// Copyright 2007-2010 Baptiste Lepilleur and The JsonCpp Authors // 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 JSON_WRITER_H_INCLUDED #define JSON_WRITER_H_INCLUDED #if !defined(JSON_IS_AMALGAMATION) #include "value.h" #endif // if !defined(JSON_IS_AMALGAMATION) #include #include #include // Disable warning C4251: : needs to have dll-interface to // be used by... #if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) && defined(_MSC_VER) #pragma warning(push) #pragma warning(disable : 4251) #endif // if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) #pragma pack(push) #pragma pack() namespace Json { class Value; /** * * Usage: * \code * using namespace Json; * void writeToStdout(StreamWriter::Factory const& factory, Value const& value) * { std::unique_ptr const writer( factory.newStreamWriter()); * writer->write(value, &std::cout); * std::cout << std::endl; // add lf and flush * } * \endcode */ class JSON_API StreamWriter { protected: OStream* sout_; // not owned; will not delete public: StreamWriter(); virtual ~StreamWriter(); /** Write Value into document as configured in sub-class. * Do not take ownership of sout, but maintain a reference during function. * \pre sout != NULL * \return zero on success (For now, we always return zero, so check the * stream instead.) \throw std::exception possibly, depending on * configuration */ virtual int write(Value const& root, OStream* sout) = 0; /** \brief A simple abstract factory. */ class JSON_API Factory { public: virtual ~Factory(); /** \brief Allocate a CharReader via operator new(). * \throw std::exception if something goes wrong (e.g. invalid settings) */ virtual StreamWriter* newStreamWriter() const = 0; }; // Factory }; // StreamWriter /** \brief Write into stringstream, then return string, for convenience. * A StreamWriter will be created from the factory, used, and then deleted. */ String JSON_API writeString(StreamWriter::Factory const& factory, Value const& root); /** \brief Build a StreamWriter implementation. * Usage: * \code * using namespace Json; * Value value = ...; * StreamWriterBuilder builder; * builder["commentStyle"] = "None"; * builder["indentation"] = " "; // or whatever you like * std::unique_ptr writer( * builder.newStreamWriter()); * writer->write(value, &std::cout); * std::cout << std::endl; // add lf and flush * \endcode */ class JSON_API StreamWriterBuilder : public StreamWriter::Factory { public: // Note: We use a Json::Value so that we can add data-members to this class // without a major version bump. /** Configuration of this builder. * Available settings (case-sensitive): * - "commentStyle": "None" or "All" * - "indentation": "". * - Setting this to an empty string also omits newline characters. * - "enableYAMLCompatibility": false or true * - slightly change the whitespace around colons * - "dropNullPlaceholders": false or true * - Drop the "null" string from the writer's output for nullValues. * Strictly speaking, this is not valid JSON. But when the output is being * fed to a browser's JavaScript, it makes for smaller output and the * browser can handle the output just fine. * - "useSpecialFloats": false or true * - If true, outputs non-finite floating point values in the following way: * NaN values as "NaN", positive infinity as "Infinity", and negative * infinity as "-Infinity". * - "precision": int * - Number of precision digits for formatting of real values. * - "precisionType": "significant"(default) or "decimal" * - Type of precision for formatting of real values. * - "emitUTF8": false or true * - If true, outputs raw UTF8 strings instead of escaping them. * You can examine 'settings_` yourself * to see the defaults. You can also write and read them just like any * JSON Value. * \sa setDefaults() */ Json::Value settings_; StreamWriterBuilder(); ~StreamWriterBuilder() override; /** * \throw std::exception if something goes wrong (e.g. invalid settings) */ StreamWriter* newStreamWriter() const override; /** \return true if 'settings' are legal and consistent; * otherwise, indicate bad settings via 'invalid'. */ bool validate(Json::Value* invalid) const; /** A simple way to update a specific setting. */ Value& operator[](const String& key); /** Called by ctor, but you can use this to reset settings_. * \pre 'settings' != NULL (but Json::null is fine) * \remark Defaults: * \snippet src/lib_json/json_writer.cpp StreamWriterBuilderDefaults */ static void setDefaults(Json::Value* settings); }; /** \brief Abstract class for writers. * \deprecated Use StreamWriter. (And really, this is an implementation detail.) */ class JSON_API Writer { public: virtual ~Writer(); virtual String write(const Value& root) = 0; }; /** \brief Outputs a Value in JSON format *without formatting (not human friendly). * * The JSON document is written in a single line. It is not intended for 'human' *consumption, * but may be useful to support feature such as RPC where bandwidth is limited. * \sa Reader, Value * \deprecated Use StreamWriterBuilder. */ #if defined(_MSC_VER) #pragma warning(push) #pragma warning(disable : 4996) // Deriving from deprecated class #endif class JSON_API FastWriter : public Writer { public: FastWriter(); ~FastWriter() override = default; void enableYAMLCompatibility(); /** \brief Drop the "null" string from the writer's output for nullValues. * Strictly speaking, this is not valid JSON. But when the output is being * fed to a browser's JavaScript, it makes for smaller output and the * browser can handle the output just fine. */ void dropNullPlaceholders(); void omitEndingLineFeed(); public: // overridden from Writer String write(const Value& root) override; private: void writeValue(const Value& value); String document_; bool yamlCompatibilityEnabled_{false}; bool dropNullPlaceholders_{false}; bool omitEndingLineFeed_{false}; }; #if defined(_MSC_VER) #pragma warning(pop) #endif /** \brief Writes a Value in JSON format in a *human friendly way. * * The rules for line break and indent are as follow: * - Object value: * - if empty then print {} without indent and line break * - if not empty the print '{', line break & indent, print one value per *line * and then unindent and line break and print '}'. * - Array value: * - if empty then print [] without indent and line break * - if the array contains no object value, empty array or some other value *types, * and all the values fit on one lines, then print the array on a single *line. * - otherwise, it the values do not fit on one line, or the array contains * object or non empty array, then print one value per line. * * If the Value have comments then they are outputted according to their *#CommentPlacement. * * \sa Reader, Value, Value::setComment() * \deprecated Use StreamWriterBuilder. */ #if defined(_MSC_VER) #pragma warning(push) #pragma warning(disable : 4996) // Deriving from deprecated class #endif class JSON_API StyledWriter : public Writer { public: StyledWriter(); ~StyledWriter() override = default; public: // overridden from Writer /** \brief Serialize a Value in JSON format. * \param root Value to serialize. * \return String containing the JSON document that represents the root value. */ String write(const Value& root) override; private: void writeValue(const Value& value); void writeArrayValue(const Value& value); bool isMultilineArray(const Value& value); void pushValue(const String& value); void writeIndent(); void writeWithIndent(const String& value); void indent(); void unindent(); void writeCommentBeforeValue(const Value& root); void writeCommentAfterValueOnSameLine(const Value& root); static bool hasCommentForValue(const Value& value); static String normalizeEOL(const String& text); using ChildValues = std::vector; ChildValues childValues_; String document_; String indentString_; unsigned int rightMargin_{74}; unsigned int indentSize_{3}; bool addChildValues_{false}; }; #if defined(_MSC_VER) #pragma warning(pop) #endif /** \brief Writes a Value in JSON format in a human friendly way, to a stream rather than to a string. * * The rules for line break and indent are as follow: * - Object value: * - if empty then print {} without indent and line break * - if not empty the print '{', line break & indent, print one value per line * and then unindent and line break and print '}'. * - Array value: * - if empty then print [] without indent and line break * - if the array contains no object value, empty array or some other value types, * and all the values fit on one lines, then print the array on a single line. * - otherwise, it the values do not fit on one line, or the array contains * object or non empty array, then print one value per line. * * If the Value have comments then they are outputted according to their #CommentPlacement. * * \sa Reader, Value, Value::setComment() * \deprecated Use StreamWriterBuilder. */ #if defined(_MSC_VER) #pragma warning(push) #pragma warning(disable : 4996) // Deriving from deprecated class #endif class JSON_API StyledStreamWriter { public: /** * \param indentation Each level will be indented by this amount extra. */ StyledStreamWriter(String indentation = "\t"); ~StyledStreamWriter() = default; public: /** \brief Serialize a Value in JSON format. * \param out Stream to write to. (Can be ostringstream, e.g.) * \param root Value to serialize. * \note There is no point in deriving from Writer, since write() should not * return a value. */ void write(OStream& out, const Value& root); private: void writeValue(const Value& value); void writeArrayValue(const Value& value); bool isMultilineArray(const Value& value); void pushValue(const String& value); void writeIndent(); void writeWithIndent(const String& value); void indent(); void unindent(); void writeCommentBeforeValue(const Value& root); void writeCommentAfterValueOnSameLine(const Value& root); static bool hasCommentForValue(const Value& value); static String normalizeEOL(const String& text); using ChildValues = std::vector; ChildValues childValues_; OStream* document_; String indentString_; unsigned int rightMargin_{74}; String indentation_; bool addChildValues_ : 1; bool indented_ : 1; }; #if defined(_MSC_VER) #pragma warning(pop) #endif #if defined(JSON_HAS_INT64) String JSON_API valueToString(Int value); String JSON_API valueToString(UInt value); #endif // if defined(JSON_HAS_INT64) String JSON_API valueToString(LargestInt value); String JSON_API valueToString(LargestUInt value); String JSON_API valueToString( double value, unsigned int precision = Value::defaultRealPrecision, PrecisionType precisionType = PrecisionType::significantDigits); String JSON_API valueToString(bool value); String JSON_API valueToQuotedString(const char* value); /// \brief Output using the StyledStreamWriter. /// \see Json::operator>>() JSON_API OStream& operator<<(OStream&, const Value& root); } // namespace Json #pragma pack(pop) #if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) #pragma warning(pop) #endif // if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) #endif // JSON_WRITER_H_INCLUDED