javascript - d3.js svg image dragging works, but raises many type errors -

javascript - d3.js svg image dragging works, but raises many type errors -

i working on little project d3.js (https://github.com/giordanoarman/note_app).

i used code enables panning, zooming , dragging of svg image. works fine, when open console see

uncaught typeerror: cannot read property 'x' of undefined

and plenty of

uncaught typeerror: cannot read property '0' of undefined.

i have tried re-write can not understand wrong. works fine, have clean output on console. can help me out?

it looks in dragged = function (d), d null. case "property '0'" errors there's lot of in d3.v3.js. have line number / file names these errors?

are svg images ever beingness hidden? cause events passing null value.

running code, both errors have origin, happens when click somewhere other top of svg. can't calculate offset between mouse , svg's location.

javascript svg d3.js drag