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Jquery custom events attached to .show and .hide

I am exploring the potential of jquery to satisfy some of our user interface requirements, and am experiencing some interesting actions. I am very new to jQuery and I am trying to implement a basic pub-sub template that connects to a show and hides functions.

Despite the fact that the custom event engine looks completely simple on the surface, it does not behave as I expect. I do not see my syntax error, so I must misunderstand how these user events are designed to work.

When I execute this code, this is what I think should happen.

Initially (after doc.Ready) the question2 element should be hidden.

When I click on the “Vermont” switch, question 2 should be visible, followed by one warning box indicating that “question2 has become visible.”

When I click on another switch, question 2 should be hidden, followed by one warning field indicating that question 2 is hidden.

What really happens is that I get a lot of warning boxes when I make question 2 visible, and not when I hide it? Please help me understand why this is done.

Here is the script:

    <script type="text/javascript">

    function processRadioButtonASD() {
        var isChecked = ($("input[name=question1]:checked").val() == "question1.Vermont");
        if (isChecked == true) {
            $("[data-uniquename=question2]").show(250);
        } else {
            $("[data-uniquename=question2]").hide(250);
        }
    }

    function detectVisibilityChange(uniqueName) {
        $("[data-uniquename=" + uniqueName + "]").bind("madeVisible", function () {
            alert($(this).attr("data-uniquename") + " was made visible");
        });
        $("[data-uniquename=" + uniqueName + "]").bind("madeHidden", function () {
            alert($(this).attr("data-uniquename") + " was made hidden");
        });
    }

    $(function () {
        $.each(["show", "hide"], function () {
            var _oldFn = $.fn[this];
            $.fn[this] = function () {
                var wasVisible = $(this).is(':visible');
                var result = _oldFn.apply(this, arguments);
                var isVisible = $(this).is(':visible');

                if ((isVisible == true) && (wasVisible == false)) {
                    $(this).triggerHandler("madeVisible");
                } else if ((isVisible == false) && (wasVisible == true)) {
                    $(this).triggerHandler("madeHidden");
                }
                return result;
            }
        });
    });

    $(document).ready(function () {
        processRadioButtonASD();
        detectVisibilityChange("question2");
        $("input[name='question1']").change(function () { processRadioButtonASD(); });
    });
</script>

Here is the html:

    <div id="content">
    <div id="radioButtonASD" class="example">
        <h2>radio button visibility trigger</h2>
        <div data-uniquename="question1" class="question">
            <label for="question1">
                Question 1) (select Vermont to show Question2)
            </label>
            <br />
            <label data-uniquename="question1.Maine">
                <input name="question1" data-uniquename="question1.Maine" type="radio" value="me" />Maine</label><br />
            <label data-uniquename="question1.Vermont">
                <input name="question1" data-uniquename="question1.Vermont" type="radio" value="question1.Vermont" />Vermont</label><br />
            <label data-uniquename="question1.NewHampshire">
                <input name="question1" data-uniquename="question1.NewHampshire" type="radio" value="question1.NewHampshire" />New
                Hampshire</label><br />
            <label data-uniquename="question1.Conneticut">
                <input name="question1" data-uniquename="question1.Conneticut" type="radio" value="question1.Conneticut" />Conneticut</label><br />
            <label data-uniquename="question1.Massachusetts">
                <input name="question1" data-uniquename="question1.Massachusetts" type="radio" value="question1.Massachusetts" />Massachusetts
            </label>
        </div>
    <br />
        <div data-uniquename="question2" class="question">
            <label>
                Question 2)
            </label>
            <br />
            <select>
                <option data-uniquename="question2.honda" value="honda">Honda</option>
                <option data-uniquename="question2.volvo" value="volvo">Volvo</option>
                <option data-uniquename="question2.saab" value="saab">Saab</option>
                <option data-uniquename="question2.mercedes" value="mercedes">Mercedes</option>
                <option data-uniquename="question2.audi" value="audi">Audi</option>
            </select>
        </div>
    </div>
</div>

Thanks for watching.

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1 answer

I came up with an alternative way.

$.each(["show", "hide"], function() {
    var effect = $.fn[this];
    $.fn[this] = function(duration, move, callback) {
        // Match the arguments
        var speed = duration;
        var easing = callback && move || move && !jQuery.isFunction( move ) && move;
        var fn = callback || !callback && move || jQuery.isFunction( duration ) && duration;
        // Wrap the callback function   
        var wrapped = fn;
        var wasVisible = $(this).is(':visible');
        fn = function(){
            var isVisible = $(this).is(':visible');
            $.proxy(wrapped, this);
            if ((isVisible == true) && (wasVisible == false)) {
                $(this).triggerHandler("madeVisible");
            } else if ((isVisible == false) && (wasVisible == true)) {
                $(this).triggerHandler("madeHidden");
            }
        };   
        // Run the effect with the wrapped callback             
        return effect.call(this, speed, easing, fn);
    };
});

The idea is to use a function callback. From there, you can reorganize and clear the code.

.

+1

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