Async AJAX requests in each loop

var $ = jQuery.noConflict();

/*
* jQuery.ajaxQueue - A queue for ajax requests
* 
* (c) 2011 Corey Frang
* Dual licensed under the MIT and GPL licenses.
*
* Requires jQuery 1.5+
*/ 
(function($) {

// jQuery on an empty object, we are going to use this as our Queue
var ajaxQueue = $({});

$.ajaxQueue = function( ajaxOpts ) {
var jqXHR,
    dfd = $.Deferred(),
    promise = dfd.promise();

// queue our ajax request
ajaxQueue.queue( doRequest );

// add the abort method
promise.abort = function( statusText ) {

    // proxy abort to the jqXHR if it is active
    if ( jqXHR ) {
        return jqXHR.abort( statusText );
    }

    // if there wasn't already a jqXHR we need to remove from queue
    var queue = ajaxQueue.queue(),
        index = $.inArray( doRequest, queue );

    if ( index > -1 ) {
        queue.splice( index, 1 );
    }

    // and then reject the deferred
    dfd.rejectWith( ajaxOpts.context || ajaxOpts,
        [ promise, statusText, "" ] );

    return promise;
};

// run the actual query
function doRequest( next ) {
    jqXHR = $.ajax( ajaxOpts )
        .done( dfd.resolve )
        .fail( dfd.reject )
        .then( next, next );
}

return promise;
};

})(jQuery);

function add_log( log ) {

var $textarea = $('#log');
var content = $textarea.val();

$textarea.val( content + log + "n" ); 
$textarea.scrollTop( $textarea[0].scrollHeight );

}

function process_post(post_id, post_title) {

return $.ajaxQueue({
	type: 'POST',
	async: true,
	url: ajaxurl,
	data: {
		'action': 'process_post',
		'nonce': $('input#steps').val(),
		'post': post_id
	},
	success: function(response) {

    	if ( response.success == false ) {
    		add_log('Processing post: ' + post_title + ' failed. Please restore the database backup.' );
    		throw new Error();
    	}

    	add_log('Post: ' + post_title + ' processed successfully' );

    }
}); // ajax post

}

function process_posts(post_type) {

// processing posts each
	
return $.ajaxQueue({
	type: 'POST',
	async: true,
	url: ajaxurl,
	data: {
		'action': 'get_posts',
		'nonce': $('input#steps').val(),
		'post_type': post_type
	},
	success: function(response) {

    	if ( response.success == false ) {
    		return false;
    	}

    	var $posts = response.data;
    	add_log("n" + '# Posts loaded and ready to convert');

    	$.each($posts, function( post_id, post_title ) {
			process_post(post_id, post_title);
    	}); // each post

    }
}); // ajax posts

}

function process_term( term_id, term_title ) {

$.ajaxQueue({
	type: 'POST',
	async: true,
	url: ajaxurl,
	data: {
		'action': 'process_term',
		'nonce': $('input#steps').val(),
		'term': term_id
	},
	success: function(response) {

    	if ( response.success == false ) {
    		add_log('Processing term: ' + term_title + ' failed. Please restore the database backup.' );
    		throw new Error();
    	}

    	add_log('Term: ' + term_title + ' processed successfully' );

    }
});

}

function get_terms( taxonomy ) {

$.ajaxQueue({
	type: 'POST',
	async: true,
	url: ajaxurl,
	data: {
		'action': 'get_terms',
		'nonce': $('input#steps').val(),
		'taxonomy': taxonomy
	},
	success: function(response) {

    	if ( response.success == false ) {
    		throw new Error();
    	}

    	var $terms = response.data;

    	if ( $.isEmptyObject($terms) ) {
    		add_log('# Taxonomy: ' + taxonomy + ' has no terms - skipping' );
    	} else {

    		add_log('# Terms loaded and ready to convert');

    		$.each($terms, function( term_id, term_title ) {
    			process_term( term_id, term_title );
    		}); // each terms

    	} // endif

    }

});

}

function process_taxonomies( taxonomies ) {

// processing taxonomies
	
$.each(taxonomies, function( taxonomy ) {

	add_log("n" + '## Processing taxonomy: ' + taxonomy);

	get_terms( taxonomy );

}); // each taxonomy

}

function process( $data ) {

// processing each post type
$.each($data, function( post_type, taxonomies ) {

	add_log( "n" + '## Processing post type: ' + post_type);

	process_taxonomies( taxonomies );
    process_posts( post_type );

}); // each post type

}