WordPress/wp-content/themes/twentytwentyone/inc/template-functions.php

<?php
/**
 * Functions which enhance the theme by hooking into WordPress
 *
 * @package WordPress
 * @subpackage Twenty_Twenty_One
 * @since Twenty Twenty-One 1.0
 */

/**
 * Adds custom classes to the array of body classes.
 *
 * @since Twenty Twenty-One 1.0
 *
 * @param array $classes Classes for the body element.
 * @return array
 */
function twenty_twenty_one_body_classes( $classes ) {

	// Helps detect if JS is enabled or not.
	$classes[] = 'no-js';

	// Adds `singular` to singular pages, and `hfeed` to all other pages.
	$classes[] = is_singular() ? 'singular' : 'hfeed';

	// Add a body class if main navigation is active.
	if ( has_nav_menu( 'primary' ) ) {
		$classes[] = 'has-main-navigation';
	}

	// Add a body class if there are no footer widgets.
	if ( ! is_active_sidebar( 'sidebar-1' ) ) {
		$classes[] = 'no-widgets';
	}

	return $classes;
}
add_filter( 'body_class', 'twenty_twenty_one_body_classes' );

/**
 * Adds custom class to the array of posts classes.
 *
 * @since Twenty Twenty-One 1.0
 *
 * @param array $classes An array of CSS classes.
 * @return array
 */
function twenty_twenty_one_post_classes( $classes ) {
	$classes[] = 'entry';

	return $classes;
}
add_filter( 'post_class', 'twenty_twenty_one_post_classes', 10, 3 );

/**
 * Add a pingback url auto-discovery header for single posts, pages, or attachments.
 *
 * @since Twenty Twenty-One 1.0
 *
 * @return void
 */
function twenty_twenty_one_pingback_header() {
	if ( is_singular() && pings_open() ) {
		echo '<link rel="pingback" href="', esc_url( get_bloginfo( 'pingback_url' ) ), '">';
	}
}
add_action( 'wp_head', 'twenty_twenty_one_pingback_header' );

/**
 * Remove the `no-js` class from body if JS is supported.
 *
 * @since Twenty Twenty-One 1.0
 *
 * @return void
 */
function twenty_twenty_one_supports_js() {
	echo '<script>document.body.classList.remove("no-js");</script>';
}
add_action( 'wp_footer', 'twenty_twenty_one_supports_js' );

/**
 * Changes comment form default fields.
 *
 * @since Twenty Twenty-One 1.0
 *
 * @param array $defaults The form defaults.
 * @return array
 */
function twenty_twenty_one_comment_form_defaults( $defaults ) {

	// Adjust height of comment form.
	$defaults['comment_field'] = preg_replace( '/rows="\d+"/', 'rows="5"', $defaults['comment_field'] );

	return $defaults;
}
add_filter( 'comment_form_defaults', 'twenty_twenty_one_comment_form_defaults' );

/**
 * Determines if post thumbnail can be displayed.
 *
 * @since Twenty Twenty-One 1.0
 *
 * @return bool
 */
function twenty_twenty_one_can_show_post_thumbnail() {
	/**
	 * Filters whether post thumbnail can be displayed.
	 *
	 * @since Twenty Twenty-One 1.0
	 *
	 * @param bool $show_post_thumbnail Whether to show post thumbnail.
	 */
	return apply_filters(
		'twenty_twenty_one_can_show_post_thumbnail',
		! post_password_required() && ! is_attachment() && has_post_thumbnail()
	);
}

/**
 * Returns the size for avatars used in the theme.
 *
 * @since Twenty Twenty-One 1.0
 *
 * @return int
 */
function twenty_twenty_one_get_avatar_size() {
	return 60;
}

/**
 * Creates continue reading text.
 *
 * @since Twenty Twenty-One 1.0
 */
function twenty_twenty_one_continue_reading_text() {
	$continue_reading = sprintf(
		/* translators: %s: Post title. Only visible to screen readers. */
		esc_html__( 'Continue reading %s', 'twentytwentyone' ),
		the_title( '<span class="screen-reader-text">', '</span>', false )
	);

	return $continue_reading;
}

/**
 * Creates the continue reading link for excerpt.
 *
 * @since Twenty Twenty-One 1.0
 */
function twenty_twenty_one_continue_reading_link_excerpt() {
	if ( ! is_admin() ) {
		return '&hellip; <a class="more-link" href="' . esc_url( get_permalink() ) . '">' . twenty_twenty_one_continue_reading_text() . '</a>';
	}
}

// Filter the excerpt more link.
add_filter( 'excerpt_more', 'twenty_twenty_one_continue_reading_link_excerpt' );

/**
 * Creates the continue reading link.
 *
 * @since Twenty Twenty-One 1.0
 */
function twenty_twenty_one_continue_reading_link() {
	if ( ! is_admin() ) {
		return '<div class="more-link-container"><a class="more-link" href="' . esc_url( get_permalink() ) . '#more-' . esc_attr( get_the_ID() ) . '">' . twenty_twenty_one_continue_reading_text() . '</a></div>';
	}
}

// Filter the content more link.
add_filter( 'the_content_more_link', 'twenty_twenty_one_continue_reading_link' );

if ( ! function_exists( 'twenty_twenty_one_post_title' ) ) {
	/**
	 * Adds a title to posts and pages that are missing titles.
	 *
	 * @since Twenty Twenty-One 1.0
	 *
	 * @param string $title The title.
	 * @return string
	 */
	function twenty_twenty_one_post_title( $title ) {
		return '' === $title ? esc_html_x( 'Untitled', 'Added to posts and pages that are missing titles', 'twentytwentyone' ) : $title;
	}
}
add_filter( 'the_title', 'twenty_twenty_one_post_title' );

/**
 * Gets the SVG code for a given icon.
 *
 * @since Twenty Twenty-One 1.0
 *
 * @param string $group The icon group.
 * @param string $icon  The icon.
 * @param int    $size  The icon size in pixels.
 * @return string
 */
function twenty_twenty_one_get_icon_svg( $group, $icon, $size = 24 ) {
	return Twenty_Twenty_One_SVG_Icons::get_svg( $group, $icon, $size );
}

/**
 * Changes the default navigation arrows to svg icons
 *
 * @since Twenty Twenty-One 1.0
 *
 * @param string $calendar_output The generated HTML of the calendar.
 * @return string
 */
function twenty_twenty_one_change_calendar_nav_arrows( $calendar_output ) {
	$calendar_output = str_replace( '&laquo; ', is_rtl() ? twenty_twenty_one_get_icon_svg( 'ui', 'arrow_right' ) : twenty_twenty_one_get_icon_svg( 'ui', 'arrow_left' ), $calendar_output );
	$calendar_output = str_replace( ' &raquo;', is_rtl() ? twenty_twenty_one_get_icon_svg( 'ui', 'arrow_left' ) : twenty_twenty_one_get_icon_svg( 'ui', 'arrow_right' ), $calendar_output );
	return $calendar_output;
}
add_filter( 'get_calendar', 'twenty_twenty_one_change_calendar_nav_arrows' );

/**
 * Get custom CSS.
 *
 * Return CSS for non-latin language, if available, or null
 *
 * @since Twenty Twenty-One 1.0
 *
 * @param string $type Whether to return CSS for the "front-end", "block-editor", or "classic-editor".
 * @return string
 */
function twenty_twenty_one_get_non_latin_css( $type = 'front-end' ) {

	// Fetch site locale.
	$locale = get_bloginfo( 'language' );

	/**
	 * Filters the fallback fonts for non-latin languages.
	 *
	 * @since Twenty Twenty-One 1.0
	 *
	 * @param array $font_family An array of locales and font families.
	 */
	$font_family = apply_filters(
		'twenty_twenty_one_get_localized_font_family_types',
		array(

			// Arabic.
			'ar'    => array( 'Tahoma', 'Arial', 'sans-serif' ),
			'ary'   => array( 'Tahoma', 'Arial', 'sans-serif' ),
			'azb'   => array( 'Tahoma', 'Arial', 'sans-serif' ),
			'ckb'   => array( 'Tahoma', 'Arial', 'sans-serif' ),
			'fa-IR' => array( 'Tahoma', 'Arial', 'sans-serif' ),
			'haz'   => array( 'Tahoma', 'Arial', 'sans-serif' ),
			'ps'    => array( 'Tahoma', 'Arial', 'sans-serif' ),

			// Chinese Simplified (China) - Noto Sans SC.
			'zh-CN' => array( '\'PingFang SC\'', '\'Helvetica Neue\'', '\'Microsoft YaHei New\'', '\'STHeiti Light\'', 'sans-serif' ),

			// Chinese Traditional (Taiwan) - Noto Sans TC.
			'zh-TW' => array( '\'PingFang TC\'', '\'Helvetica Neue\'', '\'Microsoft YaHei New\'', '\'STHeiti Light\'', 'sans-serif' ),

			// Chinese (Hong Kong) - Noto Sans HK.
			'zh-HK' => array( '\'PingFang HK\'', '\'Helvetica Neue\'', '\'Microsoft YaHei New\'', '\'STHeiti Light\'', 'sans-serif' ),

			// Cyrillic.
			'bel'   => array( '\'Helvetica Neue\'', 'Helvetica', '\'Segoe UI\'', 'Arial', 'sans-serif' ),
			'bg-BG' => array( '\'Helvetica Neue\'', 'Helvetica', '\'Segoe UI\'', 'Arial', 'sans-serif' ),
			'kk'    => array( '\'Helvetica Neue\'', 'Helvetica', '\'Segoe UI\'', 'Arial', 'sans-serif' ),
			'mk-MK' => array( '\'Helvetica Neue\'', 'Helvetica', '\'Segoe UI\'', 'Arial', 'sans-serif' ),
			'mn'    => array( '\'Helvetica Neue\'', 'Helvetica', '\'Segoe UI\'', 'Arial', 'sans-serif' ),
			'ru-RU' => array( '\'Helvetica Neue\'', 'Helvetica', '\'Segoe UI\'', 'Arial', 'sans-serif' ),
			'sah'   => array( '\'Helvetica Neue\'', 'Helvetica', '\'Segoe UI\'', 'Arial', 'sans-serif' ),
			'sr-RS' => array( '\'Helvetica Neue\'', 'Helvetica', '\'Segoe UI\'', 'Arial', 'sans-serif' ),
			'tt-RU' => array( '\'Helvetica Neue\'', 'Helvetica', '\'Segoe UI\'', 'Arial', 'sans-serif' ),
			'uk'    => array( '\'Helvetica Neue\'', 'Helvetica', '\'Segoe UI\'', 'Arial', 'sans-serif' ),

			// Devanagari.
			'bn-BD' => array( 'Arial', 'sans-serif' ),
			'hi-IN' => array( 'Arial', 'sans-serif' ),
			'mr'    => array( 'Arial', 'sans-serif' ),
			'ne-NP' => array( 'Arial', 'sans-serif' ),

			// Greek.
			'el'    => array( '\'Helvetica Neue\', Helvetica, Arial, sans-serif' ),

			// Gujarati.
			'gu'    => array( 'Arial', 'sans-serif' ),

			// Hebrew.
			'he-IL' => array( '\'Arial Hebrew\'', 'Arial', 'sans-serif' ),

			// Japanese.
			'ja'    => array( 'sans-serif' ),

			// Korean.
			'ko-KR' => array( '\'Apple SD Gothic Neo\'', '\'Malgun Gothic\'', '\'Nanum Gothic\'', 'Dotum', 'sans-serif' ),

			// Thai.
			'th'    => array( '\'Sukhumvit Set\'', '\'Helvetica Neue\'', 'Helvetica', 'Arial', 'sans-serif' ),

			// Vietnamese.
			'vi'    => array( '\'Libre Franklin\'', 'sans-serif' ),

		)
	);

	// Return if the selected language has no fallback fonts.
	if ( empty( $font_family[ $locale ] ) ) {
		return '';
	}

	/**
	 * Filters the elements to apply fallback fonts to.
	 *
	 * @since Twenty Twenty-One 1.0
	 *
	 * @param array $elements An array of elements for "front-end", "block-editor", or "classic-editor".
	 */
	$elements = apply_filters(
		'twenty_twenty_one_get_localized_font_family_elements',
		array(
			'front-end'      => array( 'body', 'input', 'textarea', 'button', '.button', '.faux-button', '.wp-block-button__link', '.wp-block-file__button', '.has-drop-cap:not(:focus)::first-letter', '.entry-content .wp-block-archives', '.entry-content .wp-block-categories', '.entry-content .wp-block-cover-image', '.entry-content .wp-block-latest-comments', '.entry-content .wp-block-latest-posts', '.entry-content .wp-block-pullquote', '.entry-content .wp-block-quote.is-large', '.entry-content .wp-block-quote.is-style-large', '.entry-content .wp-block-archives *', '.entry-content .wp-block-categories *', '.entry-content .wp-block-latest-posts *', '.entry-content .wp-block-latest-comments *', '.entry-content p', '.entry-content ol', '.entry-content ul', '.entry-content dl', '.entry-content dt', '.entry-content cite', '.entry-content figcaption', '.entry-content .wp-caption-text', '.comment-content p', '.comment-content ol', '.comment-content ul', '.comment-content dl', '.comment-content dt', '.comment-content cite', '.comment-content figcaption', '.comment-content .wp-caption-text', '.widget_text p', '.widget_text ol', '.widget_text ul', '.widget_text dl', '.widget_text dt', '.widget-content .rssSummary', '.widget-content cite', '.widget-content figcaption', '.widget-content .wp-caption-text' ),
			'block-editor'   => array( '.editor-styles-wrapper > *', '.editor-styles-wrapper p', '.editor-styles-wrapper ol', '.editor-styles-wrapper ul', '.editor-styles-wrapper dl', '.editor-styles-wrapper dt', '.editor-post-title__block .editor-post-title__input', '.editor-styles-wrapper .wp-block h1', '.editor-styles-wrapper .wp-block h2', '.editor-styles-wrapper .wp-block h3', '.editor-styles-wrapper .wp-block h4', '.editor-styles-wrapper .wp-block h5', '.editor-styles-wrapper .wp-block h6', '.editor-styles-wrapper .has-drop-cap:not(:focus)::first-letter', '.editor-styles-wrapper cite', '.editor-styles-wrapper figcaption', '.editor-styles-wrapper .wp-caption-text' ),
			'classic-editor' => array( 'body#tinymce.wp-editor', 'body#tinymce.wp-editor p', 'body#tinymce.wp-editor ol', 'body#tinymce.wp-editor ul', 'body#tinymce.wp-editor dl', 'body#tinymce.wp-editor dt', 'body#tinymce.wp-editor figcaption', 'body#tinymce.wp-editor .wp-caption-text', 'body#tinymce.wp-editor .wp-caption-dd', 'body#tinymce.wp-editor cite', 'body#tinymce.wp-editor table' ),
		)
	);

	// Return if the specified type doesn't exist.
	if ( empty( $elements[ $type ] ) ) {
		return '';
	}

	// Include file if function doesn't exist.
	if ( ! function_exists( 'twenty_twenty_one_generate_css' ) ) {
		require_once get_theme_file_path( 'inc/custom-css.php' ); // phpcs:ignore WPThemeReview.CoreFunctionality.FileInclude.FileIncludeFound
	}

	// Return the specified styles.
	return twenty_twenty_one_generate_css( // @phpstan-ignore-line.
		implode( ',', $elements[ $type ] ),
		'font-family',
		implode( ',', $font_family[ $locale ] ),
		null,
		null,
		false
	);
}

/**
 * Print the first instance of a block in the content, and then break away.
 *
 * @since Twenty Twenty-One 1.0
 *
 * @param string      $block_name The full block type name, or a partial match.
 *                                Example: `core/image`, `core-embed/*`.
 * @param string|null $content    The content to search in. Use null for get_the_content().
 * @param int         $instances  How many instances of the block will be printed (max). Default  1.
 * @return bool Returns true if a block was located & printed, otherwise false.
 */
function twenty_twenty_one_print_first_instance_of_block( $block_name, $content = null, $instances = 1 ) {
	$instances_count = 0;
	$blocks_content  = '';

	if ( ! $content ) {
		$content = get_the_content();
	}

	// Parse blocks in the content.
	$blocks = parse_blocks( $content );

	// Loop blocks.
	foreach ( $blocks as $block ) {

		// Sanity check.
		if ( ! isset( $block['blockName'] ) ) {
			continue;
		}

		// Check if this the block matches the $block_name.
		$is_matching_block = false;

		// If the block ends with *, try to match the first portion.
		if ( '*' === $block_name[-1] ) {
			$is_matching_block = 0 === strpos( $block['blockName'], rtrim( $block_name, '*' ) );
		} else {
			$is_matching_block = $block_name === $block['blockName'];
		}

		if ( $is_matching_block ) {
			// Increment count.
			$instances_count++;

			// Add the block HTML.
			$blocks_content .= render_block( $block );

			// Break the loop if the $instances count was reached.
			if ( $instances_count >= $instances ) {
				break;
			}
		}
	}

	if ( $blocks_content ) {
		/** This filter is documented in wp-includes/post-template.php */
		echo apply_filters( 'the_content', $blocks_content ); // phpcs:ignore WordPress.Security.EscapeOutput
		return true;
	}

	return false;
}

/**
 * Retrieve protected post password form content.
 *
 * @since Twenty Twenty-One 1.0
 * @since Twenty Twenty-One 1.4 Corrected parameter name for `$output`,
 *                              added the `$post` parameter.
 *
 * @param string      $output The password form HTML output.
 * @param int|WP_Post $post   Optional. Post ID or WP_Post object. Default is global $post.
 * @return string HTML content for password form for password protected post.
 */
function twenty_twenty_one_password_form( $output, $post = 0 ) {
	$post   = get_post( $post );
	$label  = 'pwbox-' . ( empty( $post->ID ) ? wp_rand() : $post->ID );
	$output = '<p class="post-password-message">' . esc_html__( 'This content is password protected. Please enter a password to view.', 'twentytwentyone' ) . '</p>
	<form action="' . esc_url( site_url( 'wp-login.php?action=postpass', 'login_post' ) ) . '" class="post-password-form" method="post">
	<label class="post-password-form__label" for="' . esc_attr( $label ) . '">' . esc_html_x( 'Password', 'Post password form', 'twentytwentyone' ) . '</label><input class="post-password-form__input" name="post_password" id="' . esc_attr( $label ) . '" type="password" size="20" /><input type="submit" class="post-password-form__submit" name="' . esc_attr_x( 'Submit', 'Post password form', 'twentytwentyone' ) . '" value="' . esc_attr_x( 'Enter', 'Post password form', 'twentytwentyone' ) . '" /></form>
	';
	return $output;
}
add_filter( 'the_password_form', 'twenty_twenty_one_password_form', 10, 2 );

/**
 * Filters the list of attachment image attributes.
 *
 * @since Twenty Twenty-One 1.0
 *
 * @param string[]     $attr       Array of attribute values for the image markup, keyed by attribute name.
 *                                 See wp_get_attachment_image().
 * @param WP_Post      $attachment Image attachment post.
 * @param string|int[] $size       Requested image size. Can be any registered image size name, or
 *                                 an array of width and height values in pixels (in that order).
 * @return string[] The filtered attributes for the image markup.
 */
function twenty_twenty_one_get_attachment_image_attributes( $attr, $attachment, $size ) {

	if ( is_admin() ) {
		return $attr;
	}

	if ( isset( $attr['class'] ) && false !== strpos( $attr['class'], 'custom-logo' ) ) {
		return $attr;
	}

	$width  = false;
	$height = false;

	if ( is_array( $size ) ) {
		$width  = (int) $size[0];
		$height = (int) $size[1];
	} elseif ( $attachment && is_object( $attachment ) && $attachment->ID ) {
		$meta = wp_get_attachment_metadata( $attachment->ID );
		if ( isset( $meta['width'] ) && isset( $meta['height'] ) ) {
			$width  = (int) $meta['width'];
			$height = (int) $meta['height'];
		}
	}

	if ( $width && $height ) {

		// Add style.
		$attr['style'] = isset( $attr['style'] ) ? $attr['style'] : '';
		$attr['style'] = 'width:100%;height:' . round( 100 * $height / $width, 2 ) . '%;max-width:' . $width . 'px;' . $attr['style'];
	}

	return $attr;
}
add_filter( 'wp_get_attachment_image_attributes', 'twenty_twenty_one_get_attachment_image_attributes', 10, 3 );