流星-仅发布集合的计数

问题描述：

是否可以仅将集合的计数发布给用户?我想在首页上显示总数，但不希望将所有数据传递给用户.这是我尝试过的方法，但是不起作用:

Is it possible to publish just the count for a collection to the user? I want to display the total count on the homepage, but not pass all the data to the user. This is what I tried but it does not work:

Meteor.publish('task-count', function () {
    return Tasks.find().count();
});

this.route('home', { 
    path: '/',
    waitOn: function () {
        return Meteor.subscribe('task-count');
    }
});

尝试此操作时，我会得到无尽的加载动画.

When I try this I get an endless loading animation.

答

Meteor.publish函数应该返回游标，但是在这里，您直接返回的是Number，它是Tasks集合中文档的总数.

Meteor.publish functions should return cursors, but here you're returning directly a Number which is the total count of documents in your Tasks collection.

在Meteor中对文档进行计数比要以正确的方式完成任务要困难得多:使用既优雅又有效的解决方案.

Counting documents in Meteor is a surprisingly more difficult task than it appears if you want to do it the proper way : using a solution both elegant and effective.

包 ros:publish-counts (fastCount选项.

The package ros:publish-counts (a fork of tmeasday:publish-counts) provides accurate counts for small collections (100-1000) or "nearly accurate" counts for larger collections (tens of thousands) using the fastCount option.

您可以通过这种方式使用它:

You can use it this way :

// server-side publish (small collection)
Meteor.publish("tasks-count",function(){
  Counts.publish(this,"tasks-count",Tasks.find());
});

// server-side publish (large collection)
Meteor.publish("tasks-count",function(){
  Counts.publish(this,"tasks-count",Tasks.find(), {fastCount: true});
});

// client-side use
Template.myTemplate.helpers({
  tasksCount:function(){
    return Counts.get("tasks-count");
  }
});

您将获得客户端的响应计数以及服务器端的合理性能实现.

You'll get a client-side reactive count as well as a server-side reasonably performant implementation.

在(收费的)防弹流星课程中讨论了此问题，该课程建议阅读: https://bulletproofmeteor.com /

This problem is discussed in a (paid) bullet proof Meteor lesson which is a recommended reading : https://bulletproofmeteor.com/

流星-仅发布集合的计数

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