aboutsummaryrefslogtreecommitdiffhomepage
path: root/inc/Twig/Environment.php
blob: 3afa73d639d22719857d28b1c170d7ba816d7dbb (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
<?php

/*
 * This file is part of Twig.
 *
 * (c) 2009 Fabien Potencier
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * Stores the Twig configuration.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class Twig_Environment
{
    const VERSION = '1.13.1';

    protected $charset;
    protected $loader;
    protected $debug;
    protected $autoReload;
    protected $cache;
    protected $lexer;
    protected $parser;
    protected $compiler;
    protected $baseTemplateClass;
    protected $extensions;
    protected $parsers;
    protected $visitors;
    protected $filters;
    protected $tests;
    protected $functions;
    protected $globals;
    protected $runtimeInitialized;
    protected $extensionInitialized;
    protected $loadedTemplates;
    protected $strictVariables;
    protected $unaryOperators;
    protected $binaryOperators;
    protected $templateClassPrefix = '__TwigTemplate_';
    protected $functionCallbacks;
    protected $filterCallbacks;
    protected $staging;

    /**
     * Constructor.
     *
     * Available options:
     *
     *  * debug: When set to true, it automatically set "auto_reload" to true as
     *           well (default to false).
     *
     *  * charset: The charset used by the templates (default to UTF-8).
     *
     *  * base_template_class: The base template class to use for generated
     *                         templates (default to Twig_Template).
     *
     *  * cache: An absolute path where to store the compiled templates, or
     *           false to disable compilation cache (default).
     *
     *  * auto_reload: Whether to reload the template is the original source changed.
     *                 If you don't provide the auto_reload option, it will be
     *                 determined automatically base on the debug value.
     *
     *  * strict_variables: Whether to ignore invalid variables in templates
     *                      (default to false).
     *
     *  * autoescape: Whether to enable auto-escaping (default to html):
     *                  * false: disable auto-escaping
     *                  * true: equivalent to html
     *                  * html, js: set the autoescaping to one of the supported strategies
     *                  * PHP callback: a PHP callback that returns an escaping strategy based on the template "filename"
     *
     *  * optimizations: A flag that indicates which optimizations to apply
     *                   (default to -1 which means that all optimizations are enabled;
     *                   set it to 0 to disable).
     *
     * @param Twig_LoaderInterface $loader  A Twig_LoaderInterface instance
     * @param array                $options An array of options
     */
    public function __construct(Twig_LoaderInterface $loader = null, $options = array())
    {
        if (null !== $loader) {
            $this->setLoader($loader);
        }

        $options = array_merge(array(
            'debug'               => false,
            'charset'             => 'UTF-8',
            'base_template_class' => 'Twig_Template',
            'strict_variables'    => false,
            'autoescape'          => 'html',
            'cache'               => false,
            'auto_reload'         => null,
            'optimizations'       => -1,
        ), $options);

        $this->debug              = (bool) $options['debug'];
        $this->charset            = strtoupper($options['charset']);
        $this->baseTemplateClass  = $options['base_template_class'];
        $this->autoReload         = null === $options['auto_reload'] ? $this->debug : (bool) $options['auto_reload'];
        $this->strictVariables    = (bool) $options['strict_variables'];
        $this->runtimeInitialized = false;
        $this->setCache($options['cache']);
        $this->functionCallbacks = array();
        $this->filterCallbacks = array();

        $this->addExtension(new Twig_Extension_Core());
        $this->addExtension(new Twig_Extension_Escaper($options['autoescape']));
        $this->addExtension(new Twig_Extension_Optimizer($options['optimizations']));
        $this->extensionInitialized = false;
        $this->staging = new Twig_Extension_Staging();
    }

    /**
     * Gets the base template class for compiled templates.
     *
     * @return string The base template class name
     */
    public function getBaseTemplateClass()
    {
        return $this->baseTemplateClass;
    }

    /**
     * Sets the base template class for compiled templates.
     *
     * @param string $class The base template class name
     */
    public function setBaseTemplateClass($class)
    {
        $this->baseTemplateClass = $class;
    }

    /**
     * Enables debugging mode.
     */
    public function enableDebug()
    {
        $this->debug = true;
    }

    /**
     * Disables debugging mode.
     */
    public function disableDebug()
    {
        $this->debug = false;
    }

    /**
     * Checks if debug mode is enabled.
     *
     * @return Boolean true if debug mode is enabled, false otherwise
     */
    public function isDebug()
    {
        return $this->debug;
    }

    /**
     * Enables the auto_reload option.
     */
    public function enableAutoReload()
    {
        $this->autoReload = true;
    }

    /**
     * Disables the auto_reload option.
     */
    public function disableAutoReload()
    {
        $this->autoReload = false;
    }

    /**
     * Checks if the auto_reload option is enabled.
     *
     * @return Boolean true if auto_reload is enabled, false otherwise
     */
    public function isAutoReload()
    {
        return $this->autoReload;
    }

    /**
     * Enables the strict_variables option.
     */
    public function enableStrictVariables()
    {
        $this->strictVariables = true;
    }

    /**
     * Disables the strict_variables option.
     */
    public function disableStrictVariables()
    {
        $this->strictVariables = false;
    }

    /**
     * Checks if the strict_variables option is enabled.
     *
     * @return Boolean true if strict_variables is enabled, false otherwise
     */
    public function isStrictVariables()
    {
        return $this->strictVariables;
    }

    /**
     * Gets the cache directory or false if cache is disabled.
     *
     * @return string|false
     */
    public function getCache()
    {
        return $this->cache;
    }

     /**
      * Sets the cache directory or false if cache is disabled.
      *
      * @param string|false $cache The absolute path to the compiled templates,
      *                            or false to disable cache
      */
    public function setCache($cache)
    {
        $this->cache = $cache ? $cache : false;
    }

    /**
     * Gets the cache filename for a given template.
     *
     * @param string $name The template name
     *
     * @return string The cache file name
     */
    public function getCacheFilename($name)
    {
        if (false === $this->cache) {
            return false;
        }

        $class = substr($this->getTemplateClass($name), strlen($this->templateClassPrefix));

        return $this->getCache().'/'.substr($class, 0, 2).'/'.substr($class, 2, 2).'/'.substr($class, 4).'.php';
    }

    /**
     * Gets the template class associated with the given string.
     *
     * @param string  $name  The name for which to calculate the template class name
     * @param integer $index The index if it is an embedded template
     *
     * @return string The template class name
     */
    public function getTemplateClass($name, $index = null)
    {
        return $this->templateClassPrefix.md5($this->getLoader()->getCacheKey($name)).(null === $index ? '' : '_'.$index);
    }

    /**
     * Gets the template class prefix.
     *
     * @return string The template class prefix
     */
    public function getTemplateClassPrefix()
    {
        return $this->templateClassPrefix;
    }

    /**
     * Renders a template.
     *
     * @param string $name    The template name
     * @param array  $context An array of parameters to pass to the template
     *
     * @return string The rendered template
     */
    public function render($name, array $context = array())
    {
        return $this->loadTemplate($name)->render($context);
    }

    /**
     * Displays a template.
     *
     * @param string $name    The template name
     * @param array  $context An array of parameters to pass to the template
     */
    public function display($name, array $context = array())
    {
        $this->loadTemplate($name)->display($context);
    }

    /**
     * Loads a template by name.
     *
     * @param string  $name  The template name
     * @param integer $index The index if it is an embedded template
     *
     * @return Twig_TemplateInterface A template instance representing the given template name
     */
    public function loadTemplate($name, $index = null)
    {
        $cls = $this->getTemplateClass($name, $index);

        if (isset($this->loadedTemplates[$cls])) {
            return $this->loadedTemplates[$cls];
        }

        if (!class_exists($cls, false)) {
            if (false === $cache = $this->getCacheFilename($name)) {
                eval('?>'.$this->compileSource($this->getLoader()->getSource($name), $name));
            } else {
                if (!is_file($cache) || ($this->isAutoReload() && !$this->isTemplateFresh($name, filemtime($cache)))) {
                    $this->writeCacheFile($cache, $this->compileSource($this->getLoader()->getSource($name), $name));
                }

                require_once $cache;
            }
        }

        if (!$this->runtimeInitialized) {
            $this->initRuntime();
        }

        return $this->loadedTemplates[$cls] = new $cls($this);
    }

    /**
     * Returns true if the template is still fresh.
     *
     * Besides checking the loader for freshness information,
     * this method also checks if the enabled extensions have
     * not changed.
     *
     * @param string    $name The template name
     * @param timestamp $time The last modification time of the cached template
     *
     * @return Boolean true if the template is fresh, false otherwise
     */
    public function isTemplateFresh($name, $time)
    {
        foreach ($this->extensions as $extension) {
            $r = new ReflectionObject($extension);
            if (filemtime($r->getFileName()) > $time) {
                return false;
            }
        }

        return $this->getLoader()->isFresh($name, $time);
    }

    public function resolveTemplate($names)
    {
        if (!is_array($names)) {
            $names = array($names);
        }

        foreach ($names as $name) {
            if ($name instanceof Twig_Template) {
                return $name;
            }

            try {
                return $this->loadTemplate($name);
            } catch (Twig_Error_Loader $e) {
            }
        }

        if (1 === count($names)) {
            throw $e;
        }

        throw new Twig_Error_Loader(sprintf('Unable to find one of the following templates: "%s".', implode('", "', $names)));
    }

    /**
     * Clears the internal template cache.
     */
    public function clearTemplateCache()
    {
        $this->loadedTemplates = array();
    }

    /**
     * Clears the template cache files on the filesystem.
     */
    public function clearCacheFiles()
    {
        if (false === $this->cache) {
            return;
        }

        foreach (new RecursiveIteratorIterator(new RecursiveDirectoryIterator($this->cache), RecursiveIteratorIterator::LEAVES_ONLY) as $file) {
            if ($file->isFile()) {
                @unlink($file->getPathname());
            }
        }
    }

    /**
     * Gets the Lexer instance.
     *
     * @return Twig_LexerInterface A Twig_LexerInterface instance
     */
    public function getLexer()
    {
        if (null === $this->lexer) {
            $this->lexer = new Twig_Lexer($this);
        }

        return $this->lexer;
    }

    /**
     * Sets the Lexer instance.
     *
     * @param Twig_LexerInterface A Twig_LexerInterface instance
     */
    public function setLexer(Twig_LexerInterface $lexer)
    {
        $this->lexer = $lexer;
    }

    /**
     * Tokenizes a source code.
     *
     * @param string $source The template source code
     * @param string $name   The template name
     *
     * @return Twig_TokenStream A Twig_TokenStream instance
     */
    public function tokenize($source, $name = null)
    {
        return $this->getLexer()->tokenize($source, $name);
    }

    /**
     * Gets the Parser instance.
     *
     * @return Twig_ParserInterface A Twig_ParserInterface instance
     */
    public function getParser()
    {
        if (null === $this->parser) {
            $this->parser = new Twig_Parser($this);
        }

        return $this->parser;
    }

    /**
     * Sets the Parser instance.
     *
     * @param Twig_ParserInterface A Twig_ParserInterface instance
     */
    public function setParser(Twig_ParserInterface $parser)
    {
        $this->parser = $parser;
    }

    /**
     * Parses a token stream.
     *
     * @param Twig_TokenStream $tokens A Twig_TokenStream instance
     *
     * @return Twig_Node_Module A Node tree
     */
    public function parse(Twig_TokenStream $tokens)
    {
        return $this->getParser()->parse($tokens);
    }

    /**
     * Gets the Compiler instance.
     *
     * @return Twig_CompilerInterface A Twig_CompilerInterface instance
     */
    public function getCompiler()
    {
        if (null === $this->compiler) {
            $this->compiler = new Twig_Compiler($this);
        }

        return $this->compiler;
    }

    /**
     * Sets the Compiler instance.
     *
     * @param Twig_CompilerInterface $compiler A Twig_CompilerInterface instance
     */
    public function setCompiler(Twig_CompilerInterface $compiler)
    {
        $this->compiler = $compiler;
    }

    /**
     * Compiles a Node.
     *
     * @param Twig_NodeInterface $node A Twig_NodeInterface instance
     *
     * @return string The compiled PHP source code
     */
    public function compile(Twig_NodeInterface $node)
    {
        return $this->getCompiler()->compile($node)->getSource();
    }

    /**
     * Compiles a template source code.
     *
     * @param string $source The template source code
     * @param string $name   The template name
     *
     * @return string The compiled PHP source code
     */
    public function compileSource($source, $name = null)
    {
        try {
            return $this->compile($this->parse($this->tokenize($source, $name)));
        } catch (Twig_Error $e) {
            $e->setTemplateFile($name);
            throw $e;
        } catch (Exception $e) {
            throw new Twig_Error_Runtime(sprintf('An exception has been thrown during the compilation of a template ("%s").', $e->getMessage()), -1, $name, $e);
        }
    }

    /**
     * Sets the Loader instance.
     *
     * @param Twig_LoaderInterface $loader A Twig_LoaderInterface instance
     */
    public function setLoader(Twig_LoaderInterface $loader)
    {
        $this->loader = $loader;
    }

    /**
     * Gets the Loader instance.
     *
     * @return Twig_LoaderInterface A Twig_LoaderInterface instance
     */
    public function getLoader()
    {
        if (null === $this->loader) {
            throw new LogicException('You must set a loader first.');
        }

        return $this->loader;
    }

    /**
     * Sets the default template charset.
     *
     * @param string $charset The default charset
     */
    public function setCharset($charset)
    {
        $this->charset = strtoupper($charset);
    }

    /**
     * Gets the default template charset.
     *
     * @return string The default charset
     */
    public function getCharset()
    {
        return $this->charset;
    }

    /**
     * Initializes the runtime environment.
     */
    public function initRuntime()
    {
        $this->runtimeInitialized = true;

        foreach ($this->getExtensions() as $extension) {
            $extension->initRuntime($this);
        }
    }

    /**
     * Returns true if the given extension is registered.
     *
     * @param string $name The extension name
     *
     * @return Boolean Whether the extension is registered or not
     */
    public function hasExtension($name)
    {
        return isset($this->extensions[$name]);
    }

    /**
     * Gets an extension by name.
     *
     * @param string $name The extension name
     *
     * @return Twig_ExtensionInterface A Twig_ExtensionInterface instance
     */
    public function getExtension($name)
    {
        if (!isset($this->extensions[$name])) {
            throw new Twig_Error_Runtime(sprintf('The "%s" extension is not enabled.', $name));
        }

        return $this->extensions[$name];
    }

    /**
     * Registers an extension.
     *
     * @param Twig_ExtensionInterface $extension A Twig_ExtensionInterface instance
     */
    public function addExtension(Twig_ExtensionInterface $extension)
    {
        if ($this->extensionInitialized) {
            throw new LogicException(sprintf('Unable to register extension "%s" as extensions have already been initialized.', $extension->getName()));
        }

        $this->extensions[$extension->getName()] = $extension;
    }

    /**
     * Removes an extension by name.
     *
     * This method is deprecated and you should not use it.
     *
     * @param string $name The extension name
     *
     * @deprecated since 1.12 (to be removed in 2.0)
     */
    public function removeExtension($name)
    {
        if ($this->extensionInitialized) {
            throw new LogicException(sprintf('Unable to remove extension "%s" as extensions have already been initialized.', $name));
        }

        unset($this->extensions[$name]);
    }

    /**
     * Registers an array of extensions.
     *
     * @param array $extensions An array of extensions
     */
    public function setExtensions(array $extensions)
    {
        foreach ($extensions as $extension) {
            $this->addExtension($extension);
        }
    }

    /**
     * Returns all registered extensions.
     *
     * @return array An array of extensions
     */
    public function getExtensions()
    {
        return $this->extensions;
    }

    /**
     * Registers a Token Parser.
     *
     * @param Twig_TokenParserInterface $parser A Twig_TokenParserInterface instance
     */
    public function addTokenParser(Twig_TokenParserInterface $parser)
    {
        if ($this->extensionInitialized) {
            throw new LogicException('Unable to add a token parser as extensions have already been initialized.');
        }

        $this->staging->addTokenParser($parser);
    }

    /**
     * Gets the registered Token Parsers.
     *
     * @return Twig_TokenParserBrokerInterface A broker containing token parsers
     */
    public function getTokenParsers()
    {
        if (!$this->extensionInitialized) {
            $this->initExtensions();
        }

        return $this->parsers;
    }

    /**
     * Gets registered tags.
     *
     * Be warned that this method cannot return tags defined by Twig_TokenParserBrokerInterface classes.
     *
     * @return Twig_TokenParserInterface[] An array of Twig_TokenParserInterface instances
     */
    public function getTags()
    {
        $tags = array();
        foreach ($this->getTokenParsers()->getParsers() as $parser) {
            if ($parser instanceof Twig_TokenParserInterface) {
                $tags[$parser->getTag()] = $parser;
            }
        }

        return $tags;
    }

    /**
     * Registers a Node Visitor.
     *
     * @param Twig_NodeVisitorInterface $visitor A Twig_NodeVisitorInterface instance
     */
    public function addNodeVisitor(Twig_NodeVisitorInterface $visitor)
    {
        if ($this->extensionInitialized) {
            throw new LogicException('Unable to add a node visitor as extensions have already been initialized.', $extension->getName());
        }

        $this->staging->addNodeVisitor($visitor);
    }

    /**
     * Gets the registered Node Visitors.
     *
     * @return Twig_NodeVisitorInterface[] An array of Twig_NodeVisitorInterface instances
     */
    public function getNodeVisitors()
    {
        if (!$this->extensionInitialized) {
            $this->initExtensions();
        }

        return $this->visitors;
    }

    /**
     * Registers a Filter.
     *
     * @param string|Twig_SimpleFilter               $name   The filter name or a Twig_SimpleFilter instance
     * @param Twig_FilterInterface|Twig_SimpleFilter $filter A Twig_FilterInterface instance or a Twig_SimpleFilter instance
     */
    public function addFilter($name, $filter = null)
    {
        if (!$name instanceof Twig_SimpleFilter && !($filter instanceof Twig_SimpleFilter || $filter instanceof Twig_FilterInterface)) {
            throw new LogicException('A filter must be an instance of Twig_FilterInterface or Twig_SimpleFilter');
        }

        if ($name instanceof Twig_SimpleFilter) {
            $filter = $name;
            $name = $filter->getName();
        }
        
        if ($this->extensionInitialized) {
            throw new LogicException(sprintf('Unable to add filter "%s" as extensions have already been initialized.', $name));
        }
        
        $this->staging->addFilter($name, $filter);
    }

    /**
     * Get a filter by name.
     *
     * Subclasses may override this method and load filters differently;
     * so no list of filters is available.
     *
     * @param string $name The filter name
     *
     * @return Twig_Filter|false A Twig_Filter instance or false if the filter does not exist
     */
    public function getFilter($name)
    {
        if (!$this->extensionInitialized) {
            $this->initExtensions();
        }

        if (isset($this->filters[$name])) {
            return $this->filters[$name];
        }

        foreach ($this->filters as $pattern => $filter) {
            $pattern = str_replace('\\*', '(.*?)', preg_quote($pattern, '#'), $count);

            if ($count) {
                if (preg_match('#^'.$pattern.'$#', $name, $matches)) {
                    array_shift($matches);
                    $filter->setArguments($matches);

                    return $filter;
                }
            }
        }

        foreach ($this->filterCallbacks as $callback) {
            if (false !== $filter = call_user_func($callback, $name)) {
                return $filter;
            }
        }

        return false;
    }

    public function registerUndefinedFilterCallback($callable)
    {
        $this->filterCallbacks[] = $callable;
    }

    /**
     * Gets the registered Filters.
     *
     * Be warned that this method cannot return filters defined with registerUndefinedFunctionCallback.
     *
     * @return Twig_FilterInterface[] An array of Twig_FilterInterface instances
     *
     * @see registerUndefinedFilterCallback
     */
    public function getFilters()
    {
        if (!$this->extensionInitialized) {
            $this->initExtensions();
        }

        return $this->filters;
    }

    /**
     * Registers a Test.
     *
     * @param string|Twig_SimpleTest             $name The test name or a Twig_SimpleTest instance
     * @param Twig_TestInterface|Twig_SimpleTest $test A Twig_TestInterface instance or a Twig_SimpleTest instance
     */
    public function addTest($name, $test = null)
    {
        if (!$name instanceof Twig_SimpleTest && !($test instanceof Twig_SimpleTest || $test instanceof Twig_TestInterface)) {
            throw new LogicException('A test must be an instance of Twig_TestInterface or Twig_SimpleTest');
        }

        if ($name instanceof Twig_SimpleTest) {
            $test = $name;
            $name = $test->getName();
        }
        
        if ($this->extensionInitialized) {
            throw new LogicException(sprintf('Unable to add test "%s" as extensions have already been initialized.', $name));
        }

        $this->staging->addTest($name, $test);
    }

    /**
     * Gets the registered Tests.
     *
     * @return Twig_TestInterface[] An array of Twig_TestInterface instances
     */
    public function getTests()
    {
        if (!$this->extensionInitialized) {
            $this->initExtensions();
        }

        return $this->tests;
    }

    /**
     * Gets a test by name.
     *
     * @param string $name The test name
     *
     * @return Twig_Test|false A Twig_Test instance or false if the test does not exist
     */
    public function getTest($name)
    {
        if (!$this->extensionInitialized) {
            $this->initExtensions();
        }

        if (isset($this->tests[$name])) {
            return $this->tests[$name];
        }

        return false;
    }

    /**
     * Registers a Function.
     *
     * @param string|Twig_SimpleFunction                 $name     The function name or a Twig_SimpleFunction instance
     * @param Twig_FunctionInterface|Twig_SimpleFunction $function A Twig_FunctionInterface instance or a Twig_SimpleFunction instance
     */
    public function addFunction($name, $function = null)
    {
        if (!$name instanceof Twig_SimpleFunction && !($function instanceof Twig_SimpleFunction || $function instanceof Twig_FunctionInterface)) {
            throw new LogicException('A function must be an instance of Twig_FunctionInterface or Twig_SimpleFunction');
        }

        if ($name instanceof Twig_SimpleFunction) {
            $function = $name;
            $name = $function->getName();
        }
        
        if ($this->extensionInitialized) {
            throw new LogicException(sprintf('Unable to add function "%s" as extensions have already been initialized.', $name));
        }
        
        $this->staging->addFunction($name, $function);
    }

    /**
     * Get a function by name.
     *
     * Subclasses may override this method and load functions differently;
     * so no list of functions is available.
     *
     * @param string $name function name
     *
     * @return Twig_Function|false A Twig_Function instance or false if the function does not exist
     */
    public function getFunction($name)
    {
        if (!$this->extensionInitialized) {
            $this->initExtensions();
        }

        if (isset($this->functions[$name])) {
            return $this->functions[$name];
        }

        foreach ($this->functions as $pattern => $function) {
            $pattern = str_replace('\\*', '(.*?)', preg_quote($pattern, '#'), $count);

            if ($count) {
                if (preg_match('#^'.$pattern.'$#', $name, $matches)) {
                    array_shift($matches);
                    $function->setArguments($matches);

                    return $function;
                }
            }
        }

        foreach ($this->functionCallbacks as $callback) {
            if (false !== $function = call_user_func($callback, $name)) {
                return $function;
            }
        }

        return false;
    }

    public function registerUndefinedFunctionCallback($callable)
    {
        $this->functionCallbacks[] = $callable;
    }

    /**
     * Gets registered functions.
     *
     * Be warned that this method cannot return functions defined with registerUndefinedFunctionCallback.
     *
     * @return Twig_FunctionInterface[] An array of Twig_FunctionInterface instances
     *
     * @see registerUndefinedFunctionCallback
     */
    public function getFunctions()
    {
        if (!$this->extensionInitialized) {
            $this->initExtensions();
        }

        return $this->functions;
    }

    /**
     * Registers a Global.
     *
     * New globals can be added before compiling or rendering a template;
     * but after, you can only update existing globals.
     *
     * @param string $name  The global name
     * @param mixed  $value The global value
     */
    public function addGlobal($name, $value)
    {
        if ($this->extensionInitialized || $this->runtimeInitialized) {
            if (null === $this->globals) {
                $this->globals = $this->initGlobals();
            }

            /* This condition must be uncommented in Twig 2.0
            if (!array_key_exists($name, $this->globals)) {
                throw new LogicException(sprintf('Unable to add global "%s" as the runtime or the extensions have already been initialized.', $name));
            }
            */
        }

        if ($this->extensionInitialized || $this->runtimeInitialized) {
            // update the value
            $this->globals[$name] = $value;
        } else {
            $this->staging->addGlobal($name, $value);
        }
    }

    /**
     * Gets the registered Globals.
     *
     * @return array An array of globals
     */
    public function getGlobals()
    {
        if (!$this->runtimeInitialized && !$this->extensionInitialized) {
            return $this->initGlobals();
        }

        if (null === $this->globals) {
            $this->globals = $this->initGlobals();
        }

        return $this->globals;
    }

    /**
     * Merges a context with the defined globals.
     *
     * @param array $context An array representing the context
     *
     * @return array The context merged with the globals
     */
    public function mergeGlobals(array $context)
    {
        // we don't use array_merge as the context being generally
        // bigger than globals, this code is faster.
        foreach ($this->getGlobals() as $key => $value) {
            if (!array_key_exists($key, $context)) {
                $context[$key] = $value;
            }
        }

        return $context;
    }

    /**
     * Gets the registered unary Operators.
     *
     * @return array An array of unary operators
     */
    public function getUnaryOperators()
    {
        if (!$this->extensionInitialized) {
            $this->initExtensions();
        }

        return $this->unaryOperators;
    }

    /**
     * Gets the registered binary Operators.
     *
     * @return array An array of binary operators
     */
    public function getBinaryOperators()
    {
        if (!$this->extensionInitialized) {
            $this->initExtensions();
        }

        return $this->binaryOperators;
    }

    public function computeAlternatives($name, $items)
    {
        $alternatives = array();
        foreach ($items as $item) {
            $lev = levenshtein($name, $item);
            if ($lev <= strlen($name) / 3 || false !== strpos($item, $name)) {
                $alternatives[$item] = $lev;
            }
        }
        asort($alternatives);

        return array_keys($alternatives);
    }

    protected function initGlobals()
    {
        $globals = array();
        foreach ($this->extensions as $extension) {
            $extGlob = $extension->getGlobals();
            if (!is_array($extGlob)) {
                throw new UnexpectedValueException(sprintf('"%s::getGlobals()" must return an array of globals.', get_class($extension)));
            }

            $globals[] = $extGlob;
        }

        $globals[] = $this->staging->getGlobals();

        return call_user_func_array('array_merge', $globals);
    }

    protected function initExtensions()
    {
        if ($this->extensionInitialized) {
            return;
        }

        $this->extensionInitialized = true;
        $this->parsers = new Twig_TokenParserBroker();
        $this->filters = array();
        $this->functions = array();
        $this->tests = array();
        $this->visitors = array();
        $this->unaryOperators = array();
        $this->binaryOperators = array();

        foreach ($this->extensions as $extension) {
            $this->initExtension($extension);
        }
        $this->initExtension($this->staging);
    }

    protected function initExtension(Twig_ExtensionInterface $extension)
    {
        // filters
        foreach ($extension->getFilters() as $name => $filter) {
            if ($name instanceof Twig_SimpleFilter) {
                $filter = $name;
                $name = $filter->getName();
            } elseif ($filter instanceof Twig_SimpleFilter) {
                $name = $filter->getName();
            }

            $this->filters[$name] = $filter;
        }

        // functions
        foreach ($extension->getFunctions() as $name => $function) {
            if ($name instanceof Twig_SimpleFunction) {
                $function = $name;
                $name = $function->getName();
            } elseif ($function instanceof Twig_SimpleFunction) {
                $name = $function->getName();
            }

            $this->functions[$name] = $function;
        }

        // tests
        foreach ($extension->getTests() as $name => $test) {
            if ($name instanceof Twig_SimpleTest) {
                $test = $name;
                $name = $test->getName();
            } elseif ($test instanceof Twig_SimpleTest) {
                $name = $test->getName();
            }

            $this->tests[$name] = $test;
        }

        // token parsers
        foreach ($extension->getTokenParsers() as $parser) {
            if ($parser instanceof Twig_TokenParserInterface) {
                $this->parsers->addTokenParser($parser);
            } elseif ($parser instanceof Twig_TokenParserBrokerInterface) {
                $this->parsers->addTokenParserBroker($parser);
            } else {
                throw new LogicException('getTokenParsers() must return an array of Twig_TokenParserInterface or Twig_TokenParserBrokerInterface instances');
            }
        }

        // node visitors
        foreach ($extension->getNodeVisitors() as $visitor) {
            $this->visitors[] = $visitor;
        }

        // operators
        if ($operators = $extension->getOperators()) {
            if (2 !== count($operators)) {
                throw new InvalidArgumentException(sprintf('"%s::getOperators()" does not return a valid operators array.', get_class($extension)));
            }

            $this->unaryOperators = array_merge($this->unaryOperators, $operators[0]);
            $this->binaryOperators = array_merge($this->binaryOperators, $operators[1]);
        }
    }

    protected function writeCacheFile($file, $content)
    {
        $dir = dirname($file);
        if (!is_dir($dir)) {
            if (false === @mkdir($dir, 0777, true) && !is_dir($dir)) {
                throw new RuntimeException(sprintf("Unable to create the cache directory (%s).", $dir));
            }
        } elseif (!is_writable($dir)) {
            throw new RuntimeException(sprintf("Unable to write in the cache directory (%s).", $dir));
        }

        $tmpFile = tempnam(dirname($file), basename($file));
        if (false !== @file_put_contents($tmpFile, $content)) {
            // rename does not work on Win32 before 5.2.6
            if (@rename($tmpFile, $file) || (@copy($tmpFile, $file) && unlink($tmpFile))) {
                @chmod($file, 0666 & ~umask());

                return;
            }
        }

        throw new RuntimeException(sprintf('Failed to write cache file "%s".', $file));
    }
}