具有构造函数和方法的nodejs模块

Question

How can I create a constructor in a nodejs module?

The documentation says something like this:

module.exports = function(width) {
  return {
    area: function() {
      return width * width;
    }
  };
}

So you can do: var v = square(10);

I want to acieve something similar, but I have several other methods in my file.

File: test.js

exports = module.exports;

// ctor
exports = function(val) {

};

exports.test1 = function(param1) {
    return 'a';
};

exports.test2 = function(param1, param2) {
    return 'b';
};

How can I add a constructor-like function to my code so I can do this:

test('val');
var t1 = test.test1('param');
var t2 = test.test1('param');

Answer 1

You were quite close.

The problem is with the first and the second line. You begin with setting the variable exports to module.exports (and forget to use var), then you override it with the function.

So if you want to do that, you need to first set exports.module to the function, and then var exports = module.exports;

Anyway, I wouldn't suggest that you use this shortcut, since it's confusing and exports is already a global variable in that context.

You better use the long syntax and be more clear:

module.exports = function(val) {
    console.log ('test');
};

module.exports.test1 = function(param1) {
    console.log('a');
};

module.exports.test2 = function(param1, param2) {
    console.log ('b');
};

Here's a good example: https://github.com/rvagg/through2/blob/master/through2.js