HP Data Entry and Forms Management System (VPLUS) Reference Manual (32209-90024)

342 Chapter6
USING VPLUS INTRINSICS
INTRINSIC DESCRIPTIONS
VREADBATCH
Reads contents of current batch record into data buffer in memory.
Syntax
VREADBATCH { comarea }
Parameters
comarea Must be comarea name used when the batch file was opened with
VOPENBATCH. If not already set, the following
comarea items must be set
before calling VREADBATCH:
cstatus Set to zero.
comarealen Set to total number of two-byte words in comarea .
recnum Set to the number of the record in the open batch file from
which data is to be read (records are numbered from zero).
VREADBATCH may set the following
comarea items:
nfname Set to the name of the form associated with the data read
from the batch file (used by VGETNEXTFORM to retrieve this
form from forms file).
dbuflen Set to length of data buffer (in bytes) based on length of
data read from batch record.
deleteflag Set to TRUE (all ones) if delete flag in batch record
indicates record is deleted; set to FALSE (all zeros)
otherwise.
cstatus Set to nonzero value if call unsuccessful.
filerrnum Set to file error code if MPE file error.
Discussion
Use of this intrinsic is demonstrated by the browse/modify mode of ENTRY. It enables a
user to view the data in the batch file. VREADBATCH may also be used to bring the data from
a batch file into the data buffer so that it can be retrieved by an application with the
VGETBUFFER, VGETFIELD, or VGETtype intrinsics.
To display the data just read onto its associated form, VGETNEXTFORM must be called before
the call to VSHOWFORM.
VREADBATCH reads the record (
recnum ) in the batch file opened by VOPENBATCH. The record
is read into memory, where VREADBATCH extracts the batch record control information
(refer to the VOPENBATCH description). This information includes the current form name
which is moved to
nfname , the delete flag which is moved to deleteflag , and the data
length in bytes which is moved to
dbuflen . The data buffer is not updated if the
deleteflag has been set.
In order to use VREADBATCH, the batch file must be on a direct-access device and must be
created with fixed-length records,
not variable-length records.