It is possible to define custom JointJS elements with hyperlinks
pointing to external sites - by including the
in the markup of a custom element.
The navigation path is then specified in individual elements' attributes of the custom type.
The two most important XLink attributes in this context are the following:
xlink:href- set the target resource URL.
xlink:show- how should the linked content be presented? Possible values are
'replace'(show in current window; default) and
'new'(show in new window).
JointJS source code: hyperlinks.js