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As of V3.4, all use of sourceAttributeID is fully deprecated, and the old <Dependency> element itself has been replaced by explicit use of <InputAttributeDefinition> and <InputDataConnector> elements. Most of the examples have been updated to reflect this syntax.
XML Namespaces 3.3
In all versions prior to V3.3, the configuration will contain elements in multiple namespaces. With V3.3, every non-deprecated feature can be defined in the main urn:mace:shibboleth:2.0:resolver namespace (and thus defaulted to avoid the need for prefixes). The lone exception is the specification of security credentials when connecting to data sources (LDAP mainly).
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The PrincipalAuthenticationMethod attribute defintion is deprecated because the support for managing multiple authenitcation methods throughout the IdP makes it impractical to expose a single method value.
Dependency Element and sourceAttributeID XML Attribute
V3.4 has corrected some ambiguities surrounding this element with the new <InputAttributeDefinition> and <InputDataConnector> elements, and replaces the old sourceAttributeID setting. Note that sourceAttributeID is ignored once you convert to the newer dependency element syntax, so carefully consider which input data is meant to be consumed by the containing definition.