Control default depth of categorical tree specification, and "more choices" option

[Public-Health-Bioinformatics]

Right now when one selects a categorical tree input for a form element, the whole hierarchy is shown from the ontology. It would be good to add depth controls to selectively show depth of a tree, say down 3 or four levels, and allow a "more choices" option to carry the user deeper in the hierarchy. The more choices option can either consult the remainder of the tree stored locally, or do a real-time fetch of subsequent depth of choices from live ontology lookup sources.

As well, ideally disable "more choices" if there aren't any for a given item. Requires marking (on a cached basis) which items have no subordinates.

[Public-Health-Bioinformatics]

This is implemented now with a depth:X parameter which cuts the displayed branch to that depth.

[Public-Health-Bioinformatics]

Note: above feature, and following lookup feature need to be documented.

A curator can specify a URI for a given term and lookup will be dynamically performed - using OLS - to get underlying terms. E.g.

lookup:http://purl.obolibrary.org/obo/GAZ_00000448