get_message_objT_get_message_objGetMessageObjGetMessageObj (Operator)

Name

get_message_objT_get_message_objGetMessageObjGetMessageObj — Retrieve an object associated with the key from the message.

Signature

get_message_obj( : ObjectData : MessageHandle, Key : )

Description

get_message_objget_message_objGetMessageObjGetMessageObjGetMessageObj retrieves an object associated with the KeyKeyKeyKeykey from the message denoted by the MessageHandleMessageHandleMessageHandleMessageHandlemessageHandle. The object has to be previously stored to the message using set_message_objset_message_objSetMessageObjSetMessageObjSetMessageObj.

The operator returns the data in the parameter ObjectDataObjectDataObjectDataObjectDataobjectData. The iconic object is copied by the operation. Threrefore, clearing or reusing the message object afterwards will not have any side-effect on the returned iconic object, afterwards.

If the given KeyKeyKeyKeykey is not present in the message or if the data associated with the key is not an object, get_message_objget_message_objGetMessageObjGetMessageObjGetMessageObj fails. Presence of keys and information about the data associated with the key can be verified using get_message_paramget_message_paramGetMessageParamGetMessageParamGetMessageParam.

Execution Information

Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
Processed without parallelization.

Parameters

ObjectDataObjectDataObjectDataObjectDataobjectData (output_object) object(-array) → object

Tuple value retrieved from the message.

MessageHandleMessageHandleMessageHandleMessageHandlemessageHandle (input_control) message → (handle)

Message handle.

Number of elements: MessageHandle == 1

Restriction: MessageHandle != 0

KeyKeyKeyKeykey (input_control) string → (string / integer)

Key string or integer.

Number of elements: Key == 1

Example (HDevelop)

* ...
get_message_param (Message,'key_exists',['simple_string','foo','my_image'],\
                   KeysPresence)
get_message_param (Message,'key_data_type',['simple_string','my_image'],\
                   KeysType)
get_message_obj (Image, Message, 'my_image')

Result

If the operation succeeds, get_message_objget_message_objGetMessageObjGetMessageObjGetMessageObj returns 2 (H_MSG_TRUE). Otherwise an exception is raised. Possible error conditions include invalid parameters (handle or key), the required key not found in the message or other than object data associated with given key.