ABAP Keyword Documentation → ABAP - Reference → Obsolete Language Elements → Obsolete Processing of External Data → Contexts (Obsolete)
DEMAND
Other versions: 7.31 | 7.40 | 7.54
Obsolete Syntax
DEMAND val1 = f1 val2 = f2 ...
FROM CONTEXT context_ref
[MESSAGES INTO itab].
Addition
Effect
This statement assigns the values of derived fields val1 val2 ... of a
context instance to the data
objects f1 f2 .... context_ref expects a data
object that points to a context instance (see CONTEXTS).
The names of derived fields of the corresponding context can be specified for val1
val2 .... f1 f2 ... expects data objects whose data type conforms with the corresponding context field val1 val2 ....
If the context instance contains valid derived values for the current key, these are assigned directly. Otherwise, the cross-transaction
buffer of the context is searched for the corresponding
data record, which is then passed to the context instance and from there to the data objects f1
f2 .... Only if no corresponding data is found here, are the values in the modules of the context derived and placed in the buffer, the context instance, and the data objects f1 f2 ....
If not all required values can be derived since not enough key fields are known, processing is stopped, the derived values are initialized, and the module sends the message specified in the context for this purpose.
System Fields
| sy-subrc | Meaning |
|---|---|
| 0 | The addition MESSAGES is not specified or the internal table specified after MESSAGES is empty |
| Not 0 | The internal table specified after MESSAGES contains messages. |
Note
The structured type context_t_con, created using CONTEXTS, can be used to create suitable fields.
Addition
... MESSAGES INTO itab
Effect
The addition MESSAGES is used for handling any messages sent by the modules
of a context. If the addition MESSAGES is not specified, each message is sent in accordance with its definition in the context, as described under
Messages. If the addition MESSAGES
is specified, the messages are not sent; instead, for each message, a row is appended to the internal
table itab, which is specified after INTO. The
row type of the internal table must refer to the structure SYMSG in ABAP
Dictionary. The columns msgty, msgid, msgno,
and msgv1 to msgv4 contain the message type, message
class, message number, and content of any placeholders. The internal table itab is initialized at the start of the statement DEMAND.
Example
Creates an instance of the context demo_travel, fills the key fields, and requests the derived values.
CONTEXTS demo_travel.
PARAMETERS: p_carrid TYPE context_t_demo_travel-carrid,
p_connid TYPE context_t_demo_travel-connid.
DATA: context_ref TYPE context_demo_travel,
fields TYPE context_t_demo_travel.
SUPPLY carrid = p_carrid
connid = p_connid
TO CONTEXT context_ref.
DEMAND cityfrom = fields-cityfrom
cityto = fields-cityto
fltime = fields-fltime
FROM CONTEXT context_ref.
cl_demo_output=>display_text( |{ fields-cityfrom } {
fields-cityto } {
fields-fltime }| ).