EMA C++ RDM Usage Guide : Appendix A ReqMsg Payload
 
Appendix A ReqMsg Payload
A.1 View Definition
The client application can specify interest in a specific subset of fields or elements (known as a ‘View’). This is done by encoding an array of the desired fields or elements in the request message payload. The response Message will contain a list of the requested fields or elements and possibly some others depending on factors such as aggregation and the ability of the provider to supply the requested view. Unless otherwise specified, this is supported on any non-administrative Domain Model and any user defined DMM. For more information, refer to the Enterprise Message API C++ Edition Developers Guide. When requesting a new view or changing a view, at a minimum, the request message payload contains an element list with the following entries (any default behavior is included in the element’s description):
 
Table 74: View Definition in Payload  
ELEMENT NAME
TYPE
RANGE/EXAMPLES
DESCRIPTION
:ViewType
UInt
1 | 2
Conditional. Specifies the content type of the :ViewData array.
Required when specifying a view or when reissuing while wanting to keep the same view.
Not required when re-issuing to remove a view. In this case, do not send a payload or view.
Available values are:
1 = VT_FIELD_ID_LIST (this is the default)
2 = VT_ELEMENT_NAME_LIST
:ViewData
Array of Int or Array of ASCII
An Array of desired entries whose content matches the type as specified by :ViewType.
e.g., a :ViewType of VT_FIELD_ID_LIST uses an array of field IDs.
Required. Field Ids will be encoded as an array of 2 byte fixed length field identifiers.
Element names will be variable length Ascii string fields.
:ViewData does not use a default value.