JQuery - Widget Public Methods

问题

If I create a JQuery widget (code example below), and then define a "public" method, is there any other way to call the method other than using the following form?

$("#list").list("publicMethod");

I would like to create a series of widgets that all define the same methods (basically implementing the same interface), and be able to call the method without knowing anything about which widget I currently am invoking the method on. In the current form, I need to know that I am executing the method on the "list" widget.

Below is an example of creating a widget with the "public" method.

 (function($) {
    var items = [];
    var itemFocusIdx = 0;

    $.widget("ui.list", {
        // Standard stuff
        options : { ... },
        _create : function() { ... },
        destroy : function() { ... },

        // My Public Methods
        publicMethod : function() { ... }
        ...
    });
}(jQuery));

回答1:

jQuery UI widgets use jQuery's $.data(...) method to indirectly associate the widget class with the DOM element. The preferred way to call a method on the widget is exactly what was described by Max...

$('#list').list('publicMethod');

...but if you want to field a return value, you'll have better luck calling it this way, via the data method:

$('#list').data('list').publicMethod();

However, using the second way side-steps the whole jQuery UI widget pattern, and should probably be avoided if possible.

回答2:

Slightly off-topic, I know, but you may want to look at jquery Entwine.

This provides a form of inheritance and polymorphism which allows some clever behaviour with simple code. It sounds like this would do what you are trying to do.

回答3:

lets say you have list, list2, and superList... let's call "publicMethod" on for each of them:

$.fn.callWidgetMethod = function(method) {
  var $this = this,
      args = Array.prototype.slice.call(arguments, 1);

  // loop though the data and check each piece of data to
  // see if it has the method
  $.each(this.data(), function(key, val) {
    if ($.isFunction(val[method])) {
      $this[key].apply($this, args);

      // break out of the loop
      return false;
    }
  });
}

$("#some-element").list();
$("#another-element").list2();
$("#hydrogen").superList();

$("#some-element").callWidgetMethod("publicMethod");
$("#another-element").callWidgetMethod("publicMethod");
$("#hydrogen").callWidgetMethod("publicMethod");

回答4:

This solution is inspired by @Jiaaro's solution, but I needed a return value and implemented as a JavaScript function rather than extending jQuery:

var invokeWidgetMethod = function(methodName, widgetElem)
    {
        var $widgetElem = $(widgetElem),
            widgetData = $widgetElem.data(),
            dataName,
            dataObject;

        for(dataName in widgetData)
        {
            dataObject = widgetData[dataName];
            if ($.isFunction(dataObject[methodName])) {
                return dataObject[methodName]();
            }
        }
    }