JavaScript库模板

Question

Let say that i need to create a javascript library like so:

;(function(){

    var root = this;

    var Ctor = function(value) {
        this.value = value;
    };

    var _ = new Ctor(value);

    _.doSome = function(value) {
        // do some work to the value
        // if no value assigned, get the value of the previous method
    };

   _.doSome2 = function(value) {
        // do some work to the value
        // if no value assigned, get the value of the previous method
    };

   _.doSome3 = function(value) {
        // do some work to the value
        // if no value assigned, get the value of the previous method
    };

   root._ = _;

}.call(this));

If doSome method work the value of the _ object, and doSome2 and doSome3 too.

But what about chaining the methods like so:

// the doSome2 and doSome3 work with the value of doSome
_.doSome(value).doSome2().doSome3();

// the doSome3 work with the value of doSome2 cuz it has a value
_.doSome(value).doSome2(value).doSome3();

// every method work with the value assigned to it
_.doSome(value).doSome2(value).doSome3(value); // the same as:
_.doSome(value);
_.doSome2(value);
_.doSome3(value);

note: methods can be chained randomly, like:

_.doSome2(value).doSome().doSome3();

Live example: https://jsbin.com/vijehotora/edit?js,console

Answer 1

You could do something like this:

var Ctor = function() {};

Ctor.prototype = {
    doSome: function(value) {
        if(value) {
            this.value = value;
        }

        return this;
    },

    doSome2: function(value) {
        if(value) {
            this.value = value;
        }

        return this;
    }    
};

new Ctor().doSome('value1').doSome2('value2').doSome();

Working example