chainlang.js

/*
 * Author: Jared Breeden
 * File: chainlang.js
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2013 Jared Breeden
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 */

(function(){
    "use strict";

    var chainlang;

    if (typeof module !== 'undefined' && module.exports) {

        chainlang = module.exports;
    } else {

        chainlang = {};
        window.chainlang = chainlang;
    }

    chainlang.append = function append(root, path, leaf) {
        if(arguments.length < 3){

            leaf = arguments[1];
            path = arguments[0];
            root = this;
        }
        
        var descendants = path.split('.');
        
        var currentNode = root;
        var finalIndex = descendants.length - 1;
        
        for (var i = 0; i <= finalIndex; ++i) {
            var childName = descendants[i];
            var child = currentNode[childName];
            
            if (i !== finalIndex) {

                currentNode[childName] = (undefined === child) ? {} : child; 
                currentNode = currentNode[childName];
            } else {
                currentNode[childName] = leaf;
            }
        }
    };

    chainlang.create = function(lang){
        if(arguments.length !== 1){
            throw "chainlang.create expects one argument: An object containing the methods of the new chain language";
        }

        var theChain = createChainableProxy(lang);

        function chain(obj){
            if(arguments.length > 1){
                throw "Chain constructors can only accept one argument";
            }

            theChain._subject = obj;
            theChain._data = {};
            
            return theChain;
        }

        return chain;
    };

    function createChainableProxy(language){
        var chain = {};

        createChainableProxyNode(
            chain,
            chain, 
            language);

        return chain;
    }

    function createChainableProxyNode(node, chain, language){
        Object.keys(language).forEach(function(key){

            var prop = language[key];
            if(prop === undefined || prop === null){
               return;
            }
            
            if(typeof prop == "function"){
                node[key] = createChainableProxiedMethod(chain, prop);
                createChainableProxyNode(node[key], chain, prop);
            }
            else if(typeof prop == "object"){
                node[key] = {};
                createChainableProxyNode(node[key], chain, prop);
            }
            else{
                node[key] = prop;
            }    
        });
    }

    function createChainableProxiedMethod(chain, fn){
        var i,
            proxiedMethod;

        proxiedMethod = function(){
            var result = fn.apply(chain, arguments);

            return (undefined === result) ? chain : result;
        };

        return proxiedMethod;
    }
}());