1: <?php
 2: 
 3: /*
 4:  * This file is part of the Symfony package.
 5:  *
 6:  * (c) Fabien Potencier <fabien@symfony.com>
 7:  *
 8:  * For the full copyright and license information, please view the LICENSE
 9:  * file that was distributed with this source code.
10:  */
11: 
12: namespace Symfony\Component\Yaml;
13: 
14: /**
15:  * Escaper encapsulates escaping rules for single and double-quoted
16:  * YAML strings.
17:  *
18:  * @author Matthew Lewinski <matthew@lewinski.org>
19:  */
20: class Escaper
21: {
22:     // Characters that would cause a dumped string to require double quoting.
23:     const REGEX_CHARACTER_TO_ESCAPE = "[\\x00-\\x1f]|\xc2\x85|\xc2\xa0|\xe2\x80\xa8|\xe2\x80\xa9";
24: 
25:     // Mapping arrays for escaping a double quoted string. The backslash is
26:     // first to ensure proper escaping because str_replace operates iteratively
27:     // on the input arrays. This ordering of the characters avoids the use of strtr,
28:     // which performs more slowly.
29:     private static $escapees = array('\\', '\\\\', '\\"', '"',
30:                                      "\x00",  "\x01",  "\x02",  "\x03",  "\x04",  "\x05",  "\x06",  "\x07",
31:                                      "\x08",  "\x09",  "\x0a",  "\x0b",  "\x0c",  "\x0d",  "\x0e",  "\x0f",
32:                                      "\x10",  "\x11",  "\x12",  "\x13",  "\x14",  "\x15",  "\x16",  "\x17",
33:                                      "\x18",  "\x19",  "\x1a",  "\x1b",  "\x1c",  "\x1d",  "\x1e",  "\x1f",
34:                                      "\xc2\x85", "\xc2\xa0", "\xe2\x80\xa8", "\xe2\x80\xa9",);
35:     private static $escaped = array('\\\\', '\\"', '\\\\', '\\"',
36:                                      "\\0",   "\\x01", "\\x02", "\\x03", "\\x04", "\\x05", "\\x06", "\\a",
37:                                      "\\b",   "\\t",   "\\n",   "\\v",   "\\f",   "\\r",   "\\x0e", "\\x0f",
38:                                      "\\x10", "\\x11", "\\x12", "\\x13", "\\x14", "\\x15", "\\x16", "\\x17",
39:                                      "\\x18", "\\x19", "\\x1a", "\\e",   "\\x1c", "\\x1d", "\\x1e", "\\x1f",
40:                                      "\\N", "\\_", "\\L", "\\P",);
41: 
42:     /**
43:      * Determines if a PHP value would require double quoting in YAML.
44:      *
45:      * @param string $value A PHP value
46:      *
47:      * @return bool True if the value would require double quotes.
48:      */
49:     public static function requiresDoubleQuoting($value)
50:     {
51:         return preg_match('/'.self::REGEX_CHARACTER_TO_ESCAPE.'/u', $value);
52:     }
53: 
54:     /**
55:      * Escapes and surrounds a PHP value with double quotes.
56:      *
57:      * @param string $value A PHP value
58:      *
59:      * @return string The quoted, escaped string
60:      */
61:     public static function escapeWithDoubleQuotes($value)
62:     {
63:         return sprintf('"%s"', str_replace(self::$escapees, self::$escaped, $value));
64:     }
65: 
66:     /**
67:      * Determines if a PHP value would require single quoting in YAML.
68:      *
69:      * @param string $value A PHP value
70:      *
71:      * @return bool True if the value would require single quotes.
72:      */
73:     public static function requiresSingleQuoting($value)
74:     {
75:         // Determines if a PHP value is entirely composed of a value that would
76:         // require single quoting in YAML.
77:         if (in_array(strtolower($value), array('null', '~', 'true', 'false', 'y', 'n', 'yes', 'no', 'on', 'off'))) {
78:             return true;
79:         }
80: 
81:         // Determines if the PHP value contains any single characters that would
82:         // cause it to require single quoting in YAML.
83:         return preg_match('/[ \s \' " \: \{ \} \[ \] , & \* \# \?] | \A[ \- ? | < > = ! % @ ` ]/x', $value);
84:     }
85: 
86:     /**
87:      * Escapes and surrounds a PHP value with single quotes.
88:      *
89:      * @param string $value A PHP value
90:      *
91:      * @return string The quoted, escaped string
92:      */
93:     public static function escapeWithSingleQuotes($value)
94:     {
95:         return sprintf("'%s'", str_replace('\'', '\'\'', $value));
96:     }
97: }
98: