// 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 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 // 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 { class Value; class StreamWriterBuilder; /** Usage: using namespace Json; Value value; StreamWriter::Builder builder; builder.setCommentStyle(StreamWriter::CommentStyle::None); std::shared_ptr writer( builder.newStreamWriter(&std::cout)); writer->write(value); std::cout.flush(); */ class JSON_API StreamWriter { protected: std::ostream& sout_; // not owned; will not delete public: /// `All`: Keep all comments. /// `None`: Drop all comments. /// Use `Most` to recover the odd behavior of previous versions. /// Only `All` is currently implemented. enum class CommentStyle {None, Most, All}; /// Keep a reference, but do not take ownership of `sout`. StreamWriter(std::ostream* sout); virtual ~StreamWriter(); /// Write Value into document as configured in sub-class. /// \return zero on success /// \throw std::exception possibly, depending on configuration virtual int write(Value const& root) = 0; /// Because this Builder is non-virtual, we can safely add /// methods without a major version bump. /// \see http://stackoverflow.com/questions/14875052/pure-virtual-functions-and-binary-compatibility class Builder { StreamWriterBuilder* own_; Builder(Builder const&); // noncopyable void operator=(Builder const&); // noncopyable public: Builder(); ~Builder(); // delete underlying StreamWriterBuilder void setCommentStyle(CommentStyle cs); /// default: All /** \brief Write in human-friendly style. If "", then skip all indentation, newlines, and comments, which implies CommentStyle::None. Default: "\t" */ void setIndentation(std::string indentation); /** \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 setDropNullPlaceholders(bool v); /** \brief Do not add \n at end of document. * Normally, we add an extra newline, just because. */ void setOmitEndingLineFeed(bool v); /** \brief Add a space after ':'. * If indentation is non-empty, we surround colon with whitespace, * e.g. " : " * This will add back the trailing space when there is no indentation. * This seems dubious when the entire document is on a single line, * but we leave this here to repduce the behavior of the old `FastWriter`. */ void setEnableYAMLCompatibility(bool v); /// Do not take ownership of sout, but maintain a reference. StreamWriter* newStreamWriter(std::ostream* sout) const; }; }; /// \brief Write into stringstream, then return string, for convenience. std::string writeString(Value const& root, StreamWriter::Builder const& builder); /** \brief Abstract class for writers. */ class JSON_API Writer { public: virtual ~Writer(); virtual std::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 usefull to support feature such as RPC where bandwith is limited. * \sa Reader, Value */ class JSON_API FastWriter : public Writer { public: FastWriter(); virtual ~FastWriter() {} 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 virtual std::string write(const Value& root); private: void writeValue(const Value& value); std::string document_; bool yamlCompatiblityEnabled_; bool dropNullPlaceholders_; bool omitEndingLineFeed_; }; /** \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 outputed according to their *#CommentPlacement. * * \sa Reader, Value, Value::setComment() */ class JSON_API StyledWriter : public Writer { public: StyledWriter(); virtual ~StyledWriter() {} 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. */ virtual std::string write(const Value& root); private: void writeValue(const Value& value); void writeArrayValue(const Value& value); bool isMultineArray(const Value& value); void pushValue(const std::string& value); void writeIndent(); void writeWithIndent(const std::string& value); void indent(); void unindent(); void writeCommentBeforeValue(const Value& root); void writeCommentAfterValueOnSameLine(const Value& root); bool hasCommentForValue(const Value& value); static std::string normalizeEOL(const std::string& text); typedef std::vector ChildValues; ChildValues childValues_; std::string document_; std::string indentString_; int rightMargin_; int indentSize_; bool addChildValues_; }; /** \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 outputed according to their #CommentPlacement. * * \param indentation Each level will be indented by this amount extra. * \sa Reader, Value, Value::setComment() */ class JSON_API StyledStreamWriter { public: StyledStreamWriter(std::string indentation = "\t"); ~StyledStreamWriter() {} 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(std::ostream& out, const Value& root); private: void writeValue(const Value& value); void writeArrayValue(const Value& value); bool isMultineArray(const Value& value); void pushValue(const std::string& value); void writeIndent(); void writeWithIndent(const std::string& value); void indent(); void unindent(); void writeCommentBeforeValue(const Value& root); void writeCommentAfterValueOnSameLine(const Value& root); bool hasCommentForValue(const Value& value); static std::string normalizeEOL(const std::string& text); typedef std::vector ChildValues; ChildValues childValues_; std::ostream* document_; std::string indentString_; int rightMargin_; std::string indentation_; bool addChildValues_ : 1; bool indented_ : 1; }; #if defined(JSON_HAS_INT64) std::string JSON_API valueToString(Int value); std::string JSON_API valueToString(UInt value); #endif // if defined(JSON_HAS_INT64) std::string JSON_API valueToString(LargestInt value); std::string JSON_API valueToString(LargestUInt value); std::string JSON_API valueToString(double value); std::string JSON_API valueToString(bool value); std::string JSON_API valueToQuotedString(const char* value); /// \brief Output using the StyledStreamWriter. /// \see Json::operator>>() JSON_API std::ostream& operator<<(std::ostream&, const Value& root); } // namespace Json #if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) #pragma warning(pop) #endif // if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) #endif // JSON_WRITER_H_INCLUDED