<?php
/**
* @package Polylang
*/
/**
* A class to display a language switcher on frontend
*
* @since 1.2
*/
class PLL_Switcher {
public const DEFAULTS = array(
'dropdown' => 0, // Display as list and not as dropdown.
'echo' => 1, // Echoes the list.
'hide_if_empty' => 1, // Hides languages with no posts (or pages).
'show_flags' => 0, // Don't show flags.
'show_names' => 1, // Show language names.
'display_names_as' => 'name', // Display the language name.
'force_home' => 0, // Tries to find a translation.
'hide_if_no_translation' => 0, // Don't hide the link if there is no translation.
'hide_current' => 0, // Don't hide the current language.
'post_id' => null, // Link to the translations of the current page.
'raw' => 0, // Build the language switcher.
'item_spacing' => 'preserve', // Preserve whitespace between list items.
'admin_render' => 0, // Make the switcher in a frontend context.
'admin_current_lang' => null, // Use the global current language.
);
/**
* @var PLL_Links|null
*/
protected $links;
/**
* Returns options available for the language switcher - menu or widget
* either strings to display the options or default values
*
* @since 0.7
*
* @param string $type optional either 'menu', 'widget' or 'block', defaults to 'widget'
* @param string $key optional either 'string' or 'default', defaults to 'string'
* @return array list of switcher options strings or default values
*/
public static function get_switcher_options( $type = 'widget', $key = 'string' ) {
$options = array(
'dropdown' => array( 'string' => __( 'Displays as a dropdown', 'polylang' ), 'default' => 0 ),
'show_names' => array( 'string' => __( 'Displays language names', 'polylang' ), 'default' => 1 ),
'show_flags' => array( 'string' => __( 'Displays flags', 'polylang' ), 'default' => 0 ),
'force_home' => array( 'string' => __( 'Forces link to front page', 'polylang' ), 'default' => 0 ),
'hide_current' => array( 'string' => __( 'Hides the current language', 'polylang' ), 'default' => 0 ),
'hide_if_no_translation' => array( 'string' => __( 'Hides languages with no translation', 'polylang' ), 'default' => 0 ),
);
return wp_list_pluck( $options, $key );
}
/**
* Returns the current language code.
*
* @since 3.0
*
* @param array $args Arguments passed to {@see PLL_Switcher::the_languages()}.
* @return string
*/
protected function get_current_language( $args ) {
if ( $args['admin_current_lang'] ) {
return $args['admin_current_lang'];
}
if ( isset( $this->links->curlang ) ) {
return $this->links->curlang->slug;
}
return $this->links->options['default_lang'];
}
/**
* Returns the link for a given language.
*
* @since 3.0
*
* @param PLL_Language $language Language.
* @param array $args Arguments passed to {@see PLL_Switcher::the_languages()}.
* @return string|null
*/
protected function get_link( $language, $args ) {
global $post;
// Priority to the post passed in parameters.
if ( null !== $args['post_id'] ) {
$tr_id = $this->links->model->post->get( $args['post_id'], $language );
if ( $tr_id && $this->links->model->post->current_user_can_read( $tr_id ) ) {
return get_permalink( $tr_id );
}
}
// If we are on frontend.
if ( $this->links instanceof PLL_Frontend_Links ) {
return $this->links->get_translation_url( $language );
}
// For blocks in posts in REST requests.
if ( $post instanceof WP_Post ) {
$tr_id = $this->links->model->post->get( $post->ID, $language );
if ( $tr_id && $this->links->model->post->current_user_can_read( $tr_id ) ) {
return get_permalink( $tr_id );
}
}
return null;
}
/**
* Get the language elements for use in a walker
*
* @since 1.2
*
* @param array $args Arguments passed to {@see PLL_Switcher::the_languages()}.
* @return array Language switcher elements.
*/
protected function get_elements( $args ) {
$first = true;
$out = array();
$filter = $args['hide_if_empty'] ? 'hide_empty' : '';
foreach ( $this->links->model->languages->filter( $filter )->get_list() as $language ) {
$id = (int) $language->term_id;
$order = (int) $language->term_group;
$slug = $language->slug;
$locale = $language->get_locale( 'display' );
$is_rtl = $language->is_rtl;
$item_classes = array( 'lang-item', 'lang-item-' . $id, 'lang-item-' . esc_attr( $slug ) );
$classes = isset( $args['classes'] ) && is_array( $args['classes'] ) ?
array_merge(
$item_classes,
$args['classes']
) :
$item_classes;
$link_classes = $args['link_classes'] ?? array();
$current_lang = $this->get_current_language( $args ) === $slug;
if ( $current_lang ) {
if ( $args['hide_current'] && ! ( $args['dropdown'] && ! $args['raw'] ) ) {
continue; // Hide current language except for dropdown
} else {
$classes[] = 'current-lang';
}
}
$url = $this->get_link( $language, $args );
if ( $no_translation = empty( $url ) ) {
$classes[] = 'no-translation';
}
/**
* Filter the link in the language switcher
*
* @since 0.7
*
* @param string|null $url The link, null if no translation was found.
* @param string $slug The language code.
* @param string $locale The language locale
*/
$url = apply_filters( 'pll_the_language_link', $url, $slug, $language->locale );
// Hide if no translation exists
if ( empty( $url ) && $args['hide_if_no_translation'] ) {
continue;
}
$url = empty( $url ) || $args['force_home'] ? $this->links->get_home_url( $language ) : $url; // If the page is not translated, link to the home page
$name = $args['show_names'] || ! $args['show_flags'] || $args['raw'] ? ( 'slug' == $args['display_names_as'] ? $slug : $language->name ) : '';
if ( $args['raw'] && ! $args['show_flags'] ) {
$flag = $language->get_display_flag_url();
} elseif ( $args['show_flags'] ) {
$flag = $language->get_display_flag( empty( $args['show_names'] ) ? 'alt' : 'no-alt' );
} else {
$flag = '';
}
if ( $first ) {
$classes[] = 'lang-item-first';
$first = false;
}
$out[ $slug ] = compact( 'id', 'order', 'slug', 'locale', 'is_rtl', 'name', 'url', 'flag', 'current_lang', 'no_translation', 'classes', 'link_classes' );
}
return $out;
}
/**
* Displays a language switcher
* or returns the raw elements to build a custom language switcher.
*
* @since 0.1
*
* @param PLL_Links $links Instance of PLL_Links.
* @param array $args {
* Optional array of arguments.
*
* @type int $dropdown The list is displayed as dropdown if set, defaults to 0.
* @type int $echo Echoes the list if set to 1, defaults to 1.
* @type int $hide_if_empty Hides languages with no posts ( or pages ) if set to 1, defaults to 1.
* @type int $show_flags Displays flags if set to 1, defaults to 0.
* @type int $show_names Shows language names if set to 1, defaults to 1.
* @type string $display_names_as Whether to display the language name or its slug, valid options are 'slug' and 'name', defaults to name.
* @type int $force_home Will always link to home in translated language if set to 1, defaults to 0.
* @type int $hide_if_no_translation Hides the link if there is no translation if set to 1, defaults to 0.
* @type int $hide_current Hides the current language if set to 1, defaults to 0.
* @type int $post_id Returns links to the translations of the post defined by post_id if set, defaults not set.
* @type int $raw Return a raw array instead of html markup if set to 1, defaults to 0.
* @type string $item_spacing Whether to preserve or discard whitespace between list items, valid options are 'preserve' and 'discard', defaults to 'preserve'.
* @type int $admin_render Allows to force the current language code in an admin context if set, default to 0. Need to set the admin_current_lang argument below.
* @type string $admin_current_lang The current language code in an admin context. Need to set the admin_render to 1, defaults not set.
* @type string[] $classes A list of CSS classes to set to each elements outputted.
* @type string[] $link_classes A list of CSS classes to set to each link outputted.
* }
* @return string|array either the html markup of the switcher or the raw elements to build a custom language switcher
*/
public function the_languages( $links, $args = array() ) {
$this->links = $links;
$args = wp_parse_args( $args, self::DEFAULTS );
/**
* Filter the arguments of the 'pll_the_languages' template tag
*
* @since 1.5
*
* @param array $args
*/
$args = apply_filters( 'pll_the_languages_args', $args );
// Force not to hide the language for the widget preview even if the option is checked.
if ( $this->links instanceof PLL_Admin_Links ) {
$args['hide_if_no_translation'] = 0;
}
// Prevents showing empty options in `<select>`.
if ( $args['dropdown'] && ! $args['raw'] ) {
$args['show_names'] = 1;
}
$elements = $this->get_elements( $args );
if ( $args['raw'] ) {
return $elements;
}
if ( $args['dropdown'] ) {
$args['name'] = 'lang_choice_' . $args['dropdown'];
$args['class'] = 'pll-switcher-select';
$args['value'] = 'url';
$args['selected'] = $this->get_link( $this->links->model->get_language( $this->get_current_language( $args ) ), $args );
$walker = new PLL_Walker_Dropdown();
} else {
$walker = new PLL_Walker_List();
}
// Cast each element to stdClass because $walker::walk() expects an array of objects.
foreach ( $elements as $i => $element ) {
$elements[ $i ] = (object) $element;
}
/**
* Filter the whole html markup returned by the 'pll_the_languages' template tag
*
* @since 0.8
*
* @param string $html html returned/outputted by the template tag
* @param array $args arguments passed to the template tag
*/
$out = apply_filters( 'pll_the_languages', $walker->walk( $elements, -1, $args ), $args );
// Javascript to switch the language when using a dropdown list.
if ( $args['dropdown'] && 0 === $args['admin_render'] ) {
// Accept only few valid characters for the urls_x variable name (as the widget id includes '-' which is invalid).
$out .= sprintf(
'<script%1$s>
document.getElementById( "%2$s" ).addEventListener( "change", function ( event ) { location.href = event.currentTarget.value; } )
</script>',
current_theme_supports( 'html5', 'script' ) ? '' : ' type="text/javascript"',
esc_js( $args['name'] )
);
}
if ( $args['echo'] ) {
echo $out; // phpcs:ignore WordPress.Security.EscapeOutput
}
return $out;
}
}