The sixth example provides an illustration a different type of request, one in which the Clientis interested in displaying part of the AddressSpaceof the Server. This request includes listing a Referenceas something that is to be returned.

Example 6: Get PersonType.NodeId, AnimalType.NodeId, PersonType.HasChild Reference, PersonType.HasAnimal Reference where a person has a child who has a Animal.

Table B.18describes the NodeTypeDescription parameters used in the example.

Table B.18– Example 6 NodeTypeDescription

Type Definition Node

Include

Subtypes

QueryDataDescription

Relative Path

Attribute

Index Range

PersonType

FALSE

“.12:NodeId”

value

N/A

<12:HasChild>12:PersonType<12:HasAnimal>12:AnimalType.NodeId

value

N/A

<12:HasChild>

value

N/A

<12:HasChild>12:PersonType<12:HasAnimal>

value

N/A

The corresponding ContentFilteris illustrated in Figure B.10.

image052.png

Figure B.10– Example 6 Filter Logic Tree

Table B.19describes the elements, operators and operands used in the example.

Table B.19– Example 6 ContentFilter

Element[]

Operator

Operand[0]

Operand[1]

Operand[2]

Operand[3]

0

RelatedTo

AttributeOperand = NodeId: 12:PersonType, BrowsePath “.”, Attribute: NodeId

ElementOperand = 1

AttributeOperand = Node: 12:HasChild, BrowsePath “.”,Attribute:NodeId

LiteralOperand = ‘1’

1

RelatedTo

AttributeOperand = NodeId: 12:PersonType, BrowsePath “.”, Attribute: NodeId

AttributeOperand = NodeId: 12:AnimalType, BrowsePath “.”, Attribute: NodeId

AttributeOperand = NodeId: 12:HasAnimal, BrowsePath “.”, Attribute: NodeId

LiteralOperand = ‘1’

The results from this query would contain the QueryDataSetsshownin Table B.20.

Table B.20– Example 6 QueryDataSets

NodeId

TypeDefinition

NodeId

RelativePath

Value

12:42 (HFamily1)

PersonType

“.NodeId”

12:42 (HFamily1)

<12:HasChild>12:PersonType<12:HasAnimal>

12:AnimalType.NodeId

12:91 (Pig1)

<12:HasChild>

HasChild

ReferenceDescription

<12:HasChild>12:PersonType<12:HasAnimal>

HasFarmAnimal

ReferenceDescription

12:48 (HFamily2)

PersonType

“.NodeId”

12:48 (HFamily2)

<12:HasChild>12:PersonType<12:HasAnimal>

12:AnimalType.NodeId

12:91 (Pig1)

<12:HasChild>

HasChild

ReferenceDescription

<12:HasChild>12:PersonType<12:HasAnimal>

HasPet

ReferenceDescription

NOTE The RelativePathand browse name (in parentheses) is not in the QueryDataSetand is only shown here for clarity and the TypeDefinition NodeIdwould be an integer, not the symbolic name that is included in the table. The value field would in this case be the NodeIdwhere it was requested, but for the example the browse name is provided in parentheses and in the case of Referencetypes on the browse name is provided. For the Referenceslisted in Table B.20, the value would be a ReferenceDescription which are described in 7.25.

Table B.21provides an example of the same QueryDataSet as shown in Table B.20without any additional fields and minimal symbolic Ids. There is an entry for each requested Attribute, in the cases where an Attribute would return multiple entries the entries are separated by comas. If a structure is being returned then the structure is enclosed in square brackets. In the case of a ReferenceDescription the structure contains a structure and DisplayName and BrowseName are assumed to be the same and defined in Figure B.4.

Table B.21– Example 6 QueryDataSets without Additional Information

NodeId

TypeDefinition

NodeId

Value

12:42

PersonType

12:42

12:91

[HasChild,TRUE,[48,HFamily2,HFamily2,PersonType]],

[HasFarmAnimal,TRUE[91,Pig1,Pig1,PigType]

12:48

PersonType

12:54

12:91

[HasChild,TRUE,[ 54,HFamily3,HFamily3,PersonType]]

[HasPet, TRUE,[ 91,Pig1,Pig1,PigType]]

The PersonType, HasChild, PigType, HasPet, HasFarmAnimal identifiers used in the above table would be translated to actual ExpandedNodeId.