This article demonstrates how to upload images using Ajax and display a thumbnail preview without page reloads. The process involves client-side JavaScript for handling the upload and a PHP backend for thumbnail generation and image storage.
Client-Side (JavaScript):
The core functionality resides in the uploadImage
function, which uses $.ajaxFileUpload
to send the image to the server. Upon successful upload, the server returns JSON data containing the URLs for both the original and thumbnail images. The JavaScript then updates the src
attribute of the image elements (#image-thumb
, representing the preview) to display the thumbnail. Error handling and loading indicators are also included.
uploadImage: function() { // ... (Existing code) ... $.ajaxFileUpload({ // ... (Existing code) ... success: function(data) { // Update image preview _this.cache.$imgPreview.attr('src', data.thumb.img_src); _this.cache.$imgOriginal.attr('src', data.master.img_src); // ... (Existing code) ... }, error: function(xhr, textStatus, errorThrown) { // ... (Existing code) ... }, complete: function() { // ... (Existing code) ... } }); }
The image preview element is initially set with a placeholder image:
<img src="/static/imghwm/default1.png" data-src="https://img.php.cn/upload/article/000/000/000/174036625652715.jpg?x-oss-process=image/resize,p_40" class="lazy" alt="jQuery AJAX Image Upload Thumbnail Example " />
Form submission includes the thumbnail's src
attribute:
submitForm: function() { // ... (Existing code) ... formData += '&image-thumb=' + $('#image-thumb').attr('src'); // ... (Existing code) ... }
Server-Side (PHP):
The PHP script receives the uploaded image, generates a thumbnail using a suitable image manipulation library (e.g., GD or ImageMagick), and returns the URLs of both the original and thumbnail images as JSON. The images are initially saved to a temporary directory and moved to the final location upon form submission.
Security Considerations:
The script emphasizes the importance of setting appropriate file permissions (e.g., 774) on the image directory to prevent unauthorized access. Further security measures, such as file type validation and size limits, are recommended.
Frequently Asked Questions (FAQs):
The article concludes with a FAQ section addressing common concerns regarding multiple image uploads, progress bars, file validation, error handling, image resizing, form-less uploads, security, database storage, image display, and image deletion. These FAQs provide valuable insights into best practices for robust image upload functionality. The solutions proposed leverage various techniques like the HTML5 File API, Canvas API, and server-side validation.
The above is the detailed content of jQuery AJAX Image Upload Thumbnail Example. For more information, please follow other related articles on the PHP Chinese website!

Detailed explanation of JavaScript string replacement method and FAQ This article will explore two ways to replace string characters in JavaScript: internal JavaScript code and internal HTML for web pages. Replace string inside JavaScript code The most direct way is to use the replace() method: str = str.replace("find","replace"); This method replaces only the first match. To replace all matches, use a regular expression and add the global flag g: str = str.replace(/fi

This tutorial shows you how to integrate a custom Google Search API into your blog or website, offering a more refined search experience than standard WordPress theme search functions. It's surprisingly easy! You'll be able to restrict searches to y

This article series was rewritten in mid 2017 with up-to-date information and fresh examples. In this JSON example, we will look at how we can store simple values in a file using JSON format. Using the key-value pair notation, we can store any kind

So here you are, ready to learn all about this thing called AJAX. But, what exactly is it? The term AJAX refers to a loose grouping of technologies that are used to create dynamic, interactive web content. The term AJAX, originally coined by Jesse J

Enhance Your Code Presentation: 10 Syntax Highlighters for Developers Sharing code snippets on your website or blog is a common practice for developers. Choosing the right syntax highlighter can significantly improve readability and visual appeal. T

Leverage jQuery for Effortless Web Page Layouts: 8 Essential Plugins jQuery simplifies web page layout significantly. This article highlights eight powerful jQuery plugins that streamline the process, particularly useful for manual website creation

This article presents a curated selection of over 10 tutorials on JavaScript and jQuery Model-View-Controller (MVC) frameworks, perfect for boosting your web development skills in the new year. These tutorials cover a range of topics, from foundatio

Core points This in JavaScript usually refers to an object that "owns" the method, but it depends on how the function is called. When there is no current object, this refers to the global object. In a web browser, it is represented by window. When calling a function, this maintains the global object; but when calling an object constructor or any of its methods, this refers to an instance of the object. You can change the context of this using methods such as call(), apply(), and bind(). These methods call the function using the given this value and parameters. JavaScript is an excellent programming language. A few years ago, this sentence was


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

Dreamweaver Mac version
Visual web development tools

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.

Zend Studio 13.0.1
Powerful PHP integrated development environment

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

SublimeText3 English version
Recommended: Win version, supports code prompts!
