public final class ExternalTarget
extends Object
"When set to External, the target attribute may be a relative
reference or a URI. If the target attribute is a relative
reference, then that reference is interpreted relative to the
location of the package."
Note: this method assumes an absolute location.
ECMA 376 is a little bit ambiguous about whether an
external resource is a "part" or not.
- the definition of part implies that it is; there is no definition of resource
- but the definition of part name in 8.1.1 "refers to parts _within_ a package"
(but is within logical or physical?)
- 8.3 Relationships: "Parts often contain references to other parts
in the package and to resources outside the package"
(POI has TargetMode and POIXMLRelation; they have PackagePart.addExternalRelationship
We'll call them external resources.
When we load an external resource, it is loaded as a part.
But it is not stored in the package's parts collection; instead it is stored
in a collection called ExternalResources.
An ExternalTarget is the value of @target, made absolute
if necessary.
We don't need explicit support in RelationshipsPart for adding an external
resource; you can do that by creating a Relationship object, then calling
addRelationship (your reference in your @target should be relative, not absolute).