Upload Progress Indicators For Fetch

If you're looking to enhance the user experience of your web application while fetching data, using upload progress indicators can be a great way to keep your users informed and engaged. In this article, we'll explore how you can implement upload progress indicators for the Fetch API in your software projects.

When working with the Fetch API to make HTTP requests in JavaScript, we often encounter scenarios where we need to upload files or large amounts of data to a server. While the Fetch API is powerful and efficient, it lacks built-in support for tracking upload progress. This is where upload progress indicators come in handy.

To implement upload progress indicators for Fetch, we can leverage the `fetch` function's ability to handle request and response objects. By tapping into the `fetch` function's `body` property, we can access the data being sent in the request and monitor its upload progress.

One common approach is to use the `FormData` API to construct a form data object that includes the file or data you want to upload. You can then pass this `FormData` object as the `body` of your Fetch request. When using `FormData`, you can listen for the `progress` event on the request object to track the upload progress in real-time.

Here's a simple example of how you can add an upload progress indicator to your Fetch request:

const fileInput = document.querySelector('input[type="file"]');
const progressBar = document.querySelector('.progress-bar');

fileInput.addEventListener('change', async () => {
  const file = fileInput.files[0];
  const formData = new FormData();
  formData.append('file', file);

  const response = await fetch('https://api.example.com/upload', {
    method: 'POST',
    body: formData
  });

  const reader = response.body.getReader();
  let received = 0;

  while (true) {
    const { done, value } = await reader.read();

    if (done) {
      break;
    }

    received += value.length;
    const progress = (received / file.size) * 100;

    progressBar.style.width = `${progress}%`;
  }
});

In this example, we listen for changes in a file input field and construct a FormData object with the selected file. We then make a Fetch POST request with the FormData object as the body. As data is being uploaded, we read the response body in chunks and update the progress bar accordingly.

By implementing upload progress indicators for Fetch, you can provide your users with real-time feedback on the status of their uploads, making for a more engaging and transparent user experience. Experiment with different design styles and animations to create a seamless and intuitive upload process for your web application.