HTML Code

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>ajaxPrefilter basic</title>
  <style>
    body { font-family: sans-serif; padding: 16px; max-width: 520px; }
    button { padding: 8px 14px; cursor: pointer; background: #2563eb; color: #fff; border: none; border-radius: 6px; }
    .log { margin-top: 14px; padding: 12px; background: #eff6ff; border-radius: 6px; font-size: 14px; }
    .hint { color: #64748b; font-size: 13px; margin-top: 8px; }
  </style>
</head>
<body>
  <button type="button" id="load">Load post #1</button>
  <div class="log">Click to trigger $.ajax() through the prefilter.</div>
  <p class="hint">Open DevTools → Console to see prefilter logs.</p>
  <script src="https://code.jquery.com/jquery-3.7.1.min.js"></script>
  <script>
    $.ajaxPrefilter(function(options) {
      console.log("Ajax prefilter:", options.url);
      options.headers = $.extend({}, options.headers, {
        "X-App-Client": "CodeToFun-Demo"
      });
    });

    $("#load").on("click", function() {
      $.ajax({
        url: "https://jsonplaceholder.typicode.com/posts/1",
        dataType: "json"
      }).done(function(data) {
        $(".log").text("Loaded: " + data.title);
      });
    });
  </script>
</body>
</html>

Lines: 0 | Characters: 0

Live Preview Auto-refresh on Run

jQuery.ajaxPrefilter() — basic registration (Try It)