What Are The Features Of A File Uploader?
When it comes to building a file uploader, we need to create a front-end file upload button that will enable users to upload their desired files to the website or web app. We can also allow multiple file uploads and display progress bars for a better user experience. Additionally, we should also show image previews when a user uploads an image file. Once the file is uploaded, we need to read it, send it to the backend, and store it on the server. Sometimes, users upload large files, resulting in slow uploaders. For this reason, it’s best to upload large files to the server in chunks to prevent errors and improve speed. These chunks of files are more manageable than one single large file.
Additionally, developers must create an efficient file uploader that supports fast uploads. You also need to ensure a file uploader is secure to prevent cyber attackers from deploying malware and viruses into your server.
Step 1: Setting Up The Server Side
We’ll use the built-in HTTP package to set up the Node.js server. We’ll start by creating a new folder for the project:
Next, we’ll create an index.js file. This will be the entry point of our server.
Finally, we’ll create the HTTP server that’ll run on port 8080
While we’re creating a simple file upload button, you can also edit the text of the button or change the color of the button for design purposes.
Next, we’ll send this file from the backend:
Step 3: Reading The Uploaded File On The Front End
To read the file content on the front end, we’ll use the ‘FileReader’ object. It enables web apps to read the file content (stored on the system of the user) asynchronously. The ‘FileReader’ object offers several methods to read a file. For example, we can read the uploaded file as an array buffer or in raw binary data. We can even read the file as a data URL. Here, we’ll use the array method to read the file:
The selected files can be accessed under the ‘files’ field for the input:
The ‘FileReader’ object also provides several event listeners, such as ‘onprogress’ and ‘onload,’ to track the reading of the uploaded file on the front end. Here, we’ll use the ‘onload’ event:
Step 4: Sending The Uploaded File To The Backend
Before we send the file uploaded by the user to the backend, it’s best to divide it into small chunks or pieces and send the file chunks periodically, especially if the file size is big. This is because uploading files that are very large can cause issues related to latency and speed. Additionally, sometimes cyber attackers also upload files that are too large, which can cause the server to malfunction.
So, we’ll first split the file into chunks and send them to the backend one by one. We also need to ensure we send the chunks in order so that the file doesn’t get corrupted. We’ll also use ‘async await’ so that we don’t overload the server with requests.
Step 5: Storing The File Chunks On The Server
Lastly, we’ll receive the chunks and store them on the server.
<input type=”file” id=”files” multiple>
We’ll break each file into chunks one by one and send them to the backend.
A file uploader allows end-users to upload files, such as images, videos, and documents, to a website or web app. The uploader then sends the file to the backend and stores them on the server.