This is a simple frontend utility to help the file-upload process on your website. It is written in pure JavaScript, has no dependencies, and is a small 13.55 kB (gzipped). You can check out the live demo here.

For the most part, browsers do a good job of handling image-uploads. That being said - we find that the ability to show our users a preview of their upload can go a long way in increasing the confidence in their upload.

file-upload-with-preview aims to address the issue of showing a preview of a user's uploaded image in a simple to use package.

Features

Shows the actual image preview in the case of a single uploaded .jpg, .jpeg, .gif, or .png image. Shows a success-image in the case of an uploaded .pdf file, uploaded video, or other unrenderable file - so the user knows their image was collected successfully. In the case of multiple selected files, the user's selected images will be shown in a grid.
Shows the image name in the input bar. Shows the count of selected images in the case of multiple selections within the same input.
Allows the user to clear their upload, and clear individual images in the multiple grid.
Looks great - styling based on Bootstrap 4's custom file-upload style.
Framework agnostic - to access the uploaded file/files just use the cachedFileArray (always will be an array) property of your FileUploadWithPreview object.
For every file-group you want just initialize another FileUploadWithPreview object with its own uniqueId - this way you can have multiple file-uploads on the same page. You also can just use a single input designated with a multiple property to allow multiple files on the same input.

Installation

# npm
npm i file-upload-with-preview

# yarn
yarn add file-upload-with-preview

Or you can include it through the browser at the bottom of your page. When using the browser version make sure update your target version as needed.

<script src="https://unpkg.com/file-upload-with-preview@4.1.0/dist/file-upload-with-preview.min.js"></script>

Usage

When installed through npm or yarn:

// using require
const FileUploadWithPreview = require("file-upload-with-preview");

// using import
import FileUploadWithPreview from "file-upload-with-preview";

// initialize a new FileUploadWithPreview object
const upload = new FileUploadWithPreview("myUniqueUploadId");

...or through the browser:

<script>
    var upload = new FileUploadWithPreview("myUniqueUploadId");
</script>

You'll also want to include the css:

// JavaScript
import "file-upload-with-preview/dist/file-upload-with-preview.min.css";

Or in your <head></head> if you're in the browser:

<!-- Browser -->
<link
    rel="stylesheet"
    type="text/css"
    href="https://unpkg.com/file-upload-with-preview@4.1.0/dist/file-upload-with-preview.min.css"
/>

The JavaScript looks for a specific set of HTML elements to display the file input, label, image preview, and clear-button. Make sure to populate the custom-file-container element with the uniqueId:

<div class="custom-file-container" data-upload-id="myUniqueUploadId">
    <label
        >Upload File
        <a
            href="javascript:void(0)"
            class="custom-file-container__image-clear"
            title="Clear Image"
            >&times;</a
        ></label
    >
    <label class="custom-file-container__custom-file">
        <input
            type="file"
            class="custom-file-container__custom-file__custom-file-input"
            accept="*"
            multiple
            aria-label="Choose File"
        />
        <input type="hidden" name="MAX_FILE_SIZE" value="10485760" />
        <span
            class="custom-file-container__custom-file__custom-file-control"
        ></span>
    </label>
    <div class="custom-file-container__image-preview"></div>
</div>

Then when you're ready to use the user's file for an API call or whatever, just access the user's uploaded file/files in the cachedFileArray property of your initialized object like this:

upload.cachedFileArray;

You can optionally trigger image browser and clear selected images by script code:

upload.emulateInputSelection(); // to open image browser
upload.clearPreviewPanel(); // clear all selected images

You may also want to capture the event when an image is selected:

window.addEventListener("fileUploadWithPreview:imagesAdded", function (e) {
    // e.detail.uploadId
    // e.detail.cachedFileArray
    // e.detail.addedFilesCount
    // Use e.detail.uploadId to match up to your specific input
    if (e.detail.uploadId === "mySecondImage") {
        console.log(e.detail.cachedFileArray);
        console.log(e.detail.addedFilesCount);
    }
});

Note

The cachedFileArray property is always an array. So if you are only allowing the user to upload a single file, you can access that file at cachedFileArray[0] - otherwise just send the entire array to your backend to handle it normally.

Make sure to set multiple on your input if you want to allow the user to select multiple images.

Properties

name	type	description
el	Element	The main container for the instance
input	Element	The main container for the instance
inputLabel	Element	The label for the image name/count
uploadId	String	The id you set for the instance
cachedFileArray	Array	The current selected files
currentFileCount	Number	The count of the currently selected files
clearButton	Element	The button to reset the instance
imagePreview	Element	The display panel for the images
options.images.baseImage	String	Replace placeholder image.
options.images.backgroundImage	String	Replace background image for image grid.
options.images.successFileAltImage	String	Replace successful alternate file upload image.
options.images.successPdfImage	String	Replace successful PDF upload image.
options.images.successVideoImage	String	Replace successful video upload image.
options.presetFiles	Array	Provide an array of image paths to be automatically uploaded and displayed on page load (can be images hosted on server or URLs)
options.showDeleteButtonOnImages	Boolean	Show a delete button on images in the grid. Default `true`
options.text.browse	String	Edit button text. Default `'Browse'`
options.text.chooseFile	String	Edit input placeholder text. Default `'Choose file...'`
options.text.selectedCount	String	Edit input text when multiple files have been selected in one input. Default `${ n } 'files selected'`
options.maxFileCount	Number	Set a maximum number of files you'd like the component to deal with. Must be `> 0` if set. By default there is no limit.

Methods

method	parameters	description
addFiles	array of File objects	Populate the `cachedFileArray` with images as File objects
processFile	file object	Take a single File object and append it to the image preview panel
addImagesFromPath	array of image paths	Take an array of image paths, convert them to File objects, and display them in the image preview panel (can be paths to images on the server or urls)
replaceFiles	array of File objects	Replace files in `cachedFileArray` and image preview panel with array of File objects
replaceFileAtIndex	file object, index (Number)	Take a single file object and index, replace existing file at that index
deleteFileAtIndex	index (Number)	Delete specified file from `cachedFileArray`
refreshPreviewPanel	none	Refresh image preview panel with current `cachedFileArray`
addBrowseButton	text	Appends browse button to input with custom button text
emulateInputSelection	none	Open the image browser programmatically
clearPreviewPanel	none	Clear the `cachedFileArray`

Events

event	value	description
fileUploadWithPreview:imagesAdded	`e` (e.detail.uploadId, e.detail.cachedFileArray, e.detail.addedFilesCount)	Triggered each time file/files are selected. Delivers the `uploadId`, updated `cachedFilesArray`, and `addedFilesCount` for the event.
fileUploadWithPreview:imageDeleted	`e` (e.detail.uploadId, e.detail.cachedFileArray, e.detail.currentFileCount)	Triggered each time a file is deleted. Delivers the `uploadId`, updated `cachedFilesArray`, and `currentFileCount` for the event.
fileUploadWithPreview:clearButtonClicked	`e` (e.detail.uploadId)	Triggered when the clear button is clicked. Delivers the `uploadId`.

Full Example

<html>
    <head>
        ...
        <link
            rel="stylesheet"
            type="text/css"
            href="https://unpkg.com/file-upload-with-preview@4.1.0/dist/file-upload-with-preview.min.css"
        />

        <!-- You'll want to make sure to at least set a width on the -->
        <!-- .custom-file-container class... -->
        ...
    </head>
    <body>
        ...

        <div class="custom-file-container" data-upload-id="myUniqueUploadId">
            <label
                >Upload File
                <a
                    href="javascript:void(0)"
                    class="custom-file-container__image-clear"
                    title="Clear Image"
                    >&times;</a
                ></label
            >

            <label class="custom-file-container__custom-file">
                <input
                    type="file"
                    class="custom-file-container__custom-file__custom-file-input"
                    accept="*"
                    multiple
                    aria-label="Choose File"
                />
                <input type="hidden" name="MAX_FILE_SIZE" value="10485760" />
                <span
                    class="custom-file-container__custom-file__custom-file-control"
                ></span>
            </label>
            <div class="custom-file-container__image-preview"></div>
        </div>

        ...

        <script src="https://unpkg.com/file-upload-with-preview@4.1.0/dist/file-upload-with-preview.min.js"></script>

        <script>
            var upload = new FileUploadWithPreview("myUniqueUploadId", {
                showDeleteButtonOnImages: true,
                text: {
                    chooseFile: "Custom Placeholder Copy",
                    browse: "Custom Button Copy",
                    selectedCount: "Custom Files Selected Copy",
                },
                images: {
                    baseImage: importedBaseImage,
                },
                presetFiles: [
                    "https://images.unsplash.com/photo-1557090495-fc9312e77b28?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=668&q=80",
                ],
            });
        </script>
    </body>
</html>

In this example we set the MAX_FILE_SIZE value to 10485760 (10MB), the accepted images to * (everything), and designate multiple to allow the user to select multiple files - you can adjust those settings to whatever you like. For example, if you'd like to limit uploads to only images and pdf's and only allow a single file upload use the following:

<input
    type="file"
    class="custom-file-container__custom-file__custom-file-input"
    accept="application/pdf,image/*"
    aria-label="Choose File"
/>
<input type="hidden" name="MAX_FILE_SIZE" value="10485760" />

Browser Support

If you are supporting a browser like IE11, you'll need a polyfill for fetch and promise at the bottom of your index.html:

<script src="https://cdn.jsdelivr.net/npm/es6-promise@4/dist/es6-promise.auto.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/fetch/2.0.3/fetch.js"></script>

Or, you can install babel-polyfill and import that in the main script of your app. You can read more about babel-polyfill here. In the example folder, we use the external script method.

Testing

Use yarn test to run the tests.

Development

Clone the repo, then use the following to work on the project locally:

# Install dependencies
yarn

# Watch changes
yarn start

# When done working
yarn build

Other

Go ahead and fork the project! Submit an issue if needed. Have fun!

License

MIT

使用案例

vue el-upload 文件上传

el-upload 用到的一些参数参数说明类型可选值默认值 action 必选参数，上传的地址 string — — headers 设置上传的请求头部 object — — multiple 是否支持多选文件 boolean — — data 上传时附带的额外参数 object — — name 上传的文件字段名 string — file with-credentials 支持发送
el-upload multiple多文件上传，只传上一个的问题

问题：使用el-upload上传多文件时，on-success钩子只拿到了一个response，上传只成功上传了一个。解决：使用:http-requst来覆盖默认的上传行为，可以自定义上传的实现。代码： <template> <el-upload :disabled="disabled" :drag="type === 'drag'" :multiple="tru
ng-file-upload - samples

<script src="angular.min.js"></script>  <script src="ng-file-upload-shim.min.js"></script> <script src="ng-file-upload.min.js"></sc
java+vue使用el-upload上传到阿里云oss

前言项目中要实现上传到阿里云oss功能，为了降低服务器压力，使用STS方式进行上传 1.后端返回AccessKey ID，AccessKey Secret，stsToekn。 2.前端调用接口获取秘钥等信息进行上传官方文档后端地址：https://help.aliyun.com/document_detail/32007.html 前端地址：https://help.aliyun.com/d

file-upload-with-preview

file-upload-with-preview

Links

About

Features

Installation

Usage

Note

Properties

Methods

Events

Full Example

Browser Example

Vue Example

jQuery Sort Example

Browser Support

Testing

Development

Other

License

同类工具

相关阅读

相关文章

相关问答

相关文档