IOpcRelationship interface (msopc.h)

Article
07/22/2021

Represents a relationship, which is a link between a source, which is a part or the package, and a target. The relationship's target can be a part or external resource.

Inheritance

The IOpcRelationship interface inherits from the IUnknown interface. IOpcRelationship also has these types of members:

Methods

The IOpcRelationship interface has these methods.


IOpcRelationship::GetId Gets the unique identifier of the relationship.
IOpcRelationship::GetRelationshipType Gets the relationship type.
IOpcRelationship::GetSourceUri Gets the URI of the relationship�source.
IOpcRelationship::GetTargetMode Gets a value that describes whether the relationship's target is internal or external to the package.
IOpcRelationship::GetTargetUri Gets the URI of the relationship�target.

Remarks

To create a relationship object to represent a relationship, call the IOpcRelationshipSet::CreateRelationship method. To get a pointer to the interface of a relationship object that represents an existing relationship, call the IOpcRelationshipSet::GetRelationship or IOpcRelationshipEnumerator::GetCurrent method.

Example relationship markup for a relationship that targets a part:

<Relationship Id="rId1"
    Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument"
    Target="word/document.xml" />

Using the relationship type (Type attribute of the Relationship element) is the definitive way find a part in a package. For more information about why the relationship type is used, see the Parts Overview. For an example of to use the relationship type to find a part, see Finding the Core Properties Part.

Valid identifiers for relationships conform to the restrictions for xsd:ID, which are documented in section 3.3.8 ID of the W3C Recommendation, XML Schema Part 2: Datatypes Second Edition (http://www.w3.org/TR/xmlschema-2/#ID).

IOpcRelationship interface methods provide access to relationship properties for a relationship (which is represented by a relationship object). The methods, associated properties and descriptions are listed in the following table.

Method	Property	Description
GetId	Relationship identifier	The unique, arbitrary identifier of a relationship that is local to the package.
GetRelationshipType	Relationship type	The qualified name of a relationship defined by the package designer.
GetSourceUri	Source URI	The URI of the relationship's source. The source URI can be the URI of the package or of a part.
GetTargetMode	Target mode	Indicates whether the relationship's target is internal or external to the package.
GetTargetUri	Target URI	The URI of the relationship's target.

For more information about relationships, see the Open Packaging Conventions Fundamentals and the ECMA-376 OpenXML, 1st Edition, Part 2: Open Packaging Conventions (OPC).

Thread Safety

Packaging objects are not thread-safe.

For more information, see the Getting Started with the Packaging API.

Requirements

Requirement	Value
Minimum supported client	Windows 7 [desktop apps only]
Minimum supported server	Windows Server 2008 R2 [desktop apps only]
Target Platform	Windows
Header	msopc.h