javascript观察者模式实现自动刷新效果

本文实例为大家分享了js观察者模式实现自动刷新的具体代码，供大家参考，具体内容如下

const observable = obj => {
const observers = Symbol();
const set = function(target,key,value) {
const result = Reflect.set(target,value);
//console.log("set key:" + key);
if ( target[observers].has(key) ) {
target[observers].get(key).forEach(observer => observer());
}

return result;

}

const get = function(target,key) {
const result = Reflect.get(target,key);
//console.log("get key:" + key);
if (arguments.callee.caller) {
if (!target[observers].has(key)) {
target[observers].set(key,new Set())
}
target[observers].get(key).add(arguments.callee.caller);
}

return result;

}

obj[observers] = new Map(); // string => Set()
return new Proxy(obj,{set,get});
};

const autorun = fn => fn();

var person = observable({
firstName: 'Matt',lastName: 'Ruby',age: 18,weight: 50
});

autorun(function () {
console.log('autorun.getAge: ' + person.firstName + ' ' + person.age);
});

autorun(function () {
console.log('autorun.getName: ' + person.firstName + ' ' + person.lastName);
});

person.age = 19;
person.weight = 55;
person.firstName = 'test';
person.lastName = 'MyLast';
console.log(person.lastName);
person.age = 20;

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持编程之家。