Sum parent groups from Json

I have a treetable with multiple parents, in which I am trying to make the sum of the children items.
They are loaded already grouped by Json like this:

data = [
        { item: "01", data: [
            {item: "01.01", data: [
                {item: "01.01.01", value: 100 },
                {item: "01.01.02", value: 50  } ]},
            {item: "01.02" , data: [
                {item: "01.02.01", value: 100 },
                {item: "01.02.02", value: 50  } ]}
        ]},
        { item: "02", data: [
            {item: "02.01", data: [
                {item: "02.01.01", value: 100 },
                {item: "02.01.02", value: 50  } ]},
            {item: "02.02" , data: [
                {item: "01.02.01", value: 100 },
                {item: "02.02.02", value: 50  } ]}
        ]}
    ]

I need parents to present the sums of their children’s values. How can I do this?

You need to define a complex template to a value column.

Within the template function you can iterate through all the children of the specified branch and calculate the sum.

Check the related snippet, please: http://webix.com/snippet/1802a85e

Wow! That’s it. Thank you very much!

^^