID
Assembler
    IDBF
    return long bufferid
C
    long DDbufferid(long *result);

errors, code,   meaning
none
Or you can set it like this :
Sbasic
    DEFbuffer id
    id : long
Assembler
    DEFB
    long bufferid
C
    long DDdefbuffer(long bufferid);

errors, code,   meaning
itnf    -7      invalid bufferid
ijob    -2      this buffer is owned by another job

Default field

Every buffer can have a default field. You have to keep track of this, as you can't find out what the default field is at a given moment.

Sbasic
    DEFfield #bufferid, field
Assembler
    DEFF
    bufferid
    short field
C
    long DDdeffield(long bufferid, short field);

errors, code,   meaning
itnf    -7      invalid bufferid

Default index

Every buffer also has a default index for it. Reading is done like this :

Sbasic
    id= indexID (#bufferid)
Assembler
    IDIN
    bufferid
    return long indexid
C
    long DDindexid(long bufferid, long *result);

errors, code,   meaning
itnf    -7      invalid bufferid
Or you can set it like this :
Sbasic
    DEFindex #bufferid, id
    id : long
Assembler
    DEFI
    bufferid
    long indexid
C
    long DDdefindex(long bufferid, long indexid);

errors, code,   meaning
itnf    -7      invalid bufferid or indexid
PROGS, Professional & Graphical Software
last edited September 3, 1996