完成Wechat的OAuth功能

index.js

@@ -1,4 +1,5 @@
 var wechat = require('./lib/wechat');
 wechat.List = require('./lib/list');
 wechat.API = require('./lib/common');
-module.exports = wechat;
+wechat.OAuth = require('./lib/oauth');
+module.exports = wechat;

lib/common.js

@@ -2,39 +2,9 @@ var path = require('path');
 var fs = require('fs');
 var urllib = require('urllib');
 var formstream = require('formstream');
-
-/*!
- * 对返回结果的一层封装，如果遇见微信返回的错误，将返回一个错误
- * 参见：http://mp.weixin.qq.com/wiki/index.php?title=返回码说明
- */
-var wrapper = function (callback) {
-  return function (err, data, res) {
-    if (err) {
-      err.name = 'WeChatAPI' + err.name;
-      return callback(err, data, res);
-    }
-    if (data.errcode) {
-      err = new Error(data.errmsg);
-      err.name = 'WeChatAPIError';
-      return callback(err, data, res);
-    }
-    callback(null, data, res);
-  };
-};
-
-/*!
- * 对提交参数一层封装，当POST JSON，并且结果也为JSON时使用
- */
-var postJSON = function (data) {
-  return {
-    dataType: 'json',
-    type: 'POST',
-    data: data,
-    headers: {
-      'Content-Type': 'application/json'
-    }
-  };
-};
+var util = require('./util');
+var wrapper = util.wrapper;
+var postJSON = util.postJSON;
 
 /**
  * 根据appid和appsecret创建API的构造函数

lib/oauth.js

@@ -0,0 +1,197 @@
+var urllib = require('urllib');
+var wrapper = require('./util').wrapper;
+var querystring = require('querystring');
+
+/*!
+ * 处理token，更新过期时间
+ */
+var processToken = function (that, callback) {
+  return function (err, data, res) {
+    if (err) {
+      return callback(err, data);
+    }
+    that.accessToken = data.access_token;
+    that.refreshToken = data.refresh_token;
+    that.expireTime = (new Date().getTime()) + (data.expires_in - 10) * 1000;
+    callback(err, data);
+  };
+};
+
+/**
+ * 根据appid和appsecret创建OAuth接口的构造函数
+ *
+ * Examples:
+ * ```
+ * var OAuth = require('wechat').OAuth;
+ * var api = new OAuth('appid', 'secret');
+ * ```
+ * @param {String} appid 在公众平台上申请得到的appid
+ * @param {String} appsecret 在公众平台上申请得到的app secret
+ */
+var OAuth = function (appid, appsecret) {
+  this.appid = appid;
+  this.appsecret = appsecret;
+};
+
+/**
+ * 获取授权页面的URL地址
+ * @param {String} redirect 授权后要跳转的地址
+ * @param {String} state 开发者可提供的数据
+ * @param {String} scope 作用范围，值为snsapi_userinfo和snsapi_base，前者用于弹出，后者用于跳转
+ */
+OAuth.prototype.getAuthorizeURL = function (redirect, state, scope) {
+  var url = 'https://open.weixin.qq.com/connect/oauth2/authorize';
+  var info = {
+    appid: this.appid,
+    redirect_uri: encodeURIComponent(redirect),
+    response_type: 'code',
+    scope: scope || 'snsapi_base',
+    state: state || ''
+  };
+
+  return url + '?' + querystring.stringify(info) + '#wechat_redirect';
+};
+
+/**
+ * 返回当前的access token是否有效
+ */
+OAuth.prototype.isAccessTokenValid = function () {
+  return this.expireTime && (new Date().getTime()) < this.expireTime;
+};
+
+/**
+ * 根据授权获取到的code，换取access token
+ * 获取openid之后，可以调用`wechat.API`来获取更多信息
+ * Examples:
+ * ```
+ * api.getAccessToken(code, callback);
+ * ```
+ * Callback:
+ *
+ * - `err`, 获取access token出现异常时的异常对象
+ * - `result`, 成功时得到的响应结果
+ *
+ * Result:
+ * ```
+ * {
+ *  "access_token": "ACCESS_TOKEN",
+ *  "expires_in": 7200,
+ *  "refresh_token": "REFRESH_TOKEN",
+ *  "openid": "OPENID",
+ *  "scope": "SCOPE"
+ * }
+ * ```
+ * @param {String} code 授权获取到的code
+ * @param {Function} callback 回调函数
+ */
+OAuth.prototype.getAccessToken = function (code, callback) {
+  var url = 'https://api.weixin.qq.com/sns/oauth2/access_token';
+  var info = {
+    appid: this.appid,
+    secret: this.appsecret,
+    code: code,
+    grant_type: 'authorization_code'
+  };
+  var args = {
+    data: info,
+    dataType: 'json'
+  };
+  urllib.request(url, args, wrapper(processToken(this, callback)));
+};
+
+/**
+ * 根据refresh token，刷新access token，调用getAccessToken后才有效
+ * Examples:
+ * ```
+ * api.refreshAccessToken(callback);
+ * ```
+ * Callback:
+ *
+ * - `err`, 刷新access token出现异常时的异常对象
+ * - `result`, 成功时得到的响应结果
+ *
+ * Result:
+ * ```
+ * {
+ *  "access_token": "ACCESS_TOKEN",
+ *  "expires_in": 7200,
+ *  "refresh_token": "REFRESH_TOKEN",
+ *  "openid": "OPENID",
+ *  "scope": "SCOPE"
+ * }
+ * ```
+ * @param {Function} callback 回调函数
+ */
+OAuth.prototype.refreshAccessToken = function (callback) {
+  var that = this;
+  var url = 'https://api.weixin.qq.com/sns/oauth2/refresh_token';
+  var info = {
+    appid: this.appid,
+    grant_type: 'refresh_token',
+    refresh_token: that.refreshToken
+  };
+  var args = {
+    data: info,
+    dataType: 'json'
+  };
+  urllib.request(url, args, wrapper(processToken(this, callback)));
+};
+
+OAuth.prototype._getUser = function (openid, callback) {
+  var url = 'https://api.weixin.qq.com/sns/userinfo';
+  var info = {
+    access_token: this.appid,
+    openid: openid
+  };
+  var args = {
+    data: info,
+    dataType: 'json'
+  };
+  urllib.request(url, args, wrapper(callback));
+};
+
+/**
+ * 根据openid，获取用户信息。
+ * 当access token无效时，自动通过refresh token获取新的access token。然后再获取用户信息
+ * Examples:
+ * ```
+ * api.refreshAccessToken(callback);
+ * ```
+ * Callback:
+ *
+ * - `err`, 获取用户信息出现异常时的异常对象
+ * - `result`, 成功时得到的响应结果
+ *
+ * Result:
+ * ```
+ * {
+ *  "openid": "OPENID",
+ *  "nickname": "NICKNAME",
+ *  "sex": "1",
+ *  "province": "PROVINCE"
+ *  "city": "CITY",
+ *  "country": "COUNTRY",
+ *  "headimgurl": "http://wx.qlogo.cn/mmopen/g3MonUZtNHkdmzicIlibx6iaFqAc56vxLSUfpb6n5WKSYVY0ChQKkiaJSgQ1dZuTOgvLLrhJbERQQ4eMsv84eavHiaiceqxibJxCfHe/46", 
+ *  "privilege": [
+ *    "PRIVILEGE1"
+ *    "PRIVILEGE2"
+ *  ]
+ * }
+ * ```
+ * @param {Function} callback 回调函数
+ */
+OAuth.prototype.getUser = function (openid, callback) {
+  var that = this;
+  if (this.isAccessTokenValid()) {
+    that._getUser(openid, callback);
+  } else {
+    that.refreshAccessToken(function (err, data) {
+      if (err) {
+        return callback(err);
+      }
+      that._getUser(openid, callback);
+    });
+  }
+};
+
+module.exports = OAuth;

lib/util.js

@@ -0,0 +1,32 @@
+/*!
+ * 对返回结果的一层封装，如果遇见微信返回的错误，将返回一个错误
+ * 参见：http://mp.weixin.qq.com/wiki/index.php?title=返回码说明
+ */
+exports.wrapper = function (callback) {
+  return function (err, data, res) {
+    if (err) {
+      err.name = 'WeChatAPI' + err.name;
+      return callback(err, data, res);
+    }
+    if (data.errcode) {
+      err = new Error(data.errmsg);
+      err.name = 'WeChatAPIError';
+      return callback(err, data, res);
+    }
+    callback(null, data, res);
+  };
+};
+
+/*!
+ * 对提交参数一层封装，当POST JSON，并且结果也为JSON时使用
+ */
+exports.postJSON = function (data) {
+  return {
+    dataType: 'json',
+    type: 'POST',
+    data: data,
+    headers: {
+      'Content-Type': 'application/json'
+    }
+  };
+};