// Copyright 2007-2010 Baptiste Lepilleur // Distributed under MIT license, or public domain if desired and // recognized in your jurisdiction. // See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE #ifndef CPPTL_JSON_READER_H_INCLUDED #define CPPTL_JSON_READER_H_INCLUDED #if !defined(JSON_IS_AMALGAMATION) #include "features.h" #include "value.h" #endif // if !defined(JSON_IS_AMALGAMATION) #include #include #include #include #include // Disable warning C4251: : needs to have dll-interface to // be used by... #if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) #pragma warning(push) #pragma warning(disable : 4251) #endif // if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) namespace Json { /** \brief Unserialize a JSON document into a *Value. * * \deprecated Use CharReader and CharReaderBuilder. */ class JSON_API Reader { public: typedef char Char; typedef const Char* Location; /** \brief An error tagged with where in the JSON text it was encountered. * * The offsets give the [start, limit) range of bytes within the text. Note * that this is bytes, not codepoints. * */ struct StructuredError { size_t offset_start; size_t offset_limit; std::string message; }; /** \brief Constructs a Reader allowing all features * for parsing. */ Reader(); /** \brief Constructs a Reader allowing the specified feature set * for parsing. */ Reader(const Features& features); /** \brief Read a Value from a JSON * document. * \param document UTF-8 encoded string containing the document to read. * \param root [out] Contains the root value of the document if it was * successfully parsed. * \param collectComments \c true to collect comment and allow writing them * back during * serialization, \c false to discard comments. * This parameter is ignored if * Features::allowComments_ * is \c false. * \return \c true if the document was successfully parsed, \c false if an * error occurred. */ bool parse(const std::string& document, Value& root, bool collectComments = true); /** \brief Read a Value from a JSON document. * \param beginDoc Pointer on the beginning of the UTF-8 encoded string of the document to read. * \param endDoc Pointer on the end of the UTF-8 encoded string of the document to read. * Must be >= beginDoc. * \param root [out] Contains the root value of the document if it was * successfully parsed. * \param collectComments \c true to collect comment and allow writing them back during * serialization, \c false to discard comments. * This parameter is ignored if Features::allowComments_ * is \c false. * \return \c true if the document was successfully parsed, \c false if an error occurred. */ bool parse(const char* beginDoc, const char* endDoc, Value& root, bool collectComments = true); /// \brief Parse from input stream. /// \see Json::operator>>(std::istream&, Json::Value&). bool parse(std::istream& is, Value& root, bool collectComments = true); /** \brief Returns a user friendly string that list errors in the parsed * document. * \return Formatted error message with the list of errors with their location * in * the parsed document. An empty string is returned if no error * occurred * during parsing. * \deprecated Use getFormattedErrorMessages() instead (typo fix). */ JSONCPP_DEPRECATED("Use getFormattedErrorMessages instead") std::string getFormatedErrorMessages() const; /** \brief Returns a user friendly string that list errors in the parsed * document. * \return Formatted error message with the list of errors with their location * in * the parsed document. An empty string is returned if no error * occurred * during parsing. */ std::string getFormattedErrorMessages() const; /** \brief Returns a vector of structured erros encounted while parsing. * \return A (possibly empty) vector of StructuredError objects. Currently * only one error can be returned, but the caller should tolerate * multiple * errors. This can occur if the parser recovers from a non-fatal * parse error and then encounters additional errors. */ std::vector getStructuredErrors() const; /** \brief Add a semantic error message. * \param value JSON Value location associated with the error * \param message The error message. * \return \c true if the error was successfully added, \c false if the * Value offset exceeds the document size. */ bool pushError(const Value& value, const std::string& message); /** \brief Add a semantic error message with extra context. * \param value JSON Value location associated with the error * \param message The error message. * \param extra Additional JSON Value location to contextualize the error * \return \c true if the error was successfully added, \c false if either * Value offset exceeds the document size. */ bool pushError(const Value& value, const std::string& message, const Value& extra); /** \brief Return whether there are any errors. * \return \c true if there are no errors to report \c false if * errors have occurred. */ bool good() const; private: enum TokenType { tokenEndOfStream = 0, tokenObjectBegin, tokenObjectEnd, tokenArrayBegin, tokenArrayEnd, tokenString, tokenNumber, tokenTrue, tokenFalse, tokenNull, tokenArraySeparator, tokenMemberSeparator, tokenComment, tokenError }; class Token { public: TokenType type_; Location start_; Location end_; }; class ErrorInfo { public: Token token_; std::string message_; Location extra_; }; typedef std::deque Errors; bool readToken(Token& token); void skipSpaces(); bool match(Location pattern, int patternLength); bool readComment(); bool readCStyleComment(); bool readCppStyleComment(); bool readString(); void readNumber(); bool readValue(); bool readObject(Token& token); bool readArray(Token& token); bool decodeNumber(Token& token); bool decodeNumber(Token& token, Value& decoded); bool decodeString(Token& token); bool decodeString(Token& token, std::string& decoded); bool decodeDouble(Token& token); bool decodeDouble(Token& token, Value& decoded); bool decodeUnicodeCodePoint(Token& token, Location& current, Location end, unsigned int& unicode); bool decodeUnicodeEscapeSequence(Token& token, Location& current, Location end, unsigned int& unicode); bool addError(const std::string& message, Token& token, Location extra = 0); bool recoverFromError(TokenType skipUntilToken); bool addErrorAndRecover(const std::string& message, Token& token, TokenType skipUntilToken); void skipUntilSpace(); Value& currentValue(); Char getNextChar(); void getLocationLineAndColumn(Location location, int& line, int& column) const; std::string getLocationLineAndColumn(Location location) const; void addComment(Location begin, Location end, CommentPlacement placement); void skipCommentTokens(Token& token); typedef std::stack Nodes; Nodes nodes_; Errors errors_; std::string document_; Location begin_; Location end_; Location current_; Location lastValueEnd_; Value* lastValue_; std::string commentsBefore_; Features features_; bool collectComments_; }; // Reader /** Interface for reading JSON from a char array. */ class JSON_API CharReader { public: virtual ~CharReader() {} /** \brief Read a Value from a JSON document. * The document must be a UTF-8 encoded string containing the document to read. * * \param beginDoc Pointer on the beginning of the UTF-8 encoded string of the document to read. * \param endDoc Pointer on the end of the UTF-8 encoded string of the document to read. * Must be >= beginDoc. * \param root [out] Contains the root value of the document if it was * successfully parsed. * \param errs [out] Formatted error messages (if not NULL) * a user friendly string that lists errors in the parsed * document. * \return \c true if the document was successfully parsed, \c false if an error occurred. */ virtual bool parse( char const* beginDoc, char const* endDoc, Value* root, std::string* errs) = 0; class Factory { public: /// \brief Allocate a CharReader via operator new(). virtual CharReader* newCharReader() const = 0; }; // Factory }; // CharReader /** \brief Build a CharReader implementation. Usage: \code using namespace Json; CharReaderBuilder builder; builder.collectComments_ = false; Value value; std::string errs; bool ok = parseFromStream(builder, std::cin, &value, &errs); \endcode */ class CharReaderBuilder : public CharReader::Factory { public: /** default: true * * It is possible to "allow" comments but still not "collect" them. */ bool collectComments_; /** default: all() * * For historical reasons, Features is a separate structure. */ Features features_; CharReaderBuilder(); virtual ~CharReaderBuilder(); virtual CharReader* newCharReader() const; }; /** Consume entire stream and use its begin/end. * Someday we might have a real StreamReader, but for now this * is convenient. */ bool parseFromStream( CharReader::Factory const&, std::istream&, Value* root, std::string* errs); /** \brief Read from 'sin' into 'root'. Always keep comments from the input JSON. This can be used to read a file into a particular sub-object. For example: \code Json::Value root; cin >> root["dir"]["file"]; cout << root; \endcode Result: \verbatim { "dir": { "file": { // The input stream JSON would be nested here. } } } \endverbatim \throw std::exception on parse error. \see Json::operator<<() */ JSON_API std::istream& operator>>(std::istream&, Value&); } // namespace Json #if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) #pragma warning(pop) #endif // if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) #endif // CPPTL_JSON_READER_H_INCLUDED