Fire callback within function

Question

I am trying to create my first own jQuery function to re-order some rows in a table.

The function works fairly well, I am just unsure how to fire the callback functions which i should be able to set in the settings object. Also is this the way to make a jQuery function? The code can be seen in action here: http://jsfiddle.net/fcHQh/

The function is:

(function( $ ){
 $.fn.reorder = function(options) {
 var settings = {
 'up': '.up',
 'down': '.down',
 'timeout': 1000,
 'url': '',
 'success': null,
 'error': null
 };
 var methods = {
 init : function(element) {
 $(settings.up + ',' + settings.down).on('click', function (event) {
 event.preventDefault();
 var row = $(this).parents('tr:first');
 if ($(this).is(settings.up)) {
 row.insertBefore(row.prev());
 } else {
 row.insertAfter(row.next());
 }
 tools.delay(function() { methods.sort(element) }, settings.timeout);
 });
 },
 sort : function(element) {
 $(element).find('tr').find('input:hidden').each(function () {
 element.priorities.push($(this).val());
 }); 
 if (settings.url) {
 methods.callback(element);
 }
 },
 callback : function(element) {
 // THIS SHOULD ONLY BE FIRED IF CALLBACK IS DEFINED?
 $.ajax({
 type: 'GET',
 url: settings.url,
 data: { priorities: element.priorities.join(',') },
 success: function() {
 // FIRE THE 'settings.success' if its set
 },
 error: function() {
 // FIRE THE 'settings.error' if its set 
 }
 });
 }
 };
 var tools = {
 delay : (function () {
 var timer = 0;
 return function (callback, ms) {
 clearTimeout(timer);
 timer = setTimeout(callback, ms);
 };
 })()
 } 
 return this.each(function() {
 if (options) $.extend(settings, options);
 this.priorities = [];
 methods.init(this);
 });
 };
})( jQuery );

Answer 1

I suggest you have a defaults object, and merge that with your options:

var defaults = {
 up: '.up',
 down: '.down',
 timeout: 1000,
 url: '',
 success: function() {},
 error: function() {}
};
var settings = $.extend({}, defaults, options);
// ...
callback: function() {
 $.ajax({
 success: settings.success,
 error: settings.error
 });
},
// ...

• Linus Thiel: The gist is that you don't want to overwrite your defaults, and possibly not the options passed, but you want to create a copy where you have your defaults, and if present, your options. $.extend achieves that. See api.jquery.com/jQuery.extend
• Linus Thiel: And here is a good primer on writing jQuery plugins: docs.jquery.com/Plugins/Authoring
• Linus Thiel: I wasn't sure what you meant by // THIS SHOULD ONLY BE FIRED IF CALLBACK IS DEFINED? - I figured you wanted to control that with some setting?
• janhartmann: Yeah, I figured it out. I was a comment for my head. I have it figured out now and it works - thank you!