jQuery polling strategies

long_polling.js

(function poll(){
  $.ajax({
    url: '/poll',
    success: function(data) {
      console.log(data);
    },
    error: function(msg) { console.log('bummer...') },
    dataType: 'json',
    complete: poll,
    timeout: 30000
  });
})();

timeout_polling.js

(function poll(interval){

  // the first invocation will have an interval of zero
  // so we don't wait for the first request, only the next ones
  interval = typeof interval !== 'undefined' ? interval : 0;

  setTimeout(function(){
    $.ajax({
      url: '/poll',
      success: function(data) {

        console.log(data);

        // setup the next poll recursively
        poll(30000);
      },
      error: function(msg) { console.log('bummer...'); poll(30000); },
      dataType: 'json'
    });
  }, interval);
})();