object.watch polyfill

object-watch.js

/**
 * DEVELOPED BY
 * GIL LOPES BUENO
 * gilbueno.mail@gmail.com
 * 
 * LEARN HOW TO USE IT:
 * http://watch.k6.com.br
 * FORK:
 * https://gist.github.com/1627705
 */

Object.prototype.watch = function() {

    if (arguments.length == 1) 
        this.watchAll.apply(this, arguments);
    else if (Array.isArray(arguments[0])) 
        this.watchMany.apply(this, arguments);
    else
        this.watchOne.apply(this, arguments);

}


Object.prototype.watchAll = function(watcher) {
    var obj = this;
    
    if (obj instanceof String || (!(obj instanceof Object) && !Array.isArray(obj))) //accepts only objects and array (not string)
        return;
    
    var props = [];
    
    
    if(Array.isArray(obj)){
        for (var prop=0; prop<obj.length; prop++) { //for each item if obj is an array 
            props.push(prop); //put in the props
        }
    }else{
        for (var prop2 in obj) { //for each attribute if obj is an object
            props.push(prop2); //put in the props
        }
    }
    
    obj.watchMany(props, watcher); //watch all itens of the props
};


Object.prototype.watchMany = function(props, watcher) {
    var obj = this;
    
    if(Array.isArray(obj)){
        for (var prop in props) { //watch each iten of "props" if is an array
            obj.watchOne(props[prop], watcher);
        }
    }else{
        for (var prop2 in props) { //watch each attribute of "props" if is an object
            obj.watchOne(props[prop2], watcher);
        }
    }
};

Object.prototype.watchOne = function(prop, watcher) {
    var obj = this;
    
    var val = obj[prop];
    
    if(obj[prop]===undefined || isFunction(obj[prop]) || prop == "watchers" || prop == "__proto__") //dont watch if it is null, is a function, named "watchers" or "__proto__"
        return;

    if(obj[prop]!=null)
        obj[prop].watchAll(watcher); //recursively watch all attributes of this
        
    obj.watchFunctions(prop);


    if (!obj.watchers) {
        obj.watchers = {};
    }

    if (!obj.watchers[prop]) 
        obj.watchers[prop] = [];
    

    obj.watchers[prop].push(watcher); //add the new watcher in the watchers array


    var getter = function() {
        return val;
    };


    var setter = function(newval) {
        var oldval = val;
        val = newval;

        obj[prop].watchAll(watcher);
        obj.watchFunctions(prop);

        var oldvalAtr = oldval.attributes() || oldval;
        var newvalAtr = newval.attributes() || newval;
        
        if (JSON.stringify(oldvalAtr) != JSON.stringify(newvalAtr) && arguments.callee.caller != watcher) {
            obj.callWatchers(prop);
        }
    };

    if (Object.defineProperty) { // ECMAScript 5
        Object.defineProperty(obj, prop, {
            get: getter,
            set: setter,
            enumerable: true,
            configurable: true
        });
    } else if (Object.prototype.__defineGetter__ && Object.prototype.__defineSetter__) { // legacy
        Object.prototype.__defineGetter__.call(obj, prop, getter);
        Object.prototype.__defineSetter__.call(obj, prop, setter);
    }


};

Object.prototype.callWatchers = function(prop) {
    var obj = this;
    
    for (var wr in obj.watchers[prop]) {
        if (isInt(wr)){
            obj.watchers[prop][wr]();
        }
    }
};

Object.prototype.attributes = function(){
    var obj = this;
    
  var response;
  
  if(obj instanceof Boolean || obj instanceof Number || obj instanceof String){
      return obj;
  }else if(Array.isArray(obj)){
        response = [];
        for (var prop=0; prop<obj.length; prop++) {
            
            if(!obj[prop] || isFunction(obj[prop]) || prop == "watchers" || prop == "__proto__")
                continue;
            
            if(obj[prop].attributes)
                response.push(obj[prop].attributes());
            else
                response.push(obj[prop]);
        }
    }else if(obj instanceof Object){
        response = {};
        for (var prop2 in obj) { 
            
            if(obj[prop2]===undefined || isFunction(obj[prop2]) || prop2 == "watchers" || prop2 == "__proto__")
                continue;
            
            if(obj[prop2] && obj[prop2].attributes)
                response[prop2] = obj[prop2].attributes();
            else
                response[prop2] = obj[prop2];
        }
    }else{
        return obj;
    }
    
    return response;
};



Object.prototype.watchFunctions = function(prop) {
    var obj = this;
    
    if(!obj[prop])
        return;

    if (!(obj[prop] instanceof String) && (Array.isArray(obj[prop]))) {//is array?
    
        obj[prop].pop = (function() {
            var original = Array.prototype.pop;
            return function() {
                var response = original.apply(this, arguments);

                obj.watchOne(obj[prop]);
                obj.callWatchers(prop);
                
                return response;
            };
        })();
        
        
        obj[prop].push = (function() {
            var original = Array.prototype.push;
            return function() {
                var response = original.apply(this, arguments);

                obj.watchOne(obj[prop]);
                obj.callWatchers(prop);
                
                return response;
            };
        })();
        
        
        obj[prop].reverse = (function() {
            var original = Array.prototype.reverse;
            return function() {
                var response = original.apply(this, arguments);

                obj.watchOne(obj[prop]);
                obj.callWatchers(prop);
                
                return response;
            };
        })();
        
        
        obj[prop].shift = (function() {
            var original = Array.prototype.shift;
            return function() {
                var response = original.apply(this, arguments);

                obj.watchOne(obj[prop]);
                obj.callWatchers(prop);
                
                return response;
            };
        })();
        
        
        obj[prop].sort = (function() {
            var original = Array.prototype.sort;
            return function() {
                var response = original.apply(this, arguments);

                obj.watchOne(obj[prop]);
                obj.callWatchers(prop);
                
                return response;
            };
        })();
        
        
        obj[prop].splice = (function() {
            var original = Array.prototype.splice;
            return function() {
                var response = original.apply(this, arguments);

                obj.watchOne(obj[prop]);
                obj.callWatchers(prop);
                
                return response;
            };
        })();
        
        
        obj[prop].unshift = (function() {
            var original = Array.prototype.unshift;
            return function() {
                var response = original.apply(this, arguments);

                obj.watchOne(obj[prop]);
                obj.callWatchers(prop);
                
                return response;
            };
        })();
        
    }
    
    

};



function isFunction(functionToCheck) {
    var getType = {};
    return functionToCheck && getType.toString.call(functionToCheck) == '[object Function]';
}

function isInt(x) {
    var y = parseInt(x);
    if (isNaN(y)) return false;
    return x == y && x.toString() == y.toString();
}