Merge An Array Of Javascript Objects Based On A Key Property (multilevel)

I have an array of Javascript objects that look like these: data = [{PK: 'Country1', Prop1: 'true', children:[ {PK: 'State1', Prop1: 'true', children:[

Solution 1:

Here is a simple script using a custom merge functionality I've written sometime ago for json-easy-filter Hope it does the right stuff for you. See it in this plunk

var input = ... your data here ...

var groupByPk = function (arr) {
    var res = {};
    arr.forEach(function (node) {
        if (!res[node.PK]) {
            res[node.PK] = [
                node
            ];
        } else {
            res[node.PK].push(node);
        }
    });
    return res;
};

var mergeByPk = function (arr) {
    var groups = groupByPk(arr);
    var groups2 = [];

    for ( var pk in groups) {
        var group = groups[pk];
        var ress = merge.apply(this, group);
        groups2.push(ress.value);
    }
    return groups2;
};

var mergeData = function(data){
    var mergedCountries = mergeByPk(data);
    mergedCountries.forEach(function (country) {
        var mergedStates = mergeByPk(country.children);
        country.children = mergedStates;
        mergedStates.forEach(function (state) {
            var mergedCities = mergeByPk(state.children);
            state.children = mergedCities;
        });
    });
    return mergedCountries;
};

console.log(JSON.stringify(mergeData(input), null, 4));