The DISPLAY ARRAY sub-dialog
The DISPLAY ARRAY
sub-dialog is the controller to implement the
navigation in a list of records, with option data modification actions.
Program array to screen array binding
The DISPLAY ARRAY
sub-dialog binds the members of the flat record (or the
primitive member) of an array to the screen-array or screen-record fields specified with the TO
keyword.
The number of variables in each record of the program array must be the same as the number of fields in each screen record (that is, in a single row of the screen array).
You typically bind a program array to a screen-array
in order to display a page of records. However, the DIALOG
instruction can also
bind the program array to a simple flat screen-record. In this case, only one record will be visible
at a time.
The next code example defines an array with a flat record and binds it to a screen array:
DEFINE p_items DYNAMIC ARRAY OF RECORD
item_num INTEGER,
item_name VARCHAR(50),
item_price DECIMAL(6,2)
END RECORD
...
DIALOG
DISPLAY ARRAY p_items TO sa.*
BEFORE ROW
...
END DISPLAY
...
END DIALOG
If the screen array is defined with one field only, you can bind an array defined with a primitive type:
DEFINE p_names DYNAMIC ARRAY OF VARCHAR(50)
...
DIALOG
DISPLAY ARRAY p_names TO sa.*
BEFORE DELETE
...
END DISPLAY
...
END DIALOG
Identifying a DISPLAY ARRAY sub-dialog
The name of the screen array specified with the TO
clause identifies the list.
The dialog class method takes the name of the screen array as the parameter, identifying the list.
For example, you would use DIALOG.getCurrentRow("screen-array")
to query for the current row in the
list identified by 'screen-array'. The name of the screen-array is also used to qualify sub-dialog actions with a prefix.
Control blocks in DISPLAY ARRAY
Read-only record lists declared with the DISPLAY
ARRAY
sub-dialog can raise the following triggers:
In the singular DISPLAY ARRAY
instruction, BEFORE DISPLAY
and
AFTER DISPLAY
blocks are typically used as initialization and
finalization blocks. In a DISPLAY ARRAY
sub-dialog of a
DIALOG
block, BEFORE DISPLAY
and AFTER
DISPLAY
blocks will be executed each time the focus goes to
(BEFORE
) or leaves (AFTER
) the group of fields
defined by this sub-dialog.