Identify circular dependency in a Json object and remove all element after 2 depth

Issue

I have a json object something like this:

var temp1 = {
    name: "AMC",
    children: [
        {
            name: "cde",
            children: [
                {
                    name: "AMC",
                    children: [
                        {
                            name: "cde",
                            children: [
                                {
                                    name: "AMC",
                                    children: [
                                        //.............. continues as curcular depndency
                                    ]
                                }
                            ]
                        }
                    ]
                }
            ]
        },
        {
            name: "mnp",
            children: [
                {
                    name: "xyz",
                    children: []
                }
            ]
        }
    ]
}

Due to this cicular dependency, JSON.stringify is failing. I have done enough google and searching to get the solution for this but could not find much help.

So here basically I want to detect a circular dependency in the json object and add a new key to the object, saying cricular: true and remove all the subsequent node.

So here is the result output what I am looking :

var temp1 = {
    name: "AMC",
    children: [
        {
            name: "cde",
            circular: true,
            children: [ // No children here as it is curcular dependency
            ]
        },
        {
            name: "mnp",
            children: [
                {
                    name: "xyz",
                    children: []
                }
            ]
        }
    ]
}

There is a way, which I think can solve it, where I can loop through all the children unless there is no children upto maximum 2 levels, but that way I will miss valid children which are having depth more than 3.

I hope my question is clear. If not please let me know I will try to expand this further.

Solution

A recursive function solves this:

function check(stack,parent, obj){
    stack = stack || []; //stack contains a list of all previously occurred names
    var found = stack.find(function(parent){
        return (parent==obj.name && obj.children.length>0); //checks to see if the current object name matches any in the stack.
    });
    if(!found && obj.children.length>0){
        stack.push(obj.name); //adds the current object name to the list.
        obj.children.forEach(function(child){
            check(stack,obj, child);//recursively checks for all children.
        })
    }
    else if(found){
        parent.children=[];
        parent.circular=true;
        stack.pop(obj.name);
        return;
    }
    else{
        return;
    }
}
check([],temp1, temp1) 

This leads to alteration of the original object passed.

Hope this helps!

Answered By - Parama Kar