How to count total number of leaf nodes from Jstree Data Model?

[Tree Rocker]

Is there any way to calculate total number of leaf nodes from the Jstree Model not from DOM?

[Ivan Bozhanov]

Use:
instance.get_json('#', { "flat" : true }).length

[Tree Rocker]

I think that will include parent node as well. I need to fetch only those nodes which are at the bottom most heirarchy.

For ex:

Parent1
  - Child 1
     -Sub Child 1
     -Sub Child 2
     -Sub Child 3
Parent2
  - Child 2
     -Sub Child 4
     -Sub Child 5
     -Sub Child 6
Parent3
  - Child 3
     -Sub Child 7
     -Sub Child 8
     -Sub Child 9

Now I need to count only "Sub Childs". Condition is that all nodes are closed initially.

[Ivan Bozhanov]

Ah, sorry - I was too quick to answer.
Well - get that result (from get_json) and instead of using .length loop through it, and only count nodes that have a children array that is zero length:

var res = instance.get_json('#', { flat : true });
var cnt = 0;
for(var i = 0, j = res.length; i < j; i++) {
  if(!res[i].children || !res[i].children.length) { cnt++; }
}

// cnt is what you need.

[Gulam sarwar]

var res = jQuery.jstree.reference('#divJsTree').get_json('#', { flat: true });
                var cnt = 0;
                for (var i = 0, j = res.length; i < j; i++) {
                    if (res[i].parent !== '#') {
                        cnt++;
                    }
                }