jquery-deferred

I need to make a series of N ajax requests without locking the browser, and want to use the jquery deferred object to accomplish this. Here is a simplified example with three requests, but my program may need to queue up over 100 (note that this is not the exact use case, the actual code does need to ensure the success of step (N-1) before executing the next step): $(document).ready(function(){ var deferred = $.Deferred(); var countries = ["US", "CA", "MX"]; $.each(countries, function(index, country){ deferred.pipe(getData(country)); }); }); function getData(country){ var data = { "country":

I have an $.ajax promise and want to check whether my (syntactically valid) response contains an error, triggering the rejected status in that case. I have worked with my own promise library which deals such tasks easily. I do not really like jQuery's Promise ( cache ) implementation with its Deferred object and may have overlooked something, because I seldom use it. I think the way to go is just using .then() , which seems to be rather complicated: return $.ajax(...).then(function success(response) { var problem = hasError(response); if (problem) { var error = new $.Deferred; error.reject

jQuery's Deferred has two functions which can be used to implement asynchronous chaining of functions: then() deferred.then( doneCallbacks, failCallbacks ) Returns: Deferred doneCallbacks A function, or array of functions, called when the Deferred is resolved. failCallbacks A function, or array of functions, called when the Deferred is rejected. pipe() deferred.pipe( [doneFilter] [, failFilter] ) Returns: Promise doneFilter An optional function that is called when the Deferred is resolved. failFilter An optional function that is called when the Deferred is rejected. I know then() has been

jQuery 1.5 adds "Deferred Objects". What are they, and what exactly do they do? Deferred Object As of jQuery 1.5, the Deferred object provides a way to register multiple callbacks into self-managed callback queues, invoke callback queues as appropriate, and relay the success or failure state of any synchronous or asynchronous function. Deferred Methods: deferred.done() Add handlers to be called when the Deferred object is resolved. deferred.fail() Add handlers to be called when the Deferred object is rejected. deferred.isRejected() Determine whether a Deferred object has been rejected.

I use jQuery. And I don't want parallel AJAX calls on my application, each call must wait the previous before starting. How to implement it? There is any helper? UPDATE If there is any synchronous version of the XMLHttpRequest or jQuery.post I would like to know. But sequential != synchronous, and I would like an asynchronous and sequential solution. There's a much better way to do this than using synchronous ajax calls. Jquery ajax returns a deferred so you can just use pipe chaining to make sure that each ajax call finishes before the next runs. Here's a working example with a more in depth