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// Copyright 2007-2010 Baptiste Lepilleur and The JsonCpp Authors
// Distributed under MIT license, or public domain if desired and
// recognized in your jurisdiction.
#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 <ostream>
#include <string>
#include <vector>
// Disable warning C4251: <data member>: <type> 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, 8)
namespace Json {
class Value;
/**
*
* Usage:
* \code
* using namespace Json;
* void writeToStdout(StreamWriter::Factory const& factory, Value const& value)
* { std::unique_ptr<StreamWriter> 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<Json::StreamWriter> 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": "<anything>".
* - 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;
};
*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
*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()
* \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
* \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<String>;
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
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.
*
* \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:
* \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<String>;
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