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const req = new XMLHttpRequest();

req.addEventListener("progress", updateProgress);
req.addEventListener("load", transferComplete);
req.addEventListener("error", transferFailed);
req.addEventListener("abort", transferCanceled);'GET', productsApiEndpoint);

// ...

// progress on transfers from the server to the client (downloads)
function updateProgress(event) {
  if (event.lengthComputable) {
    const percentComplete = (event.loaded / * 100;
  } else {
    // Unable to compute progress information since the total size is unknown

function transferComplete(evt) {
  console.log("The transfer is complete.");

function transferFailed(evt) {
  console.log("An error occurred while transferring the file.");

function transferCanceled(evt) {
  console.log("The transfer has been canceled by the user.");