PARAMETERS
Short Reference
ABAP Syntax PARAMETERS {para[(len)]}|{para [LENGTH len]}
[ type_options ]
[ screen_options ]
[ value_options ]
[ ldb_options ].
What does it do? Declaration of a parameter para of length len
. Parameters are components of a
selection screen that are assigned a global elementary data object in
the ABAP program and an input field on the selection screen.
The name of the parameter para can contain a maximum of eight
characters. This statement is allowed in the global declaration part of
executable programs ,
function groups , and
module pools . In function groups and
module pools, the statement is only allowed within the definition of an
independent selection screen . In
executable programs, the statement is otherwise automatically assigned
to the standard selection screen .
The length len can only be specified if the data type specified
in type_options has a generic length
( c , n , p , and x ). The length len must
be specified directly as a number or as a numeric constant within the
associated interval ranges . If
len is not specified, the length is set to 1 for a generic data type;
otherwise it is set to the length of the data type.
The PARAMETERS statement has the following effect:
The statement declares a global variable ( para ) of the
specified length in the program. The type of the data object is
specified in type_options .
An input field with the same name and a suitable external data type is
created in a new row at position 35 on the current selection screen. The
length of the input field is determined by the length of the parameter.
The maximum length of the input field is 255. The maximum visible length
of the input field is between 39 and 45, depending on the nesting depth
in blocks with frames. If the length len is greater than the
maximum visible length, the content is displayed as movable.
An output field generated automatically is displayed in the first
position available to the left of the input field as a description with
a length of between 23 and 30, depending on the nesting depth in blocks
with frames. The output field contains either the name of the parameter
para or the selection text to which the parameter is assigned in
the text elements of the program. If the user requests a field help or
input help in the output field by pressing F1 or F4 , the
same data is displayed as when the input field itself is selected.
The attributes of the elements on the selection screen can be modified
in screen_options and with the
SELECTION-SCREEN statement.
Before the selection screen is sent, the content of the para
data object is transported to the input field on the selection screen
and a conversion routine may be
executed. If the length of the parameter is greater than 255, the
content is truncated from the right. You can configure settings for the
content of the input field in
value_options . After a user action on the selection screen, the
content of the input field is transported to the data object and the
content of character-like fields is converted to uppercase by default. A
conversion routine may then be executed. Various
selection screen events are
triggered after the transport.
If parameters are defined in the selection include of a
logical database , further
ldb_options additions are necessary or
possible.
Latest notes: If a parameter is given data using
SUBMIT when an executable program is called, a
conversion routine may also be
called and the content truncated on the right at position 255. The
conversion routine is skipped and the content not truncated only if the
parameter is declared with the addition
NO-DISPLAY .
To ensure legibility, we recommend that you do not omit the length
specification for the generic types and always use the LENGTH
addition instead of parentheses.
The name of a parameter must not be one of the keywords of the screen
flow logic ( MODULE , SELECT , or VALUES ).
If the parameter is a decimal floating point
number which does not relate to a data type in the ABAP Dictionary,
the output style scaling retained is set for the entry field on
the selection screen, which means that closing zeros are retained after
the decimal point. If there is a reference to a data type in the ABAP
Dictionary, the output style defined there is used.
If the type of the selection criteria is a
packed number or a
decimal floating point number defined in the
ABAP Dictionary, the property sign must be set for the type
property, so that negative numbers can be displayed on the selection
screen. This setting is only possible for domains
and not for the direct specification of a predefined type for
data elements or structure components.
If a negative number is entered on the selection screen and this
property is not set, the system rejects it with an error message. If the
parameter contains a negative number when the selection screen is
called, an unhandleable exception occurs.
If the parameter type is a decimal floating
point number defined in the ABAP Dictionary for which the output
style "currency amount" is specified, only numbers with the
corresponding amount of decimal places can be entered on the selection
screen. If, when the selection screen is called, the corresponding ABAP
data object is a number with more decimal places, an unhandleable
exception occurs. If the output style is "extended currency amount",
additional decimal places can be displayed.
Documentation extract taken from SAP system, � Copyright SAP AG. All rights reserved