前端学习案例-手动封装一个日历组件

首先搭建一个npm的环境

npm init -y

安装所需的依赖

yarn add vite sass -D

error解决 vite@3.0.3: The engine “node” is incompatible with this module. Expected version “^14.18.0 || >=16.0.0”. Got “14.16.0”

yarn config set ignore-engines true

error解决 Cannot use import statement outside a module的解决方法

<script type="module" src="./src/app.js"></script>

## 目录结构
## utils.js

//拿到当月是周几
export function getFirstWeekDay(year,month){
    const date=new Date(year,month-1 ,1);
    return date.getDay()
}
//拿到当月的最后一个日期
export function getMonthDayCount(year,month){
    const date=new Date(year,month,0);
    return date.getDate()
}
 
//上月的日期形成数组
export function getLastMonthRestDays(year,month){
    const days=getFirstWeekDay(year,month)
    let lastDate=getMonthDayCount(year,month-1)
    const restDays=[]
 
    while(restDays.length<days){
        restDays.push(lastDate--)
    }
    return restDays.reverse()
}
 
//本月的日期形成数组
export function getNextMonthRestDays(year,month){
    const LastMonthRestDayCount=getFirstWeekDay(year,month)
    let currentMothDayCount=getMonthDayCount(year,month-1)
    const nextMonthRestDayCount=42-(LastMonthRestDayCount+currentMothDayCount)
    let restDays=[]
 
    for(let i=1;i<=nextMonthRestDayCount;i++){
        restDays.push(i)
    }
    return restDays
}
 
//
export function getDateInfo(timeStamp){
    var date=timeStamp?new Date(timeStamp):new Date();
    return [date.getFullYear(),date.getMonth()+1,date.getDate()]
}
 
export function getFormatDate(year,month,date){
    const dateArr=[year,month,date]
    for(let i=1;i<dateArr.length;i++){
        dateArr[i]<10&&(dataArr[i]='0'+dateArr[i])
    }
    return dataArr.join("-")
}

app.js

import MyCalendar from './components/Calendar';
 
 
;(()=>{
    
    const myCalendar = MyCalendar()
    console.log(myCalendar,"myCalendar")
    const oApp=document.querySelector("#app")
    //返回值
    const dataInfo=myCalendar.getDateInfo();
    const init=()=>{
        render(...dataInfo)
    }
 
    function render(...args){
        oApp.appendChild(myCalendar.render(...args))
    }
    init()
})();

render.js

import { createWeekDaysNode } from "./creator"
 
 
export function render(container){
    const oThead = document.createElement("thead")
    const oTBody = document.createElement("tbody")
    const weekDaysNode=createWeekDaysNode()
    return function(year,month){
        oThead.appendChild(weekDaysNode)
        container.appendChild(oThead)
        return container
    }
 
  
}
 
export function update(){}
 
## index.js
 
```javascript
import {getDateInfo} from "./utils"
 
import {
    render,
    update
} from "./render"
 
export default ()=>{
    const oContainer = document.createElement("table")
    oContainer.className="my-calendar"
 
    return {
        render:render(oContainer),
        update,
        getDateInfo
    }
}
 

## creator.js

import { WEEK_DAYS } from "./config"
export function createWeekDaysNode(){
    const oTr=document.createElement("tr")
    oTr.className="week-day"
    oTr.innerHTML=WEEK_DAYS.map(item=>(
        `<th>${item}</th>`
    )).join('')
    return oTr
}

config.js

export const WEEK_DAYS=[
    "日",
    "一",
    "二",
    "三",
    "四",
    "五",
    "六", 
]