Ajax jqery and if data returned is not new

A common scenario!

When using AJAX with jQuery, you can check if the data returned is not new by comparing the timestamp of the last update with the current timestamp. Here's an example:

$.ajax({
  type: 'GET',
  url: '/api/data',
  dataType: 'json',
  success: function(data) {
    var lastUpdate = data.lastUpdate; // assume 'lastUpdate' is a property in the data object
    var currentTime = new Date().getTime();
    if (currentTime - lastUpdate < 1000) { // 1000ms = 1 second
      // data is not new, do something
      console.log('Data is not new');
    } else {
      // data is new, do something else
      console.log('Data is new');
    }
  }
});

In this example, we assume that the server returns a JSON object with a lastUpdate property, which represents the timestamp of the last update.

We then compare the lastUpdate timestamp with the current timestamp using the getTime() method, which returns the number of milliseconds since the Unix epoch (January 1, 1970, 00:00:00 UTC).

If the difference between the two timestamps is less than 1 second (1000ms), we consider the data to be not new. Otherwise, we consider it to be new.

You can adjust the threshold value (1000ms in this example) to suit your specific requirements.

Alternatively, you can use a cachebuster token or a version number in the URL to check if the data has changed. For example:

var cachebuster = new Date().getTime();
$.ajax({
  type: 'GET',
  url: '/api/data?cachebuster=' + cachebuster,
  dataType: 'json',
  success: function(data) {
    if (data.version!== cachebuster) {
      // data is new, do something
      console.log('Data is new');
    } else {
      // data is not new, do something
      console.log('Data is not new');
    }
  }
});

In this example, we add a cachebuster parameter to the URL with the current timestamp. The server can then check if the version property in the response data matches the cachebuster value. If they don't match, it means the data has changed, and we consider it to be new.