Thank you for taking the time to report this issue! What information does ChoiceView provide that you cannot access via FormView?

See also #4171.

This information is the ChoiceView's 'data' property.

In my use case, it was an entity type, so this property contained an
object, in the query builder I was ordering them by category, and my
goal was to be able to render them as groups of checkboxes.

So in my custom theme when iterating over the forms I was expecting a
way to somehow access the original data, and then you know whenever the
category changes I would start to render another section (eg. put them
in another div tag), but I couldn't as this information is only under
the 'choices' var. And I could't find a way to do the correlation
between a FormView and its related ChoiceView.

I had a similar task and managed to get the corresponding entity in form.vars.choices[child.vars.value].data; if form is the entity widget and child the current child. Some more obvious places don’t work:

• form.vars.data - array (or alike) only containing checked entries’ entities
• child.vars.data - empty (this should be changed imho)
• child.vars.choice - index missing

(Disclaimer: Maybe I included mistakes; didn’t remember my GitHub password and thus couldn’t login from work.)

Any news on this problem?

ping @webmozart

I was unable to access this way: {{ form.field.vars.choices[id].data.attribute }}

His solution worked perfectly for me :
{%for child in form%}
{% set entity = form.vars.choices[child.vars.value].data %}
{%endfor%}

I think this is a duplicate of #5489.