Object normalization - needs to be improved

obj_normalize.js

var obj_normalize = (function() {

    function runNormalizer(currentValue, normalizer) {

        if (typeof normalizer === 'function')
            return normalizer(currentValue);


        // other types of normalization, like Regexp-Replace
        return currentValue.replace(normalizer[0], normalizer[1]);

        // ...
    }

    function normalizeProperty(obj, path, names, normalizers) {

        var value = obj_getProperty(obj, path),
            x;

        names.forEach(function(name) {
            x = runNormalizer(value, normalizers[name]);

            if (x !== value)
                obj_setProperty(obj, path, x);

            value = x;
        });

    }

    return function(obj, properties, normalizers) {
        for (var path in properties)
            normalizeProperty(obj, path, properties[path], normalizers);
    };
}());

function obj_getProperty(obj, property) {
    var chain = property.split('.'),
        imax = chain.length,
        i = 0;
    for (; i < imax; i++) {
        if (obj == null)
            return null;

        obj = obj[chain[i]];
    }
    return obj;
}

function obj_setProperty(obj, property, value) {
    var chain = property.split('.'),
        imax = chain.length,
        i = 0,
        key = null;

    for (; i < imax - 1; i++) {
        key = chain[i];
        if (obj[key] == null) {
            obj[key] = {};
        }
        obj = obj[key];
    }

    obj[chain[i]] = value;
}