Nikunj Mehta wrote:
Intermediaries such as libraries, synchronization tools, and aggregators won't understand 10,000 new link relations that every vendor dealing with AtomPub is currently producing. IMHO, the rel value should be understandable to intermediaries not only end points.
If an intermediary is Atom-generic then it should not be attempting to understand link relations. A library would ideally provide an interface to retrieve links by (rel, type) pair, possibly also allowing constraining by hreflang.
The meaning of specific values of rel is for endpoints to determine, not intermediaries. Intermediaries should just be concerned with getting the data from A to B without loss of meaning.
How is introducing another dimension for application-specified text worse than creating a huge number of non-standard rel values? It doesn't break any existing clients or servers.
Adding a new attribute to link seems likely to break more intermediaries than adding new rel values. Existing libraries will likely not provide a convenient means to access the new attribute, and entry re-publishing systems may drop the new attribute on the floor when the entry round-trips through their data model.
However, I do agree with your general principle that new link relationships should be generic and not specific to a given application. rel and type are two orthogonal dimensions that should be considered together by applications.
