用JS实现面向对象方法实现京东的五星好评效果。
鼠标滑过时的显示：
当评价完成后，关闭浏览器重新打开页面，还是上次的评价结果。用cookie实现。
具体实现如下：
import Componenet from "./Component.js";
export default class Stars extends Componenet {
label;
STARS_NUM = 5;
starArr = [];
score = 0;
starsCon;
faceIcon;
scoreCon;
index = -1;
name;
static STARS_LIST={}; //存储当前页面中所有的五星评价结果，一个商品为一组。用商品的id作为key，用商品评价组成一个数组，作为value。
date=new Date();
constructor(_label,_name) {
super("div");
this.name=_name;
this.label = _label;
Object.assign(this.elem.style, {
width:"200px",
height: "16px",
float: "left",
marginRight: "20px",
marginBottom: "10px",
fontSize: "12px",
color: "#666",
lineHeight: "16px",
userSelect: "none",
position: "relative",
top: "20px",
left: "20px",
})
// 解析cookie中存储的评论结果并在创建每个评论时初始化score的值。
this.initScore();
// 创建评价标签部分
this.createLabel();
// 创建星星部分
this.createStars();
// 创建分数部分
this.createScore();
// 初始化星星样式。
this.changeStarStyle(this.score-1);
// 初始化分数
this.changeScore(this.score);
// 添加鼠标滑过点击事件。
this.starsCon.addEventListener("mouseenter", e => this.mouseHandler(e));
this.starsCon.addEventListener("mouseleave", e => this.mouseHandler(e));
this.starsCon.addEventListener("mouseover", e => this.mouseHandler(e));
this.starsCon.addEventListener("click", e => this.clickHandler(e));
this.date.setFullYear(2021);
}
appendTo(_parent){
super.appendTo(_parent);
if(!Stars.STARS_LIST[this.name]) Stars.STARS_LIST[this.name]=[];
Stars.STARS_LIST[this.name].push(this.label+"="+this.score);
}
clickHandler(e){
if(e.target.constructor!==HTMLLIElement) return
this.index = this.starArr.indexOf(e.target);
this.score = this.index+1;
this.changeStarStyle(this.index);
this.changeScore(this.index+1);
// 每次点击都将评论的结果存储到cookie中，以便下次打开页面时读取。STARS_LIST中存储的是label作为key，score作为value的数据。
this.storageScore();
}
storageScore(){
for(let prop in Stars.STARS_LIST){
if(prop === this.name){
Stars.STARS_LIST[prop].forEach((item,index)=>{
if(item.includes(this.label)) Stars.STARS_LIST[prop][index] = this.label+"="+this.score;
});
}
}
document.cookie="comment="+ JSON.stringify(Stars.STARS_LIST)+";expires="+this.date.toUTCString();
}
mouseHandler(e) {
switch (e.type) {
case "mouseenter":
this.faceIcon.style.display = "block";
break;
case "mouseleave":
this.faceIcon.style.display = "none";
this.changeStarStyle(this.index);
this.changeScore(this.score);
break;
case "mouseover":
let index = this.starArr.indexOf(e.target);
this.changeStarStyle(index);
this.changeScore(index + 1);
this.changeFaceStyle(index);
break;
}
}
changeStarStyle(_i) {
for (let n = 0; n < this.starArr.length; n++) {
if (n <= _i || n < this.score) {
this.starArr[n].style.backgroundPositionY = "-16px";
} else {
this.starArr[n].style.backgroundPositionY = "0px";
}
}
}
changeFaceStyle(_i) {
this.faceIcon.style.left = _i * 16 + "px";
this.faceIcon.style.backgroundPositionX = (_i + 1) * 20 + "px";
}
changeScore(_i) {
this.scoreCon.textContent = _i + "分";
}
createLabel() {
let label = document.createElement("span");
Object.assign(label.style, {
float: "left",
padding: "0 5px",
})
label.textContent = this.label;
this.elem.appendChild(label);
}
createStars() {
this.starsCon = document.createElement("ul");
Object.assign(this.starsCon.style, {
margin: 0,
padding: 0,
listStyle: "none",
width: "80px",
height: "16px",
float: "left",
position: "relative",
})
for (let i = 0; i < this.STARS_NUM; i++) {
let li = document.createElement("li");
Object.assign(li.style, {
width: "16px",
height: "16px",
float: "left",
backgroundImage: "url(./star_img/commstar.png)",
})
this.starArr.push(li);
this.starsCon.appendChild(li);
}
this.faceIcon = document.createElement("div");
Object.assign(this.faceIcon.style, {
width: "16px",
height: "16px",
backgroundImage: "url(./star_img/face-red.png)",
backgroundPositionX: "-80px",
position: "absolute",
left: "0",
top: "-16px",
display: "none",
})
this.starsCon.appendChild(this.faceIcon);
this.elem.appendChild(this.starsCon);
}
createScore() {
this.scoreCon = document.createElement("div");
Object.assign(this.scoreCon.style, {
height: "16px",
width:"20px",
float: "left",
padding: "0 5px",
})
this.scoreCon.textContent = this.score + "分",
this.elem.appendChild(this.scoreCon);
}
initScore(){
// 直接读取cookie显示如下
// comment={"1001":["商品符合度=5","店家服务态度=0","快递配送速度=0","快递员服务=0","快递包装=0"],"1002":["商品符合度=0","店家服务态度=0","快递配送速度=0","快递员服务=0","快递包装=0"]}
// 解析cookie中存储的评论结果。
if(!document.cookie.includes("comment=")) return
let o = JSON.parse(document.cookie.match(/(\{.*?\})/)[1]);
if(!o) return
// 解析后的o如下
// ["商品符合度=1", "店家服务态度=0", "快递配送速度=0", "快递员服务=0", "快递包装=0"]
for(let prop in o){
if(this.name===prop){
this.score=o[prop].reduce((value,item,index)=>{
let arr=item.split("=");
if(arr[0].includes(this.label)) value=parseInt(arr[1]);
return value;
},0)
}
}
}
}
使用时传入标签，新建实例。
import Stars from './js/Stars.js';
let list=["商品符合度","店家服务态度","快递配送速度","快递员服务","快递包装"];
// let star = new Stars(list[0]);
// star.appendTo("body");
list.forEach(item=>{
// 传入标签和对应的商品id
let star = new Stars(item,"1001");
star.appendTo(".div1");
})
list.forEach(item=>{
let star = new Stars(item,"1002");
star.appendTo(".div2");
})
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NICE源码。
