Debugging Traitlets and Backbone.js?

Is there a simple method to debug Traitlets when creating a custom widget?

I’ve spent hours trying to track down why my state hasn’t been updating, and it often has to do with a Traitlet not being updated because it is incompatible, or indexing that silently fails. Is this logged somewhere?

This is likely also a backbone issue. I’m mostly trying to update an array, which does not cause an event to fire:

   const idx = this.model.get("hoveredImage")
   const judgements = [...this.model.get("judgements")]

    judgements[idx][0] = 1;

    this.model.set("judgements", judgements);
    this.model.save_changes();

does not work while this does:

   const idx = this.model.get("hoveredImage")
   const judgements = [...this.model.get("judgements")]

    judgements[idx][0] = 1;

    this.model.unset("judgements", { silent: true })
    this.model.set("judgements", judgements);
    this.model.save_changes();

[ianhi]

@cabreraalex something else I should have recommended is asking about this on the jupyter widgets gitter: https://gitter.im/jupyter-widgets/Lobby

Also maybe this would help (haven’t tried it, just found by googling) https://chrome.google.com/webstore/detail/backbone-debugger/bhljhndlimiafopmmhjlgfpnnchjjbhd?hl=en

[jvail]

We seem to have the same issues 😃 I had the same problem and I pass a sliced array into the set method otherwise backbone ignores the change since it just compares the old vs the new array in its isEqual fn with a === b and returns true if you don’t slice or clone the array.