使用Vue3实现一个Upload组件的示例代码
通用上传组件开发
开发上传组件前我们需要了解:
首先实现一个最基本的上传流程:
基本上传流程,点击按钮选择,完成上传
代码如下:
<template> <div class="app-container"> <!--使用change事件--> <input type="file" @change="handleFileChange"> </div> </template> <script lang="ts"> import { defineComponent } from 'vue' import axios from 'axios' export default defineComponent({ name: 'App', setup() { const handleFileChange = (e: Event) => { // 断言为HTMLInputElement const target = e.target as HTMLInputElement const files = target.files if(files) { const uploadedFile = files[0] const formData = new FormData() formData.append('file', uploadedFile) // 使用node模拟上传接口 axios.post('http://localhost:3001/upload', formData, { headers: { "Content-Type": 'multipart/form-data' } }).then(resp=> { console.log('resp', resp) }).catch(error=> { }) } } return { handleFileChange } } }) </script> <style> .page-title { color: #fff; } </style>
结果如下:
到这里我们基本的上传已经处理完成了,相对来说还是比较简单的,接下来我们创建Uploader.vue文件用来封装Upload组件。
我们需要实现如下功能
自定义模版
我们知道使用<input type="file">系统自带样式比较难看所用我们需要如下处理:
- 对样式进行优化,隐藏input
- 点击<div class="upload-area" @click="triggerUpload"></div>使用js出发input的click事件
- 处理上传状态
代码如下:
<template> <div class="file-upload"> <div class="upload-area" @click="triggerUpload"></div> <span v-if="fileStatus==='loading'">正在上传</span> <span v-else-if="fileStatus==='success'">上传成功</span> <span v-else-if="fileStatus==='error'">上传失败</span> <span v-else>点击上传</span> <input ref="fileInput" type="file" name="file" style="display: none" /> </div> </template> <script lang="ts"> import { computed, defineComponent, PropType, reactive, ref } from 'vue' import axios from 'axios' type UploadStatus = 'ready' | 'loading' | 'success' | 'error' export default defineComponent({ props: { action: { // url地址 type: String, required: true } }, setup(props) { // input实例对象,通过与ref="fileInput"的关联获取到input实例对象 const fileInput = ref<null | HTMLInputElement>(null) const fileStatus = ref<UploadStatus>('ready') // 1.div点击事件 const triggerUpload = () => { if(fileInput.value) { fileInput.value.click() } } // 通过div来触发input的change事件 const handleFileChange = (e: Event) => { const target = e.target as HTMLInputElement const files = target.files if(files) { const uploadedFile = files[0] const formData = new FormData() formData.append('file', uploadedFile) readyFile.status = 'loading' // 上传之前将状态设置为loading axios.post(props.actions, formData, { headers: { "Content-Type": 'multipart/form-data' } }).then(resp=> { console.log('resp', resp) readyFile.status = 'success' // 上传成功将状态设置为success }).catch(error=> { readyFile.status = 'error' // // 上传失败将状态设置为error }) } } return { fileInput, triggerUpload, handleFileChange, fileStatus } } }) </script>
现在我们已经完成了对上传组件样式的优化,和上传状态的处理,接下来我们需要处理文件上传列表
支持文件上传列表
处理文件上传列表我们需要有如下实现:
- 显示文件名称
- 状态
- 可删除
- 显示上传进度
- 有可能有更丰富的显示
在上一步代码的基础上做一些修改:
<template> <div class="file-upload"> <div class="upload-area" @click="triggerUpload"></div> <!-- 点击上传态 --> <slot v-if="isUploading" name='loading'> <button disabled>正在上传</button> </slot> <!-- 上传完毕态 --> <slot name="uploaded" v-else-if="lastFileData && lastFileData.loaded" :uploadData="lastFileData.data"> <button disabled>点击上传</button> </slot> <!-- 默认态 --> <slot v-else name='default'> <!-- <button disabled>点击上传</button> --> <span>点击上传</span> </slot> <input ref="fileInput" type="file" name="file" style="display: none" /> <!--展示fileList--> <ul> <li v-for="file in filesList" :key="file.uid" :class="`uploaded-file upload-${file.status}`" > <span class="filname"> {{ file.name }} </span> <button class="delete-icon" @click="reomveFile(file.uid)">Del</button> </li> </ul> </div> </template> <script lang="ts"> import { last } from 'lodash-es' import { v4 as uuidv4 } from 'uuid'; // 定义上传状态 type UploadStatus = 'ready' | 'loading' | 'success' | 'error' // step1 定义上传文件对象接口类 export interface UploadFile { uid: string; // 文件唯一id size: number; // 文件大小 name: string; // 文件名称 status: UploadStatus; // 上传状态 raw: File; // 文件 progress?: string; // 文件上传进度 resp?: any; // 服务端返回数据 url?: string // 对应展示的url } export default defineComponent({ props: { action: { // url地址 type: String, required: true } }, setup(props) { // input实例对象,通过与ref="fileInput"的关联获取到input实例对象 const fileInput = ref<null | HTMLInputElement>(null) // step2 上传文件列表 const filesList = ref<UploadFile[]>([]) // step4-1 判断是否正在上传中 const isUploading = computed(()=> { return filesList.value.some((file)=>file.status==='loading') }) //step4-2 获取上传文件的最后一项 const lastFileData = computed(()=>{ const lastFile = last(filesList.value) if(!lastFile) return false return { loaded: lastFile?.status === 'success', data: lastFile?.resp } }) // 1.div点击事件 const triggerUpload = () => { if(fileInput.value) { fileInput.value.click() } } // 通过div来触发input的change事件 const handleFileChange = (e: Event) => { const target = e.target as HTMLInputElement const files = target.files if(files) { const uploadedFile = files[0] const formData = new FormData() formData.append('file', uploadedFile) // step3 设置响应式对象,存储到filesList中,以便在页面中展示 const fileObj = reactive<UploadFile>({ uid: uuid(); // 文件唯一id size: uploadedFile.size, name: uploadedFile.name, status: 'loading', raw: uploadedFile }) filesList.value.push(fileObj) axios.post(props.actions, formData, { headers: { "Content-Type": 'multipart/form-data' }, //step6 处理上传进度 onUploadProgress: (progressEvent)=> { const complete = (progressEvent.loaded / progressEvent.total * 100 | 0) + '%' fileObj.progress = complete } }).then(resp=> { console.log('resp', resp) fileObj.status = 'success' }).catch(error=> { fileObj.status = 'error' }).finally(()=> { // 一张图片重复上传时无法继续上传bug if(fileInput.value) { fileInput.value.value = '' } }) } } // step7 处理删除 const reomveFile = (uid: string) => { filesList.value = filesList.value.filter(file=>file.uid!==uid) } return { fileInput, triggerUpload, handleFileChange, fileStatus, isUploading, filesList, lastFileData } } }) </script>
- 首先我们定义上传文件对象接口类UploadFile
- 创建了一个filesList响应式对象
- 去掉了fileStatus,因为在UploadFile接口中我们已经有定义status
- 修改模版中的状态,利用computed来判读是否是处于上传状态,并增加slot进行自定义
- 展示上传的图片
- 处理上传进度
- 处理删除
注意点:如果选择相同的图片不会进行上传操作,因为我们使用的是input的change事件,所以我们需要在上传后将input的value设置为null
支持一系列生命周期钩子事件,上传事件
beforeUpload
<template> ... </template> <script lang="ts"> import { last } from 'lodash-es' import { v4 as uuidv4 } from 'uuid'; // 定义上传状态 type UploadStatus = 'ready' | 'loading' | 'success' | 'error' // 定义上传文件为boolean或promsie且接受一个File type CheckUpload = ()=> boolean | Promise<File> export interface UploadFile { ... } export default defineComponent({ props: { action: { // url地址 type: String, required: true }, beforeUpload: { type: Function as PropType<CheckUpload> } }, setup(props) { const fileInput = ref<null | HTMLInputElement>(null) const filesList = ref<UploadFile[]>([]) // step4-1 判断是否正在上传中 const isUploading = computed(()=> { return filesList.value.some((file)=>file.status==='loading') }) const lastFileData = computed(()=>{ const lastFile = last(filesList.value) if(!lastFile) return false return { loaded: lastFile?.status === 'success', data: lastFile?.resp } }) const triggerUpload = () => { if(fileInput.value) { fileInput.value.click() } } const handleFileChange = (e: Event) => { const target = e.target as HTMLInputElement const files = target.files const uploadedFile = files[0] if(props.beforeUpload) { const result = props.beforeUpload(uploadedFile) if(result && result instanceof Promise) { result.then((processFile)=> { if(uploadedFile instanceof File) { postFile(uploadedFile) } }).catch(error=>{ console.error(error) }) } esle if(result===true) { postFile(uploadedFile) } }else{ postFile(uploadedFile) } } const reomveFile = (uid: string) => { filesList.value = filesList.value.filter(file=>file.uid!==uid) } // 处理文件上传 const postFile = (readyFile:UploadFile)=> { const formData = new FormData() formData.append('file', readyFile.raw) readyFile.status = 'loading' axios.post(props.action, formData, { headers: { "Content-Type": 'multipart/form-data' }, onUploadProgress: (progressEvent)=> { const complete = (progressEvent.loaded / progressEvent.total * 100 | 0) + '%' // console.log('上传 ' + complete) readyFile.progress = complete } }, ).then(resp=> { console.log('resp', resp) // fileStatus.value = 'success' readyFile.status = 'success' readyFile.resp = resp.data }).catch(error=> { // fileStatus.value = 'error' readyFile.status = 'error' }) .finally(()=> { // 一张图片重复上传时无法继续上传bug if(fileInput.value) { fileInput.value.value = '' } }) } return { fileInput, triggerUpload, handleFileChange, fileStatus, isUploading, filesList, lastFileData } } }) </script>
实现步骤:
- 在poops处定义属性beforeUpload,同时定义上传文件为boolean或promsie且接受一个File
- 将原上传方法进行封装为postFile
- 根据beforeUpload返回结果,进行接下来的流程处理
onProgress,onSuccess,onError,onChange与之类似
拖拽支持
大致流程如下图:
- dragover和dragleave添加和删除对应的class
- drop拿到正在被拖拽的文件,删除class,并且触发上传
- 只有在属性drag为true才能触发
需要注意v-on的使用具体可参考vue官方文档
上代码:
<template> <div class="file-upload"> <div :class="['upload-area', drag && isDragOver ? 'is-dragover': '' ]" v-on="events" > <!-- 点击上传态 --> <slot v-if="isUploading" name='loading'> <button disabled>正在上传</button> </slot> <!-- 上传完毕态 --> <slot name="uploaded" v-else-if="lastFileData && lastFileData.loaded" :uploadData="lastFileData.data"> <button disabled>点击上传</button> </slot> <!-- 默认态 --> <slot v-else name='default'> <!-- <button disabled>点击上传</button> --> <span>点击上传</span> </slot> </div> <input ref="fileInput" type="file" name="file" style="display: none" @change="handleFileChange" /> <ul> <li v-for="file in filesList" :key="file.uid" :class="`uploaded-file upload-${file.status}`" > <img v-if="file.url && listType === 'picture'" class="upload-list-thumbnail" :src="file.url" :alt="file.name" > <span class="filname"> {{ file.name }} </span> <span class="progress"> {{ file.progress }} </span> <button class="delete-icon" @click="reomveFile(file.uid)">Del</button> </li> </ul> </div> </template> <script lang="ts"> import { computed, defineComponent, PropType, reactive, ref } from 'vue' import axios from 'axios' import { v4 as uuidv4 } from 'uuid'; import { last } from 'lodash-es' type UploadStatus = 'ready' | 'loading' | 'success' | 'error' type fileListType = 'text' | 'picture' type CheckUpload = ()=> boolean | Promise<File> export interface UploadFile { uid: string; // 文件唯一id size: number; // 文件大小 name: string; // 文件名称 status: UploadStatus; // 上传状态 raw: File; // 文件 progress?: string; resp?: any; // 服务端返回数据 url?: string // 对应展示的url } // dragOver 文件拖拽到区域时触发 // dragLeave 文件离开拖动区域 // drop 事件拿到正在被拖拽的文件删除class并且触发上传 // 只有设置drag的时候才有效 export default defineComponent({ name: 'Uploader', props: { action: { // url地址 type: String, required: true }, beofreUpload:{ // 上传之前的处理 type: Function as PropType<CheckUpload> }, drag: { // 是否拖拽 type: Boolean, default: false }, autoUpload: { // 自动上传 type: Boolean, default: true }, listType: { type: String as PropType<fileListType>, default: 'text' } }, setup(props) { const fileInput = ref<null | HTMLInputElement>(null) const fileStatus = ref<UploadStatus>('ready') // 存储上传的文件 const filesList = ref<UploadFile[]>([]) // 定义了一个isDragOver标识,处理拖动后样式.upload-area显示 const isDragOver = ref<boolean>(false) const triggerUpload = () => { if(fileInput.value) { fileInput.value.click() } } let events: {[key:string]: (e: any)=>void} = { 'click': triggerUpload, } // 只要有一个文件状态是loading态就说明是正在上传 const isUploading = computed(()=>{ return filesList.value.some((file)=> file.status==='loading') }) // 获取上传文件的最后一项 const lastFileData = computed(()=>{ const lastFile = last(filesList.value) if(!lastFile) return false return { loaded: lastFile?.status === 'success', data: lastFile?.resp } }) // 处理dragover,dragleave const handleDrag = (e: DragEvent,over: boolean)=> { // 阻止默认事件 e.preventDefault() // dragover为true,dragleave为fasle isDragOver.value = over } // 处理drop const handleDrop = (e: DragEvent) => { e.preventDefault() isDragOver.value = false if(e.dataTransfer) { beforeUploadCheck(e.dataTransfer.files) } } if(props.drag){ events = { ...events, 'dragover': (e: DragEvent) => { handleDrag(e, true)}, 'dragleave': (e: DragEvent) => { handleDrag(e, false)}, 'drop': handleDrop } // console.log(events) } // 删除文件 const reomveFile = (uid: string)=> { filesList.value = filesList.value.filter(file=>file.uid!==uid) } const postFile = (readyFile:UploadFile) => { const formData = new FormData() formData.append('file', readyFile.raw) readyFile.status = 'loading' // 选择文件后push到存储对象里面 axios.post(props.action, formData, { headers: { "Content-Type": 'multipart/form-data' }, onUploadProgress: (progressEvent)=> { const complete = (progressEvent.loaded / progressEvent.total * 100 | 0) + '%' // console.log('上传 ' + complete) readyFile.progress = complete } }, ).then(resp=> { console.log('resp', resp) // fileStatus.value = 'success' readyFile.status = 'success' readyFile.resp = resp.data }).catch(error=> { // fileStatus.value = 'error' readyFile.status = 'error' }) .finally(()=> { // 一张图片重复上传时无法继续上传bug if(fileInput.value) { fileInput.value.value = '' } }) } const addFileToList = (uploadedFile: File) => { const fileObj = reactive<UploadFile>({ uid: uuidv4(), size: uploadedFile.size, name: uploadedFile.name, status: 'ready', raw: uploadedFile }) // 处理图片格式并显示 if(props.listType==='picture') { // try { // fileObj.url = URL.createObjectURL(uploadedFile) // }catch(err) { // console.error('upload file err', err) // } const fileReader = new FileReader() fileReader.readAsDataURL(uploadedFile) fileReader.addEventListener('load', ()=> { fileObj.url = fileReader.result as string }) } filesList.value.push(fileObj) if(props.autoUpload) { postFile(fileObj) } } const uploadFiles = ()=> { // filesList.value.filter(file => file.status === 'ready').forEach(readyFile => postFile(readyFile)) filesList.value.filter(file => file.status === 'ready').forEach(readyFile=>postFile(readyFile)) } const beforeUploadCheck = (files: null | FileList ) => { if(files) { fileStatus.value = 'loading' const uploadedFile = files[0] if(props.beofreUpload) { const result = props.beofreUpload() // 如果有返回值 if(result && result instanceof Promise) { result.then(processedFile=> { if(processedFile instanceof File) { addFileToList(processedFile) } else { throw new Error('beforeUpload promise should return file object') } }).catch(err=> { console.log(err) }) } else if(result === true) { addFileToList(uploadedFile) } } else { addFileToList(uploadedFile) } } } const handleFileChange = (e: Event) => { const target = e.target as HTMLInputElement const files = target.files beforeUploadCheck(files) } return { fileInput, triggerUpload, handleFileChange, isUploading, filesList, reomveFile, lastFileData, beforeUploadCheck, isDragOver, events } } }) </script>
以上就是基本的基于vue3实现的上传通用组件
另附上上传接口代码:
// 引入模块 const Koa = require('koa'); const fs = require('fs'); const path = require('path'); const router = require('koa-router')(); const koaBody = require('koa-body'); const static = require('koa-static'); const cors = require('koa2-cors') // 实例化 const app = new Koa(); app.use(koaBody({ multipart: true, // 支持文件上传 formidable: { maxFieldsSize: 2 * 1024 * 1024, // 最大文件为2兆 multipart: true // 是否支持 multipart-formdate 的表单 } })); const uploadUrl = "http://localhost:3001/static/upload"; // 配置路由 router.get('/', (ctx) => { // 设置头类型, 如果不设置,会直接下载该页面 ctx.type = 'html'; // 读取文件 const pathUrl = path.join(__dirname, '/static/upload.html'); ctx.body = fs.createReadStream(pathUrl); }); // 上传文件 router.post('/upload', (ctx) => { // 获取上传文件 const file = ctx.request.files.file; console.log(file); // 读取文件流 const fileReader = fs.createReadStream(file.path); // 设置文件保存路径 const filePath = path.join(__dirname, '/static/upload/'); // 组装成绝对路径 const fileResource = filePath + `/${file.name}`; /** * 使用 createWriteStream 写入数据,然后使用管道流pipe拼接 */ const writeStream = fs.createWriteStream(fileResource); // 判断 /static/upload 文件夹是否存在,如果不在的话就创建一个 if (!fs.existsSync(filePath)) { fs.mkdir(filePath, (err) => { if (err) { throw new Error(err); } else { fileReader.pipe(writeStream); ctx.body = { url: uploadUrl + `/${file.name}`, code: 0, message: '上传成功1' }; } }); } else { fileReader.pipe(writeStream); ctx.body = { url: uploadUrl + `/${file.name}`, code: 0, message: '上传成功1' }; } }); // 配置静态资源路径 app.use(static(path.join(__dirname))); // 开启跨域 app.use(cors()) // 启动路由 app.use(router.routes()).use(router.allowedMethods()); // 监听端口号 app.listen(3001, () => { console.log('server is listen in 3001'); });
写在最后
已上只是一个简单的实现,当然了我们也可以添加自定义headers,自定义传递数据data,accecpt等等
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