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Christopher Dunne0d72242007-06-14 17:58:59 +00001/**
2\mainpage
3\section _intro Introduction
4
5<a HREF="http://www.json.org/">JSON (JavaScript Object Notation)</a>
6 is a lightweight data-interchange format.
Christopher Dunne0d72242007-06-14 17:58:59 +00007
8Here is an example of JSON data:
9\verbatim
Christopher Dunn948f2902015-01-25 12:19:30 -060010{
11 "encoding" : "UTF-8",
12 "plug-ins" : [
13 "python",
14 "c++",
15 "ruby"
16 ],
17 "indent" : { "length" : 3, "use_space": true }
18}
19\endverbatim
20<b>JsonCpp</b> supports comments as <i>meta-data</i>:
21\code
Christopher Dunne0d72242007-06-14 17:58:59 +000022// Configuration options
23{
24 // Default encoding for text
25 "encoding" : "UTF-8",
26
27 // Plug-ins loaded at start-up
28 "plug-ins" : [
29 "python",
Christopher Dunn948f2902015-01-25 12:19:30 -060030 "c++", // trailing comment
Christopher Dunne0d72242007-06-14 17:58:59 +000031 "ruby"
32 ],
33
34 // Tab indent size
Christopher Dunn948f2902015-01-25 12:19:30 -060035 // (multi-line comment)
36 "indent" : { /*embedded comment*/ "length" : 3, "use_space": true }
Christopher Dunne0d72242007-06-14 17:58:59 +000037}
Christopher Dunn948f2902015-01-25 12:19:30 -060038\endcode
Christopher Dunne0d72242007-06-14 17:58:59 +000039
40\section _features Features
41- read and write JSON document
Christopher Dunn35bea412014-07-05 12:13:37 -070042- attach C++ style comments to element during parsing
Christopher Dunne0d72242007-06-14 17:58:59 +000043- rewrite JSON document preserving original comments
44
Christopher Dunn948f2902015-01-25 12:19:30 -060045Notes: Comments used to be supported in JSON but were removed for
Baptiste Lepilleure6a77412010-03-11 21:02:26 +000046portability (C like comments are not supported in Python). Since
47comments are useful in configuration/input file, this feature was
48preserved.
49
50\section _example Code example
51
Christopher Dunne0d72242007-06-14 17:58:59 +000052\code
Christopher Dunn66a8ba22015-02-09 01:29:43 -060053Json::Value root; // 'root' will contain the root value after parsing.
Christopher Dunnf3b33582015-02-09 11:51:06 -060054std::cin >> root;
Christopher Dunne0d72242007-06-14 17:58:59 +000055
Christopher Dunn694dbcb2015-02-09 15:25:57 -060056// You can also read into a particular sub-value.
57std::cin >> root["subtree"];
58
Christopher Dunnaa13a8b2015-02-13 09:37:39 -060059// Get the value of the member of root named 'encoding',
60// and return 'UTF-8' if there is no such member.
Christopher Dunne0d72242007-06-14 17:58:59 +000061std::string encoding = root.get("encoding", "UTF-8" ).asString();
Christopher Dunnaa13a8b2015-02-13 09:37:39 -060062
63// Get the value of the member of root named 'plug-ins'; return a 'null' value if
Christopher Dunne0d72242007-06-14 17:58:59 +000064// there is no such member.
65const Json::Value plugins = root["plug-ins"];
Christopher Dunnaa13a8b2015-02-13 09:37:39 -060066
67// Iterate over the sequence elements.
68for ( int index = 0; index < plugins.size(); ++index )
Christopher Dunne0d72242007-06-14 17:58:59 +000069 loadPlugIn( plugins[index].asString() );
70
Christopher Dunnaa13a8b2015-02-13 09:37:39 -060071// Try other datatypes. Some are auto-convertible to others.
Christopher Dunn694dbcb2015-02-09 15:25:57 -060072foo::setIndentLength( root["indent"].get("length", 3).asInt() );
73foo::setIndentUseSpace( root["indent"].get("use_space", true).asBool() );
Christopher Dunne0d72242007-06-14 17:58:59 +000074
Christopher Dunnaa13a8b2015-02-13 09:37:39 -060075// Since Json::Value has an implicit constructor for all value types, it is not
76// necessary to explicitly construct the Json::Value object.
Christopher Dunn694dbcb2015-02-09 15:25:57 -060077root["encoding"] = foo::getCurrentEncoding();
78root["indent"]["length"] = foo::getCurrentIndentLength();
79root["indent"]["use_space"] = foo::getCurrentIndentUseSpace();
Christopher Dunne0d72242007-06-14 17:58:59 +000080
Christopher Dunnc7b39c22015-01-25 18:45:59 -060081// If you like the defaults, you can insert directly into a stream.
Christopher Dunnf3b33582015-02-09 11:51:06 -060082std::cout << root;
83// Of course, you can write to `std::ostringstream` if you prefer.
Christopher Dunnc7b39c22015-01-25 18:45:59 -060084
Christopher Dunn28a20912015-01-26 10:43:39 -060085// If desired, remember to add a linefeed and flush.
86std::cout << std::endl;
Christopher Dunn8df98f62015-02-09 11:15:39 -060087\endcode
Christopher Dunn28a20912015-01-26 10:43:39 -060088
Christopher Dunn8df98f62015-02-09 11:15:39 -060089\section _advanced Advanced usage
Christopher Dunn694dbcb2015-02-09 15:25:57 -060090
91Configure *builders* to create *readers* and *writers*. For
92configuration, we use our own `Json::Value` (rather than
93standard setters/getters) so that we can add
94features without losing binary-compatibility.
95
Christopher Dunn8df98f62015-02-09 11:15:39 -060096\code
Christopher Dunn694dbcb2015-02-09 15:25:57 -060097// For convenience, use `writeString()` with a specialized builder.
Christopher Dunn8df98f62015-02-09 11:15:39 -060098Json::StreamWriterBuilder wbuilder;
Christopher Dunn37dde9d2015-03-04 15:04:19 -060099wbuilder["indentation"] = "\t";
Christopher Dunn694dbcb2015-02-09 15:25:57 -0600100std::string document = Json::writeString(wbuilder, root);
Christopher Dunn9da9f842015-01-25 19:20:43 -0600101
Christopher Dunn694dbcb2015-02-09 15:25:57 -0600102// Here, using a specialized Builder, we discard comments and
103// record errors as we parse.
Christopher Dunn8df98f62015-02-09 11:15:39 -0600104Json::CharReaderBuilder rbuilder;
Christopher Dunn37dde9d2015-03-04 15:04:19 -0600105rbuilder["collectComments"] = false;
Christopher Dunn8df98f62015-02-09 11:15:39 -0600106std::string errs;
Christopher Dunn694dbcb2015-02-09 15:25:57 -0600107bool ok = Json::parseFromStream(rbuilder, std::cin, &root, &errs);
Christopher Dunne0d72242007-06-14 17:58:59 +0000108\endcode
109
Christopher Dunn3cf91752015-02-09 18:16:24 -0600110Yes, compile-time configuration-checking would be helpful,
111but `Json::Value` lets you
112write and read the builder configuration, which is better! In other words,
113you can configure your JSON parser using JSON.
114
115CharReaders and StreamWriters are not thread-safe, but they are re-usable.
116\code
117Json::CharReaderBuilder rbuilder;
118cfg >> rbuilder.settings_;
119std::unique_ptr<Json::CharReader> const reader(rbuilder.newCharReader());
120reader->parse(start, stop, &value1, &errs);
121// ...
122reader->parse(start, stop, &value2, &errs);
123// etc.
124\endcode
125
Baptiste Lepilleura11e47d2010-03-12 10:17:46 +0000126\section _pbuild Build instructions
Baptiste Lepilleure6a77412010-03-11 21:02:26 +0000127The build instructions are located in the file
Christopher Dunn5a651322014-07-05 20:44:33 -0700128<a HREF="https://github.com/open-source-parsers/jsoncpp/blob/master/README.md">README.md</a> in the top-directory of the project.
Christopher Dunne0d72242007-06-14 17:58:59 +0000129
Christopher Dunn35bea412014-07-05 12:13:37 -0700130The latest version of the source is available in the project's GitHub repository:
Christopher Dunnbef834e2014-07-05 19:05:10 -0700131<a HREF="https://github.com/open-source-parsers/jsoncpp/">
Christopher Dunn35bea412014-07-05 12:13:37 -0700132jsoncpp</a>
Christopher Dunne0d72242007-06-14 17:58:59 +0000133
Baptiste Lepilleur130730f2010-03-13 11:14:49 +0000134\section _news What's New?
135The description of latest changes can be found in
Christopher Dunn5a651322014-07-05 20:44:33 -0700136<a HREF="https://github.com/open-source-parsers/jsoncpp/wiki/NEWS">
137 the NEWS wiki
138</a>.
Christopher Dunne0d72242007-06-14 17:58:59 +0000139
140\section _rlinks Related links
141- <a HREF="http://www.json.org/">JSON</a> Specification and alternate language implementations.
142- <a HREF="http://www.yaml.org/">YAML</a> A data format designed for human readability.
143- <a HREF="http://www.cl.cam.ac.uk/~mgk25/unicode.html">UTF-8 and Unicode FAQ</a>.
144
Christopher Dunn35bea412014-07-05 12:13:37 -0700145\section _plinks Old project links
146- <a href="https://sourceforge.net/projects/jsoncpp/">https://sourceforge.net/projects/jsoncpp/</a>
147- <a href="http://jsoncpp.sourceforge.net">http://jsoncpp.sourceforge.net</a>
148- <a href="http://sourceforge.net/projects/jsoncpp/files/">http://sourceforge.net/projects/jsoncpp/files/</a>
149- <a href="http://jsoncpp.svn.sourceforge.net/svnroot/jsoncpp/trunk/">http://jsoncpp.svn.sourceforge.net/svnroot/jsoncpp/trunk/</a>
150- <a href="http://jsoncpp.sourceforge.net/old.html">http://jsoncpp.sourceforge.net/old.html</a>
151
Christopher Dunne0d72242007-06-14 17:58:59 +0000152\section _license License
Christopher Dunnbef834e2014-07-05 19:05:10 -0700153See file <a href="https://github.com/open-source-parsers/jsoncpp/blob/master/LICENSE"><code>LICENSE</code></a> in the top-directory of the project.
Baptiste Lepilleur7469f1d2010-04-20 21:35:19 +0000154
155Basically JsonCpp is licensed under MIT license, or public domain if desired
156and recognized in your jurisdiction.
Christopher Dunne0d72242007-06-14 17:58:59 +0000157
Christopher Dunn35bea412014-07-05 12:13:37 -0700158\author Baptiste Lepilleur <blep@users.sourceforge.net> (originator)
Christopher Dunnda0fcfb2015-02-12 11:18:23 -0600159\author Christopher Dunn <cdunn2001@gmail.com> (primary maintainer)
Christopher Dunn249fd182015-02-09 00:46:20 -0600160\version \include version
Christopher Dunn3cf91752015-02-09 18:16:24 -0600161We make strong guarantees about binary-compatibility, consistent with
162<a href="http://apr.apache.org/versioning.html">the Apache versioning scheme</a>.
Christopher Dunn249fd182015-02-09 00:46:20 -0600163\sa version.h
Christopher Dunne0d72242007-06-14 17:58:59 +0000164*/