/** \mainpage \section _intro Introduction JSON (JavaScript Object Notation) is a lightweight data-interchange format. Here is an example of JSON data: \verbatim { "encoding" : "UTF-8", "plug-ins" : [ "python", "c++", "ruby" ], "indent" : { "length" : 3, "use_space": true } } \endverbatim JsonCpp supports comments as meta-data: \code // Configuration options { // Default encoding for text "encoding" : "UTF-8", // Plug-ins loaded at start-up "plug-ins" : [ "python", "c++", // trailing comment "ruby" ], // Tab indent size // (multi-line comment) "indent" : { /*embedded comment*/ "length" : 3, "use_space": true } } \endcode \section _features Features - read and write JSON document - attach C++ style comments to element during parsing - rewrite JSON document preserving original comments Notes: Comments used to be supported in JSON but were removed for portability (C like comments are not supported in Python). Since comments are useful in configuration/input file, this feature was preserved. \section _example Code example \code Json::Value root; // 'root' will contain the root value after parsing. std::cin >> root; // You can also read into a particular sub-value. std::cin >> root["subtree"]; // Get the value of the member of root named 'encoding', // and return 'UTF-8' if there is no such member. std::string encoding = root.get("encoding", "UTF-8" ).asString(); // Get the value of the member of root named 'plug-ins'; return a 'null' value if // there is no such member. const Json::Value plugins = root["plug-ins"]; // Iterate over the sequence elements. for ( int index = 0; index < plugins.size(); ++index ) loadPlugIn( plugins[index].asString() ); // Try other datatypes. Some are auto-convertible to others. foo::setIndentLength( root["indent"].get("length", 3).asInt() ); foo::setIndentUseSpace( root["indent"].get("use_space", true).asBool() ); // Since Json::Value has an implicit constructor for all value types, it is not // necessary to explicitly construct the Json::Value object. root["encoding"] = foo::getCurrentEncoding(); root["indent"]["length"] = foo::getCurrentIndentLength(); root["indent"]["use_space"] = foo::getCurrentIndentUseSpace(); // If you like the defaults, you can insert directly into a stream. std::cout << root; // Of course, you can write to `std::ostringstream` if you prefer. // If desired, remember to add a linefeed and flush. std::cout << std::endl; \endcode \section _advanced Advanced usage Configure *builders* to create *readers* and *writers*. For configuration, we use our own `Json::Value` (rather than standard setters/getters) so that we can add features without losing binary-compatibility. \code // For convenience, use `writeString()` with a specialized builder. Json::StreamWriterBuilder wbuilder; wbuilder.settings_["indentation"] = "\t"; // simple Json::Value std::string document = Json::writeString(wbuilder, root); // Here, using a specialized Builder, we discard comments and // record errors as we parse. Json::CharReaderBuilder rbuilder; rbuilder.settings_["collectComments"] = false; // simple Json::Value std::string errs; bool ok = Json::parseFromStream(rbuilder, std::cin, &root, &errs); \endcode Yes, compile-time configuration-checking would be helpful, but `Json::Value` lets you write and read the builder configuration, which is better! In other words, you can configure your JSON parser using JSON. CharReaders and StreamWriters are not thread-safe, but they are re-usable. \code Json::CharReaderBuilder rbuilder; cfg >> rbuilder.settings_; std::unique_ptr const reader(rbuilder.newCharReader()); reader->parse(start, stop, &value1, &errs); // ... reader->parse(start, stop, &value2, &errs); // etc. \endcode \section _pbuild Build instructions The build instructions are located in the file README.md in the top-directory of the project. The latest version of the source is available in the project's GitHub repository: jsoncpp \section _news What's New? The description of latest changes can be found in the NEWS wiki . \section _rlinks Related links - JSON Specification and alternate language implementations. - YAML A data format designed for human readability. - UTF-8 and Unicode FAQ. \section _plinks Old project links - https://sourceforge.net/projects/jsoncpp/ - http://jsoncpp.sourceforge.net - http://sourceforge.net/projects/jsoncpp/files/ - http://jsoncpp.svn.sourceforge.net/svnroot/jsoncpp/trunk/ - http://jsoncpp.sourceforge.net/old.html \section _license License See file LICENSE in the top-directory of the project. Basically JsonCpp is licensed under MIT license, or public domain if desired and recognized in your jurisdiction. \author Baptiste Lepilleur (originator) \author Christopher Dunn (primary maintainer) \version \include version We make strong guarantees about binary-compatibility, consistent with the Apache versioning scheme. \sa version.h */