Eliminates the need to do obj && obj.prop && obj.prop.subprop testing

resolver.js

function resolver(prop_string, obj) {
    if (!obj) return;
    if (prop_string.indexOf('.') === -1) return obj[prop_string];
    var props = prop_string.split('.'),
        p = props.length,
        result = obj,
        i = 0,
        prop;
    for (;  i<p; i++) {
        prop = props[i];
        result = result[prop];
        if (result === undefined) return result;
    }
    return result;
}