Have you written a web application that accepts user-uploaded images, only to later realize that users keep providing images of all shapes and sizes that ruin your site's theme? Working with images on the web can easily become a pain—unless, of course, you use the right tools.
In this tutorial, we'll explore how to use JavaScript libraries to manipulate images in the browser, prepare them for storage on the server, and use them in web programs. We'll do this using Vue.js instead of native JavaScript.
To see what this article is trying to accomplish, please look at the picture above. The original image is on the left and the new image preview is on the right. We can move and resize the crop box and the preview image will change accordingly. Users can download preview images as needed.
We will use a library called Cropper.js to do the heavy lifting.
Create a new Vue.js project with image cropping dependencies
The first step is to create a new project and install the necessary dependencies. It is assumed that you have Vue CLI installed and configured.
Execute the following command at the command line:
vue create cropper-project
When prompted, select the default option. This will be a simple project, so don't worry about routing and stuff.
Navigate to the new project and do the following:
npm install cropperjs --save
The above command will install Cropper.js into our project. It's easy to use a CDN, but since we're using a framework that leverages webpack, the npm route makes the most sense.
Although our dependencies are installed, there is one more thing that needs to be done. Because I'm using npm, I don't include CSS information - only JavaScript information. We need to include CSS information locally or through a CDN. This article uses CDN.
Open your project's public/index.html and include the following HTML tags:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width,initial-scale=1.0">
<link rel="icon" href="<%= BASE_URL %>favicon.ico">
<title>image-cropping</title>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/cropperjs/1.5.1/cropper.min.css">
</head>
<body>
<noscript>
<strong>
We're sorry but image-cropping doesn't work properly without JavaScript enabled.
Please enable it to continue.
</strong>
</noscript>
<div id="app"></div>
<!-- built files will be auto injected -->
</body>
</html>Note that in the tag, We have included the cropper.min.css file. Again, it doesn't matter how you get the CSS information as long as you get the file. Without the CSS information, our image wouldn't have the fancy cropping box.
Crop images using JavaScript in a Vue.js project
Now the project should be almost configured and ready to crop images on the web. To keep our project tidy, we'll create a new Vue.js component to handle all of our image processing.
Create the src/components/ImageCropper.vue file in your project and include the following boilerplate code:
<template>
<div>
<div class="img-container">
<img src="/static/imghwm/default1.png" data-src="src" class="lazy" ref="image" : crossorigin alt="Implement image cropping function using Vue.js" >
</div>
<img class="img-preview lazy" src="/static/imghwm/default1.png" data-src="destination" : alt="Implement image cropping function using Vue.js" >
</div>
</template>
<script>
import Cropper from "cropperjs";
export default {
name: "ImageCropper",
data() {
return {
cropper: {},
destination: {},
image: {}
}
},
props: {
src: String
},
mounted() { }
}
</script>
<style scoped>
.img-container {
width: 640px;
height: 480px;
float: left;
}
.img-preview {
width: 200px;
height: 200px;
float: left;
margin-left: 10px;
}
</style>For this example, <style># The information in the ## tag is not important, it just cleans up the page and doesn't get any real effect from the library. </style>
src and destination variables that appear in the block. These variables represent the source image defined by the user through the props object, and the target image that has been manipulated. We will be able to access the source image directly via the ref variable, similar to using a querySelector on a DOM object.
mounted method, which will be triggered after the view is initialized. The
mounted method looks like this:
mounted() {
this.image = this.$refs.image;
this.cropper = new Cropper(this.image, {
zoomable: false,
scalable: false,
aspectRatio: 1,
crop: () => {
const canvas = this.cropper.getCroppedCanvas();
this.destination = canvas.toDataURL("image/png");
}
});
}When this method is called, we get a copy of the image in the block Quote. Then use the image when initializing the crop tool and define some configurations, which are not mandatory.
crop Method is where the magic happens. This crop method is called whenever we process an image. When the crop method is executed, we should be able to get the cropping, scaling, etc. information and create a new image from it - the target image.
src/App.vue file and include the following content:
<template>
<div id="app">
<ImageCropper src="/logo.png" />
</div>
</template>
<script>
import ImageCropper from "./components/ImageCropper.vue"
export default {
name: "app",
components: {
ImageCropper
}
}
</script>
<style></style>Please note that we have imported the ImageCropper If you want to learn how to upload files (such as cropping images), you can check out my previous tutorial "Uploading files to a remote web server using Vue.js". This article explains how to use the Cropper.js library in a Vue.js web program to manipulate images. This is useful if you need to accept images from users and use them as part of a profile or something like that, as you'll need to resize those images to a consistent size so your theme doesn't get broken. Using the image cropping library is no different than using native JavaScript, but there are a few things required to interact with HTML components using Vue.js. English original address: https://dev.to/lydiahallie/javascript-visualized-event-loop-3dif 2020 Summary of front-end vue interview questions (with answers) vue tutorial recommendation: 2020 latest 5 vue.js video tutorial selection Introduction to Programming! ! component, and Use it in a block. Remember, the src property is one of the props in JavaScript. In my example, there is a public/logo.png file, feel free to modify it as needed. In a real scenario, you would use images that the user would upload. Conclusion
##Related recommendations:
For more programming-related knowledge, please visit:
The above is the detailed content of Implement image cropping function using Vue.js. For more information, please follow other related articles on the PHP Chinese website!
Vue.js and the Frontend: A Deep Dive into the FrameworkApr 22, 2025 am 12:04 AMVue.js is loved by developers because it is easy to use and powerful. 1) Its responsive data binding system automatically updates the view. 2) The component system improves the reusability and maintainability of the code. 3) Computing properties and listeners enhance the readability and performance of the code. 4) Using VueDevtools and checking for console errors are common debugging techniques. 5) Performance optimization includes the use of key attributes, computed attributes and keep-alive components. 6) Best practices include clear component naming, the use of single-file components and the rational use of life cycle hooks.
The Power of Vue.js on the Frontend: Key Features and BenefitsApr 21, 2025 am 12:07 AMVue.js is a progressive JavaScript framework suitable for building efficient and maintainable front-end applications. Its key features include: 1. Responsive data binding, 2. Component development, 3. Virtual DOM. Through these features, Vue.js simplifies the development process, improves application performance and maintainability, making it very popular in modern web development.
Is vue.js better than React?Apr 20, 2025 am 12:05 AMVue.js and React each have their own advantages and disadvantages, and the choice depends on project requirements and team conditions. 1) Vue.js is suitable for small projects and beginners because of its simplicity and easy to use; 2) React is suitable for large projects and complex UIs because of its rich ecosystem and component design.
Vue.js's Function: Enhancing User Experience on the FrontendApr 19, 2025 am 12:13 AMVue.js improves user experience through multiple functions: 1. Responsive system realizes real-time data feedback; 2. Component development improves code reusability; 3. VueRouter provides smooth navigation; 4. Dynamic data binding and transition animation enhance interaction effect; 5. Error processing mechanism ensures user feedback; 6. Performance optimization and best practices improve application performance.
Vue.js: Defining Its Role in Web DevelopmentApr 18, 2025 am 12:07 AMVue.js' role in web development is to act as a progressive JavaScript framework that simplifies the development process and improves efficiency. 1) It enables developers to focus on business logic through responsive data binding and component development. 2) The working principle of Vue.js relies on responsive systems and virtual DOM to optimize performance. 3) In actual projects, it is common practice to use Vuex to manage global state and optimize data responsiveness.
Understanding Vue.js: Primarily a Frontend FrameworkApr 17, 2025 am 12:20 AMVue.js is a progressive JavaScript framework released by You Yuxi in 2014 to build a user interface. Its core advantages include: 1. Responsive data binding, automatic update view of data changes; 2. Component development, the UI can be split into independent and reusable components.
Netflix's Frontend: Examples and Applications of React (or Vue)Apr 16, 2025 am 12:08 AMNetflix uses React as its front-end framework. 1) React's componentized development model and strong ecosystem are the main reasons why Netflix chose it. 2) Through componentization, Netflix splits complex interfaces into manageable chunks such as video players, recommendation lists and user comments. 3) React's virtual DOM and component life cycle optimizes rendering efficiency and user interaction management.
The Frontend Landscape: How Netflix Approached its ChoicesApr 15, 2025 am 12:13 AMNetflix's choice in front-end technology mainly focuses on three aspects: performance optimization, scalability and user experience. 1. Performance optimization: Netflix chose React as the main framework and developed tools such as SpeedCurve and Boomerang to monitor and optimize the user experience. 2. Scalability: They adopt a micro front-end architecture, splitting applications into independent modules, improving development efficiency and system scalability. 3. User experience: Netflix uses the Material-UI component library to continuously optimize the interface through A/B testing and user feedback to ensure consistency and aesthetics.
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
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
SublimeText3 English version
Recommended: Win version, supports code prompts!
mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
SublimeText3 Mac version
God-level code editing software (SublimeText3)
MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.
Atom editor mac version download
The most popular open source editor
