meteor - 如何让 onBeforeAction 调用等到 meteor.js 中的函数调用完成？

Question

我有一个与 meteor.js 同步的 onBeforeAction 方法

Router.onBeforeAction(function() {
    var self;

    self = this;

    authToken = Session.get('authToken');

   if (!authToken) {
       this.redirect('login');
       this.next();
   } else {
       Meteor.call('validateAuthToken', authToken, function (error, result)) {
           if (result) {
               self.next();
           } else {
               self.redirect('login');
               self.next();
           }
       }
   }
});

我需要通过调用服务器调用来验证存储在 Session 中的身份验证 token 。但是这个方法在我执行的时候总是抛出异常。我发现原因是因为 onBeforeAction 调用在 validateAuthToken 调用返回之前终止。因此 self.next() 不会采取行动。所以我想知道我可以做些什么来防止 onBeforeAction 调用停止，直到 validateAuthToken 返回验证结果然后继续？

---

我已经通过等待 session 变量尝试了不同的实现，但似乎就绪状态从未设置为 true

Router.onBeforeAction(function() {
    var authToken;

    authToken = Session.get('authToken');

    if (!authToken) {
        this.redirect('login');
        this.next();
    } else {
        Meteor.call('validateAuthToken', authToken, function (error, result) {
            if (!error) {
                Session.set("tokenValidated", result);
            }
        });

        this.wait(Meteor.subscribe('token', Session.get('tokenValidated')));
        if (this.ready()) {
            if (!Session.get("tokenValidated")) {
                this.redirect('login');
                this.next();
            } else {
                this.next();
            }
        }
    }

});

Answer 1

编辑 :在稍微解决这个问题之后，我想出了一个工作示例(没有无限循环)。您可以使用以下代码:

Util = {};

// We need to store the dep, ready flag, and data for each call
Util.d_waitOns = {};

// This function returns a handle with a reactive ready function, which
// is what waitOn expects. waitOn will complete when the reactive function
// returns true.
Util.waitOnServer = function(name) {
  // This prevents the waitOnServer call from being called multiple times
  // and the resulting infinite loop.
  if (this.d_waitOns[name] !== undefined &&
      this.d_waitOns[name].ready === true) {
    return;
  }
  else {
    this.d_waitOns[name] = {};
  }
  var self = this;
  // We need to store the dependency and the ready flag.
  this.d_waitOns[name].dep = new Deps.Dependency();
  this.d_waitOns[name].ready = false;

  // Perform the actual async call.
  Meteor.call(name, function(err, or) {
    // The call has complete, so set the ready flag, notify the reactive
    // function that we are ready, and store the data.
    self.d_waitOns[name].ready = true;
    self.d_waitOns[name].dep.changed();
    self.d_waitOns[name].data = (err || or);
  });

  // The reactive handle that we are returning.
  var handle = {
    ready: function() {
      self.d_waitOns[name].dep.depend();
      return self.d_waitOns[name].ready;
    }
  };
  return handle;
}

// Retrieve the data that we stored in the async callback.
Util.getResponse = function(name) {
  return this.d_waitOns[name].data;
}

像这样从 waitOn 调用:

Router.route("/test", {
  name: "test",
  action: function() {
    console.log("The data is ", Util.getResponse("testWaitOn"));
  },
  waitOn: function() {
    return Util.waitOnServer("testWaitOn");
  }
})

我写了一篇博文，里面有更深入的解释，你可以在这里找到:

http://www.curtismlarson.com/blog/2015/05/04/meteor-ironrouter-waitOn-server/