This class provides all query settings and the continuation point handling.
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#include <continuationpoint.h>
This class provides all query settings and the continuation point handling.
The class provides all settings for a query call like node types and the filter settings. It keeps also the settings and the continuation point if not all results can be returned in one query result. The same object is provided in a second query call triggered through a QueryNext service call. In this case the continuation point is provided in addition to the query settings.
setUserData is used to store the implementation specific context. You must derive your data handling class from ContinuationPointUserDataBase.
isFirstQuery is used to check if it is a first query or a query next.
detachUserData is used to get the stored continuation point data.
The SDK handles the release of continuation point data if QueryNext is not called or just called to release the continuation point.
| QueryContext::QueryContext |
( |
OpcUa_ViewDescription * |
pView, |
|
|
OpcUa_Int32 |
noOfNodeTypes, |
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OpcUa_NodeTypeDescription * |
pNodeTypes, |
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OpcUa_ContentFilter * |
pFilter, |
|
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OpcUa_UInt32 |
uMaxDataSetsToReturn, |
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OpcUa_UInt32 |
uMaxReferencesToReturn |
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) |
| |
construction
Construction.
- Parameters
-
| pView | The View context used for the browse. |
| noOfNodeTypes | The number of NodeType entries. |
| pNodeTypes | The list of NodeTypes. |
| pFilter | The filter for the query results. |
| uMaxDataSetsToReturn | The maximum number of data sets to return. |
| uMaxReferencesToReturn | The maximum number of references to return. |
| OpcUa_Byte QueryContext::CPCounter |
( |
| ) |
const |
|
inline |
This member is used for management of the continuation point in the SDK.
- Returns
- the counted continuation point in the SDK.
Detach user data to continue query.
The user of the SDK is responsible to delete the user data after detach is called.
- Returns
- a pointer to the continuation point user data base.
| OpcUa_Boolean QueryContext::isFirstQuery |
( |
| ) |
const |
|
inline |
Can be used to check if it is the first query with this context In the case of OpcUa_True, it is the first query call with this query context.
In the case of OpcUa_False, it is a query next call with a continuation point.
- Returns
- a bool value to check whether this was the first query with the current context.
| OpcUa_Boolean QueryContext::isLastQuery |
( |
| ) |
const |
|
inline |
Flag that tells the SDK if it was the last query call and all references are returned.
The flag is set by the methods setUserData (OpcUa_False) since this indicates that a continuation point is necessary or by detachUserData (OpcUa_True) since the continuation point is handled in a next query. The default value is OpcUa_True.
- Returns
- a value used to recognize whether this was the last query call or not.
| OpcUa_Int32 QueryContext::noOfNodeTypes |
( |
| ) |
const |
|
inline |
Returns the number of NodeType entries.
- See Also
- setUserData
| OpcUa_ContentFilter* QueryContext::pFilter |
( |
| ) |
const |
|
inline |
Returns the filter for the query results.
- See Also
- bIncludeSubtype
| OpcUa_ViewDescription* QueryContext::pView |
( |
| ) |
const |
|
inline |
Returns the OPC UA View context for the query.
If the view is not set, the whole address space is queried.
| void QueryContext::setCPCounter |
( |
OpcUa_Byte |
CPCounter | ) |
|
|
inline |
This member is used for management of the continuation point in the SDK.
- Parameters
-
| CPCounter | This Variable is set to the Value of the member variable. |
Set user data if not all nodes can be returned to prepare Continuation Point for next query.
The data handling class must be derived from ContinuationPointUserDataBase. The SDK handles the release of continuation point data if QueryNext is not called or just called to release the continuation point.
- Parameters
-
| pContinuationPointUserDataBase | used to check if not all nodes can be returned to prepare Continuation Point for next query. |
| OpcUa_UInt32 QueryContext::uMaxDataSetsToReturn |
( |
| ) |
const |
|
inline |
Returns the maximum number of data sets to return.
If the maximum is exceeded, a continuation point needs to be created.
- See Also
- setUserData
| OpcUa_UInt32 QueryContext::uMaxReferencesToReturn |
( |
| ) |
const |
|
inline |
Returns the maximum number of references to return.
If the maximum is exceeded, a continuation point needs to be created.
- See Also
- setUserData
The documentation for this class was generated from the following files:
- D:/work/uasdkcpp/src/uaserver/uaservercpp/coremodule/continuationpoint.h
- D:/work/uasdkcpp/src/uaserver/uaservercpp/coremodule/continuationpoint.cpp
