javascript - Iron-Router 在 Meteor 中随机返回未定义

Question

出于某种奇怪的原因，iron-router 随机返回 undefined。

this.route('pollyShow', {
    path: '/polly/:_id',
    template: 'polly_show',
    notFoundTemplate: 'notFound',
    before: function () {
        var id = this.params._id;
        var poll = Polls.findOne({_id: id});
        console.log(poll);
        var ip_array = poll.already_voted;
        $.getJSON("http://smart-ip.net/geoip-json?callback=?", function(data){
            ip_voted = ip_array.indexOf(data.host);

            if (ip_voted > -1) {
                Router.go('pollyResults', {_id: id});
            }
        });
    },
    data: function() {

        return Polls.findOne({_id: this.params._id});
    }
});

有时它正常返回，而其他时候它只是返回未定义。

这背后有什么原因吗？

Answer 1

出现此问题的原因是 Polly当路由执行时，集合有时会被填充，有时则不会填充。

可以通过显式 waiting on a subscription 来防止此问题使用waitOn路由配置中的选项。

<小时/>

来自docs :

By default, a new Meteor app includes the autopublish and insecure packages, which together mimic the effect of each client having full read/write access to the server's database. These are useful prototyping tools, but typically not appropriate for production applications. When you're ready, just remove the packages.

要删除软件包，请调用meteor remove <package-name> .

然后您需要在服务器上显式发布您希望在客户端上看到的记录:

server/publications.js:

Meteor.publish('all_of_polly', function () { return Polls.find({}); });

并在客户端订阅:

this.route('pollyShow', {
    path: '/polly/:_id',
    template: 'polly_show',
    notFoundTemplate: 'notFound',
    waitOn: function () { return Meteor.subscribe('all_of_polly'); }
    // ...
});