Vue生命周期函数的应用
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>vue生命周期学习</title> <script src="https://cdn.bootcss.com/vue/2.4.2/vue.js"></script> </head> <body> <div id="app"> <input v-model="message"></input> <h1>{{message1}}</h1> </div> </body> <script> var vm = new Vue({/*创建vue对象*/ el: '#app',/****挂载目标****/ data: {/****数据对象****/ message: 'Hello World!' }, computed:{/****实现某一属性的实时计算****/ message1:function(){ return this.message.split("").reverse().join(""); } }, watched:{/****检测某一属性值的变化****/ }, methods:{/****组件内部的方法****/ }, beforeCreate: function() { console.group('------beforeCreate创建前状态------'); console.log("%c%s", "color:red", "el : " + this.$el); //undefined console.log("%c%s", "color:red", "data : " + this.$data); //undefined console.log("%c%s", "color:red", "message: " + this.message)//undefined }, /** * 1.在beforeCreate和created钩子之间,程序开始监控Data对象数据的变化及vue内部的初始化事件 * * */ created: function() { console.group('------created创建完毕状态------'); console.log("%c%s", "color:red", "el : " + this.$el); //undefined console.log("%c%s", "color:red", "data : " + this.$data); //已被初始化 console.log("%c%s", "color:red", "message: " + this.message); //已被初始化 }, /** * 2.在created和beforeMount之间,判断是否有el选项,若有则继续编译,无,则暂停生命周期; * 然后程序会判断是否有templete参数选项,若有,则将其作为模板编译成render函数。若无,则将外部html作为模板编译(template优先级比外部html高) * * */ beforeMount: function() { console.group('------beforeMount挂载前状态------'); console.log("%c%s", "color:red", "el : " + (this.$el)); //已被初始化 console.log(this.$el); console.log("%c%s", "color:red", "data : " + this.$data); //已被初始化 console.log("%c%s", "color:red", "message: " + this.message); //已被初始化 }, /** * 3.在beforeMount和mounted之间,程序将上一步编辑好的html内容替换el属性指向的dom对象或者选择权对应的html标签里面的内容 * * */ mounted: function() { console.group('------mounted 挂载结束状态------'); console.log("%c%s", "color:red", "el : " + this.$el); //已被初始化 console.log(this.$el); console.log("%c%s", "color:red", "data : " + this.$data); //已被初始化 console.log("%c%s", "color:red", "message: " + this.message); //已被初始化 }, /** * 4.mounted和beforeUpdate之间,程序实时监控数据变化 * * */ beforeUpdate: function() { console.group('beforeUpdate 更新前状态===============》'); console.log("%c%s", "color:red", "el : " + this.$el); console.log(this.$el); console.log("%c%s", "color:red", "data : " + this.$data); console.log("%c%s", "color:red", "message: " + this.message); }, /** * 5.beforeUpdate和updated之间,实时更新dom * * */ updated: function() { console.group('updated 更新完成状态===============》'); console.log("%c%s", "color:red", "el : " + this.$el); console.log(this.$el); console.log("%c%s", "color:red", "data : " + this.$data); console.log("%c%s", "color:red", "message: " + this.message); }, beforeDestroy: function() { console.group('beforeDestroy 销毁前状态===============》'); console.log("%c%s", "color:red", "el : " + this.$el); console.log(this.$el); console.log("%c%s", "color:red", "data : " + this.$data); console.log("%c%s", "color:red", "message: " + this.message); }, /** * 6.实例销毁 * * */ destroyed: function() { console.group('destroyed 销毁完成状态===============》'); console.log("%c%s", "color:red", "el : " + this.$el); console.log(this.$el); console.log("%c%s", "color:red", "data : " + this.$data); console.log("%c%s", "color:red", "message: " + this.message) } }) </script> </html>