1: <?php
2:
3: /**
4: * Class responsible for generating HTMLPurifier_Language objects, managing
5: * caching and fallbacks.
6: * @note Thanks to MediaWiki for the general logic, although this version
7: * has been entirely rewritten
8: * @todo Serialized cache for languages
9: */
10: class HTMLPurifier_LanguageFactory
11: {
12:
13: /**
14: * Cache of language code information used to load HTMLPurifier_Language objects
15: * Structure is: $factory->cache[$language_code][$key] = $value
16: * @value array map
17: */
18: public $cache;
19:
20: /**
21: * Valid keys in the HTMLPurifier_Language object. Designates which
22: * variables to slurp out of a message file.
23: * @value array list
24: */
25: public $keys = array('fallback', 'messages', 'errorNames');
26:
27: /**
28: * Instance of HTMLPurifier_AttrDef_Lang to validate language codes
29: * @value object HTMLPurifier_AttrDef_Lang
30: */
31: protected $validator;
32:
33: /**
34: * Cached copy of dirname(__FILE__), directory of current file without
35: * trailing slash
36: * @value string filename
37: */
38: protected $dir;
39:
40: /**
41: * Keys whose contents are a hash map and can be merged
42: * @value array lookup
43: */
44: protected $mergeable_keys_map = array('messages' => true, 'errorNames' => true);
45:
46: /**
47: * Keys whose contents are a list and can be merged
48: * @value array lookup
49: */
50: protected $mergeable_keys_list = array();
51:
52: /**
53: * Retrieve sole instance of the factory.
54: * @param $prototype Optional prototype to overload sole instance with,
55: * or bool true to reset to default factory.
56: */
57: public static function instance($prototype = null) {
58: static $instance = null;
59: if ($prototype !== null) {
60: $instance = $prototype;
61: } elseif ($instance === null || $prototype == true) {
62: $instance = new HTMLPurifier_LanguageFactory();
63: $instance->setup();
64: }
65: return $instance;
66: }
67:
68: /**
69: * Sets up the singleton, much like a constructor
70: * @note Prevents people from getting this outside of the singleton
71: */
72: public function setup() {
73: $this->validator = new HTMLPurifier_AttrDef_Lang();
74: $this->dir = HTMLPURIFIER_PREFIX . '/HTMLPurifier';
75: }
76:
77: /**
78: * Creates a language object, handles class fallbacks
79: * @param $config Instance of HTMLPurifier_Config
80: * @param $context Instance of HTMLPurifier_Context
81: * @param $code Code to override configuration with. Private parameter.
82: */
83: public function create($config, $context, $code = false) {
84:
85: // validate language code
86: if ($code === false) {
87: $code = $this->validator->validate(
88: $config->get('Core.Language'), $config, $context
89: );
90: } else {
91: $code = $this->validator->validate($code, $config, $context);
92: }
93: if ($code === false) $code = 'en'; // malformed code becomes English
94:
95: $pcode = str_replace('-', '_', $code); // make valid PHP classname
96: static $depth = 0; // recursion protection
97:
98: if ($code == 'en') {
99: $lang = new HTMLPurifier_Language($config, $context);
100: } else {
101: $class = 'HTMLPurifier_Language_' . $pcode;
102: $file = $this->dir . '/Language/classes/' . $code . '.php';
103: if (file_exists($file) || class_exists($class, false)) {
104: $lang = new $class($config, $context);
105: } else {
106: // Go fallback
107: $raw_fallback = $this->getFallbackFor($code);
108: $fallback = $raw_fallback ? $raw_fallback : 'en';
109: $depth++;
110: $lang = $this->create($config, $context, $fallback);
111: if (!$raw_fallback) {
112: $lang->error = true;
113: }
114: $depth--;
115: }
116: }
117:
118: $lang->code = $code;
119:
120: return $lang;
121:
122: }
123:
124: /**
125: * Returns the fallback language for language
126: * @note Loads the original language into cache
127: * @param $code string language code
128: */
129: public function getFallbackFor($code) {
130: $this->loadLanguage($code);
131: return $this->cache[$code]['fallback'];
132: }
133:
134: /**
135: * Loads language into the cache, handles message file and fallbacks
136: * @param $code string language code
137: */
138: public function loadLanguage($code) {
139: static $languages_seen = array(); // recursion guard
140:
141: // abort if we've already loaded it
142: if (isset($this->cache[$code])) return;
143:
144: // generate filename
145: $filename = $this->dir . '/Language/messages/' . $code . '.php';
146:
147: // default fallback : may be overwritten by the ensuing include
148: $fallback = ($code != 'en') ? 'en' : false;
149:
150: // load primary localisation
151: if (!file_exists($filename)) {
152: // skip the include: will rely solely on fallback
153: $filename = $this->dir . '/Language/messages/en.php';
154: $cache = array();
155: } else {
156: include $filename;
157: $cache = compact($this->keys);
158: }
159:
160: // load fallback localisation
161: if (!empty($fallback)) {
162:
163: // infinite recursion guard
164: if (isset($languages_seen[$code])) {
165: trigger_error('Circular fallback reference in language ' .
166: $code, E_USER_ERROR);
167: $fallback = 'en';
168: }
169: $language_seen[$code] = true;
170:
171: // load the fallback recursively
172: $this->loadLanguage($fallback);
173: $fallback_cache = $this->cache[$fallback];
174:
175: // merge fallback with current language
176: foreach ( $this->keys as $key ) {
177: if (isset($cache[$key]) && isset($fallback_cache[$key])) {
178: if (isset($this->mergeable_keys_map[$key])) {
179: $cache[$key] = $cache[$key] + $fallback_cache[$key];
180: } elseif (isset($this->mergeable_keys_list[$key])) {
181: $cache[$key] = array_merge( $fallback_cache[$key], $cache[$key] );
182: }
183: } else {
184: $cache[$key] = $fallback_cache[$key];
185: }
186: }
187:
188: }
189:
190: // save to cache for later retrieval
191: $this->cache[$code] = $cache;
192:
193: return;
194: }
195:
196: }
197:
198: // vim: et sw=4 sts=4
199: