Currently, the built-in Link Fieldtype only allows you to link to the following "things":
URLs
First Childs
Entries
Assets
However, there's a few situations where developers might want to add their own "link types" to the dropdown in the Link Fieldtype...
Runway
In the context of Runway, it would be nice if you could select models between various models. (often people treat Eloquent Models like entries, so this is a fairly common request).
Custom Asset Browsers
If you're integrating with a custom asset browser instead of using Statamic's native asset browser, you may wish to continue linking to assets via the Link Fieldtype.
This would also be great for picking from a defined list of multi-language routes that change fairly often, where it's cumbersome for editors to keep them updated across the site.
Currently, the built-in Link Fieldtype only allows you to link to the following "things":
However, there's a few situations where developers might want to add their own "link types" to the dropdown in the Link Fieldtype...