带有函数原型的 Javascript 命名空间声明

2022-01-14 00:00:00 class namespaces javascript function-prototypes

我知道，这经常被讨论.但在像 19 世纪的人一样四处寻找之后，我需要一些建议.声明命名空间"没有问题，但是当涉及到prototype.foo 函数时，我卡住了.我找到了一种方法，但我不喜欢它:

I know, this is often discussed. But after searching around like someone out of the 19th century, I need some advice. I have no problem by declaring a "namespace", but when it comes to a prototype.foo function, I stuck. I found a way, but I don't like it:

Namespace = {}
Namespace.obj = function() {
    this.foo="bar";
}
Namespace.obj.prototype.start = function() {
    this.foo="fubar";
}

blah = new Namespace.obj();
blah.start();

现在，由于我在编写脚本时有点神经质，所以我想要这样的东西:

Now, since I'm a little neurotic in case of scripting, I would like to have something like this:

Namespace = {
    obj: function() {
        this.foo="bar";
    },
    obj.prototype.start: function(tabinst) {
        this.foo="fubar";
    }
}
...

但随后会引发错误:"Uncaught SyntaxError: Unexpected token ."

But then it throws an error: "Uncaught SyntaxError: Unexpected token ."

我知道，这是装饰性的，但我认为必须有更好的方法来声明包含类和原型函数的命名空间".

I know, this is cosmetic, but I think that there has to be a better method of declaring a "namespace" containing a class and prototype functions.

推荐答案

我的做法是使用 "模块模式".
您基本上将所有模块"逻辑封装在一个自执行函数中，该函数将返回一个具有您的类、函数、变量等的对象......将返回值视为公开您的模块 API.

The way I would do it is using the "Module pattern".
You basically encapsulate all your "Module" logic in a self executing function that would return an object having your classes, functions, variables etc... Think of the return value as exposing your Module API. 

Namespace = (function () {
    /** Class obj **/
    var obj = function () {
        this.foo = 'bar';
    };
    obj.prototype = {
        start: function () {
            this.foo = 'fubar';
        }
    };

    /** Class obj2 **/  
    var obj2 = function () {
        this.bar = 'foo'
    };
    obj2.prototype = {
        start: function () {
            this.bar = 'barfoo';
        },
        end: function () {
            this.bar = '';
        }
    };
    return {
        obj : obj,
        obj2: obj2
    };
})();

var o = new Namespace.obj()
o.start()

为了进一步封装obj"类的方法和构造函数，我们可以这样做:

In order to further encapsulate the "obj" class methods and constructor we could do the following:

/** Class obj **/
var obj = (function () {
    /** class Constructor **/
    var obj = function () {
        this.foo = 'bar';
    };
    /** class methods **/
    obj.prototype = {
        start: function () {
            this.foo = 'fubar';
        }
    };
    return obj;
})();

使用此模式还有一个免费的重要功能，即私有变量"，请考虑以下几点:

There is also an important feature that comes for free using this pattern, which is "Private variables", consider the following:

/** Class Foo **/
var Foo = (function () {
    // Private variables
    var private_number = 200
    /** class Constructor **/
    var Foo = function () {
        this.bar = 0;
    };
    /** class methods **/
    Foo.prototype = {
        add: function () {
            this.bar += private_number;
        }
    };
    return Foo;
})();

foo = new Foo();
alert(foo.bar); // 0
foo.add(); 
alert(foo.bar);// 200
alert(foo.private_number) //undefined

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