I am working on updating the Vexflow tutorial to describe how to use the new bar lines in stavebarline.js. We currently have two techniques for adding bar lines - using multiple staves per line or using one stave per line and using barnote.js to draw the bar lines. VexTab uses the second technique to draw bar lines with barnote.js. I have attempted to update barnote.js to utilize stavebarline.js here: http://code.gregjopa.com/vexflow-barnote-test/docs/tutorial.html (scroll to the bottom and check out technique 2 in step 6). However, this new barnote.js code a bit hacky since stavebarline.js inherits from stavemodifier.js while barnote.js inherits from note.js. This brings up the design question - should bar lines be derived from notes or from stave modifiers?
I see two options to resolve this issue:
I fixed this by making BarNote use StaveBarline to do the underlying rendering. BarNote now takes a "type" which specifies the type of bar.
VexTab uses a stave modifier or a barnote depending on the position of the bar.