PrototypeJS事件注册表问题

Question

在1.7.3更新之后,原型事件注册表似乎存在问题,我正在使用prototype_event_registry元素存储来访问点击事件,以便我可以重播它们.

这是为了让我能阻止事件和可选恢复他们,一切工作正常,但看的diff后为基于回调1.7.0和1.7.3它似乎被删除？

我知道这是内部构件,我可能不应该首先使用它.无论如何,直到我的问题:

我已经更新了我的代码,1.7.3但对我来说似乎非常讨厌,有没有更好的方法呢？

/**
 * creates a toggling handler for click events taking previous click events into account.
 *
 * w.r.t stopping of a click event, handles cases where the button is a submit or a normal button.
 * in the case of a submit, calling <tt>Event.stop()</tt> should be sufficient as there are no other listeners on the button.
 * however, if a normal button has a handler that calls <tt>save()</tt>, and another handler using client code and calling stop,
 * it will not affect stopping of the event, since <tt>Event.stop</tt> only stops propagation, not other handlers!
 *
 * note that this function will always execute the specified handler before any other defined events.
 *
 * @param {Element} element the element to use for this click event
 * @param {Function} handler the handler to use for this stopping click event, if this handler returns true,
 * all other actions for the click event will be prevented
 * @returns {Element} the element that was supplied as argument
 */
function stoppingClickEvent(element, handler) {
    if (!element) throw 'cannot use method, if element is undefined';

    // assign default handler if none was supplied
    handler = handler || Prototype.emptyFunction;

    if (element.type && element.type === 'submit') {
        element.on('click', function(submitEvent) {
            // call the supplied handler with the current element as context and the event as argument
            // if it returns true, we should stop the event
            var stopEvent = handler.call(element, submitEvent);

            if (stopEvent) {
                // since the element's default action will be to submit a form, we prevent it
                submitEvent.stop();
            }
        });
    } else {
        // prototype 1.7.3 removed support for 'prototype_event_registry', so we need to do multiple hacks here
        // first get the window of the element so we can access the prototype
        // event cache from the correct context (frames)
        var elementDoc = element.ownerDocument;
        var elementWindow = elementDoc.defaultView || elementDoc.parentWindow;

        if (!elementWindow) {
            throw 'cannot access the window object for element ' + element.id;
        }

        // we are dealing with a normal element's click event, so we don't know how many click events have been set up.
        // capture them all so we can decide to call them or not.
        // FIXME: need a better way of doing this
        var registry = elementWindow['Event'].cache[element._prototypeUID || element.uniqueID] || {},
            events = registry['click'] || [];

        // now that we have a copy of the events, we can stop them all and add our new handler
        element.stopObserving('click').on('click', function(clickEvent) {
            // call the supplied handler with the current element as context and the event as argument
            // if it returns true, we should stop the event
            var stopEvent = handler.call(element, clickEvent);

            if (!stopEvent) {
                // the event should not be stopped, run all the original click events
                events.each(function(wrapper) {
                    wrapper.handler.call(element, clickEvent);
                });
            }
        });
    }

    return element;
}

Answer 1

使用上面的代码运行了 3-4 个月后，我最终决定恢复它。似乎存在很多问题，特别是在处理单个页面上的多个框架和事件处理程序时。

Event.cache对于特定元素来说，最普遍的是undefined。

这可能是由于上面的处理不正确造成的，但我高度怀疑新Event框架在某种程度上是不正确的，因为恢复到1.7.0完全修复了我遇到的所有问题。

仅供参考，这是我现在使用的代码1.7.0：

/**
 * creates a toggling handler for click events taking previous click events into account.
 *
 * w.r.t stopping of a click event, handles cases where the button is a submit or a normal button.
 * in the case of a submit, calling <tt>Event.stop()</tt> should be sufficient as there are no other listeners on the button.
 * however, if a normal button has a handler that calls <tt>save()</tt>, and another handler using client code and calling stop,
 * it will not affect stopping of the event, since <tt>Event.stop</tt> only stops propagation, not other handlers!
 *
 * note that this function will always execute the specified handler before any other defined events.
 *
 * @param {Element} element the element to use for this click event
 * @param {Function} handler the handler to use for this stopping click event, if this handler returns true,
 * all other actions for the click event will be prevented
 * @returns {Element} the element that was supplied as argument
 */
function stoppingClickEvent(element, handler) {
    if (!element) throw 'cannot use method, if element is undefined';

    // assign default handler if none was supplied
    handler = handler || Prototype.emptyFunction;

    if (element.type && element.type === 'submit') {
        element.on('click', function(submitEvent) {
            // call the supplied handler with the current element as context and the event as argument
            // if it returns true, we should stop the event
            var stopEvent = handler.call(element, submitEvent);

            if (stopEvent) {
                // since the element's default action will be to submit a form, we prevent it
                submitEvent.stop();
            }
        });
    } else {
        // we are dealing with a normal element's click event, so we don't know how many click events have been set up.
        // capture them all so we can decide to call them or not.
        var registry = element.getStorage().get('prototype_event_registry') || $H(),
            events = registry.get('click') || [];

        // now that we have a copy of the events, we can stop them all and add our new handler
        element.stopObserving('click').on('click', function(clickEvent) {
            // call the supplied handler with the current element as context and the event as argument
            // if it returns true, we should stop the event
            var stopEvent = handler.call(element, clickEvent);

            if (!stopEvent) {
                // the event should not be stopped, run all the original click events
                events.each(function(func) {
                    func.call(element, clickEvent);
                });
            }
        });
    }

    return element;
}