How to draw this link?

GoJS
1

How to this link Drawing??

2

For straight links, you might be interested in [EDIT: obsolete]

For orthogonal links I’m not so sure. How was the point at which the stroke switched from dashed to solid determined in your screenshot? What would happen if one of the nodes was moved?

3

This is obsolete – please see Gradient Link or two coloured link - #3 by walter