render_block_core_navigation_link

render_block_core_navigation_link: 这个函数用来渲染WordPress中的导航链接块。导航链接块允许用户在其网站的导航菜单中添加一个指向特定页面或文章的链接: 这个函数负责生成导航链接块的HTML标记。

渲染`core/navigation-link`区块。

function render_block_core_navigation_link( $attributes, $content, $block ) {
	$navigation_link_has_id = isset( $attributes['id'] ) && is_numeric( $attributes['id'] );
	$is_post_type           = isset( $attributes['kind'] ) && 'post-type' === $attributes['kind'];
	$is_post_type           = $is_post_type || isset( $attributes['type'] ) && ( 'post' === $attributes['type'] || 'page' === $attributes['type'] );

	// Don't render the block's subtree if it is a draft or if the ID does not exist.
	if ( $is_post_type && $navigation_link_has_id ) {
		$post = get_post( $attributes['id'] );
		if ( ! $post || 'publish' !== $post->post_status ) {
			return '';
		}
	}

	// Don't render the block's subtree if it has no label.
	if ( empty( $attributes['label'] ) ) {
		return '';
	}

	$colors          = block_core_navigation_link_build_css_colors( $block->context, $attributes );
	$font_sizes      = block_core_navigation_link_build_css_font_sizes( $block->context );
	$classes         = array_merge(
		$colors['css_classes'],
		$font_sizes['css_classes']
	);
	$style_attribute = ( $colors['inline_styles'] . $font_sizes['inline_styles'] );

	$css_classes = trim( implode( ' ', $classes ) );
	$has_submenu = count( $block->inner_blocks ) > 0;
	$is_active   = ! empty( $attributes['id'] ) && ( get_queried_object_id() === (int) $attributes['id'] );

	$wrapper_attributes = get_block_wrapper_attributes(
		array(
			'class' => $css_classes . ' wp-block-navigation-item' . ( $has_submenu ? ' has-child' : '' ) .
				( $is_active ? ' current-menu-item' : '' ),
			'style' => $style_attribute,
		)
	);
	$html               = '<li ' . $wrapper_attributes . '>' .
		'<a class="wp-block-navigation-item__content" ';

	// Start appending HTML attributes to anchor tag.
	if ( isset( $attributes['url'] ) ) {
		$html .= ' href="' . esc_url( $attributes['url'] ) . '"';
	}

	if ( $is_active ) {
		$html .= ' aria-current="page"';
	}

	if ( isset( $attributes['opensInNewTab'] ) && true === $attributes['opensInNewTab'] ) {
		$html .= ' target="_blank"  ';
	}

	if ( isset( $attributes['rel'] ) ) {
		$html .= ' rel="' . esc_attr( $attributes['rel'] ) . '"';
	} elseif ( isset( $attributes['nofollow'] ) && $attributes['nofollow'] ) {
		$html .= ' rel="nofollow"';
	}

	if ( isset( $attributes['title'] ) ) {
		$html .= ' title="' . esc_attr( $attributes['title'] ) . '"';
	}

	// End appending HTML attributes to anchor tag.

	// Start anchor tag content.
	$html .= '>' .
		// Wrap title with span to isolate it from submenu icon.
		'<span class="wp-block-navigation-item__label">';

	if ( isset( $attributes['label'] ) ) {
		$html .= wp_kses_post( $attributes['label'] );
	}

	$html .= '</span>';

	// Add description if available.
	if ( ! empty( $attributes['description'] ) ) {
		$html .= '<span class="wp-block-navigation-item__description">';
		$html .= wp_kses_post( $attributes['description'] );
		$html .= '</span>';
	}

	$html .= '</a>';
	// End anchor tag content.

	if ( isset( $block->context['showSubmenuIcon'] ) && $block->context['showSubmenuIcon'] && $has_submenu ) {
		// The submenu icon can be hidden by a CSS rule on the Navigation Block.
		$html .= '<span class="wp-block-navigation__submenu-icon">' . block_core_navigation_link_render_submenu_icon() . '</span>';
	}

	if ( $has_submenu ) {
		$inner_blocks_html = '';
		foreach ( $block->inner_blocks as $inner_block ) {
			$inner_blocks_html .= $inner_block->render();
		}

		$html .= sprintf(
			'<ul class="wp-block-navigation__submenu-container">%s</ul>',
			$inner_blocks_html
		);
	}

	$html .= '</li>';

	return $html;
}