The INPUT sub-dialog

Program variable to form field binding

Each record member variable is bound to the corresponding field of a screen record, in order to manipulate the values that the user enters in the form fields.

The INPUT clause can be used in two forms:

1. INPUT BY NAME variable-list
2. INPUT variable-list FROM field-list

The BY NAME clause implicitly binds the fields to the variables that have the same identifiers as the field names. The variables must be declared with the same names as the fields from which they accept input. The runtime system ignores any record name prefix when making the match. The unqualified names of the variables and of the fields must be unique and unambiguous within their respective domains. If they are not, the runtime system generates an exceptions, and sets the status variable to a negative value.

DEFINE p_cust RECORD
       cust_num INTEGER,
       cust_name VARCHAR(50),
       cust_address VARCHAR(100)
   END RECORD
   ...
DIALOG
   INPUT BY NAME p_cust.*
      BEFORE FIELD cust_name 
       ...
   END INPUT
   ...
END DIALOG

The FROM clause explicitly binds the fields in the screen record to a list of program variables by position. The number of variables or record members must equal the number of fields listed in the FROM clause. Each variable must be of the same (or a compatible) data type as the corresponding screen field. When the user enters data, the runtime system checks the entered value against the data type of the variable, not the data type of the screen field.

DEFINE c_name VARCHAR(50)
       c_addr VARCHAR(100)
   ...
DIALOG
  INPUT c_name,
        c_addr
   FROM FORMONLY.field01,
        FORMONLY.field02 
    BEFORE FIELD cust_name 
       ...
  END INPUT
   ...
END DIALOG

Identifying an INPUT sub-dialog

The name of an INPUT sub-dialog can be used to qualify sub-dialog actions with a prefix.

In order to identify the INPUT sub-dialog with a specific name, you can use the ATTRIBUTES clause to set the NAME attribute:

INPUT BY NAME p_cust.*
      ATTRIBUTES (NAME = "cust")
  ...

Control blocks in INPUT

In the singular INPUT instruction, BEFORE INPUT and AFTER INPUT blocks are typically used as initialization and finalization blocks. In an INPUT sub-dialog of a DIALOG block, BEFORE INPUT and AFTER INPUT blocks will be executed each time the focus goes to (BEFORE) or leaves (AFTER) the group of fields defined by this sub-dialog.