Pathway/iTS SCREEN COBOL Reference Manual (G06.24+, H06.03+, Pathway/iTS 1.0+)

Procedure Division
Compaq NonStop™ Pathway/iTS SCREEN COBOL Reference Manual—426750-001
6-34
DISPLAY BASE Statement
second DISPLAY BASE can execute at any time to establish a new screen, or to
reestablish the same screen.
DYNAMIC
specifies that nonliteral screen fields can acquire their initial contents from their
FROM or USING Working-Storage data item. A subsequent DISPLAY statement is
not needed to display the initial Working-Storage values.
In addition, the DYNAMIC modifier provides the capability of changing the screen
field attribute settings at run-time by using the contents of individual attribute
elements in an associated control structure.
base-screen-name
is the name of the base screen.
When a shadowed screen field has an associated Working-Storage item with its
SELECT bit set to 1, the screen field acquires its initial screen contents from its FROM
or USING Working-Storage data item. Otherwise, the initial screen contents are
acquired from the compile-time literal value or the default initial value.
DISPLAY BASE (without the DYNAMIC modifier) does not physically display the
screen. The screen data is displayed when one of the following events occurs:
•
Terminal buffer (TERMBUF) fills up
•
One of the following statements is executed: ACCEPT; BEGIN-TRANSACTION,
END-TRANSACTION, RESTART-TRANSACTION, or ABORT-TRANSACTION;
CALL; CHECKPOINT; DELAY; EXIT PROGRAM; PRINT SCREEN; or
SEND
•
The DISPLAY statement is executed for a conversational terminal
During execution of the first DISPLAY BASE statement for a SCREEN COBOL
program, the I/O startup messages prepare the terminal for Pathway/iTS operation. The
program can then act on any terminal I/O errors through the CALL ON ERROR clause.
For the DISPLAY BASE statement in block mode, the input and output fields of the
screen are filled with the values specified in the VALUE clauses for the fields (unless
the DYNAMIC modifier is used and the field’s SELECT bits are set to 1, in which case
the values are taken from the associated Working-Storage data items). A field that has
no VALUE clause is filled with the fill character. For variable-length tables (defined
with OCCURS DEPENDING ON), the table is filled to the maximum length possible as
specified in the definition, regardless of the current value of the table's controlling
variable.
DISPLAY BASE [DYNAMIC] base-screen-name