1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | JSON::XS - JSON serialising/deserialising, done correctly and fast |
3 | JSON::XS - JSON serialising/deserialising, done correctly and fast |
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4 | |
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5 | JSON::XS - 正しくて高速な JSON シリアライザ/デシリアライザ |
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6 | (http://fleur.hio.jp/perldoc/mix/lib/JSON/XS.html) |
4 | |
7 | |
5 | =head1 SYNOPSIS |
8 | =head1 SYNOPSIS |
6 | |
9 | |
7 | use JSON::XS; |
10 | use JSON::XS; |
8 | |
11 | |
9 | # exported functions, they croak on error |
12 | # exported functions, they croak on error |
10 | # and expect/generate UTF-8 |
13 | # and expect/generate UTF-8 |
11 | |
14 | |
12 | $utf8_encoded_json_text = to_json $perl_hash_or_arrayref; |
15 | $utf8_encoded_json_text = to_json $perl_hash_or_arrayref; |
13 | $perl_hash_or_arrayref = from_json $utf8_encoded_json_text; |
16 | $perl_hash_or_arrayref = from_json $utf8_encoded_json_text; |
14 | |
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15 | # objToJson and jsonToObj aliases to to_json and from_json |
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16 | # are exported for compatibility to the JSON module, |
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17 | # but should not be used in new code. |
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18 | |
17 | |
19 | # OO-interface |
18 | # OO-interface |
20 | |
19 | |
21 | $coder = JSON::XS->new->ascii->pretty->allow_nonref; |
20 | $coder = JSON::XS->new->ascii->pretty->allow_nonref; |
22 | $pretty_printed_unencoded = $coder->encode ($perl_scalar); |
21 | $pretty_printed_unencoded = $coder->encode ($perl_scalar); |
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41 | |
40 | |
42 | =head2 FEATURES |
41 | =head2 FEATURES |
43 | |
42 | |
44 | =over 4 |
43 | =over 4 |
45 | |
44 | |
46 | =item * correct unicode handling |
45 | =item * correct Unicode handling |
47 | |
46 | |
48 | This module knows how to handle Unicode, and even documents how and when |
47 | This module knows how to handle Unicode, and even documents how and when |
49 | it does so. |
48 | it does so. |
50 | |
49 | |
51 | =item * round-trip integrity |
50 | =item * round-trip integrity |
… | |
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71 | This module has both a simple functional interface as well as an OO |
70 | This module has both a simple functional interface as well as an OO |
72 | interface. |
71 | interface. |
73 | |
72 | |
74 | =item * reasonably versatile output formats |
73 | =item * reasonably versatile output formats |
75 | |
74 | |
76 | You can choose between the most compact guarenteed single-line format |
75 | You can choose between the most compact guaranteed single-line format |
77 | possible (nice for simple line-based protocols), a pure-ascii format |
76 | possible (nice for simple line-based protocols), a pure-ascii format |
78 | (for when your transport is not 8-bit clean, still supports the whole |
77 | (for when your transport is not 8-bit clean, still supports the whole |
79 | unicode range), or a pretty-printed format (for when you want to read that |
78 | Unicode range), or a pretty-printed format (for when you want to read that |
80 | stuff). Or you can combine those features in whatever way you like. |
79 | stuff). Or you can combine those features in whatever way you like. |
81 | |
80 | |
82 | =back |
81 | =back |
83 | |
82 | |
84 | =cut |
83 | =cut |
85 | |
84 | |
86 | package JSON::XS; |
85 | package JSON::XS; |
87 | |
86 | |
88 | use strict; |
87 | use strict; |
89 | |
88 | |
90 | our $VERSION = '1.4'; |
89 | our $VERSION = '1.53'; |
91 | our @ISA = qw(Exporter); |
90 | our @ISA = qw(Exporter); |
92 | |
91 | |
93 | our @EXPORT = qw(to_json from_json objToJson jsonToObj); |
92 | our @EXPORT = qw(to_json from_json); |
94 | |
93 | |
95 | use Exporter; |
94 | use Exporter; |
96 | use XSLoader; |
95 | use XSLoader; |
97 | |
96 | |
98 | =head1 FUNCTIONAL INTERFACE |
97 | =head1 FUNCTIONAL INTERFACE |
99 | |
98 | |
100 | The following convinience methods are provided by this module. They are |
99 | The following convenience methods are provided by this module. They are |
101 | exported by default: |
100 | exported by default: |
102 | |
101 | |
103 | =over 4 |
102 | =over 4 |
104 | |
103 | |
105 | =item $json_text = to_json $perl_scalar |
104 | =item $json_text = to_json $perl_scalar |
106 | |
105 | |
107 | Converts the given Perl data structure (a simple scalar or a reference to |
106 | Converts the given Perl data structure to a UTF-8 encoded, binary string |
108 | a hash or array) to a UTF-8 encoded, binary string (that is, the string contains |
107 | (that is, the string contains octets only). Croaks on error. |
109 | octets only). Croaks on error. |
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110 | |
108 | |
111 | This function call is functionally identical to: |
109 | This function call is functionally identical to: |
112 | |
110 | |
113 | $json_text = JSON::XS->new->utf8->encode ($perl_scalar) |
111 | $json_text = JSON::XS->new->utf8->encode ($perl_scalar) |
114 | |
112 | |
115 | except being faster. |
113 | except being faster. |
116 | |
114 | |
117 | =item $perl_scalar = from_json $json_text |
115 | =item $perl_scalar = from_json $json_text |
118 | |
116 | |
119 | The opposite of C<to_json>: expects an UTF-8 (binary) string and tries to |
117 | The opposite of C<to_json>: expects an UTF-8 (binary) string and tries |
120 | parse that as an UTF-8 encoded JSON text, returning the resulting simple |
118 | to parse that as an UTF-8 encoded JSON text, returning the resulting |
121 | scalar or reference. Croaks on error. |
119 | reference. Croaks on error. |
122 | |
120 | |
123 | This function call is functionally identical to: |
121 | This function call is functionally identical to: |
124 | |
122 | |
125 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
123 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
126 | |
124 | |
… | |
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136 | Perl. |
134 | Perl. |
137 | |
135 | |
138 | =back |
136 | =back |
139 | |
137 | |
140 | |
138 | |
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139 | =head1 A FEW NOTES ON UNICODE AND PERL |
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140 | |
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141 | Since this often leads to confusion, here are a few very clear words on |
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142 | how Unicode works in Perl, modulo bugs. |
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143 | |
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144 | =over 4 |
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145 | |
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146 | =item 1. Perl strings can store characters with ordinal values > 255. |
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147 | |
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148 | This enables you to store Unicode characters as single characters in a |
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149 | Perl string - very natural. |
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150 | |
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151 | =item 2. Perl does I<not> associate an encoding with your strings. |
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152 | |
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153 | Unless you force it to, e.g. when matching it against a regex, or printing |
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154 | the scalar to a file, in which case Perl either interprets your string as |
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155 | locale-encoded text, octets/binary, or as Unicode, depending on various |
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156 | settings. In no case is an encoding stored together with your data, it is |
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157 | I<use> that decides encoding, not any magical metadata. |
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158 | |
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159 | =item 3. The internal utf-8 flag has no meaning with regards to the |
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160 | encoding of your string. |
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161 | |
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162 | Just ignore that flag unless you debug a Perl bug, a module written in |
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163 | XS or want to dive into the internals of perl. Otherwise it will only |
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164 | confuse you, as, despite the name, it says nothing about how your string |
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165 | is encoded. You can have Unicode strings with that flag set, with that |
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166 | flag clear, and you can have binary data with that flag set and that flag |
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167 | clear. Other possibilities exist, too. |
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168 | |
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169 | If you didn't know about that flag, just the better, pretend it doesn't |
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170 | exist. |
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171 | |
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172 | =item 4. A "Unicode String" is simply a string where each character can be |
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173 | validly interpreted as a Unicode codepoint. |
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174 | |
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175 | If you have UTF-8 encoded data, it is no longer a Unicode string, but a |
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176 | Unicode string encoded in UTF-8, giving you a binary string. |
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177 | |
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178 | =item 5. A string containing "high" (> 255) character values is I<not> a UTF-8 string. |
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179 | |
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180 | It's a fact. Learn to live with it. |
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181 | |
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182 | =back |
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183 | |
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184 | I hope this helps :) |
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185 | |
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186 | |
141 | =head1 OBJECT-ORIENTED INTERFACE |
187 | =head1 OBJECT-ORIENTED INTERFACE |
142 | |
188 | |
143 | The object oriented interface lets you configure your own encoding or |
189 | The object oriented interface lets you configure your own encoding or |
144 | decoding style, within the limits of supported formats. |
190 | decoding style, within the limits of supported formats. |
145 | |
191 | |
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156 | my $json = JSON::XS->new->utf8->space_after->encode ({a => [1,2]}) |
202 | my $json = JSON::XS->new->utf8->space_after->encode ({a => [1,2]}) |
157 | => {"a": [1, 2]} |
203 | => {"a": [1, 2]} |
158 | |
204 | |
159 | =item $json = $json->ascii ([$enable]) |
205 | =item $json = $json->ascii ([$enable]) |
160 | |
206 | |
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207 | =item $enabled = $json->get_ascii |
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208 | |
161 | If C<$enable> is true (or missing), then the C<encode> method will not |
209 | If C<$enable> is true (or missing), then the C<encode> method will not |
162 | generate characters outside the code range C<0..127> (which is ASCII). Any |
210 | generate characters outside the code range C<0..127> (which is ASCII). Any |
163 | unicode characters outside that range will be escaped using either a |
211 | Unicode characters outside that range will be escaped using either a |
164 | single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence, |
212 | single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence, |
165 | as per RFC4627. The resulting encoded JSON text can be treated as a native |
213 | as per RFC4627. The resulting encoded JSON text can be treated as a native |
166 | unicode string, an ascii-encoded, latin1-encoded or UTF-8 encoded string, |
214 | Unicode string, an ascii-encoded, latin1-encoded or UTF-8 encoded string, |
167 | or any other superset of ASCII. |
215 | or any other superset of ASCII. |
168 | |
216 | |
169 | If C<$enable> is false, then the C<encode> method will not escape Unicode |
217 | If C<$enable> is false, then the C<encode> method will not escape Unicode |
170 | characters unless required by the JSON syntax or other flags. This results |
218 | characters unless required by the JSON syntax or other flags. This results |
171 | in a faster and more compact format. |
219 | in a faster and more compact format. |
… | |
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177 | JSON::XS->new->ascii (1)->encode ([chr 0x10401]) |
225 | JSON::XS->new->ascii (1)->encode ([chr 0x10401]) |
178 | => ["\ud801\udc01"] |
226 | => ["\ud801\udc01"] |
179 | |
227 | |
180 | =item $json = $json->latin1 ([$enable]) |
228 | =item $json = $json->latin1 ([$enable]) |
181 | |
229 | |
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230 | =item $enabled = $json->get_latin1 |
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231 | |
182 | If C<$enable> is true (or missing), then the C<encode> method will encode |
232 | If C<$enable> is true (or missing), then the C<encode> method will encode |
183 | the resulting JSON text as latin1 (or iso-8859-1), escaping any characters |
233 | the resulting JSON text as latin1 (or iso-8859-1), escaping any characters |
184 | outside the code range C<0..255>. The resulting string can be treated as a |
234 | outside the code range C<0..255>. The resulting string can be treated as a |
185 | latin1-encoded JSON text or a native unicode string. The C<decode> method |
235 | latin1-encoded JSON text or a native Unicode string. The C<decode> method |
186 | will not be affected in any way by this flag, as C<decode> by default |
236 | will not be affected in any way by this flag, as C<decode> by default |
187 | expects unicode, which is a strict superset of latin1. |
237 | expects Unicode, which is a strict superset of latin1. |
188 | |
238 | |
189 | If C<$enable> is false, then the C<encode> method will not escape Unicode |
239 | If C<$enable> is false, then the C<encode> method will not escape Unicode |
190 | characters unless required by the JSON syntax or other flags. |
240 | characters unless required by the JSON syntax or other flags. |
191 | |
241 | |
192 | The main use for this flag is efficiently encoding binary data as JSON |
242 | The main use for this flag is efficiently encoding binary data as JSON |
193 | text, as most octets will not be escaped, resulting in a smaller encoded |
243 | text, as most octets will not be escaped, resulting in a smaller encoded |
194 | size. The disadvantage is that the resulting JSON text is encoded |
244 | size. The disadvantage is that the resulting JSON text is encoded |
195 | in latin1 (and must correctly be treated as such when storing and |
245 | in latin1 (and must correctly be treated as such when storing and |
196 | transfering), a rare encoding for JSON. It is therefore most useful when |
246 | transferring), a rare encoding for JSON. It is therefore most useful when |
197 | you want to store data structures known to contain binary data efficiently |
247 | you want to store data structures known to contain binary data efficiently |
198 | in files or databases, not when talking to other JSON encoders/decoders. |
248 | in files or databases, not when talking to other JSON encoders/decoders. |
199 | |
249 | |
200 | JSON::XS->new->latin1->encode (["\x{89}\x{abc}"] |
250 | JSON::XS->new->latin1->encode (["\x{89}\x{abc}"] |
201 | => ["\x{89}\\u0abc"] # (perl syntax, U+abc escaped, U+89 not) |
251 | => ["\x{89}\\u0abc"] # (perl syntax, U+abc escaped, U+89 not) |
202 | |
252 | |
203 | =item $json = $json->utf8 ([$enable]) |
253 | =item $json = $json->utf8 ([$enable]) |
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254 | |
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255 | =item $enabled = $json->get_utf8 |
204 | |
256 | |
205 | If C<$enable> is true (or missing), then the C<encode> method will encode |
257 | If C<$enable> is true (or missing), then the C<encode> method will encode |
206 | the JSON result into UTF-8, as required by many protocols, while the |
258 | the JSON result into UTF-8, as required by many protocols, while the |
207 | C<decode> method expects to be handled an UTF-8-encoded string. Please |
259 | C<decode> method expects to be handled an UTF-8-encoded string. Please |
208 | note that UTF-8-encoded strings do not contain any characters outside the |
260 | note that UTF-8-encoded strings do not contain any characters outside the |
209 | range C<0..255>, they are thus useful for bytewise/binary I/O. In future |
261 | range C<0..255>, they are thus useful for bytewise/binary I/O. In future |
210 | versions, enabling this option might enable autodetection of the UTF-16 |
262 | versions, enabling this option might enable autodetection of the UTF-16 |
211 | and UTF-32 encoding families, as described in RFC4627. |
263 | and UTF-32 encoding families, as described in RFC4627. |
212 | |
264 | |
213 | If C<$enable> is false, then the C<encode> method will return the JSON |
265 | If C<$enable> is false, then the C<encode> method will return the JSON |
214 | string as a (non-encoded) unicode string, while C<decode> expects thus a |
266 | string as a (non-encoded) Unicode string, while C<decode> expects thus a |
215 | unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs |
267 | Unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs |
216 | to be done yourself, e.g. using the Encode module. |
268 | to be done yourself, e.g. using the Encode module. |
217 | |
269 | |
218 | Example, output UTF-16BE-encoded JSON: |
270 | Example, output UTF-16BE-encoded JSON: |
219 | |
271 | |
220 | use Encode; |
272 | use Encode; |
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224 | |
276 | |
225 | use Encode; |
277 | use Encode; |
226 | $object = JSON::XS->new->decode (decode "UTF-32LE", $jsontext); |
278 | $object = JSON::XS->new->decode (decode "UTF-32LE", $jsontext); |
227 | |
279 | |
228 | =item $json = $json->pretty ([$enable]) |
280 | =item $json = $json->pretty ([$enable]) |
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281 | |
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282 | =item $enabled = $json->get_pretty |
229 | |
283 | |
230 | This enables (or disables) all of the C<indent>, C<space_before> and |
284 | This enables (or disables) all of the C<indent>, C<space_before> and |
231 | C<space_after> (and in the future possibly more) flags in one call to |
285 | C<space_after> (and in the future possibly more) flags in one call to |
232 | generate the most readable (or most compact) form possible. |
286 | generate the most readable (or most compact) form possible. |
233 | |
287 | |
… | |
… | |
242 | ] |
296 | ] |
243 | } |
297 | } |
244 | |
298 | |
245 | =item $json = $json->indent ([$enable]) |
299 | =item $json = $json->indent ([$enable]) |
246 | |
300 | |
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301 | =item $enabled = $json->get_indent |
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302 | |
247 | If C<$enable> is true (or missing), then the C<encode> method will use a multiline |
303 | If C<$enable> is true (or missing), then the C<encode> method will use a multiline |
248 | format as output, putting every array member or object/hash key-value pair |
304 | format as output, putting every array member or object/hash key-value pair |
249 | into its own line, identing them properly. |
305 | into its own line, indenting them properly. |
250 | |
306 | |
251 | If C<$enable> is false, no newlines or indenting will be produced, and the |
307 | If C<$enable> is false, no newlines or indenting will be produced, and the |
252 | resulting JSON text is guarenteed not to contain any C<newlines>. |
308 | resulting JSON text is guaranteed not to contain any C<newlines>. |
253 | |
309 | |
254 | This setting has no effect when decoding JSON texts. |
310 | This setting has no effect when decoding JSON texts. |
255 | |
311 | |
256 | =item $json = $json->space_before ([$enable]) |
312 | =item $json = $json->space_before ([$enable]) |
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313 | |
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314 | =item $enabled = $json->get_space_before |
257 | |
315 | |
258 | If C<$enable> is true (or missing), then the C<encode> method will add an extra |
316 | If C<$enable> is true (or missing), then the C<encode> method will add an extra |
259 | optional space before the C<:> separating keys from values in JSON objects. |
317 | optional space before the C<:> separating keys from values in JSON objects. |
260 | |
318 | |
261 | If C<$enable> is false, then the C<encode> method will not add any extra |
319 | If C<$enable> is false, then the C<encode> method will not add any extra |
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267 | Example, space_before enabled, space_after and indent disabled: |
325 | Example, space_before enabled, space_after and indent disabled: |
268 | |
326 | |
269 | {"key" :"value"} |
327 | {"key" :"value"} |
270 | |
328 | |
271 | =item $json = $json->space_after ([$enable]) |
329 | =item $json = $json->space_after ([$enable]) |
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330 | |
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331 | =item $enabled = $json->get_space_after |
272 | |
332 | |
273 | If C<$enable> is true (or missing), then the C<encode> method will add an extra |
333 | If C<$enable> is true (or missing), then the C<encode> method will add an extra |
274 | optional space after the C<:> separating keys from values in JSON objects |
334 | optional space after the C<:> separating keys from values in JSON objects |
275 | and extra whitespace after the C<,> separating key-value pairs and array |
335 | and extra whitespace after the C<,> separating key-value pairs and array |
276 | members. |
336 | members. |
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… | |
282 | |
342 | |
283 | Example, space_before and indent disabled, space_after enabled: |
343 | Example, space_before and indent disabled, space_after enabled: |
284 | |
344 | |
285 | {"key": "value"} |
345 | {"key": "value"} |
286 | |
346 | |
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347 | =item $json = $json->relaxed ([$enable]) |
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348 | |
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349 | =item $enabled = $json->get_relaxed |
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350 | |
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351 | If C<$enable> is true (or missing), then C<decode> will accept some |
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352 | extensions to normal JSON syntax (see below). C<encode> will not be |
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353 | affected in anyway. I<Be aware that this option makes you accept invalid |
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354 | JSON texts as if they were valid!>. I suggest only to use this option to |
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355 | parse application-specific files written by humans (configuration files, |
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356 | resource files etc.) |
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357 | |
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358 | If C<$enable> is false (the default), then C<decode> will only accept |
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359 | valid JSON texts. |
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360 | |
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361 | Currently accepted extensions are: |
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362 | |
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363 | =over 4 |
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364 | |
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365 | =item * list items can have an end-comma |
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366 | |
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367 | JSON I<separates> array elements and key-value pairs with commas. This |
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368 | can be annoying if you write JSON texts manually and want to be able to |
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369 | quickly append elements, so this extension accepts comma at the end of |
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370 | such items not just between them: |
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371 | |
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372 | [ |
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373 | 1, |
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374 | 2, <- this comma not normally allowed |
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375 | ] |
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376 | { |
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377 | "k1": "v1", |
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378 | "k2": "v2", <- this comma not normally allowed |
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379 | } |
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380 | |
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381 | =item * shell-style '#'-comments |
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382 | |
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383 | Whenever JSON allows whitespace, shell-style comments are additionally |
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384 | allowed. They are terminated by the first carriage-return or line-feed |
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385 | character, after which more white-space and comments are allowed. |
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386 | |
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387 | [ |
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388 | 1, # this comment not allowed in JSON |
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389 | # neither this one... |
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390 | ] |
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391 | |
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392 | =back |
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393 | |
287 | =item $json = $json->canonical ([$enable]) |
394 | =item $json = $json->canonical ([$enable]) |
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395 | |
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396 | =item $enabled = $json->get_canonical |
288 | |
397 | |
289 | If C<$enable> is true (or missing), then the C<encode> method will output JSON objects |
398 | If C<$enable> is true (or missing), then the C<encode> method will output JSON objects |
290 | by sorting their keys. This is adding a comparatively high overhead. |
399 | by sorting their keys. This is adding a comparatively high overhead. |
291 | |
400 | |
292 | If C<$enable> is false, then the C<encode> method will output key-value |
401 | If C<$enable> is false, then the C<encode> method will output key-value |
293 | pairs in the order Perl stores them (which will likely change between runs |
402 | pairs in the order Perl stores them (which will likely change between runs |
294 | of the same script). |
403 | of the same script). |
295 | |
404 | |
296 | This option is useful if you want the same data structure to be encoded as |
405 | This option is useful if you want the same data structure to be encoded as |
297 | the same JSON text (given the same overall settings). If it is disabled, |
406 | the same JSON text (given the same overall settings). If it is disabled, |
298 | the same hash migh be encoded differently even if contains the same data, |
407 | the same hash might be encoded differently even if contains the same data, |
299 | as key-value pairs have no inherent ordering in Perl. |
408 | as key-value pairs have no inherent ordering in Perl. |
300 | |
409 | |
301 | This setting has no effect when decoding JSON texts. |
410 | This setting has no effect when decoding JSON texts. |
302 | |
411 | |
303 | =item $json = $json->allow_nonref ([$enable]) |
412 | =item $json = $json->allow_nonref ([$enable]) |
|
|
413 | |
|
|
414 | =item $enabled = $json->get_allow_nonref |
304 | |
415 | |
305 | If C<$enable> is true (or missing), then the C<encode> method can convert a |
416 | If C<$enable> is true (or missing), then the C<encode> method can convert a |
306 | non-reference into its corresponding string, number or null JSON value, |
417 | non-reference into its corresponding string, number or null JSON value, |
307 | which is an extension to RFC4627. Likewise, C<decode> will accept those JSON |
418 | which is an extension to RFC4627. Likewise, C<decode> will accept those JSON |
308 | values instead of croaking. |
419 | values instead of croaking. |
… | |
… | |
318 | JSON::XS->new->allow_nonref->encode ("Hello, World!") |
429 | JSON::XS->new->allow_nonref->encode ("Hello, World!") |
319 | => "Hello, World!" |
430 | => "Hello, World!" |
320 | |
431 | |
321 | =item $json = $json->allow_blessed ([$enable]) |
432 | =item $json = $json->allow_blessed ([$enable]) |
322 | |
433 | |
|
|
434 | =item $enabled = $json->get_allow_bless |
|
|
435 | |
323 | If C<$enable> is true (or missing), then the C<encode> method will not |
436 | If C<$enable> is true (or missing), then the C<encode> method will not |
324 | barf when it encounters a blessed reference. Instead, the value of the |
437 | barf when it encounters a blessed reference. Instead, the value of the |
325 | B<convert_blessed> option will decide wether C<null> (C<convert_blessed> |
438 | B<convert_blessed> option will decide whether C<null> (C<convert_blessed> |
326 | disabled or no C<to_json> method found) or a representation of the |
439 | disabled or no C<to_json> method found) or a representation of the |
327 | object (C<convert_blessed> enabled and C<to_json> method found) is being |
440 | object (C<convert_blessed> enabled and C<to_json> method found) is being |
328 | encoded. Has no effect on C<decode>. |
441 | encoded. Has no effect on C<decode>. |
329 | |
442 | |
330 | If C<$enable> is false (the default), then C<encode> will throw an |
443 | If C<$enable> is false (the default), then C<encode> will throw an |
331 | exception when it encounters a blessed object. |
444 | exception when it encounters a blessed object. |
332 | |
445 | |
333 | =item $json = $json->convert_blessed ([$enable]) |
446 | =item $json = $json->convert_blessed ([$enable]) |
|
|
447 | |
|
|
448 | =item $enabled = $json->get_convert_blessed |
334 | |
449 | |
335 | If C<$enable> is true (or missing), then C<encode>, upon encountering a |
450 | If C<$enable> is true (or missing), then C<encode>, upon encountering a |
336 | blessed object, will check for the availability of the C<TO_JSON> method |
451 | blessed object, will check for the availability of the C<TO_JSON> method |
337 | on the object's class. If found, it will be called in scalar context |
452 | on the object's class. If found, it will be called in scalar context |
338 | and the resulting scalar will be encoded instead of the object. If no |
453 | and the resulting scalar will be encoded instead of the object. If no |
… | |
… | |
352 | enabled by this setting. |
467 | enabled by this setting. |
353 | |
468 | |
354 | If C<$enable> is false, then the C<allow_blessed> setting will decide what |
469 | If C<$enable> is false, then the C<allow_blessed> setting will decide what |
355 | to do when a blessed object is found. |
470 | to do when a blessed object is found. |
356 | |
471 | |
|
|
472 | =item $json = $json->filter_json_object ([$coderef->($hashref)]) |
|
|
473 | |
|
|
474 | When C<$coderef> is specified, it will be called from C<decode> each |
|
|
475 | time it decodes a JSON object. The only argument is a reference to the |
|
|
476 | newly-created hash. If the code references returns a single scalar (which |
|
|
477 | need not be a reference), this value (i.e. a copy of that scalar to avoid |
|
|
478 | aliasing) is inserted into the deserialised data structure. If it returns |
|
|
479 | an empty list (NOTE: I<not> C<undef>, which is a valid scalar), the |
|
|
480 | original deserialised hash will be inserted. This setting can slow down |
|
|
481 | decoding considerably. |
|
|
482 | |
|
|
483 | When C<$coderef> is omitted or undefined, any existing callback will |
|
|
484 | be removed and C<decode> will not change the deserialised hash in any |
|
|
485 | way. |
|
|
486 | |
|
|
487 | Example, convert all JSON objects into the integer 5: |
|
|
488 | |
|
|
489 | my $js = JSON::XS->new->filter_json_object (sub { 5 }); |
|
|
490 | # returns [5] |
|
|
491 | $js->decode ('[{}]') |
|
|
492 | # throw an exception because allow_nonref is not enabled |
|
|
493 | # so a lone 5 is not allowed. |
|
|
494 | $js->decode ('{"a":1, "b":2}'); |
|
|
495 | |
|
|
496 | =item $json = $json->filter_json_single_key_object ($key [=> $coderef->($value)]) |
|
|
497 | |
|
|
498 | Works remotely similar to C<filter_json_object>, but is only called for |
|
|
499 | JSON objects having a single key named C<$key>. |
|
|
500 | |
|
|
501 | This C<$coderef> is called before the one specified via |
|
|
502 | C<filter_json_object>, if any. It gets passed the single value in the JSON |
|
|
503 | object. If it returns a single value, it will be inserted into the data |
|
|
504 | structure. If it returns nothing (not even C<undef> but the empty list), |
|
|
505 | the callback from C<filter_json_object> will be called next, as if no |
|
|
506 | single-key callback were specified. |
|
|
507 | |
|
|
508 | If C<$coderef> is omitted or undefined, the corresponding callback will be |
|
|
509 | disabled. There can only ever be one callback for a given key. |
|
|
510 | |
|
|
511 | As this callback gets called less often then the C<filter_json_object> |
|
|
512 | one, decoding speed will not usually suffer as much. Therefore, single-key |
|
|
513 | objects make excellent targets to serialise Perl objects into, especially |
|
|
514 | as single-key JSON objects are as close to the type-tagged value concept |
|
|
515 | as JSON gets (it's basically an ID/VALUE tuple). Of course, JSON does not |
|
|
516 | support this in any way, so you need to make sure your data never looks |
|
|
517 | like a serialised Perl hash. |
|
|
518 | |
|
|
519 | Typical names for the single object key are C<__class_whatever__>, or |
|
|
520 | C<$__dollars_are_rarely_used__$> or C<}ugly_brace_placement>, or even |
|
|
521 | things like C<__class_md5sum(classname)__>, to reduce the risk of clashing |
|
|
522 | with real hashes. |
|
|
523 | |
|
|
524 | Example, decode JSON objects of the form C<< { "__widget__" => <id> } >> |
|
|
525 | into the corresponding C<< $WIDGET{<id>} >> object: |
|
|
526 | |
|
|
527 | # return whatever is in $WIDGET{5}: |
|
|
528 | JSON::XS |
|
|
529 | ->new |
|
|
530 | ->filter_json_single_key_object (__widget__ => sub { |
|
|
531 | $WIDGET{ $_[0] } |
|
|
532 | }) |
|
|
533 | ->decode ('{"__widget__": 5') |
|
|
534 | |
|
|
535 | # this can be used with a TO_JSON method in some "widget" class |
|
|
536 | # for serialisation to json: |
|
|
537 | sub WidgetBase::TO_JSON { |
|
|
538 | my ($self) = @_; |
|
|
539 | |
|
|
540 | unless ($self->{id}) { |
|
|
541 | $self->{id} = ..get..some..id..; |
|
|
542 | $WIDGET{$self->{id}} = $self; |
|
|
543 | } |
|
|
544 | |
|
|
545 | { __widget__ => $self->{id} } |
|
|
546 | } |
|
|
547 | |
357 | =item $json = $json->shrink ([$enable]) |
548 | =item $json = $json->shrink ([$enable]) |
|
|
549 | |
|
|
550 | =item $enabled = $json->get_shrink |
358 | |
551 | |
359 | Perl usually over-allocates memory a bit when allocating space for |
552 | Perl usually over-allocates memory a bit when allocating space for |
360 | strings. This flag optionally resizes strings generated by either |
553 | strings. This flag optionally resizes strings generated by either |
361 | C<encode> or C<decode> to their minimum size possible. This can save |
554 | C<encode> or C<decode> to their minimum size possible. This can save |
362 | memory when your JSON texts are either very very long or you have many |
555 | memory when your JSON texts are either very very long or you have many |
… | |
… | |
380 | strings that look like integers or floats into integers or floats |
573 | strings that look like integers or floats into integers or floats |
381 | internally (there is no difference on the Perl level), saving space. |
574 | internally (there is no difference on the Perl level), saving space. |
382 | |
575 | |
383 | =item $json = $json->max_depth ([$maximum_nesting_depth]) |
576 | =item $json = $json->max_depth ([$maximum_nesting_depth]) |
384 | |
577 | |
|
|
578 | =item $max_depth = $json->get_max_depth |
|
|
579 | |
385 | Sets the maximum nesting level (default C<512>) accepted while encoding |
580 | Sets the maximum nesting level (default C<512>) accepted while encoding |
386 | or decoding. If the JSON text or Perl data structure has an equal or |
581 | or decoding. If the JSON text or Perl data structure has an equal or |
387 | higher nesting level then this limit, then the encoder and decoder will |
582 | higher nesting level then this limit, then the encoder and decoder will |
388 | stop and croak at that point. |
583 | stop and croak at that point. |
389 | |
584 | |
… | |
… | |
393 | given character in a string. |
588 | given character in a string. |
394 | |
589 | |
395 | Setting the maximum depth to one disallows any nesting, so that ensures |
590 | Setting the maximum depth to one disallows any nesting, so that ensures |
396 | that the object is only a single hash/object or array. |
591 | that the object is only a single hash/object or array. |
397 | |
592 | |
398 | The argument to C<max_depth> will be rounded up to the next nearest power |
593 | The argument to C<max_depth> will be rounded up to the next highest power |
399 | of two. |
594 | of two. If no argument is given, the highest possible setting will be |
|
|
595 | used, which is rarely useful. |
|
|
596 | |
|
|
597 | See SECURITY CONSIDERATIONS, below, for more info on why this is useful. |
|
|
598 | |
|
|
599 | =item $json = $json->max_size ([$maximum_string_size]) |
|
|
600 | |
|
|
601 | =item $max_size = $json->get_max_size |
|
|
602 | |
|
|
603 | Set the maximum length a JSON text may have (in bytes) where decoding is |
|
|
604 | being attempted. The default is C<0>, meaning no limit. When C<decode> |
|
|
605 | is called on a string longer then this number of characters it will not |
|
|
606 | attempt to decode the string but throw an exception. This setting has no |
|
|
607 | effect on C<encode> (yet). |
|
|
608 | |
|
|
609 | The argument to C<max_size> will be rounded up to the next B<highest> |
|
|
610 | power of two (so may be more than requested). If no argument is given, the |
|
|
611 | limit check will be deactivated (same as when C<0> is specified). |
400 | |
612 | |
401 | See SECURITY CONSIDERATIONS, below, for more info on why this is useful. |
613 | See SECURITY CONSIDERATIONS, below, for more info on why this is useful. |
402 | |
614 | |
403 | =item $json_text = $json->encode ($perl_scalar) |
615 | =item $json_text = $json->encode ($perl_scalar) |
404 | |
616 | |
… | |
… | |
441 | vice versa. These mappings are designed to "do the right thing" in most |
653 | vice versa. These mappings are designed to "do the right thing" in most |
442 | circumstances automatically, preserving round-tripping characteristics |
654 | circumstances automatically, preserving round-tripping characteristics |
443 | (what you put in comes out as something equivalent). |
655 | (what you put in comes out as something equivalent). |
444 | |
656 | |
445 | For the more enlightened: note that in the following descriptions, |
657 | For the more enlightened: note that in the following descriptions, |
446 | lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl> |
658 | lowercase I<perl> refers to the Perl interpreter, while uppercase I<Perl> |
447 | refers to the abstract Perl language itself. |
659 | refers to the abstract Perl language itself. |
448 | |
660 | |
449 | |
661 | |
450 | =head2 JSON -> PERL |
662 | =head2 JSON -> PERL |
451 | |
663 | |
452 | =over 4 |
664 | =over 4 |
453 | |
665 | |
454 | =item object |
666 | =item object |
455 | |
667 | |
456 | A JSON object becomes a reference to a hash in Perl. No ordering of object |
668 | A JSON object becomes a reference to a hash in Perl. No ordering of object |
457 | keys is preserved (JSON does not preserver object key ordering itself). |
669 | keys is preserved (JSON does not preserve object key ordering itself). |
458 | |
670 | |
459 | =item array |
671 | =item array |
460 | |
672 | |
461 | A JSON array becomes a reference to an array in Perl. |
673 | A JSON array becomes a reference to an array in Perl. |
462 | |
674 | |
… | |
… | |
466 | are represented by the same codepoints in the Perl string, so no manual |
678 | are represented by the same codepoints in the Perl string, so no manual |
467 | decoding is necessary. |
679 | decoding is necessary. |
468 | |
680 | |
469 | =item number |
681 | =item number |
470 | |
682 | |
471 | A JSON number becomes either an integer or numeric (floating point) |
683 | A JSON number becomes either an integer, numeric (floating point) or |
472 | scalar in perl, depending on its range and any fractional parts. On the |
684 | string scalar in perl, depending on its range and any fractional parts. On |
473 | Perl level, there is no difference between those as Perl handles all the |
685 | the Perl level, there is no difference between those as Perl handles all |
474 | conversion details, but an integer may take slightly less memory and might |
686 | the conversion details, but an integer may take slightly less memory and |
475 | represent more values exactly than (floating point) numbers. |
687 | might represent more values exactly than (floating point) numbers. |
|
|
688 | |
|
|
689 | If the number consists of digits only, JSON::XS will try to represent |
|
|
690 | it as an integer value. If that fails, it will try to represent it as |
|
|
691 | a numeric (floating point) value if that is possible without loss of |
|
|
692 | precision. Otherwise it will preserve the number as a string value. |
|
|
693 | |
|
|
694 | Numbers containing a fractional or exponential part will always be |
|
|
695 | represented as numeric (floating point) values, possibly at a loss of |
|
|
696 | precision. |
|
|
697 | |
|
|
698 | This might create round-tripping problems as numbers might become strings, |
|
|
699 | but as Perl is typeless there is no other way to do it. |
476 | |
700 | |
477 | =item true, false |
701 | =item true, false |
478 | |
702 | |
479 | These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>, |
703 | These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>, |
480 | respectively. They are overloaded to act almost exactly like the numbers |
704 | respectively. They are overloaded to act almost exactly like the numbers |
481 | C<1> and C<0>. You can check wether a scalar is a JSON boolean by using |
705 | C<1> and C<0>. You can check whether a scalar is a JSON boolean by using |
482 | the C<JSON::XS::is_bool> function. |
706 | the C<JSON::XS::is_bool> function. |
483 | |
707 | |
484 | =item null |
708 | =item null |
485 | |
709 | |
486 | A JSON null atom becomes C<undef> in Perl. |
710 | A JSON null atom becomes C<undef> in Perl. |
… | |
… | |
522 | to_json [\0,JSON::XS::true] # yields [false,true] |
746 | to_json [\0,JSON::XS::true] # yields [false,true] |
523 | |
747 | |
524 | =item JSON::XS::true, JSON::XS::false |
748 | =item JSON::XS::true, JSON::XS::false |
525 | |
749 | |
526 | These special values become JSON true and JSON false values, |
750 | These special values become JSON true and JSON false values, |
527 | respectively. You cna alos use C<\1> and C<\0> directly if you want. |
751 | respectively. You can also use C<\1> and C<\0> directly if you want. |
528 | |
752 | |
529 | =item blessed objects |
753 | =item blessed objects |
530 | |
754 | |
531 | Blessed objects are not allowed. JSON::XS currently tries to encode their |
755 | Blessed objects are not allowed. JSON::XS currently tries to encode their |
532 | underlying representation (hash- or arrayref), but this behaviour might |
756 | underlying representation (hash- or arrayref), but this behaviour might |
… | |
… | |
549 | to_json [$value] # yields ["5"] |
773 | to_json [$value] # yields ["5"] |
550 | |
774 | |
551 | # undef becomes null |
775 | # undef becomes null |
552 | to_json [undef] # yields [null] |
776 | to_json [undef] # yields [null] |
553 | |
777 | |
554 | You can force the type to be a string by stringifying it: |
778 | You can force the type to be a JSON string by stringifying it: |
555 | |
779 | |
556 | my $x = 3.1; # some variable containing a number |
780 | my $x = 3.1; # some variable containing a number |
557 | "$x"; # stringified |
781 | "$x"; # stringified |
558 | $x .= ""; # another, more awkward way to stringify |
782 | $x .= ""; # another, more awkward way to stringify |
559 | print $x; # perl does it for you, too, quite often |
783 | print $x; # perl does it for you, too, quite often |
560 | |
784 | |
561 | You can force the type to be a number by numifying it: |
785 | You can force the type to be a JSON number by numifying it: |
562 | |
786 | |
563 | my $x = "3"; # some variable containing a string |
787 | my $x = "3"; # some variable containing a string |
564 | $x += 0; # numify it, ensuring it will be dumped as a number |
788 | $x += 0; # numify it, ensuring it will be dumped as a number |
565 | $x *= 1; # same thing, the choise is yours. |
789 | $x *= 1; # same thing, the choice is yours. |
566 | |
790 | |
567 | You can not currently output JSON booleans or force the type in other, |
791 | You can not currently force the type in other, less obscure, ways. Tell me |
568 | less obscure, ways. Tell me if you need this capability. |
792 | if you need this capability. |
569 | |
793 | |
570 | =back |
794 | =back |
571 | |
795 | |
572 | |
796 | |
573 | =head1 COMPARISON |
797 | =head1 COMPARISON |
… | |
… | |
582 | |
806 | |
583 | =item JSON 1.07 |
807 | =item JSON 1.07 |
584 | |
808 | |
585 | Slow (but very portable, as it is written in pure Perl). |
809 | Slow (but very portable, as it is written in pure Perl). |
586 | |
810 | |
587 | Undocumented/buggy Unicode handling (how JSON handles unicode values is |
811 | Undocumented/buggy Unicode handling (how JSON handles Unicode values is |
588 | undocumented. One can get far by feeding it unicode strings and doing |
812 | undocumented. One can get far by feeding it Unicode strings and doing |
589 | en-/decoding oneself, but unicode escapes are not working properly). |
813 | en-/decoding oneself, but Unicode escapes are not working properly). |
590 | |
814 | |
591 | No roundtripping (strings get clobbered if they look like numbers, e.g. |
815 | No round-tripping (strings get clobbered if they look like numbers, e.g. |
592 | the string C<2.0> will encode to C<2.0> instead of C<"2.0">, and that will |
816 | the string C<2.0> will encode to C<2.0> instead of C<"2.0">, and that will |
593 | decode into the number 2. |
817 | decode into the number 2. |
594 | |
818 | |
595 | =item JSON::PC 0.01 |
819 | =item JSON::PC 0.01 |
596 | |
820 | |
597 | Very fast. |
821 | Very fast. |
598 | |
822 | |
599 | Undocumented/buggy Unicode handling. |
823 | Undocumented/buggy Unicode handling. |
600 | |
824 | |
601 | No roundtripping. |
825 | No round-tripping. |
602 | |
826 | |
603 | Has problems handling many Perl values (e.g. regex results and other magic |
827 | Has problems handling many Perl values (e.g. regex results and other magic |
604 | values will make it croak). |
828 | values will make it croak). |
605 | |
829 | |
606 | Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}> |
830 | Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}> |
… | |
… | |
616 | Very inflexible (no human-readable format supported, format pretty much |
840 | Very inflexible (no human-readable format supported, format pretty much |
617 | undocumented. I need at least a format for easy reading by humans and a |
841 | undocumented. I need at least a format for easy reading by humans and a |
618 | single-line compact format for use in a protocol, and preferably a way to |
842 | single-line compact format for use in a protocol, and preferably a way to |
619 | generate ASCII-only JSON texts). |
843 | generate ASCII-only JSON texts). |
620 | |
844 | |
621 | Completely broken (and confusingly documented) Unicode handling (unicode |
845 | Completely broken (and confusingly documented) Unicode handling (Unicode |
622 | escapes are not working properly, you need to set ImplicitUnicode to |
846 | escapes are not working properly, you need to set ImplicitUnicode to |
623 | I<different> values on en- and decoding to get symmetric behaviour). |
847 | I<different> values on en- and decoding to get symmetric behaviour). |
624 | |
848 | |
625 | No roundtripping (simple cases work, but this depends on wether the scalar |
849 | No round-tripping (simple cases work, but this depends on whether the scalar |
626 | value was used in a numeric context or not). |
850 | value was used in a numeric context or not). |
627 | |
851 | |
628 | Dumping hashes may skip hash values depending on iterator state. |
852 | Dumping hashes may skip hash values depending on iterator state. |
629 | |
853 | |
630 | Unmaintained (maintainer unresponsive for many months, bugs are not |
854 | Unmaintained (maintainer unresponsive for many months, bugs are not |
631 | getting fixed). |
855 | getting fixed). |
632 | |
856 | |
633 | Does not check input for validity (i.e. will accept non-JSON input and |
857 | Does not check input for validity (i.e. will accept non-JSON input and |
634 | return "something" instead of raising an exception. This is a security |
858 | return "something" instead of raising an exception. This is a security |
635 | issue: imagine two banks transfering money between each other using |
859 | issue: imagine two banks transferring money between each other using |
636 | JSON. One bank might parse a given non-JSON request and deduct money, |
860 | JSON. One bank might parse a given non-JSON request and deduct money, |
637 | while the other might reject the transaction with a syntax error. While a |
861 | while the other might reject the transaction with a syntax error. While a |
638 | good protocol will at least recover, that is extra unnecessary work and |
862 | good protocol will at least recover, that is extra unnecessary work and |
639 | the transaction will still not succeed). |
863 | the transaction will still not succeed). |
640 | |
864 | |
641 | =item JSON::DWIW 0.04 |
865 | =item JSON::DWIW 0.04 |
642 | |
866 | |
643 | Very fast. Very natural. Very nice. |
867 | Very fast. Very natural. Very nice. |
644 | |
868 | |
645 | Undocumented unicode handling (but the best of the pack. Unicode escapes |
869 | Undocumented Unicode handling (but the best of the pack. Unicode escapes |
646 | still don't get parsed properly). |
870 | still don't get parsed properly). |
647 | |
871 | |
648 | Very inflexible. |
872 | Very inflexible. |
649 | |
873 | |
650 | No roundtripping. |
874 | No round-tripping. |
651 | |
875 | |
652 | Does not generate valid JSON texts (key strings are often unquoted, empty keys |
876 | Does not generate valid JSON texts (key strings are often unquoted, empty keys |
653 | result in nothing being output) |
877 | result in nothing being output) |
654 | |
878 | |
655 | Does not check input for validity. |
879 | Does not check input for validity. |
… | |
… | |
670 | my $yaml = $to_yaml->encode ($ref) . "\n"; |
894 | my $yaml = $to_yaml->encode ($ref) . "\n"; |
671 | |
895 | |
672 | This will usually generate JSON texts that also parse as valid |
896 | This will usually generate JSON texts that also parse as valid |
673 | YAML. Please note that YAML has hardcoded limits on (simple) object key |
897 | YAML. Please note that YAML has hardcoded limits on (simple) object key |
674 | lengths that JSON doesn't have, so you should make sure that your hash |
898 | lengths that JSON doesn't have, so you should make sure that your hash |
675 | keys are noticably shorter than the 1024 characters YAML allows. |
899 | keys are noticeably shorter than the 1024 characters YAML allows. |
676 | |
900 | |
677 | There might be other incompatibilities that I am not aware of. In general |
901 | There might be other incompatibilities that I am not aware of. In general |
678 | you should not try to generate YAML with a JSON generator or vice versa, |
902 | you should not try to generate YAML with a JSON generator or vice versa, |
679 | or try to parse JSON with a YAML parser or vice versa: chances are high |
903 | or try to parse JSON with a YAML parser or vice versa: chances are high |
680 | that you will run into severe interoperability problems. |
904 | that you will run into severe interoperability problems. |
… | |
… | |
698 | with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables |
922 | with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables |
699 | shrink). Higher is better: |
923 | shrink). Higher is better: |
700 | |
924 | |
701 | module | encode | decode | |
925 | module | encode | decode | |
702 | -----------|------------|------------| |
926 | -----------|------------|------------| |
703 | JSON | 7645.468 | 4208.613 | |
927 | JSON 1.x | 4990.842 | 4088.813 | |
704 | JSON::DWIW | 40721.398 | 77101.176 | |
928 | JSON::DWIW | 51653.990 | 71575.154 | |
705 | JSON::PC | 65948.176 | 78251.940 | |
929 | JSON::PC | 65948.176 | 74631.744 | |
706 | JSON::Syck | 22844.793 | 26479.192 | |
930 | JSON::PP | 8931.652 | 3817.168 | |
|
|
931 | JSON::Syck | 24877.248 | 27776.848 | |
707 | JSON::XS | 388361.481 | 199728.762 | |
932 | JSON::XS | 388361.481 | 227951.304 | |
708 | JSON::XS/2 | 218453.333 | 192399.266 | |
933 | JSON::XS/2 | 227951.304 | 218453.333 | |
709 | JSON::XS/3 | 338250.323 | 192399.266 | |
934 | JSON::XS/3 | 338250.323 | 218453.333 | |
710 | Storable | 15779.925 | 14169.946 | |
935 | Storable | 16500.016 | 135300.129 | |
711 | -----------+------------+------------+ |
936 | -----------+------------+------------+ |
712 | |
937 | |
713 | That is, JSON::XS is about five times faster than JSON::DWIW on encoding, |
938 | That is, JSON::XS is about five times faster than JSON::DWIW on encoding, |
714 | about three times faster on decoding, and over fourty times faster |
939 | about three times faster on decoding, and over forty times faster |
715 | than JSON, even with pretty-printing and key sorting. It also compares |
940 | than JSON, even with pretty-printing and key sorting. It also compares |
716 | favourably to Storable for small amounts of data. |
941 | favourably to Storable for small amounts of data. |
717 | |
942 | |
718 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
943 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
719 | search API (http://nanoref.com/yahooapis/mgPdGg): |
944 | search API (http://nanoref.com/yahooapis/mgPdGg): |
720 | |
945 | |
721 | module | encode | decode | |
946 | module | encode | decode | |
722 | -----------|------------|------------| |
947 | -----------|------------|------------| |
723 | JSON | 254.685 | 37.665 | |
948 | JSON 1.x | 55.260 | 34.971 | |
724 | JSON::DWIW | 843.343 | 1049.731 | |
949 | JSON::DWIW | 825.228 | 1082.513 | |
725 | JSON::PC | 3602.116 | 2307.352 | |
950 | JSON::PC | 3571.444 | 2394.829 | |
|
|
951 | JSON::PP | 210.987 | 32.574 | |
726 | JSON::Syck | 505.107 | 787.899 | |
952 | JSON::Syck | 552.551 | 787.544 | |
727 | JSON::XS | 5747.196 | 3690.220 | |
953 | JSON::XS | 5780.463 | 4854.519 | |
728 | JSON::XS/2 | 3968.121 | 3676.634 | |
954 | JSON::XS/2 | 3869.998 | 4798.975 | |
729 | JSON::XS/3 | 6105.246 | 3662.508 | |
955 | JSON::XS/3 | 5862.880 | 4798.975 | |
730 | Storable | 4417.337 | 5285.161 | |
956 | Storable | 4445.002 | 5235.027 | |
731 | -----------+------------+------------+ |
957 | -----------+------------+------------+ |
732 | |
958 | |
733 | Again, JSON::XS leads by far (except for Storable which non-surprisingly |
959 | Again, JSON::XS leads by far (except for Storable which non-surprisingly |
734 | decodes faster). |
960 | decodes faster). |
735 | |
961 | |
736 | On large strings containing lots of high unicode characters, some modules |
962 | On large strings containing lots of high Unicode characters, some modules |
737 | (such as JSON::PC) seem to decode faster than JSON::XS, but the result |
963 | (such as JSON::PC) seem to decode faster than JSON::XS, but the result |
738 | will be broken due to missing (or wrong) unicode handling. Others refuse |
964 | will be broken due to missing (or wrong) Unicode handling. Others refuse |
739 | to decode or encode properly, so it was impossible to prepare a fair |
965 | to decode or encode properly, so it was impossible to prepare a fair |
740 | comparison table for that case. |
966 | comparison table for that case. |
741 | |
967 | |
742 | |
968 | |
743 | =head1 SECURITY CONSIDERATIONS |
969 | =head1 SECURITY CONSIDERATIONS |
… | |
… | |
749 | any buffer overflows. Obviously, this module should ensure that and I am |
975 | any buffer overflows. Obviously, this module should ensure that and I am |
750 | trying hard on making that true, but you never know. |
976 | trying hard on making that true, but you never know. |
751 | |
977 | |
752 | Second, you need to avoid resource-starving attacks. That means you should |
978 | Second, you need to avoid resource-starving attacks. That means you should |
753 | limit the size of JSON texts you accept, or make sure then when your |
979 | limit the size of JSON texts you accept, or make sure then when your |
754 | resources run out, thats just fine (e.g. by using a separate process that |
980 | resources run out, that's just fine (e.g. by using a separate process that |
755 | can crash safely). The size of a JSON text in octets or characters is |
981 | can crash safely). The size of a JSON text in octets or characters is |
756 | usually a good indication of the size of the resources required to decode |
982 | usually a good indication of the size of the resources required to decode |
757 | it into a Perl structure. |
983 | it into a Perl structure. While JSON::XS can check the size of the JSON |
|
|
984 | text, it might be too late when you already have it in memory, so you |
|
|
985 | might want to check the size before you accept the string. |
758 | |
986 | |
759 | Third, JSON::XS recurses using the C stack when decoding objects and |
987 | Third, JSON::XS recurses using the C stack when decoding objects and |
760 | arrays. The C stack is a limited resource: for instance, on my amd64 |
988 | arrays. The C stack is a limited resource: for instance, on my amd64 |
761 | machine with 8MB of stack size I can decode around 180k nested arrays but |
989 | machine with 8MB of stack size I can decode around 180k nested arrays but |
762 | only 14k nested JSON objects (due to perl itself recursing deeply on croak |
990 | only 14k nested JSON objects (due to perl itself recursing deeply on croak |
… | |
… | |
768 | And last but least, something else could bomb you that I forgot to think |
996 | And last but least, something else could bomb you that I forgot to think |
769 | of. In that case, you get to keep the pieces. I am always open for hints, |
997 | of. In that case, you get to keep the pieces. I am always open for hints, |
770 | though... |
998 | though... |
771 | |
999 | |
772 | If you are using JSON::XS to return packets to consumption |
1000 | If you are using JSON::XS to return packets to consumption |
773 | by javascript scripts in a browser you should have a look at |
1001 | by JavaScript scripts in a browser you should have a look at |
774 | L<http://jpsykes.com/47/practical-csrf-and-json-security> to see wether |
1002 | L<http://jpsykes.com/47/practical-csrf-and-json-security> to see whether |
775 | you are vulnerable to some common attack vectors (which really are browser |
1003 | you are vulnerable to some common attack vectors (which really are browser |
776 | design bugs, but it is still you who will have to deal with it, as major |
1004 | design bugs, but it is still you who will have to deal with it, as major |
777 | browser developers care only for features, not about doing security |
1005 | browser developers care only for features, not about doing security |
778 | right). |
1006 | right). |
779 | |
1007 | |
780 | |
1008 | |
|
|
1009 | =head1 THREADS |
|
|
1010 | |
|
|
1011 | This module is I<not> guaranteed to be thread safe and there are no |
|
|
1012 | plans to change this until Perl gets thread support (as opposed to the |
|
|
1013 | horribly slow so-called "threads" which are simply slow and bloated |
|
|
1014 | process simulations - use fork, its I<much> faster, cheaper, better). |
|
|
1015 | |
|
|
1016 | (It might actually work, but you have been warned). |
|
|
1017 | |
|
|
1018 | |
781 | =head1 BUGS |
1019 | =head1 BUGS |
782 | |
1020 | |
783 | While the goal of this module is to be correct, that unfortunately does |
1021 | While the goal of this module is to be correct, that unfortunately does |
784 | not mean its bug-free, only that I think its design is bug-free. It is |
1022 | not mean its bug-free, only that I think its design is bug-free. It is |
785 | still relatively early in its development. If you keep reporting bugs they |
1023 | still relatively early in its development. If you keep reporting bugs they |
786 | will be fixed swiftly, though. |
1024 | will be fixed swiftly, though. |
|
|
1025 | |
|
|
1026 | Please refrain from using rt.cpan.org or any other bug reporting |
|
|
1027 | service. I put the contact address into my modules for a reason. |
787 | |
1028 | |
788 | =cut |
1029 | =cut |
789 | |
1030 | |
790 | our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" }; |
1031 | our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" }; |
791 | our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" }; |
1032 | our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" }; |