Define token for linked-agent

[kayakr]

e.g. [node:linked-agent:cre] for use in metatag module.

[kayakr]

Not sure this should be here, or whether Linked Agent would be best pulled out to be its own module...

[seth-shaw-unlv]

@kayakr, this looks like the appropriate place for it, although I haven't used tokens, so I'm not sure I'm the best person to test. Also, can you click that "update branch" button? Thanks.

[seth-shaw-unlv]

@kayakr, I'm sorry this PR has languished unreviewed for so long! It looks like the repo it was based on was deleted so Travis won't work with it any more. Do you want to resubmit it and I'll give it a go?

[kayakr]

@seth-shaw-unlv This work has been overtaken by PR #66 but I wonder if you know why Typed Relation fields don't generate the same same tokens as normal Entity reference fields do, even though TypedRelation extends EntityReferenceItem? It seems like there is some default entity api goodness that TypedRelation isn't using.
For Entity reference fields like Repository Item Model, the token browser traverses the relationship and allows use of fields on the taxonomy term but this doesn't happen for Linked Agent mapping to (say) Person vocabulary.

[seth-shaw-unlv]

@kayakr , honestly, 🤷‍♂️. I have no experience with tokens other than using them once or twice... so I don't know why it isn't working.

[kayakr]

@seth-shaw-unlv Fair enough. I'd like to see it working but it requires more knowledge of the Entity API than I have at present...

[kayakr]

Closing in favour of tokens added via Islandora/documentation#1171 (comment)