polylang / src / switcher.php

switcher.php in Polylang 3.8.9, at src/switcher.php

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1	<?php
2	/**
3	* @package Polylang
4	*/
5
6	/**
7	* A class to display a language switcher on frontend
8	*
9	* @since 1.2
10	*/
11	class PLL_Switcher {
12	public const DEFAULTS = array(
13	'dropdown' => 0, // Display as list and not as dropdown.
14	'echo' => 1, // Echoes the list.
15	'hide_if_empty' => 1, // Hides languages with no posts (or pages).
16	'show_flags' => 0, // Don't show flags.
17	'show_names' => 1, // Show language names.
18	'display_names_as' => 'name', // Display the language name.
19	'force_home' => 0, // Tries to find a translation.
20	'hide_if_no_translation' => 0, // Don't hide the link if there is no translation.
21	'hide_current' => 0, // Don't hide the current language.
22	'post_id' => null, // Link to the translations of the current page.
23	'raw' => 0, // Build the language switcher.
24	'item_spacing' => 'preserve', // Preserve whitespace between list items.
25	'admin_render' => 0, // Make the switcher in a frontend context.
26	'admin_current_lang' => null, // Use the global current language.
27	);
28
29	/**
30	* @var PLL_Links\|null
31	*/
32	protected $links;
33
34	/**
35	* Returns options available for the language switcher - menu or widget
36	* either strings to display the options or default values
37	*
38	* @since 0.7
39	*
40	* @param string $type optional either 'menu', 'widget' or 'block', defaults to 'widget'
41	* @param string $key optional either 'string' or 'default', defaults to 'string'
42	* @return array list of switcher options strings or default values
43	*/
44	public static function get_switcher_options( $type = 'widget', $key = 'string' ) {
45	$options = array(
46	'dropdown' => array( 'string' => __( 'Displays as a dropdown', 'polylang' ), 'default' => 0 ),
47	'show_names' => array( 'string' => __( 'Displays language names', 'polylang' ), 'default' => 1 ),
48	'show_flags' => array( 'string' => __( 'Displays flags', 'polylang' ), 'default' => 0 ),
49	'force_home' => array( 'string' => __( 'Forces link to front page', 'polylang' ), 'default' => 0 ),
50	'hide_current' => array( 'string' => __( 'Hides the current language', 'polylang' ), 'default' => 0 ),
51	'hide_if_no_translation' => array( 'string' => __( 'Hides languages with no translation', 'polylang' ), 'default' => 0 ),
52	);
53	return wp_list_pluck( $options, $key );
54	}
55
56	/**
57	* Returns the current language code.
58	*
59	* @since 3.0
60	*
61	* @param array $args Arguments passed to {@see PLL_Switcher::the_languages()}.
62	* @return string
63	*/
64	protected function get_current_language( $args ) {
65	if ( $args['admin_current_lang'] ) {
66	return $args['admin_current_lang'];
67	}
68
69	if ( isset( $this->links->curlang ) ) {
70	return $this->links->curlang->slug;
71	}
72
73	return $this->links->options['default_lang'];
74	}
75
76	/**
77	* Returns the link for a given language.
78	*
79	* @since 3.0
80	*
81	* @param PLL_Language $language Language.
82	* @param array $args Arguments passed to {@see PLL_Switcher::the_languages()}.
83	* @return string\|null
84	*/
85	protected function get_link( $language, $args ) {
86	global $post;
87
88	// Priority to the post passed in parameters.
89	if ( null !== $args['post_id'] ) {
90	$tr_id = $this->links->model->post->get( $args['post_id'], $language );
91	if ( $tr_id && $this->links->model->post->current_user_can_read( $tr_id ) ) {
92	return get_permalink( $tr_id );
93	}
94	}
95
96	// If we are on frontend.
97	if ( $this->links instanceof PLL_Frontend_Links ) {
98	return $this->links->get_translation_url( $language );
99	}
100
101	// For blocks in posts in REST requests.
102	if ( $post instanceof WP_Post ) {
103	$tr_id = $this->links->model->post->get( $post->ID, $language );
104	if ( $tr_id && $this->links->model->post->current_user_can_read( $tr_id ) ) {
105	return get_permalink( $tr_id );
106	}
107	}
108
109	return null;
110	}
111
112	/**
113	* Get the language elements for use in a walker
114	*
115	* @since 1.2
116	*
117	* @param array $args Arguments passed to {@see PLL_Switcher::the_languages()}.
118	* @return array Language switcher elements.
119	*/
120	protected function get_elements( $args ) {
121	$first = true;
122	$out = array();
123
124	$filter = $args['hide_if_empty'] ? 'hide_empty' : '';
125	foreach ( $this->links->model->languages->filter( $filter )->get_list() as $language ) {
126	$id = (int) $language->term_id;
127	$order = (int) $language->term_group;
128	$slug = $language->slug;
129	$locale = $language->get_locale( 'display' );
130	$is_rtl = $language->is_rtl;
131	$item_classes = array( 'lang-item', 'lang-item-' . $id, 'lang-item-' . esc_attr( $slug ) );
132	$classes = isset( $args['classes'] ) && is_array( $args['classes'] ) ?
133	array_merge(
134	$item_classes,
135	$args['classes']
136	) :
137	$item_classes;
138	$link_classes = $args['link_classes'] ?? array();
139	$current_lang = $this->get_current_language( $args ) === $slug;
140
141	if ( $current_lang ) {
142	if ( $args['hide_current'] && ! ( $args['dropdown'] && ! $args['raw'] ) ) {
143	continue; // Hide current language except for dropdown
144	} else {
145	$classes[] = 'current-lang';
146	}
147	}
148
149	$url = $this->get_link( $language, $args );
150
151	if ( $no_translation = empty( $url ) ) {
152	$classes[] = 'no-translation';
153	}
154
155	/**
156	* Filter the link in the language switcher
157	*
158	* @since 0.7
159	*
160	* @param string\|null $url The link, null if no translation was found.
161	* @param string $slug The language code.
162	* @param string $locale The language locale
163	*/
164	$url = apply_filters( 'pll_the_language_link', $url, $slug, $language->locale );
165
166	// Hide if no translation exists
167	if ( empty( $url ) && $args['hide_if_no_translation'] ) {
168	continue;
169	}
170
171	$url = empty( $url ) \|\| $args['force_home'] ? $this->links->get_home_url( $language ) : $url; // If the page is not translated, link to the home page
172
173	$name = $args['show_names'] \|\| ! $args['show_flags'] \|\| $args['raw'] ? ( 'slug' == $args['display_names_as'] ? $slug : $language->name ) : '';
174
175	if ( $args['raw'] && ! $args['show_flags'] ) {
176	$flag = $language->get_display_flag_url();
177	} elseif ( $args['show_flags'] ) {
178	$flag = $language->get_display_flag( empty( $args['show_names'] ) ? 'alt' : 'no-alt' );
179	} else {
180	$flag = '';
181	}
182
183	if ( $first ) {
184	$classes[] = 'lang-item-first';
185	$first = false;
186	}
187
188	$out[ $slug ] = compact( 'id', 'order', 'slug', 'locale', 'is_rtl', 'name', 'url', 'flag', 'current_lang', 'no_translation', 'classes', 'link_classes' );
189	}
190
191	return $out;
192	}
193
194	/**
195	* Displays a language switcher
196	* or returns the raw elements to build a custom language switcher.
197	*
198	* @since 0.1
199	*
200	* @param PLL_Links $links Instance of PLL_Links.
201	* @param array $args {
202	* Optional array of arguments.
203	*
204	* @type int $dropdown The list is displayed as dropdown if set, defaults to 0.
205	* @type int $echo Echoes the list if set to 1, defaults to 1.
206	* @type int $hide_if_empty Hides languages with no posts ( or pages ) if set to 1, defaults to 1.
207	* @type int $show_flags Displays flags if set to 1, defaults to 0.
208	* @type int $show_names Shows language names if set to 1, defaults to 1.
209	* @type string $display_names_as Whether to display the language name or its slug, valid options are 'slug' and 'name', defaults to name.
210	* @type int $force_home Will always link to home in translated language if set to 1, defaults to 0.
211	* @type int $hide_if_no_translation Hides the link if there is no translation if set to 1, defaults to 0.
212	* @type int $hide_current Hides the current language if set to 1, defaults to 0.
213	* @type int $post_id Returns links to the translations of the post defined by post_id if set, defaults not set.
214	* @type int $raw Return a raw array instead of html markup if set to 1, defaults to 0.
215	* @type string $item_spacing Whether to preserve or discard whitespace between list items, valid options are 'preserve' and 'discard', defaults to 'preserve'.
216	* @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.
217	* @type string $admin_current_lang The current language code in an admin context. Need to set the admin_render to 1, defaults not set.
218	* @type string[] $classes A list of CSS classes to set to each elements outputted.
219	* @type string[] $link_classes A list of CSS classes to set to each link outputted.
220	* }
221	* @return string\|array either the html markup of the switcher or the raw elements to build a custom language switcher
222	*/
223	public function the_languages( $links, $args = array() ) {
224
225	$this->links = $links;
226	$args = wp_parse_args( $args, self::DEFAULTS );
227
228	/**
229	* Filter the arguments of the 'pll_the_languages' template tag
230	*
231	* @since 1.5
232	*
233	* @param array $args
234	*/
235	$args = apply_filters( 'pll_the_languages_args', $args );
236
237	// Force not to hide the language for the widget preview even if the option is checked.
238	if ( $this->links instanceof PLL_Admin_Links ) {
239	$args['hide_if_no_translation'] = 0;
240	}
241
242	// Prevents showing empty options in `<select>`.
243	if ( $args['dropdown'] && ! $args['raw'] ) {
244	$args['show_names'] = 1;
245	}
246
247	$elements = $this->get_elements( $args );
248
249	if ( $args['raw'] ) {
250	return $elements;
251	}
252
253	if ( $args['dropdown'] ) {
254	$args['name'] = 'lang_choice_' . $args['dropdown'];
255	$args['class'] = 'pll-switcher-select';
256	$args['value'] = 'url';
257	$args['selected'] = $this->get_link( $this->links->model->get_language( $this->get_current_language( $args ) ), $args );
258	$walker = new PLL_Walker_Dropdown();
259	} else {
260	$walker = new PLL_Walker_List();
261	}
262
263	// Cast each element to stdClass because $walker::walk() expects an array of objects.
264	foreach ( $elements as $i => $element ) {
265	$elements[ $i ] = (object) $element;
266	}
267
268	/**
269	* Filter the whole html markup returned by the 'pll_the_languages' template tag
270	*
271	* @since 0.8
272	*
273	* @param string $html html returned/outputted by the template tag
274	* @param array $args arguments passed to the template tag
275	*/
276	$out = apply_filters( 'pll_the_languages', $walker->walk( $elements, -1, $args ), $args );
277
278	// Javascript to switch the language when using a dropdown list.
279	if ( $args['dropdown'] && 0 === $args['admin_render'] ) {
280	// Accept only few valid characters for the urls_x variable name (as the widget id includes '-' which is invalid).
281	$out .= sprintf(
282	'<script%1$s>
283	document.getElementById( "%2$s" ).addEventListener( "change", function ( event ) { location.href = event.currentTarget.value; } )
284	</script>',
285	current_theme_supports( 'html5', 'script' ) ? '' : ' type="text/javascript"',
286	esc_js( $args['name'] )
287	);
288	}
289
290	if ( $args['echo'] ) {
291	echo $out; // phpcs:ignore WordPress.Security.EscapeOutput
292	}
293	return $out;
294	}
295	}
296