How To Add JavaScript File Uploads to Web Apps

March 22, 2022 Programming

When you are working on a web application, you will most likely need to seamlessly and efficiently upload any file types you might need. The best and most reliable way to upload files, mainly consisting of images, is to learn how to properly utilize JavaScript. However, there are different things you should know before getting started. Keep on reading to learn how to add JavaScript file uploads to web apps. 

Choose the Right Library

First and foremost, if you want to add JavaScript file upload to web apps, you must choose the appropriate library to handle the task.

There are different types of libraries you can consider to make uploads to web apps. For instance, you can choose the Upload.js library since it is easy to use and also offers other benefits. When you select this uploader, there are different things you should follow.    

Install File Uploader

You must download the upload library and install it on your computer. You will need an account, but no infrastructure is required to write any code. All you need to do is to install the library to upload a file with JavaScript and start uploading your files once you enter your API key. To use this uploader, you don’t need expert knowledge in coding. This lightweight JavaScript file upload library is integrated with upload API to enable end-to-end file uploading. There’s no boilerplate code or configuration when you use this option. When you use API, the file uploading process can start in 60 seconds. 

Upload a file

With the API-enabled upload, you can upload your files to web apps using mainly two options including the upload function or drag and drop. The drag and drop function is easy to use as the name suggests. However, the first thing you should do is to create the drop zone. All the files dropped in this zone will be automatically uploaded to your web application. The design of your application will determine the type of content you can upload, as explained in detail below. 

The process is simple and requires you to select the files you want, then drag and drop them in the appropriate zone you have created on your webpage. When you use HTML, you may not need to create the drop zone since it comes with the zone already created. 

You can also use the upload feature when uploading a selected file to your web app. If the uploader does not have this function, you should create it. You can do this by using the code you get when you install your uploader. Just follow the prompts, which is a user-friendly procedure. This option allows you to select the files you want and then click the upload button. 

The file upload function accepts the image element together with the file from which the image data is obtained. It also creates a throbber, a feature that is designed to display progress information. The uploader comes with a dashboard that will display progress once the upload process begins. The throbber is updated with percentage information until it reaches 100% to mark the completion of the uploading process. Once the upload is complete, the throbber will disappear since it no longer serves any purpose.  

If the file upload progress is disrupted, you will get an error message. You can retry the upload when it fails until the time it succeeds. Once you upload your file, you will get a result that contains a file ID, which you can use to download the same file. Therefore, make sure you save the ID in a safe place, especially in the backend API.  

Identify Accepted Files

Another essential aspect you should consider when adding JavaScript file upload to web apps pertains to the types of files accepted. You cannot upload any type of file since other formats might be rejected. Therefore, it is vital to customize your uploader so it can identify acceptable files before the upload begins. The most common types of file uploads are images in the form of PNG and JPEG. The object URLs can also be used to display other file formats like screenshots and PDFs. If you upload the wrong file, you will get an error message implying that the process cannot be completed.

Apart from the file type, you should also take into account the size of files you upload to web apps. Extremely big files are difficult to upload, so you must customize your uploader to set the maximum limit that can be accepted at a certain point. Other uploaders can break huge files into smaller chunks which are manageable. However, apart from elements like file type and size, factor in the loading speed of your website. Many uploads fail due to the slow speed of the site. Make sure you use unlimited bandwidth and aim to get the best package from your web host.  

Transform Your Files

The upload dashboard gives you an option to transform your file to suit your web app. You can add the transformation’s slug at the end of the URL file, and use it to resize or crop the file for your web application. Remember your app should be mobile optimized so that it can be accessed from smartphones and tablets. The transformation functionality also allows you to extract zips and other features.   

You can transform your files using the URL or the custom feature you have created using JavaScript. The other advantage of the transformation feature is that you can use it to add filters to change the appearance of your site. You can also edit your images to suit your needs, but remember to retain originality. 

When developing a web application, you should know how to add JavaScript file uploads to web apps. Since there are several JavaScript libraries,  make sure you choose the ideal one. Install the uploader, and you can begin the file uploading process. Remember to check the acceptable file types, internet speed, and the size of the file you want to upload beforehand.