This class provides all browse settings and the continuation point handling. More...

#include <continuationpoint.h>

Public Member Functions
	BrowseContext (OpcUa_ViewDescription pView, OpcUa_NodeId pNodeToBrowse, OpcUa_UInt32 uMaxResultsToReturn, OpcUa_BrowseDirection BrowseDirection, OpcUa_NodeId *pReferenceTypeId, OpcUa_Boolean bIncludeSubtype, OpcUa_UInt32 uNodeClassMask, OpcUa_UInt32 uResultMask)
	Creates a BrowseContext object initialized with the browse parameters passed in. More...

virtual	~BrowseContext ()
	Destroys the BrowseContext object.

void	setUserData (ContinuationPointUserDataBase *pContinuationPointUserDataBase)
	Set user data to prepare a Continuation Point for the next browse if not all nodes can be returned. More...

ContinuationPointUserDataBase *	detachUserData ()
	Detach user data to continue browse. More...

OpcUa_ViewDescription *	pView () const
	Returns the OPC UA View context for the browse. More...

OpcUa_NodeId *	pNodeToBrowse () const
	Returns the node id of the node to browse.

OpcUa_UInt32	uMaxResultsToReturn () const
	Returns the maximum number of browse results to return. More...

void	setMaxResultsToReturn (OpcUa_UInt32 uMaxResultsToReturn)
	Allows setting of the maximum number of results to return.

OpcUa_BrowseDirection	BrowseDirection () const
	Returns the browse direction for the browse call. More...

OpcUa_NodeId *	pReferenceTypeId () const
	Returns the node id of the requested reference type or its subtypes if bIncludeSubtype is set. More...

OpcUa_Boolean	bIncludeSubtype () const
	Returns the flag indicating whether subtypes of the requested reference type should be included in the browse result. More...

OpcUa_UInt32	uNodeClassMask () const
	Returns the node class filter mask identifying the node classes to include in the browse result. More...

OpcUa_UInt32	uResultMask () const
	Returns the result filter mask identifing the information returned for each node in the browse result. More...

void	setResultMask (OpcUa_UInt32 uResultMask)
	Allows setting of the result mask.

OpcUa_Boolean	isFirstBrowse () const
	Can be used to check whether it is the first browse with this context. More...

OpcUa_Boolean	isLastBrowse () const
	Flag that tells the SDK whether it was the last browse call and all references are returned. More...

OpcUa_UInt32	nodeToBrowseCount () const
	Returns the total number of nodes to browse in the Browse service. More...

OpcUa_UInt32	nodeToBrowseIndex () const
	Returns the index of this node in the nodes to browse array in the Browse service call. More...

Detailed Description

This class provides all browse settings and the continuation point handling.

The class provides all settings for a browse call, like node to browse and the browse filter settings. It also keeps the settings and the continuation point user data if not all results can be returned in a single browse result. The same object is provided in a second browse call triggered through a BrowseNext service call. In this case, the continuation point is provided in addition to the browse settings.

If the number of browse results exeeds the uMaxResultsToReturn or a server internal limit, a continuation point is necessary and setUserData is used to store the implementation specific continuation point user data.

The following code provides an example for the functions setUserData and uMaxResultsToReturn

// Check whether we need to create a continuation point and stop browsing
if ( browseCount >= browseContext.uMaxResultsToReturn() )
{
    // Create continuation point object for browse context
    CPNodeManagerTree* pCP = new CPNodeManagerTree;
    // Set continuation point data for next browse
    pCP->m_nextChild = i+1;
    // Assign continuation point to browse context
    browseContext.setUserData(pCP);
    break;
}

The following code provides an example for a continuation point user data class

class CPNodeManagerTree : public ContinuationPointUserDataBase
{
   UA_DISABLE_COPY(CPNodeManagerTree);
public:
   CPNodeManagerTree() : m_nextChild(0){}
   virtual ~CPNodeManagerTree(){}
   OpcUa_UInt32 m_nextChild;
};

isFirstBrowse is used to check whether it is a first browse or a browse next.

detachUserData is used to get the stored continuation point data.

The following code provides an example for the functions isFirstBrowse and detachUserData

 // Check whether we have a continuation point from OPC UA browse
if ( browseContext.isFirstBrowse() == OpcUa_False )
{
    CPNodeManagerTree* pCP = (CPNodeManagerTree*)browseContext.detachUserData();
    if ( pCP )
    {
        startingChild = pCP->m_nextChild;
        delete pCP;
    }
}

The SDK handles the release of continuation point data if BrowseNext is not called or just called to release the continuation point.

Constructor & Destructor Documentation

BrowseContext::BrowseContext	(	OpcUa_ViewDescription *	pView,
		OpcUa_NodeId *	pNodeToBrowse,
		OpcUa_UInt32	uMaxResultsToReturn,
		OpcUa_BrowseDirection	BrowseDirection,
		OpcUa_NodeId *	pReferenceTypeId,
		OpcUa_Boolean	bIncludeSubtype,
		OpcUa_UInt32	uNodeClassMask,
		OpcUa_UInt32	uResultMask
	)

Creates a BrowseContext object initialized with the browse parameters passed in.

Parameters

pView	The View context used for the browse.
pNodeToBrowse	The actual Node to browse.
uMaxResultsToReturn	The maximum number of results to return.
BrowseDirection	Direction of the browse from the node to browse (Inverse/Forward/Both).
pReferenceTypeId	NodeId of the reference type to follow.
bIncludeSubtype	Flag indicating whether subtypes of the reference type should be returned.
uNodeClassMask	The node class mask used as filter.
uResultMask	The result mask used to filter the requested data returned for a result.

Member Function Documentation

OpcUa_Boolean BrowseContext::bIncludeSubtype ( ) const

inline

Returns the flag indicating whether subtypes of the requested reference type should be included in the browse result.

See Also: pReferenceTypeId

OpcUa_BrowseDirection BrowseContext::BrowseDirection ( ) const

inline

Returns the browse direction for the browse call.

Options are:

OpcUa_BrowseDirection_Forward
OpcUa_BrowseDirection_Inverse
OpcUa_BrowseDirection_Both

ContinuationPointUserDataBase * BrowseContext::detachUserData ( )

Detach user data to continue browse.

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 BrowseContext::isFirstBrowse ( ) const

inline

Can be used to check whether it is the first browse with this context.

In the case of OpcUa_True, it is the first browse call with this browse context. In the case of OpcUa_False, it is a browse next call with a continuation point.

Returns: a Boolean value to check whether this was the first browse with the current context.

OpcUa_Boolean BrowseContext::isLastBrowse ( ) const

inline

Flag that tells the SDK whether it was the last browse call and all references are returned.

The flag is set by 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 browse. The default value is OpcUa_True.

Returns: a value used to recognize whether this was the last browse call or not.

OpcUa_UInt32 BrowseContext::nodeToBrowseCount ( ) const

inline

Returns the total number of nodes to browse in the Browse service.

This BrowseContext represents only one of the nodes to browse in the Browse request. This information can be used together with the nodeToBrowseIndex() and the receiveTime and timeoutHint in the ServiceContext to decide whether the current node can still be processed or the browse for the node should be skipped and BadNoContinuationPoints returned for the remaining nodes. It would also be possible to return continuation points and an empty result list for the remaining nodes if the number is below the number of continuation points supported per session.

OpcUa_UInt32 BrowseContext::nodeToBrowseIndex ( ) const

inline

Returns the index of this node in the nodes to browse array in the Browse service call.

This BrowseContext represents only one of the nodes to browse in the Browse request. This information can be used together with the nodeToBrowseCount() and the receiveTime and timeoutHint in the ServiceContext to decide whether the current node can still be processed or the browse for the node should be skipped and BadNoContinuationPoints returned for the remaining nodes. It would also be possible to return continuation points and an empty result list for the remaining nodes if the number is below the number of continuation points supported per session.

OpcUa_NodeId* BrowseContext::pReferenceTypeId ( ) const

inline

Returns the node id of the requested reference type or its subtypes if bIncludeSubtype is set.

See Also: bIncludeSubtype

OpcUa_ViewDescription* BrowseContext::pView ( ) const

inline

Returns the OPC UA View context for the browse.

If the view is not set, the whole address space is browsed.

void BrowseContext::setUserData ( ContinuationPointUserDataBase * pContinuationPointUserDataBase )

Set user data to prepare a Continuation Point for the next browse if not all nodes can be returned.

The data handling class must be derived from ContinuationPointUserDataBase. The SDK handles the release of continuation point data if BrowseNext is not called or just called to release the continuation point.

See Also: detachUserData to get the continuation point user data in a later browse call with continuation point.

Parameters

pContinuationPointUserDataBase User data for the continuation point. BrowseContext takes ownership of the passed object.

OpcUa_UInt32 BrowseContext::uMaxResultsToReturn ( ) const

inline

Returns the maximum number of browse results to return.

If the maximum is exceeded, a continuation point needs to be created.

See Also: setUserData

OpcUa_UInt32 BrowseContext::uNodeClassMask ( ) const

inline

Returns the node class filter mask identifying the node classes to include in the browse result.

Bit mask containing the following options:

Define	Value
OpcUa_NodeClass_Object	1
OpcUa_NodeClass_Variable	2
OpcUa_NodeClass_Method	4
OpcUa_NodeClass_ObjectType	8
OpcUa_NodeClass_VariableType	16
OpcUa_NodeClass_ReferenceType	32
OpcUa_NodeClass_DataType	64
OpcUa_NodeClass_View	128

If set to zero, all node classes are returned.

OpcUa_UInt32 BrowseContext::uResultMask ( ) const

inline

Returns the result filter mask identifing the information returned for each node in the browse result.

Bit mask containing the following options:

Define	Value
OpcUa_BrowseResultMask_None	0
OpcUa_BrowseResultMask_ReferenceTypeId	1
OpcUa_BrowseResultMask_IsForward	2
OpcUa_BrowseResultMask_NodeClass	4
OpcUa_BrowseResultMask_BrowseName	8
OpcUa_BrowseResultMask_DisplayName	16
OpcUa_BrowseResultMask_TypeDefinition	32

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

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation