jQuery - 在页面加载时执行一个函数？

Question

I want to add a class on my navigation bar when a page is loaded.

Here's my try:

$(document).ready(function(){

    $('index.php').load(function(){
        $("#etusivu").addClass("selected");
        $("#quartz").removeClass("selected");
        $("#raikastimet").removeClass("selected");
        $("#sisusta").removeClass("selected");
        $("#teipit").removeClass("selected");
        $("#vaimennusmatot").removeClass("selected");
    });

    $('quartz.php').load(function(){

        $("#etusivu").removeClass("selected");
        $("#quartz").addClass("selected");
        $("#raikastimet").removeClass("selected");
        $("#sisusta").removeClass("selected");
        $("#teipit").removeClass("selected");
        $("#vaimennusmatot").removeClass("selected");
    });

    $('raikastimet.php').load(function(){

        $("#etusivu").removeClass("selected");
        $("#quartz").removeClass("selected");
        $("#raikastimet").addClass("selected");
        $("#sisusta").removeClass("selected");
        $("#teipit").removeClass("selected");
        $("#vaimennusmatot").removeClass("selected");
    });

    $('sisusta.php').load(function(){

        $("#etusivu").removeClass("selected");
        $("#quartz").removeClass("selected");
        $("#raikastimet").removeClass("selected");
        $("#sisusta").addClass("selected");
        $("#teipit").removeClass("selected");
        $("#vaimennusmatot").removeClass("selected");
    });

    $('teipit.php').load(function(){

        $("#etusivu").removeClass("selected");
        $("#quartz").removeClass("selected");
        $("#raikastimet").removeClass("selected");
        $("#sisusta").removeClass("selected");
        $("#teipit").addClass("selected");
        $("#vaimennusmatot").removeClass("selected");
    });

    $('vaimennusmatot.php').load(function(){

        $("#etusivu").removeClass("selected");
        $("#quartz").removeClass("selected");
        $("#raikastimet").removeClass("selected");
        $("#sisusta").removeClass("selected");
        $("#teipit").removeClass("selected");
        $("#vaimennusmatot").addClass("selected");
    });

});

So I'm trying to add class="selected" when user clicks a link on navigation, and browser loads a new page. But this isn't working.

Here's the navigation:

<ul id="navigation">';
        <li id="etusivu"><a href="index.php">Etusivu</a></li>
        <li id="quartz"><a href="quartz.php">Quartz-kalvot</a></li>
        <li id="raikastimet"><a href="raikastimet.php">Raikastimet</a></li>
        <li id="sisusta"><a href="sisusta.php">Sisusta</a></li>
        <li id="teipit"><a href="teipit.php">Teipit</a></li>
        <li id="vaimennusmatot"><a href="vaimennusmatot.php">Vaimennusmatot</a></li>
</ul>

Answer 1

That's not the correct usage of load method.

.load( url [, data] [, complete(responseText, textStatus, XMLHttpRequest)] )

$(document).ready(function(){

  $('#navigation a').click(function(event) {
     event.preventDefault(); // prevents the default action of the event
     $(this).parent().addClass('selected').siblings().removeClass('selected');
     var url = this.href;
     $('#whereToLoad').load(url)
  })

});

• load()
• sublings()
• parent()
• event.preventDefault()

Answer 2

Everything that you place within

$(document).ready(function(){

    ...

});

... will be executed immediately at DOMReady for every document that contains that piece of code. If you want to change the selected-class at that point, you could do something like:

$('#navigation .selected').removeClass('selected'); // remove 'selected' class from all li's that have it
$('#id-of-current-page').addClass('selected');

Now, to find out which the current element is, you could for instance inspect location.href . However, seeing asyou're using PHP, I would really recommend just adding the selected class in the rendered HTML to begin with.

What your code currently does is to fetch all those pages through AJAX requests immediately as the page loads, and then add and remove the selected class a lot for every response.