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Question

当我覆盖clone()的{​​{1}}方法时，有没有办法从我的植入中调用这个覆盖方法？像这样：

Backbone.Model

Answer 1

你想要使用：

Backbone.Model.prototype.clone.call(this);

这将调用来自clone()的原始Backbone.Model方法，其上下文为this（当前模型）。

来自Backbone docs：

  

简要介绍一下super：JavaScript没有提供一种简单的调用方式   super - 在原型上定义更高的同名函数   链。如果你覆盖核心功能，比如set，或者你想要保存   要调用父对象的实现，你必须这样做   明确地称之为。

var Note = Backbone.Model.extend({
 set: function(attributes, options) {
 Backbone.Model.prototype.set.apply(this, arguments);
 ...
 }    
});

Answer 2

您还可以使用__super__属性作为父类原型的引用：

var MyModel = Backbone.Model.extend({
  clone: function(){
    MyModel.__super__.clone.call(this);
  }
});

Answer 3

Josh Nielsen found an elegant solution for this，隐藏了很多丑陋。

只需将此代码段添加到您的应用中即可扩展Backbone的模型：

Backbone.Model.prototype._super = function(funcName){
    return this.constructor.prototype[funcName].apply(this, _.rest(arguments));
}

然后像这样使用它：

Model = Backbone.model.extend({
    set: function(arg){
        // your code here

        // call the super class function
        this._super('set', arg);
    }
});

Answer 4

根据geek_dave和charlysisto给出的答案，我写了这个，以便在具有多级继承的类中添加this._super(funcName, ...)支持。它在我的代码中运行良好。

Backbone.View.prototype._super = Backbone.Model.prototype._super = function(funcName) {
        // Find the scope of the caller.
        var scope = null;
        var scan = this.__proto__;
        search: while (scope == null && scan != null) {
            var names = Object.getOwnPropertyNames(scan);
            for (var i = 0; i < names.length; i++) {
                if (scan[names[i]] === arguments.callee.caller) {
                    scope = scan;
                    break search;
                }
            }
            scan = scan.constructor.__super__;
        }
        return scan.constructor.__super__[funcName].apply(this, _.rest(arguments));
    };

一年后，我修复了一些错误并加快了速度。下面是我现在使用的代码。

var superCache = {};

// Hack "super" functionality into backbone. 
Backbone.View.prototype._superFn = Backbone.Model.prototype._superFn = function(funcName, _caller) {
    var caller = _caller == null ? arguments.callee.caller : _caller;
    // Find the scope of the caller.
    var scope = null;
    var scan = this.__proto__;
    var className = scan.constructor.className;
    if (className != null) {
        var result = superCache[className + ":" + funcName];
        if (result != null) {
            for (var i = 0; i < result.length; i++) {
                if (result[i].caller === caller) {
                    return result[i].fn;
                }
            }
        }
    }
    search: while (scope == null && scan != null) {
        var names = Object.getOwnPropertyNames(scan);
        for (var i = 0; i < names.length; i++) {
            if (scan[names[i]] === caller) {
                scope = scan;
                break search;
            }
        }
        scan = scan.constructor.__super__;
    }
    var result = scan.constructor.__super__[funcName];
    if (className != null) {
        var entry = superCache[className + ":" + funcName];
        if (entry == null) {
            entry = [];
            superCache[className + ":" + funcName] = entry;
        }
        entry.push({
                caller: caller,
                fn: result
            });
    }
    return result;
};

Backbone.View.prototype._super = Backbone.Model.prototype._super = function(funcName) {
        var args = new Array(arguments.length - 1);
        for (var i = 0; i < args.length; i++) {
            args[i] = arguments[i + 1];
        }
        return this._superFn(funcName, arguments.callee.caller).apply(this, args);
    };

然后给出这段代码：

var A = Backbone.Model.extend({ 
 //   className: "A",
    go1: function() { console.log("A1"); },  
    go2: function() { console.log("A2"); },  
    });

var B = A.extend({ 
 //   className: "B",
    go2: function() { this._super("go2"); console.log("B2"); },  
    });

var C = B.extend({ 
 //   className: "C",
    go1: function() { this._super("go1"); console.log("C1"); },
    go2: function() { this._super("go2"); console.log("C2"); }  
    });

var c = new C();
c.go1();
c.go2();

控制台中的输出是：

A1
C1
A2
B2
C2

有趣的是，C类对this._super("go1")的调用会扫描类层次结构，直到它在A类中受到攻击。其他解决方案不会这样做。

P.S。取消注释类定义的className条目以启用_super查找的缓存。 （假设这些类名在应用程序中是唯一的。）

Answer 5

如果你只想调用this._super（）;不传递函数名作为参数

Backbone.Controller.prototype._super = function(){
    var fn = Backbone.Controller.prototype._super.caller, funcName;

    $.each(this, function (propName, prop) {
        if (prop == fn) {
            funcName = propName;
        }
    });

    return this.constructor.__super__[funcName].apply(this, _.rest(arguments));
}

更好地使用此插件： https://github.com/lukasolson/Backbone-Super

Answer 6

我相信你可以缓存原始方法（虽然未经过测试）：

var MyModel = Backbone.Model.extend({
  origclone: Backbone.Model.clone,
  clone: function(){
    origclone();//calling the original clone method
  }
});

Answer 7

backbone._super.js，来自我的要点：https://gist.github.com/sarink/a3cf3f08c17691395edf

// Forked/modified from: https://gist.github.com/maxbrunsfeld/1542120
// This method gives you an easier way of calling super when you're using Backbone in plain javascript.
// It lets you avoid writing the constructor's name multiple times.
// You still have to specify the name of the method.
//
// So, instead of having to write:
//
//    var Animal = Backbone.Model.extend({
//        word: "",
//        say: function() {
//            return "I say " + this.word;
//        }
//    });
//    var Cow = Animal.extend({
//        word: "moo",
//        say: function() {
//            return Animal.prototype.say.apply(this, arguments) + "!!!"
//        }
//    });
//
//
// You get to write:
//
//    var Animal = Backbone.Model.extend({
//        word: "",
//        say: function() {
//            return "I say " + this.word;
//        }
//    });
//    var Cow = Animal.extend({
//        word: "moo",
//        say: function() {
//            return this._super("say", arguments) + "!!!"
//        }
//    });

(function(root, factory) {
    if (typeof define === "function" && define.amd) {
        define(["underscore", "backbone"], function(_, Backbone) {
            return factory(_, Backbone);
        });
    }
    else if (typeof exports !== "undefined") {
        var _ = require("underscore");
        var Backbone = require("backbone");
        module.exports = factory(_, Backbone);
    }
    else {
        factory(root._, root.Backbone);
    }
}(this, function(_, Backbone) {
    "use strict";

    // Finds the next object up the prototype chain that has a different implementation of the method.
    var findSuper = function(methodName, childObject) {
        var object = childObject;
        while (object[methodName] === childObject[methodName]) {
            object = object.constructor.__super__;
        }
        return object;
    };

    var _super = function(methodName) {
        // Keep track of how far up the prototype chain we have traversed, in order to handle nested calls to `_super`.
        this.__superCallObjects__ || (this.__superCallObjects__ = {});
        var currentObject = this.__superCallObjects__[methodName] || this;
        var parentObject  = findSuper(methodName, currentObject);
        this.__superCallObjects__[methodName] = parentObject;

        // If `methodName` is a function, call it with `this` as the context and `args` as the arguments, if it's an object, simply return it.
        var args = _.tail(arguments);
        var result = (_.isFunction(parentObject[methodName])) ? parentObject[methodName].apply(this, args) : parentObject[methodName];
        delete this.__superCallObjects__[methodName];
        return result;
    };

    // Mix in to Backbone classes
    _.each(["Model", "Collection", "View", "Router"], function(klass) {
        Backbone[klass].prototype._super = _super;
    });

    return Backbone;
}));

Answer 8

如果你不知道父类是什么（多重继承或你想要一个辅助函数），那么你可以使用以下内容：

var ChildModel = ParentModel.extend({

  initialize: function() {
    this.__proto__.constructor.__super__.initialize.apply(this, arguments);
    // Do child model initialization.
  }

});

使用辅助功能：

function parent(instance) {
  return instance.__proto__.constructor.__super__;
};

var ChildModel = ParentModel.extend({

  initialize: function() {
    parent(this).initialize.apply(this, arguments);
    // Do child model initialization.
  }

});

Answer 9

在实例化期间将父类作为选项传递：

BaseModel = Backbone.Model.extend({
    initialize: function(attributes, options) {
        var self = this;
        this.myModel = new MyModel({parent: self});
    } 
});

然后在你的MyModel中你可以像这样调用父方法

this.options.parent.method（）; 请记住，这会在两个对象上创建一个保留周期。因此，为了让垃圾收集器完成它的工作，你需要在完成它时手动销毁其中一个对象上的retain。如果你的申请量非常大。我鼓励您更多地了解层级设置，以便事件可以传播到正确的对象。

Answer 10

下面的2个功能，一个要求你传入功能名称，另一个可以＆＃34;发现＆＃34;我们想要哪个功能

的超级版本

Discover.Model = Backbone.Model.extend({
       _super:function(func) {
        var proto = this.constructor.__super__;
        if (_.isUndefined(proto[func])) {
            throw "Invalid super method: " + func + " does not exist in prototype chain.";
        }
        return proto[func].apply(this, _.rest(arguments));
    },
    _superElegant:function() {
        t = arguments;
        var proto = this.constructor.__super__;
        var name;
        for (name in this) {
            if (this[name] === arguments.callee.caller) {
                console.log("FOUND IT " + name);
                break;
            } else {
                console.log("NOT IT " + name);
            }
        }
        if (_.isUndefined(proto[name])) {
            throw "Super method for: " + name + " does not exist.";
        } else {
            console.log("Super method for: " + name + " does exist!");
        }
        return proto[name].apply(this, arguments);
    },
});

Answer 11

我将如何做到这一点：

ParentClassName.prototype.MethodToInvokeName.apply(this);

所以你的例子就是：

Model.prototype.clone.apply(this)