This new feature will allow Folders and Collections to link to objects that provide shorthand representations for their contents, such as a thumbnail image. The link in METS is simply a smLink from the object in question to the surrogate object, having the xlink:arcrole of cdr:hasSurrogate.
Access layers showing the Collection or Folder will be able to follow these links, at index time or at runtime, to retrieve thumbnail images and/or other representations from the surrogate object.
smLink elements in METS are expected to have a xlink:from, xlink:to, and xlink:arcrole. The arcrole is set to the full URI of the link type.
CDR NOTE: When ingested these links are recorded as RELS-EXT RDF triples, with arcrole as the predicate, but implementations will vary.
User interface consists of first selecting (via CTRL-click) both the Folder/Collection and the surrogate object. Then right-click or alt-click on either selected object to bring up the context menu. Linking options will appear any time two objects are selected that can be linked. Links are shown in the navigator under the object linked from, i.e. the Collection or Folder.
All of the above is working in new code. Now grappling with the delete link feature. It will be easy enough to implement as a "one off", but I'd like to finally figure out how to use key-bindings for DEL in our left-pane navigator. This would extend to other forms of DEL as well, for parts of the arrangement, i.e. remove div.
Also need a way to specify allowIndexing property for a div..
delete for links is done