objects.js

/*
 *  Copyright 1998-2006 Helma Project
 *  Copyright 2010 Hannes Wallnöfer
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

/**
 * @fileoverview Adds utility functions for working with JavaScript Objects
 */


/**
 * copy the properties of an object into
 * a new object
 * @param {Object} object the object to clone
 * @param {Object} cloned optional clone object
 * @param {boolean} recursive pass true to create a deep clone. Otherwise a shallow clone is created.
 * @returns {Object} the clone object
 */
var clone = exports.clone = function(object, cloned, recursive) {
    if (!cloned) {
        cloned = new this.constructor();
    }
    var value;
    for (var propName in object) {
        value = object[propName];
        if (recursive && (value.constructor == Object || value.constructor == Array)) {
            cloned[propName] = clone(value, new value.constructor(), recursive);
        } else {
            cloned[propName] = value;
        }
    }
    return cloned;
}

/**
 * Creates a new object as the as the keywise union of the provided objects.
 * Whenever a key exists in a later object that already existed in an earlier
 * object, the according value of the earlier object takes precedence.
 * @param {Object} obj... The objects to merge
 */
var merge = exports.merge = function() {
    var result = {};
    for (var i = arguments.length; i > 0; --i) {
        var obj = arguments[i - 1];
        for (var property in obj) {
            result[property] = obj[property];
        }
    }
    return result;
}