The seventh example provides an illustration a request in which a Client wants to display part of the AddressSpace based on a starting point that was obtained via browsing. This request includes listing References as something that is to be returned. In this case the Person Browsed to Area2 and wanted to Query for information below this starting point.

Example 7: Get PersonType.NodeId, AnimalType.NodeId, PersonType.HasChild Reference, PersonType.HasAnimal Reference where the person is in Area2 (Cleveland nodes) and the person has a child.

Table B.22 describes the NodeTypeDescription parameters used in the example.

Table B.22 – Example 7 NodeTypeDescription

Type Definition Node

Include

Subtypes

QueryDataDescription

Relative Path

Attribute

Index Range

PersonType

FALSE

“.NodeId”

Value

N/A

<12:HasChild>

Value

N/A

<12:HasAnimal>NodeId

Value

N/A

<12:HasAnimal>

Value

N/A

The corresponding ContentFilter is illustrated in Figure B.11. Note that the Browse call would typically return a NodeId, thus the first filter is for the BaseObjectType with a NodeId of 95 where 95 is the NodeId associated with the Area2 node, all Nodes descend from BaseObjectType, and NodeId is a base Property so this filter will work for all Queries of this nature.

image053.png

Figure B.11 – Example 7 filter logic tree

Table B.23 describes the elements, operators and operands used in the example.

Table B.23 – Example 7 ContentFilter

Element[]

Operator

Operand[0]

Operand[1]

Operand[2]

Operand[3]

0

RelatedTo

ElementOperand = 2

ElementOperand = 1

AttributeOperand = Node:HierachicalReference, BrowsePath “.”, Attribute:NodeId

LiteralOperand = ‘1’

1

RelatedTo

AttributeOperand =

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

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

AttributeOperand =

NodeId: 12:HasChild, BrowsePath “.”,

Attribute: NodeId

LiteralOperand = ‘1’

2

Equals

AttributeOperand =

NodeId: BaseObjectType, BrowsePath “.”,

Attribute: NodeId,

LiteralOperand = ‘95

The results from this Query would contain the QueryDataSets shown in Table B.24.

Table B.24 – Example 7 QueryDataSets

NodeId

TypeDefinition

NodeId

RelativePath

Value

12:42 (HFamily1)

PersonType

“.NodeId”

12:42 (HFamily1)

<12:HasChild>

HasChild ReferenceDescription

<12:HasAnimal>12:AnimalType.NodeId

NULL

<12:HasAnimal>

HasFarmAnimal ReferenceDescription

12:48 (HFamily2)

PersonType

“.NodeId”

12:48 (HFamily2)

<12:HasChild>

HasChild ReferenceDescription

<12:HasAnimal>12:AnimalType.NodeId

12:91 (Pig1)

<12:HasAnimal>

HasFarmAnimal ReferenceDescription

NOTE The RelativePath and browse name (in parentheses) is not in the QueryDataSet and is only shown here for clarity and the TypeDefinition NodeId would be an integer not the symbolic name that is included in the table. The value field would in this case be the NodeId where it was requested, but for the example the browse name is provided in parentheses and in the case of Reference types on the browse name is provided. For the References listed in Table B.24, the value would be a ReferenceDescription which are described in 7.30.