MeteorJS - 监视服务器变量更改并更新模板值 [英] MeteorJS - Watch for server variable change and update the template value

问题描述

我有一个疑问.不确定是否可行，也没有找到明确的答案.

I have a doubt. Not sure if it's possible and didn't find a clear answer about it.

是否可以向服务器变量添加观察者"，以便在值更改时更新视图(客户端)?

Is it possible to add a "watcher" to a server variable so when the value changes, I can update the view (client side) ?

假设我有一个 var counter = 0 和一个每分钟更新计数器变量的超时函数.

Let say I have a var counter = 0 and a Timeout function which updates the counter variable every minute.

我想在客户端更新一个{{counter}}.我需要向这个服务器变量添加一个观察者"并使其反应性.

提前致谢！

推荐答案

正确的做法是创建一个集合并将该变量存储在该集合中(即使这意味着您的集合只有一个文档).

The correct way to do this is to make a collection and store that variable in the collection (even if this means you have a collection with one document).

关于服务器/客户端通用代码:

On server/client common code:

Counter = new Mongo.Collection("counter");

在客户端做一个帮手:

Template.myTemplate.helpers({
  counter: function () {
    return Counter.findOne();
  }
});

在服务器上确保有一个计数器:

On server make sure there is a counter:

if (Counter.find().count() === 0) {
  Counter.insert({value: 0});
}

然后，在服务器上增加计数器:

Then, on the server increment the counter:

Counter.update({}, {$inc: {value: 1}});

如果您想跟踪多个计数器，您可以使用类似的方法 - 只需将多个计数器插入到集合中并通过 _id 字段引用它们.

You can use a similar approach if you want to keep track of multiple counters - just insert multiple counters into the collection and reference them by the _id field.

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