问使用jQuery重试失败的AJAX请求的最佳方式是什么？

EN

$.ajax({
    url : 'someurl',
    type : 'POST',
    data :  ....,   
    tryCount : 0,
    retryLimit : 3,
    success : function(json) {
        //do something
    },
    error : function(xhr, textStatus, errorThrown ) {
        if (textStatus == 'timeout') {
            this.tryCount++;
            if (this.tryCount <= this.retryLimit) {
                //try again
                $.ajax(this);
                return;
            }            
            return;
        }
        if (xhr.status == 500) {
            //handle error
        } else {
            //handle error
        }
    }
});

$.ajaxSetup({
    timeout: 3000, 
    retryAfter:7000
});

function func( param ){
    $.ajax( 'http://www.example.com/' )
        .success( function() {
            console.log( 'Ajax request worked' );
        })
        .error(function() {
            console.log( 'Ajax request failed...' );
            setTimeout ( function(){ func( param ) }, $.ajaxSetup().retryAfter );
        });
}

$.ajax({...someoptions...}).done(mySuccessFunc);

const RETRY_WAIT = [10 * 1000, 5 * 1000, 2 * 1000];

// This is what tells JQuery to retry $.ajax requests
// Ideas for this borrowed from https://stackoverflow.com/a/12446363/491553
$.ajaxPrefilter(function(opts, originalOpts, jqXHR) {
  if(opts.retryCount === undefined) {
    opts.retryCount = 3;
  }

  // Our own deferred object to handle done/fail callbacks
  let dfd = $.Deferred();

  // If the request works, return normally
  jqXHR.done(dfd.resolve);

  // If the request fails, retry a few times, yet still resolve
  jqXHR.fail((xhr, textStatus, errorThrown) => {
    console.log("Caught error: " + JSON.stringify(xhr) + ", textStatus: " + textStatus + ", errorThrown: " + errorThrown);
    if (xhr && xhr.readyState === 0 && xhr.status === 0 && xhr.statusText === "error") {
      // API Gateway gave up.  Let's retry.
      if (opts.retryCount-- > 0) {
        let retryWait = RETRY_WAIT[opts.retryCount];
        console.log("Retrying after waiting " + retryWait + " ms...");
        setTimeout(() => {
          // Retry with a copied originalOpts with retryCount.
          let newOpts = $.extend({}, originalOpts, {
            retryCount: opts.retryCount
          });
          $.ajax(newOpts).done(dfd.resolve);
        }, retryWait);
      } else {
        alert("Cannot reach the server.  Please check your internet connection and then try again.");
      }
    } else {
      defaultFailFunction(xhr, textStatus, errorThrown); // or you could call dfd.reject if your users call $.ajax().fail()
    }
  });

  // NOW override the jqXHR's promise functions with our deferred
  return dfd.promise(jqXHR);
});