INZINP (Initialize Input) keyword for display files

Use this record-level keyword to initialize input/output fields without necessarily sending the initialized data to the display when the PUTOVR and ERASEINP(*ALL) keywords are both in effect.

This keyword has no parameters.

INZINP is particularly useful for applications that perform data entry from remote workstations. It can reduce line traffic between the system unit and the remote workstation.

The following steps describe how this keyword is used:

  1. An output operation displays an input/output field for which the OVRDTA or OVRATR keyword is in effect. The system initializes the input save area to the program value of the field. For example, if the program sets NAME1 to the name Bob, the input save area contains the name Bob.
  2. An input operation places data from the workstation in an input buffer. If the workstation user did not key into the input-capable field and the DSPATR(MDT) keyword is not in effect for the field, the field does not return data from the workstation. The system retrieves data from the input save area and places it in the input buffer for use by the program. Thus, all input-capable fields have data in the input buffer, either from the workstation or from the input save area.
  3. On another output operation, the following cases might occur:
    • If the INZINP and OVRDTA keywords are not in effect, the input save area is unchanged, even if the program changed the field value. For example, if the program changes the field value to the name Tom, the input save area will still have either the value entered by the workstation user or the name Bob, the earlier program value.
    • If INZINP is in effect, the input save area will have the current program value. The current program value is sent to the display for fields for which the OVRDTA keyword is in effect.

      If the OVRDTA keyword is not in effect on an output operation, the program must clear the output buffer for the fields with the OVRDTA keyword specified to ensure that the input save area matches the fields on the display (which are all blanks after the output operation).

Note: If the ERASEINP(*ALL) keyword is in effect for the output operation, input-capable fields are cleared at the display device (on the display), but the input save area is not cleared. For the contents of the input save area, see Table 1 and Table 2. Fields with the DFT keyword specified are initialized with the value specified for the DFT keyword even if the fields are not selected for display. The values are maintained unless the application program selects the fields for display, then changes their data values. This keyword requires the PUTOVR, OVERLAY, and ERASEINP(*ALL) keywords to be specified at the record level.

The following tables show the effect of the ERASEINP(*ALL) and PUTOVR keywords with and without the INZINP keyword.

Table 1. INZINP Input/output fields
OVRATR or OVRDTA keyword INZINP keyword Contents of input save area
Not specified Does not apply Previous contents
Specified but not in effect Specified but not in effect Previous contents
Specified but not in effect Specified and in effect Program value (not sent to display)
OVRATR specified and in effect Does not apply Program value (also sent to display)
OVRATR specified and in effect; OVRDTA not specified or not in effect Does not apply Previous contents (not sent to display)
Table 2. INZINP input-only fields
OVRATR keyword INZINP keyword Contents of input save area
Not specified Does not apply Previous contents
Specified and in effect Does not apply Previous contents
Specified but not in effect Does not apply

Character fields: blanks
Numeric fields: zeros
Parent topic: DDS keyword entries for display files (positions 45 through 80)