<<interface>> These are specialised DDSReadCondition objects that allow the application to also specify a filter on the locally available data. More...
Public Member Functions | |
| virtual const char * | get_query_expression ()=0 |
| Retrieves the query expression. More... | |
| virtual DDS_ReturnCode_t | get_query_parameters (DDS_StringSeq &query_parameters)=0 |
| Retrieves the query parameters. More... | |
| virtual DDS_ReturnCode_t | set_query_parameters (const DDS_StringSeq &query_parameters)=0 |
| Sets the query parameters. More... | |
 Public Member Functions inherited from DDSReadCondition | |
| virtual DDS_SampleStateMask | get_sample_state_mask ()=0 |
Retrieves the set of sample_states for the condition. More... | |
| virtual DDS_ViewStateMask | get_view_state_mask ()=0 |
Retrieves the set of view_states for the condition. More... | |
| virtual DDS_InstanceStateMask | get_instance_state_mask ()=0 |
Retrieves the set of instance_states for the condition. More... | |
| virtual DDS_StreamKindMask | get_stream_kind_mask ()=0 |
Retrieves the set of instance_states for the condition. More... | |
| virtual DDSDataReader * | get_datareader ()=0 |
| Returns the DDSDataReader associated with the DDSReadCondition. More... | |
| Public Member Functions inherited from DDSCondition | |
| virtual DDS_Boolean | get_trigger_value ()=0 |
Retrieve the trigger_value. More... | |
| virtual DDS_ReturnCode_t | set_handler (DDSConditionHandler *handler) |
| <<extension>> Registers a DDSConditionHandler in this DDSCondition. More... | |
| virtual DDSConditionHandler * | get_handler () |
| <<extension>> Returns the registered DDSConditionHandler. More... | |
| virtual void | dispatch () |
| <<extension>> Calls DDSConditionHandler::on_condition_triggered of the registered DDSConditionHandler. More... | |
Detailed Description
<<interface>> These are specialised DDSReadCondition objects that allow the application to also specify a filter on the locally available data.
Each query condition filter is composed of a DDSReadCondition state filter and a content filter expressed as a query_expression and query_parameters.
The query (query_expression) is similar to an SQL WHERE clause and can be parameterised by arguments that are dynamically changeable by the set_query_parameters() operation.
Two query conditions that have the same query_expression will require unique query condition content filters if their query_paramters differ. Query conditions that differ only in their state masks will share the same query condition content filter.
Queries and Filters Syntax describes the syntax of query_expression and query_parameters.
Member Function Documentation
◆ get_query_expression()
|
pure virtual |
Retrieves the query expression.
◆ get_query_parameters()
|
pure virtual |
Retrieves the query parameters.
- Parameters
-
query_parameters <<inout>> the query parameters are returned here. The memory for the strings in this sequence is managed according to the conventions described in String Conventions. In particular, be careful to avoid a situation in which RTI Connext allocates a string on your behalf and you then reuse that string in such a way that RTI Connext believes it to have more memory allocated to it than it actually does.
◆ set_query_parameters()
|
pure virtual |
Sets the query parameters.
- Parameters
-
query_parameters <<in>> the new query parameters