Collapse state lost via spouse toggles

[danielprosser1]

Hello,

As you can see in this amended demo...

https://code.balkan.app/sibling-collapse-state-lost#JS

If you expand the "Yuliya Nikitina" side of the tree, she has a sibling Frank. If you collapse his children with the little heart icon it works nicely. But if you navigate back to the the "Yermolai Vasiliev" side of the tree (i.e. the husband of Yuliya) which removes Frank's side of the family, and then navigate back to Yuliya's side again, the collapse state has been lost (i.e. Frank's kids are showing again).

Isn't there some way to ensure these collapse states persist despite navigating to/from different lines? It might seem trivial but in large trees it can get quite annoying to have to repetitively reapply the collapses you want just because you browsed away down a different spouse-line for a second.

Thanks for any thoughts!

[ZornitsaPesheva]

Hi @danielprosser1

Expand/collapse of children is not a fully built-in feature in Family Tree JS.
The examples only demonstrate that it’s possible to achieve.
I recommend trying Family Tree JS 2, where expand/collapse is fully integrated and the state is automatically saved.

[danielprosser1]

Thanks @ZornitsaPesheva - I will review the approach in v2 although I'm not sure I'll be able to switch for some time. In the meantime, when you say it's possible to achieve expand/collapse in v1, the behaviour I'm observing is that although I can of course track the state of collapsed children for any children in my dataset, the v1 library seems to forcibly redraw the children on spouse toggle. Is that something that can be bypassed even in v1?

[ZornitsaPesheva]

What we can try is to save the collapsed children in a variable an then collapse them again on expanding Yuliya 's parents

[danielprosser1]

Yes I can save the state in a variable but any ideas what event I could listen to that would allow me to prevent Balkan forcibly adding children after a spouse toggle? And even if I had a convenient event, in terms of updating the chart (since it seems like there's no way to suppress the default behaviour of reinserting all children after spouse toggle), I just need to iteratively call chart.expandCollapse on each child I want to re-collapse after the library has forcibly expanded them?

[ZornitsaPesheva]

You should do it under the same expcollclick event and expand collapse with the same expandCollapse function.
You need to add the id's that you'd like to collapse to the collapseIds parameter.

[danielprosser1]

Thanks @ZornitsaPesheva - I had a play with your idea, and updated my example here. As you can see, it technically works, but the main problem is that when you return from a spouse toggle and programatically collapse the nodes that you're tracking in a variable, after you've collapsed everything, there's a noticeable jump as the library re-renders positions to match this new reality - like the return from the spouse toggle throws the whole tree off (the more nodes you had collapsed the further the tree is thrown to the side).

In my example, if you toggle Yuliya Nikitina side of the family, then collapse her brother Frank Smith's kids, then go back to Yermolai Vasiliev's side of the family and then return to Yuliya Nikitina, you'll notice Frank Smith's kids are still collapsed but the tree throws off to the right. It's quite subtle in this example but imagine you've collapsed large portions of the tree - the spouse you've toggled can be thrown so far to the right/left that they end up off the viewport.

Does that make sense? If so, do you have any recommendations to deal with it and somehow fix the spouse you're toggling in position and have the tree redraw around those new positions post spouse-toggle? Maybe I'm just missing some obvious approach to design this, but collapse/expand isn't very useable without it

[ZornitsaPesheva]

We have logged your request.
Will write you again if we have a solution.

[danielprosser1]

Thanks again @ZornitsaPesheva - I wasn't sure whether you were still developing this project given the v2 implementation. Can you give any idea of the likelihood of being able to add a fix for this? E.g. whether it strikes you as a simple tweak or something much longer term that you might never be able to deploy? I'm just trying to decide whether it makes sense to turn off collapse/expand functionality altogether (given it seems to break when you account for spouse-toggle behaviour), or whether it makes sense to wait for any further update

[ZornitsaPesheva]

Thanks! Just to remind, in the current Family Tree JS, the expand/collapse functionality isn’t an out-of-the-box feature — it’s more of an example of what’s possible, which is why the behavior you’re seeing is expected. In contrast, Family Tree JS 2 does support expand/collapse natively, so that functionality is built in and fully supported there. For now, in the current version, the most reliable option is to disable expand/collapse if it doesn’t fit your scenario.