passport-auth-token/lib/utils.js

Authentication token strategy for Passport.

exports.lookup = function (obj, field) {
	if (!obj) {
		return null;
	}

	var chain = field.split(']').join('').split('[');

	for (var i = 0, len = chain.length; i < len; i++) {
		var prop = obj[chain[i]];

		if (typeof(prop) === 'undefined') {
			return null;
		}

		if (typeof(prop) !== 'object') {
			return prop;
		}

		obj = prop;
	}

	return null;
};