polylang / src / frontend / accept-languages-collection.php

accept-languages-collection.php in Polylang trunk, at src/frontend/accept-languages-collection.php

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1	<?php
2	/**
3	* @package Polylang
4	*/
5
6	/**
7	* Class PLL_Accept_Languages_Collection.
8	*
9	* Represents a collection of values parsed from an Accept-Language HTTP header.
10	*
11	* @since 3.0
12	*/
13	class PLL_Accept_Languages_Collection {
14	/**
15	* @var PLL_Accept_Language[]
16	*/
17	protected $accept_languages = array();
18
19	/**
20	* Parse Accept-Language HTTP header according to IETF BCP 47.
21	*
22	* @since 3.0
23	*
24	* @param string $http_header Value of the Accept-Language HTTP Header. Formatted as stated BCP 47 for language tags {@see https://tools.ietf.org/html/bcp47}.
25	* @return PLL_Accept_Languages_Collection
26	*/
27	public static function from_accept_language_header( $http_header ) {
28	$lang_parse = array();
29	// Break up string into pieces ( languages and q factors ).
30	$language_pattern = implode( '', PLL_Accept_Language::SUBTAG_PATTERNS );
31	$quality_pattern = '\s;\sq\s=\s((?>1\|0)(?>\.[0-9]+)?)';
32	$full_pattern = "/{$language_pattern}(?:{$quality_pattern})?/i";
33
34	preg_match_all(
35	$full_pattern,
36	$http_header,
37	$lang_parse,
38	PREG_SET_ORDER
39	);
40
41	return new PLL_Accept_Languages_Collection(
42	array_map(
43	array( PLL_Accept_Language::class, 'from_array' ),
44	$lang_parse
45	)
46	);
47	}
48
49	/**
50	* PLL_Accept_Languages_Collection constructor.
51	*
52	* @since 3.0
53	*
54	* @param PLL_Accept_Language[] $accept_languages Objects representing Accept-Language HTTP headers.
55	*/
56	public function __construct( $accept_languages = array() ) {
57	$this->accept_languages = $accept_languages;
58	}
59
60	/**
61	* Bubble sort (need a stable sort for Android, so can't use a PHP sort function).
62	*
63	* @since 3.0
64	*
65	* @return void
66	*/
67	public function bubble_sort() {
68	$k = $this->accept_languages;
69	$v = array_map(
70	function ( $accept_lang ) {
71	return $accept_lang->get_quality();
72	},
73	$this->accept_languages
74	);
75
76	if ( $n = count( $k ) ) {
77
78	if ( $n > 1 ) {
79	for ( $i = 2; $i <= $n; $i++ ) {
80	for ( $j = 0; $j <= $n - 2; $j++ ) {
81	if ( $v[ $j ] < $v[ $j + 1 ] ) {
82	// Swap values.
83	$temp = $v[ $j ];
84	$v[ $j ] = $v[ $j + 1 ];
85	$v[ $j + 1 ] = $temp;
86	// Swap keys.
87	$temp = $k[ $j ];
88	$k[ $j ] = $k[ $j + 1 ];
89	$k[ $j + 1 ] = $temp;
90	}
91	}
92	}
93	}
94	$this->accept_languages = array_filter(
95	$k,
96	function ( $accept_lang ) {
97	return $accept_lang->get_quality() > 0;
98	}
99	);
100	}
101	}
102
103	/**
104	* Looks through sorted list and use first one that matches our language list.
105	*
106	* @since 3.0
107	*
108	* @param PLL_Language[] $languages The language list.
109	* @return string\|false A language slug if there's a match, false otherwise.
110	*/
111	public function find_best_match( $languages = array() ) {
112	foreach ( $this->accept_languages as $accept_lang ) {
113	// First loop to match the exact locale.
114	foreach ( $languages as $language ) {
115	if ( 0 === strcasecmp( $accept_lang, $language->get_locale( 'display' ) ) ) {
116	return $language->slug;
117	}
118	}
119
120	// In order of priority.
121	$subsets = array();
122	if ( ! empty( $accept_lang->get_subtag( 'region' ) ) ) {
123	$subsets[] = $accept_lang->get_subtag( 'language' ) . '-' . $accept_lang->get_subtag( 'region' );
124	$subsets[] = $accept_lang->get_subtag( 'region' );
125	}
126	if ( ! empty( $accept_lang->get_subtag( 'variant' ) ) ) {
127	$subsets[] = $accept_lang->get_subtag( 'language' ) . '-' . $accept_lang->get_subtag( 'variant' );
128	}
129	$subsets[] = $accept_lang->get_subtag( 'language' );
130
131	// More loops to match the subsets.
132	foreach ( $languages as $language ) {
133	foreach ( $subsets as $subset ) {
134
135	if ( 0 === stripos( $subset, $language->slug ) \|\| 0 === stripos( $language->get_locale( 'display' ), $subset ) ) {
136	return $language->slug;
137	}
138	}
139	}
140	}
141	return false;
142	}
143	}
144