如何先设置<；李>；链接在php菜单中处于活动状态

嗨，我正在使用Wordpress图库插件

我希望过滤器菜单中的第一个链接在页面加载时自动激活。这是因为默认情况下，它加载所有类别的所有图像，而且太多了！谢谢

 <?php


wp_enqueue_script('imagesloaded', plugins_url('/assets/plugins/imagesloaded/imagesloaded.pkgd.min.js', __FILE__), array('jquery'), GO_GALLERY_VERSION, true);
wp_enqueue_script('isotope', plugins_url('/assets/plugins/isotope/isotope.pkgd.min.js', __FILE__), array('jquery'), GO_GALLERY_VERSION, true);

wp_enqueue_script('go-gallery', plugins_url('/assets/js/gallery.js', __FILE__), array('jquery', 'isotope', 'imagesloaded'), GO_GALLERY_VERSION, true);
wp_enqueue_style('go-gallery', plugins_url('/assets/css/gallery.css', __FILE__), null, GO_GALLERY_VERSION);

wp_enqueue_script('tos', plugins_url('/assets/plugins/tos/js/jquery.tosrus.min.custom.js', __FILE__), array('jquery'), GO_GALLERY_VERSION, true);
wp_enqueue_style('tos', plugins_url('/assets/plugins/tos/css/jquery.tosrus.custom.css', __FILE__), null, GO_GALLERY_VERSION);



$labels = array(
    'name'              => _x('Media Categories', 'taxonomy general name', 'go_gallery'),
    'singular_name'     => _x('Media Category', 'taxonomy singular name', 'go_gallery'),
    'search_items'      => __('Search Media Categories', 'go_gallery'),
    'all_items'         => __('All Media Categories', 'go_gallery'),
    'parent_item'       => __('Parent Media Category', 'go_gallery'),
    'parent_item_colon' => __('Parent Media Category:', 'go_gallery'),
    'edit_item'         => __('Edit Media Category', 'go_gallery'),
    'update_item'       => __('Update Media Category', 'go_gallery'),
    'add_new_item'      => __('Add New Media Category', 'go_gallery'),
    'new_item_name'     => __('New Media Category Name', 'go_gallery'),
    'menu_name'         => __('Media Categories', 'go_gallery'),
);

$args = array(
    'hierarchical'      => TRUE,
    'labels'            => $labels,
    'show_ui'           => TRUE,
    'show_admin_column' => TRUE,
    'query_var'         => TRUE,
    'rewrite'           => TRUE,
);

register_taxonomy('attachment_category', 'attachment',  $args );



$output = '';

$args = array(
    'post_type'         => 'attachment',
    'post_status'       => 'inherit',
    'posts_per_page'    => $atts['limit'],
    'order'             => 'DESC',
    'orderby'           => $atts['sort'],
    'post_mime_type'    => 'image/jpeg,image/gif,image/jpg,image/png'
);


$categories = array();

$atts['icat'] = array_map('sanitize_title', explode(',', $atts['icat']));

foreach ( $atts['icat'] as $category ) {

    if ( $term = get_term_by('slug', $category, 'attachment_category') ) {
        $categories[$term->term_id] = $term;
    }

}

if ( !empty($categories) ) {
    $args['tax_query'] = array(
        array(
            'taxonomy'  => 'attachment_category',
            'field'     => 'term_id',
            'terms'     => array_keys($categories)
        )
    );
}

$atts['menu_gap'] = min($atts['menu_gap'], 100);

$classes[] = 'go-gallery';
$classes[] = 'menu-' . $atts['menu_pos'];
$classes[] = go_gallery_bool($atts['menu_show']) ? 'menu-show' : '';
$classes[] = 'size-' . $atts['size'];
$classes[] = 'style-' . $atts['style'];

$attributes = array();
$attributes['class'] = join(' ', $classes);
$attributes['id'] = 'go-' . substr(md5(mt_rand(0, PHP_INT_MAX)), 0, 6);
$attributes['data-gap'] = intval($atts['gap']);
$attributes['data-border-color'] = $atts['border_color'];
$attributes['data-lightbox'] = go_gallery_bool($atts['lightbox']) ? 'yes' : 'no';
$attributes['data-desc-color'] = $atts['desc_color'];
$attributes['data-menu-color'] = $atts['menu_color'];
$attributes['data-menu-bg'] = $atts['menu_bg'];
$attributes['data-menu-bg-hover'] = $atts['menu_bg_hover'];
$attributes['data-menu-gap'] = $atts['menu_gap'];
$attributes['data-bg'] = $atts['bg'];
$attributes['data-border-size'] = $atts['border_size'];
$attributes['data-overlay-color'] = go_gallery_hex2rgb($atts['overlay_color']);

$thumb_size = 'medium';

if ( $atts['size'] == 'large' || ($atts['style'] == 'squared' && in_array($atts['size'], array('medium', 'large'))) ) {
    $thumb_size = 'large';
}

foreach ( $attributes as $attribute => $value ) {
    $attributes[$attribute] = $attribute . '="' . $value . '"';
}

$query = new WP_Query($args);

$output .= '<div ' . join(' ', $attributes) . '>';
$output .= '<ul class="go-gallery-filters">';
$output .= '<li>';
$output .= '<a data-filter="" href="#">' . __($atts['menu_button'], 'go_gallery') . '</a>';
$output .= '</li>';

foreach ( $categories as $category ) {

    if ( !empty($category) ) {

        $output .= '<li class="active">';
        $output .= '<a data-filter="' . $category->slug . '" href="#">' . $category->name . '</a>';
        $output .= '</li>';
    }

}

$output .= '</ul>';

$output .= '<div class="go-gallery-list-wrapper">';
$output .= '<ul class="go-gallery-list">';

foreach ( $query->posts as $post ) {

    $category_terms = wp_get_post_terms($post->ID, 'attachment_category');

    $classes = array();
    $classes[] = 'go-gallery-item';

    foreach ( $category_terms as $category_term ) {
        $classes[] = 'category-' . $category_term->slug;
    }

    $image_source = wp_get_attachment_image_src($post->ID, 'full');

    $output .= '<li data-source="' . $image_source[0] . '" class="' . join(' ', $classes) . '">';

    $output .= '<a class="image-wrap" href="' . $image_source[0] . '">';
    $output .= '<figure>';

    $output .= wp_get_attachment_image($post->ID, $thumb_size);

    $output .= '<div class="image-overlay">';

    if ( go_gallery_bool( $atts['hover_data'] ) ){
        $output .= '<h3>' . $post->post_title . '</h3>';
        $output .= '<h4>' . $post->post_content . '</h4>';
    }

    $output .= '</div>';

    $output .= '</figure>';
    $output .= '</a>';
    $output .= '</li>';
}

$output .= '</ul>';
$output .= '</div>';
$output .= '</div>';

return $output;


if(strlen($hex) == 3) {
    $r = hexdec(substr($hex,0,1).substr($hex,0,1));
    $g = hexdec(substr($hex,1,1).substr($hex,1,1));
    $b = hexdec(substr($hex,2,1).substr($hex,2,1));
} else {
    $r = hexdec(substr($hex,0,2));
    $g = hexdec(substr($hex,2,2));
    $b = hexdec(substr($hex,4,2));
}
$rgb = array($r, $g, $b);
return 'rgba(' . join(', ', $rgb) . ', ' . $alpha .')';

---

这取决于“活动”的含义

：active是一个CSS伪选择器，可以在激活链接时更改链接的外观。如果要将css类“active”添加到循环中的第一个li元素，可以尝试以下操作：

foreach($categories as $category) {

  $counter = 0; // COUNTER OF CATEGORIES... 
  $selected = ''; // THE STRING TO PRINT IN SELECTED LI-ELEMENT

  if ( !empty($category) ) {
    $selected = ($counter == 0) ? 'class="active"' : ''; // SET CLASS ACTIVE FOR THE FIRST CATEGORY

    $output .= '<li '. $selected .'>';
    $output .= '<a data-filter="' . $category->slug . '" href="#">' . $category->name . '</a>';
    $output .= '</li>';

    $counter++; //INCREMENT COUNTER OF CATEGORIES

  }

}

foreach（$categories作为$category）{
$counter=0；//类别的计数器。。。
$selected=''；//要在所选LI元素中打印的字符串
如果（！空（$category））{
$selected=（$counter==0）？'class=“active”：''；//为第一个类别设置类活动
$output.=''；
$output.=''；
$output.=''；
$counter++；//类别的递增计数器
}
}
假设您的类别通过以下简单链接发送：

<a href="gallery.php?category=1">first category</a>
<a href="gallery.php?category=2">second category</a>

其余部分取决于您的数据结构。

但这就是设置默认类别的方法。
是否有包含代码的foreach循环或任何类似内容？是的！foreach（$categories as$category）{所以您实际上想为
$category
设置一个默认值，对吗？我希望第一个类别在默认情况下在页面加载时处于活动状态是没有足够的信息来回答而没有相当多的假设
if(isset($_GET['category']) {
   $category_id = $_GET['category'];
} else {
   $category_id = 1; // default
}

// this is a blank guess, we don't know where you get your data from:
$category = $categories[$category_id];