Filter - Tree - JSON

Filter - Tree - JSON

var data = [
    {
    name: 'a1', children: [
        {
        name: 'b1', children: [
            { name: 'gap' }, { name: 'bar' }
        ]
      }
    ]
  },
  {
    name: 'a2', children: [
        {
        name: 'b2', children: [
            { name: 'foo' }, { name: 'gap' }
        ]
      }
    ]
  },
  {
    name: 'a3', children: [
        {
        name: 'b3', children: [
            { name: 'foo' }, { name: 'gap' }
        ]
      }
    ]
  }
];

function filterData(data, predicate) {

    // if no data is sent in, return null, otherwise transform the data
    return !!!data ? null : data.reduce(function (list, entry) {

        var clone = null;
        if (predicate(entry)) {
            // if the object matches the filter, clone it as it is
            clone = (JSON.parse(JSON.stringify(entry)));
        } else if (entry.children != null) {
            // if the object has childrens, filter the list of children
            var children = filterData(entry.children, predicate);
            if (children.length > 0) {
                // if any of the children matches, clone the parent object, overwrite
                // the children list with the filtered list
                clone = (JSON.parse(JSON.stringify(entry)));
                clone.children = children;
            }
        }

        // if there's a cloned object, push it to the output list
        clone && list.push(clone);
        return list;
    }, []);
}

function highlightKeyword(key, data) {
    var reg = new RegExp(key, "gi");
    return data.replace(reg, function (str) {
        return '<b class="highlight">' + str + '</b>'
    });
}

function buildList(data, isSub) {
    var html = (isSub) ? '<div class="sub-content">' : '';
    html += '<ul>';
    for (var item in data) {
        console.log(data);
        html += '<li>';
        if (typeof(data[item].children) === 'object') {
            html += '<div class="item-title">';
            html += '<a href="javascript:void(0);" data-id="' + data[item].id + '" title="' + data[item].name + '">' + data[item].name + '</a>';
            html += '<span class="arrow"><i class="fa fa-angle-right"></i></span>';
            html += '</div>';
            html += buildList(data[item].children, true);
        } else {
            html += '<div class="item-title">';
            html += '<a href="javascript:void(0);" data-id="' + data[item].id + '" title="' + data[item].name + '">' + data[item].name + '</a>';
            html += '</div>';
        }
        html += '</li>';
    }
    html += '</ul>';
    html += (isSub) ? '</div>' : '';
    return html;
}

function valueExist(key, str) {
    key = key.toLowerCase();
    str = str.toLowerCase();
    return str.indexOf(key) > -1;
}

var result = filterData(data, function (item) {
    if (valueExist('fo', item.name) {
        return item.name;
    }
});

console.log(JSON.stringify(result, null, 2));