我想添加活动类只在第一个孩子元素php它是一个基于放大器的代码

Question

我只想在li的第一个元素中添加活动类。

这是一个放大器代码，...jquery不能正常工作，我将如何实现这种逻辑请帮助

function custom_table_of_contents($content) {
    global $tableOfContents;
    global $checkvalue;
    
    $tableOfContents = '';
    $tableOfContents = "<ul class='toc-item-list'>";
    $checkvalue = 0;
    $index = 1;
    $indexes = [2 => 1, 3 => 0, 4 => 0, 5 => 0, 6 => 0];
    
    // Insert the IDs and create the TOC.
    $content = preg_replace_callback('#<(h[1-6])(.*?)>(.*?)</\1>#si', function ($matches) use (&$index, &$tableOfContents, &$indexes, &$checkvalue) {
        $tag = $matches[1];
        $title = strip_tags($matches[3]);
        $hasId = preg_match('/id=(["\'])(.*?)\1[\s>]/si', $matches[2], $matchedIds);
        $id = $hasId ? $matchedIds[2] : sanitize_title($title);
            
        // Generate the prefix based on the heading value.
        //$prefix = '';
            
        foreach (range(2, $tag[1]) as $i) {
            if ($i == $tag[1]) {
                $indexes[$i] += 1;
            }
            
            //$prefix .= $indexes[$i] . '.';
        }
        
        $title = "$title";

        //Check the tag value
        if($checkvalue<$tag)
        {
            //Condition where previous tag value is lesser than the current one
            $tableOfContents .= '<ul>';
        } else if ($checkvalue==$tag) {
            //Condition where previous tag value is same as that of current one
        } else if($checkvalue>$tag){
            $tableOfContents .='</ul>';
        }
        $checkvalue=$tag;
    
        $tableOfContents .= "<li class='$id active'><a href='#$id'>$title</a></li>";
    
        if ($hasId) {
            return $matches[0];
        }
    
        return sprintf('<%s%s id="%s">%s</%s>', $tag, $matches[2], $id, $matches[3], $tag);
        }, $content);
    
        $tableOfContents .= '</ul>';
        echo $tableOfContents;
    
        return $content;
    }

Answer 1

如果要为第一个标记添加活动类，请替换下面的行

$activeClass = ($checkvalue<$tag)?"active":"";
$tableOfContents .= "<li class='$id $activeClass'><a href='#$id'>$title</a></li>";

完整代码

function custom_table_of_contents($content) {
global $tableOfContents;
global $checkvalue;

$tableOfContents = '';
$tableOfContents = "<ul class='toc-item-list'>";
$checkvalue = 0;
$index = 1;
$indexes = [2 => 1, 3 => 0, 4 => 0, 5 => 0, 6 => 0];

// Insert the IDs and create the TOC.
$content = preg_replace_callback('#<(h[1-6])(.*?)>(.*?)</\1>#si', function ($matches) use (&$index, &$tableOfContents, &$indexes, &$checkvalue) {
    $tag = $matches[1];
    $title = strip_tags($matches[3]);
    $hasId = preg_match('/id=(["\'])(.*?)\1[\s>]/si', $matches[2], $matchedIds);
    $id = $hasId ? $matchedIds[2] : sanitize_title($title);
    
    // Generate the prefix based on the heading value.
    //$prefix = '';
    
    foreach (range(2, $tag[1]) as $i) {
        if ($i == $tag[1]) {
            $indexes[$i] += 1;
        }
        
        //$prefix .= $indexes[$i] . '.';
    }
    
    $title = "$title";

    //Check the tag value
    if($checkvalue<$tag)
    {
        //Condition where previous tag value is lesser than the current one
        $tableOfContents .= '<ul>';
    }
    else if ($checkvalue==$tag)
    {
        //Condition where previous tag value is same as that of current one
    }
    else if($checkvalue>$tag){
        $tableOfContents .='</ul>';
    }
    $checkvalue=$tag;

    $activeClass = ($checkvalue<$tag)?"active":"";
    $tableOfContents .= "<li class='$id $activeClass'><a href='#$id'>$title</a></li>";

    if ($hasId) {
        return $matches[0];
    }

    return sprintf('<%s%s id="%s">%s</%s>', $tag, $matches[2], $id, $matches[3], $tag);
}, $content);

$tableOfContents .= '</ul>';

echo $tableOfContents;

return $content;

}