Loading JSON broken

[hyanwong]

When exporting as JSON, the title is now saved as None, whereas json requires null, so the following won't work. Also it doesn't remember the edge_type and variable_edge_width options, but I guess that's intentional?

import json
import tskit_arg_visualizer
arg_json = arg_json = json.load(open("tskit_arg_visualizer.json", "r"))
d3arg = tskit_arg_visualizer.D3ARG.from_json(json=arg_json)
d3arg.draw()

[kitchensjn]

Oh that's annoying. D3ARG.from_json() has been giving me trouble as we change/add new features. Two aspects of this:

• edge_type, variable_edge_width, and title are set on draw() so they aren't a saved parameter of the D3ARG object. If you want to replicate all of these parameters, then draw_D3() is your best option. Though that doesn't allow you to modify anything. Similarly, draw_D3() is broken with the new title feature.
• None is already being treated as a string anyways in JavaScript, so I can force the title type to string which solves this JSON issue. Alternatively, we could set it to null in JavaScript, but I don't think that has any advantage over the forced typing.