


js implementation of image pasting, uploading to the server and displaying it
In this article, we will share with you an example of how to paste, upload, and display images to the server using js. After learning, I hope you can master the method of pasting, uploading, and displaying js images to the server.
Recently I have seen some demos about js implementation of image pasting and uploading. The implementation is as follows: (Only screenshot pasting and image right-click copying and pasting can be detected here)
demo1:
document.addEventListener('paste', function (event) { console.log(event) var isChrome = false; if ( event.clipboardData || event.originalEvent ) { //not for ie11 某些chrome版本使用的是event.originalEvent var clipboardData = (event.clipboardData || event.originalEvent.clipboardData); if ( clipboardData.items ) { // for chrome var items = clipboardData.items, len = items.length, blob = null; isChrome = true; //items.length比较有意思,初步判断是根据mime类型来的,即有几种mime类型,长度就是几(待验证) //如果粘贴纯文本,那么len=1,如果粘贴网页图片,len=2, items[0].type = 'text/plain', items[1].type = 'image/*' //如果使用截图工具粘贴图片,len=1, items[0].type = 'image/png' //如果粘贴纯文本+HTML,len=2, items[0].type = 'text/plain', items[1].type = 'text/html' // console.log('len:' + len); // console.log(items[0]); // console.log(items[1]); // console.log( 'items[0] kind:', items[0].kind ); // console.log( 'items[0] MIME type:', items[0].type ); // console.log( 'items[1] kind:', items[1].kind ); // console.log( 'items[1] MIME type:', items[1].type ); //阻止默认行为即不让剪贴板内容在p中显示出来 event.preventDefault(); //在items里找粘贴的image,据上面分析,需要循环 for (var i = 0; i < len; i++) { if (items[i].type.indexOf("image") !== -1) { //getAsFile() 此方法只是living standard firefox ie11 并不支持 blob = items[i].getAsFile(); uploadImgFromPaste(blob, 'paste', isChrome); } } /*if ( blob !== null ) { var reader = new FileReader(); reader.onload = function (event) { // event.target.result 即为图片的Base64编码字符串 var base64_str = event.target.result;//获得图片base64字符串 //可以在这里写上传逻辑 直接将base64编码的字符串上传(可以尝试传入blob对象,看看后台程序能否解析) uploadImgFromPaste(base64_str, 'paste', isChrome); } reader.readAsDataURL(blob);//传入blob对象,读取文件 }*/ } else { //for firefox setTimeout(function () { //设置setTimeout的原因是为了保证图片先插入到p里,然后去获取值 var imgList = document.querySelectorAll('#aaa img'), len = imgList.length, src_str = '', i; for ( i = 0; i < len; i ++ ) { if ( imgList[i].className !== 'my_img' ) { //如果是截图那么src_str就是base64 如果是复制的其他网页图片那么src_str就是此图片在别人服务器的地址 src_str = imgList[i].src; } } uploadImgFromPaste(src_str, 'paste', isChrome); }, 1); } } else { //for ie11 setTimeout(function () { var imgList = document.querySelectorAll('#aaa img'), len = imgList.length, src_str = '', i; for ( i = 0; i < len; i ++ ) { if ( imgList[i].className !== 'my_img' ) { src_str = imgList[i].src; } } uploadImgFromPaste(src_str, 'paste', isChrome); }, 1); } }) //调用图片上传接口,将file文件以formData形式上传 function uploadImgFromPaste (file, type, isChrome) { var formData = new FormData(); formData.append('files', file); formData.append('submission-type', type); var xhr = new XMLHttpRequest(); xhr.open('POST', '/upload_editor_photo3'); xhr.onload = function () { console.log(xhr.readyState); if ( xhr.readyState === 4 ) { if ( xhr.status === 200 ) { var data = JSON.parse(xhr.responseText), editor = document.getElementById('aaa'); if ( isChrome ) { var len=data.data.length; for ( var i = 0; i < len; i ++) { var img = document.createElement('img'); img.className = 'my_img'; img.src = data.data[i]; //设置上传完图片之后展示的图片 editor.appendChild(img); } } else { var imgList = document.querySelectorAll('#aaa img'), len = imgList.length, i; for ( i = 0; i < len; i ++) { if ( imgList[i].className !== 'my_img' ) { imgList[i].className = 'my_img'; imgList[i].src = data.data[i]; } } } } else { console.log( xhr.statusText ); } }; }; xhr.onerror = function (e) { console.log( xhr.statusText ); } xhr.send(formData); }
demo2:
// 处理粘贴事件 $("#aaa").on('paste', function(eventObj) { // 处理粘贴事件 var event = eventObj.originalEvent; var imageRe = new RegExp(/image\/.*/); var fileList = $.map(event.clipboardData.items, function (o) { if(!imageRe.test(o.type)){ return } var blob = o.getAsFile(); return blob; }); if(fileList.length <= 0){ return } upload(fileList); //阻止默认行为即不让剪贴板内容在p中显示出来 event.preventDefault(); }); function upload(fileList) { for(var i = 0, l = fileList.length; i < l; i++){ var fd = new FormData(); var f = fileList[i]; fd.append('files', f); var editor=document.getElementById("aaa"); $.ajax({ url:"/upload_editor_photo3", type: 'POST', dataType: 'json', data: fd, processData: false, contentType: false, xhrFields: { withCredentials: true }, headers: { 'Access-Control-Allow-Origin': '*', 'Access-Control-Allow-Credentials': 'true' }, success: function(res){ var len=res.data.length; for ( var i = 0; i < len; i ++) { var img = document.createElement('img'); img.src = res.data[i]; //设置上传完图片之后展示的图片 editor.appendChild(img); } }, error: function(){ alert("上传图片错误"); } }); } }
Note:Because only right-click copying of pictures is supported, two pictures cannot be copied at once. All pictures are copied and pasted for uploading for further study.
html:
<p id="aaa" contentEditable="true" style="height:800px;border:1px solid #ccc"></p>
Interface return data format:
{ // errno 即错误代码,0 表示没有错误。 // 如果有错误,errno != 0,可通过下文中的监听函数 fail 拿到该错误码进行自定义处理 errno: 0, // data 是一个数组,返回若干图片的线上地址 data: [ '图片1地址', '图片2地址', '……' ] }
Related recommendations:
PHP Detailed explanation of how to upload images to the server through WeChat
JavaScript image upload code encapsulation
PHP How to upload WeChat pictures to the server?
The above is the detailed content of js implementation of image pasting, uploading to the server and displaying it. For more information, please follow other related articles on the PHP Chinese website!

The shift from C/C to JavaScript requires adapting to dynamic typing, garbage collection and asynchronous programming. 1) C/C is a statically typed language that requires manual memory management, while JavaScript is dynamically typed and garbage collection is automatically processed. 2) C/C needs to be compiled into machine code, while JavaScript is an interpreted language. 3) JavaScript introduces concepts such as closures, prototype chains and Promise, which enhances flexibility and asynchronous programming capabilities.

Different JavaScript engines have different effects when parsing and executing JavaScript code, because the implementation principles and optimization strategies of each engine differ. 1. Lexical analysis: convert source code into lexical unit. 2. Grammar analysis: Generate an abstract syntax tree. 3. Optimization and compilation: Generate machine code through the JIT compiler. 4. Execute: Run the machine code. V8 engine optimizes through instant compilation and hidden class, SpiderMonkey uses a type inference system, resulting in different performance performance on the same code.

JavaScript's applications in the real world include server-side programming, mobile application development and Internet of Things control: 1. Server-side programming is realized through Node.js, suitable for high concurrent request processing. 2. Mobile application development is carried out through ReactNative and supports cross-platform deployment. 3. Used for IoT device control through Johnny-Five library, suitable for hardware interaction.

I built a functional multi-tenant SaaS application (an EdTech app) with your everyday tech tool and you can do the same. First, what’s a multi-tenant SaaS application? Multi-tenant SaaS applications let you serve multiple customers from a sing

This article demonstrates frontend integration with a backend secured by Permit, building a functional EdTech SaaS application using Next.js. The frontend fetches user permissions to control UI visibility and ensures API requests adhere to role-base

JavaScript is the core language of modern web development and is widely used for its diversity and flexibility. 1) Front-end development: build dynamic web pages and single-page applications through DOM operations and modern frameworks (such as React, Vue.js, Angular). 2) Server-side development: Node.js uses a non-blocking I/O model to handle high concurrency and real-time applications. 3) Mobile and desktop application development: cross-platform development is realized through ReactNative and Electron to improve development efficiency.

The latest trends in JavaScript include the rise of TypeScript, the popularity of modern frameworks and libraries, and the application of WebAssembly. Future prospects cover more powerful type systems, the development of server-side JavaScript, the expansion of artificial intelligence and machine learning, and the potential of IoT and edge computing.

JavaScript is the cornerstone of modern web development, and its main functions include event-driven programming, dynamic content generation and asynchronous programming. 1) Event-driven programming allows web pages to change dynamically according to user operations. 2) Dynamic content generation allows page content to be adjusted according to conditions. 3) Asynchronous programming ensures that the user interface is not blocked. JavaScript is widely used in web interaction, single-page application and server-side development, greatly improving the flexibility of user experience and cross-platform development.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment