香草Javascript操作元素的窗口大小调整

Vanilla Javascript manipulating elements on window resize

本文关键字：窗口大小 调整 元素 Javascript 操作 香草      更新时间：2023-09-26

我在玩一个Javascript标签系统。

当窗口宽度低于某个断点时，选项卡内容插入到手风琴布局的链接之后，当您增加窗口宽度时，该过程将相反。

当你减小窗口大小时，一切都按预期工作，但当你增加窗口宽度时，一切都中断了。下面的代码导致问题tabBody.appendChild( tabBodyItems[k] ); .

3个.c-Tabs_BodyItem元素中只有2个附加??

<div class="c-Tabs" id="js-Tabs">
    <div class="o-Container">
        <div class="o-Row c-Tabs_Head">
            <div class="o-Col-sm-4 c-Tabs_HeadItem">
                <a href="" class="c-Tabs_Link">Link 1</a>
            </div>
            <div class="o-Col-sm-4 c-Tabs_HeadItem is-active">
                <a href="" class="c-Tabs_Link">Link 2</a>
            </div>
            <div class="o-Col-sm-4 c-Tabs_HeadItem">
                <a href="" class="c-Tabs_Link">Link 3</a>
            </div>
        </div>
        <div class="c-Tabs_Body">
            <div class="c-Tabs_BodyItem">
                <ul>
                    <li>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</li>
                    <li>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</li>
                </ul>
            </div>
            <div class="c-Tabs_BodyItem is-active">
                <ul>
                    <li>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</li>
                    <li>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</li>
                </ul>
            </div>
            <div class="c-Tabs_BodyItem">
                <ul>
                    <li>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</li>
                    <li>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</li>
                </ul>
            </div>
        </div>
    </div>
</div>
Javascript

我不会展示实际选项卡系统的Javascript;这不是问题的原因。

function insertAfter( el, referenceNode )
{
    referenceNode.parentNode.insertBefore( el, referenceNode.nextSibling );
}
function debounce( func, wait, immediate )
{
    var timeout;
    return function() {
        var context = this, args = arguments;
        var later = function() {
            timeout = null;
            if (!immediate) func.apply(context, args);
        };
        var callNow = immediate && !timeout;
        clearTimeout(timeout);
        timeout = setTimeout(later, wait);
        if (callNow) func.apply(context, args);
    };
}
var tabHeadItems = document.getElementsByClassName( 'c-Tabs_HeadItem' );
var tabBody = document.querySelector( '.c-Tabs_Body' );
var tabBodyItems = document.getElementsByClassName( 'c-Tabs_BodyItem' );
var isTabs = true;
function setTab()
{
    if ( window.matchMedia( '(min-width: 768px)' ).matches && isTabs === false )
    {
        for( var k = 0, lenK = tabBodyItems.length; k < lenK; k++ )
        {
            tabBody.appendChild( tabBodyItems[k] );
        }
        isTabs = true;
    }
    else if ( window.matchMedia( '(max-width: 767px)' ).matches && isTabs === true )
    {
        for( var l = 0, lenL = tabBodyItems.length; l < lenL; l++ )
        {
            insertAfter( tabBodyItems[l], tabHeadItems[l] );
        }
        isTabs = false;
    }
}
setTab();
var debounceSetTab = debounce(function() {
    setTab();
}, 250 );
window.addEventListener( 'resize', debounceSetTab );

原因是getElementsByClassName返回live NodeList。这意味着随着DOM的改变，NodeList的内容也会随之改变。元素tabBodyItems的顺序是基于它们在DOM中的位置，所以当您在DOM中移动元素时，它们在tabBodyItems中的索引会改变以反映这一点。这是当你在for循环中遍历集合时发生的，所以你跳过了元素，因为它们被重新编号了。

最简单的解决方法是使用document.querySelectorAll代替document.getElementsByClassName。这将返回一个静态的NodeList。

function insertAfter( el, referenceNode )
{
    referenceNode.parentNode.insertBefore( el, referenceNode.nextSibling );
}
function debounce( func, wait, immediate )
{
    var timeout;
    return function() {
        var context = this, args = arguments;
        var later = function() {
            timeout = null;
            if (!immediate) func.apply(context, args);
        };
        var callNow = immediate && !timeout;
        clearTimeout(timeout);
        timeout = setTimeout(later, wait);
        if (callNow) func.apply(context, args);
    };
}
var tabHeadItems = document.querySelectorAll( '.c-Tabs_HeadItem' );
var tabBody = document.querySelector( '.c-Tabs_Body' );
var tabBodyItems = document.querySelectorAll( '.c-Tabs_BodyItem' );
var isTabs = true;
function setTab()
{
    if ( window.matchMedia( '(min-width: 768px)' ).matches && isTabs === false )
    {
        for( var k = 0, lenK = tabBodyItems.length; k < lenK; k++ )
        {
            tabBody.appendChild( tabBodyItems[k] );
        }
        isTabs = true;
    }
    else if ( window.matchMedia( '(max-width: 767px)' ).matches && isTabs === true )
    {
        for( var l = 0, lenL = tabBodyItems.length; l < lenL; l++ )
        {
            insertAfter( tabBodyItems[l], tabHeadItems[l] );
        }
        isTabs = false;
    }
}
setTab();
var debounceSetTab = debounce(function() {
    setTab();
}, 250 );
window.addEventListener( 'resize', debounceSetTab );
<div class="c-Tabs" id="js-Tabs">
    <div class="o-Container">
        <div class="o-Row c-Tabs_Head">
            <div class="o-Col-sm-4 c-Tabs_HeadItem">
                <a href="" class="c-Tabs_Link">Link 1</a>
            </div>
            <div class="o-Col-sm-4 c-Tabs_HeadItem is-active">
                <a href="" class="c-Tabs_Link">Link 2</a>
            </div>
            <div class="o-Col-sm-4 c-Tabs_HeadItem">
                <a href="" class="c-Tabs_Link">Link 3</a>
            </div>
        </div>
        <div class="c-Tabs_Body">
            <div class="c-Tabs_BodyItem" id="body1">
                <ul>
                    <li>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</li>
                    <li>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</li>
                </ul>
            </div>
            <div class="c-Tabs_BodyItem is-active" id="body2">
                <ul>
                    <li>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</li>
                    <li>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</li>
                </ul>
            </div>
            <div class="c-Tabs_BodyItem"id="body3">
                <ul>
                    <li>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</li>
                    <li>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</li>
                </ul>
            </div>
        </div>
    </div>
</div>

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