nodejs无法识别对象的功能

Question

I am building a reddit API wrapper in node.js to become more familiar with js and node. Here is my code so far:

./lib/reddit.js:

var request = require("request");

var reddit = function () {

  var self = this,
  userAgent = "node.js api wrapper",
  debug = false,
  uh = "",
  cookie = "";

  self.getJSON = function (url, callback) {
    request(url, function (error, response, body) {
      if (!error && response.statusCode == 200) {
        callback(body);
      }
    });
  };

  self.post = function (url, data, callback) {
    request.post(url, { form: data }, function (error, response, body) {
      if (!error && response.statusCode == 200) {
        callback(body);
      }
    });
  };

};

reddit.prototype = {

  login: function (username, password) {
    var data = {
      "user": username,
      "password": password,
      "rem": true
    };

    this.post("http://www.reddit.com/api/login", data, function (body) {
      var response = JSON.parse(body);
      this.uh = response.json.data.modhash;
      this.cookie = response.json.data.cookie;
      console.log(response);
      console.log(this.uh);
      console.log(this.cookie);
    });
  }

}

exports.reddit = reddit;

app.js:

var reddit = require("./lib.reddit").reddit;
reddit.login("username", "password");

I get this error:

[jet@cowboybebop reddit]$ node app.js 

/home/jet/projects/reddit/app.js:5
reddit.login("username", "password");
   ^
TypeError: Object function () {

  var self = this,
      userAgent = "node.js api wrapper",
      debug = false,
      uh = "",
      cookie = "";

  self.getJSON = function (url, callback) {
    request(url, function (error, response, body) {
      if (!error && response.statusCode == 200) {
        callback(body);
      }
    });
  };

  self.post = function (url, data, callback) {
    request.post(url, { form: data }, function (error, response, body) {
      if (!error && response.statusCode == 200) {
        callback(body);
      }
    });
  };

} has no method 'login'
at Object.<anonymous> (/home/jet/projects/reddit/app.js:5:8)
at Module._compile (module.js:449:26)
at Object.Module._extensions..js (module.js:467:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.runMain (module.js:492:10)
at process.startup.processNextTick.process._tickCallback (node.js:244:9)

I originally had the login function defined like

reddit.prototype.login = function () .....

but this doesn't work either. Another SO question recommended formatting it like I have it now, but it still doesn't recognize it.

Answer 1

var reddit = require("./lib.reddit").reddit;

var a = new reddit();

a.login("username", "password");

Answer 2

Changed my mind about this problem. It's not that get is reserved, rather that you are trying to run a method in a function you haven't instantiated by mixing two styles of object definition (as a function and as a prototype). self.post won't exist until you actually instantiate a reddit object.

I think the best thing would be either to move your self.post function definition to a prototype so you can use it as a static method, or to move your login function definition within the function definition and actually instantiate the object to use its' methods.

Answer 3

This construct:

var reddit = function () { };

is just defining a function, not a class. You need the new operator to invoke it and create an object. You probably want to use this:

var reddit = new function () { };

which calls the function and creates an object of your (anonymous) class. The rest of your code should work as is it!