import

npm install

npm install pubsub-js

Every module that needs to be observed or observed is imported into the js file

An example is as follows:

import '../../../../node_modules/pubsub-js/src/pubsub.js';

Create an Observer - an example here is to tell the observer the change and value of the target

var target='when target change';
//事件的名字
var targetChange='targetChange';
//告诉所有观察者 事件targetChange被触发 传递一个data为target 其他观察者可以拿来用
PubSub.publish(targetChange,target);

Create an observer - an example here is to listen for changes in the target value

// 举例 target改变事件
var targetChange='targetChange';
var target;
PubSub.subscribe(targetChange, function (msg, data) {
    target=data;//将从被观察者那里得到的数据给target 就可以开始使用已经被改变的target的值
});

Individuals draw conclusions not sure of right or wrong

1. import {target} from 'xx/xx'; The target is read-only and cannot be changed. But if it is an object var target{xxx=1}, the properties of the object can be changed, target.xxx=2; but the original referenced target and object will not change.
2. Import is asynchronous. The code written in front of import will not be executed first.