Woooo

gistfile1.js

function cus_func(input, search) {
    var list = search.split(/[\[\]\.]/);
    var new_key;

    for (var key in list) {
        new_key = list[key].replace(/^['"](.*?)['"]$/gm, '$1');
        input = ImageHelper.get(input, new_key);
    }

    console.log(input);
}

cus_fun(this.props.post, '_embedded["http://api.w.org/featuredmedia"][0].source_url');