Represents a JSON value. More...

#include <json_value.h>

Collaboration diagram for json::Value:

[legend]

Classes
class	CZString
union	ValueHolder

Public Types
using	Members = std::vector<std::string>
using	iterator = ValueIterator
using	const_iterator = ValueConstIterator
using	UInt = json::UInt
using	Int = json::Int
using	ArrayIndex = UInt
using	ObjectValues = std::map<CZString, Value>

Public Member Functions
	Value (ValueType type=ValueType::Null)
	Create a default Value of the given type.
	Value (Int value)
	Value (UInt value)
	Value (double value)
	Value (char const *value)
	Value (xrpl::Number const &value)
	Value (StaticString const &value)
	Constructs a value from a static string.
	Value (std::string const &value)
	Value (bool value)
	Value (Value const &other)
	~Value ()
Value &	operator= (Value const &other)
Value &	operator= (Value &&other)
	Value (Value &&other) noexcept
void	swap (Value &other) noexcept
	Swap values.
ValueType	type () const
char const *	asCString () const
std::string	asString () const
	Returns the unquoted string value.
Int	asInt () const
UInt	asUInt () const
double	asDouble () const
bool	asBool () const
UInt	asAbsUInt () const
	Correct absolute value from int or unsigned int.
bool	isNull () const
	isNull() tests to see if this field is null.
bool	isBool () const
bool	isInt () const
bool	isUInt () const
bool	isIntegral () const
bool	isDouble () const
bool	isNumeric () const
bool	isString () const
bool	isArray () const
bool	isArrayOrNull () const
bool	isObject () const
bool	isObjectOrNull () const
bool	isConvertibleTo (ValueType other) const
UInt	size () const
	Number of values in array or object.
	operator bool () const
	Returns false if this is an empty array, empty object, empty string, or null.
void	clear ()
	Remove all object members and array elements.
Value &	operator[] (UInt index)
	Access an array element (zero based index ).
Value const &	operator[] (UInt index) const
	Access an array element (zero based index ) (You may need to say 'value[0u]' to get your compiler to distinguish this from the operator[] which takes a string.).
Value	get (UInt index, Value const &defaultValue) const
	If the array contains at least index+1 elements, returns the element value, otherwise returns defaultValue.
bool	isValidIndex (UInt index) const
	Return true if index < size().
Value &	append (Value const &value)
	Append value to array at the end.
Value &	append (Value &&value)
Value &	operator[] (char const *key)
	Access an object value by name, create a null member if it does not exist.
Value const &	operator[] (char const *key) const
	Access an object value by name, returns null if there is no member with that name.
Value &	operator[] (std::string const &key)
	Access an object value by name, create a null member if it does not exist.
Value const &	operator[] (std::string const &key) const
	Access an object value by name, returns null if there is no member with that name.
Value &	operator[] (StaticString const &key)
	Access an object value by name, create a null member if it does not exist.
Value const &	operator[] (StaticString const &key) const
Value	get (char const *key, Value const &defaultValue) const
	Return the member named key if it exist, defaultValue otherwise.
Value	get (std::string const &key, Value const &defaultValue) const
	Return the member named key if it exist, defaultValue otherwise.
Value	removeMember (char const *key)
	Remove and return the named member.
Value	removeMember (std::string const &key)
	Same as removeMember(const char*).
bool	isMember (char const *key) const
	Return true if the object has a member named key.
bool	isMember (std::string const &key) const
	Return true if the object has a member named key.
bool	isMember (StaticString const &key) const
	Return true if the object has a member named key.
Members	getMemberNames () const
	Return a list of the member names.
std::string	toStyledString () const
const_iterator	begin () const
const_iterator	end () const
iterator	begin ()
iterator	end ()

Static Public Attributes
static Value const	kNull
static constexpr Int	kMinInt = std::numeric_limits<Int>::min()
static constexpr Int	kMaxInt = std::numeric_limits<Int>::max()
static constexpr UInt	kMaxUInt = std::numeric_limits<UInt>::max()

Private Member Functions
Value &	resolveReference (char const *key, bool isStatic)

Private Attributes
union json::Value::ValueHolder	value_
ValueType	type_: 8
int	allocated_: 1 {}

Friends
class	ValueIteratorBase
bool	operator== (Value const &x, Value const &y)
bool	operator< (Value const &x, Value const &y)

Detailed Description

Represents a JSON value.

This class is a discriminated union wrapper that can represent a:

signed integer [range: Value::kMinInt - Value::kMaxInt]
unsigned integer (range: 0 - Value::kMaxUInt)
double
UTF-8 string
boolean
'null'
an ordered list of Value
collection of name/value pairs (javascript object)

The type of the held value is represented by a ValueType and can be obtained using type().

values of an ValueType::Object or ValueType::Array can be accessed using operator[]() methods. Non const methods will automatically create the a ValueType::Null element if it does not exist. The sequence of an ValueType::Array will be automatically resize and initialized with ValueType::Null. resize() can be used to enlarge or truncate an ValueType::Array.

The get() methods can be used to obtain a default value in the case the required element does not exist.

It is possible to iterate over the list of a ValueType::Object values using the getMemberNames() method.

Definition at line 116 of file json_value.h.

Member Typedef Documentation

◆ Members

using json::Value::Members = std::vector<std::string>

Definition at line 121 of file json_value.h.

◆ iterator

using json::Value::iterator = ValueIterator

Definition at line 122 of file json_value.h.

◆ const_iterator

using json::Value::const_iterator = ValueConstIterator

Definition at line 123 of file json_value.h.

◆ UInt

using json::Value::UInt = json::UInt

Definition at line 124 of file json_value.h.

◆ Int

using json::Value::Int = json::Int

Definition at line 125 of file json_value.h.

◆ ArrayIndex

using json::Value::ArrayIndex = UInt

Definition at line 126 of file json_value.h.

◆ ObjectValues

using json::Value::ObjectValues = std::map<CZString, Value>

Definition at line 162 of file json_value.h.

Constructor & Destructor Documentation

◆ Value() [1/11]

json::Value::Value ( ValueType type = ValueType::Null )

Create a default Value of the given type.

This is a very useful constructor. To create an empty array, pass ValueType::Array. To create an empty object, pass ValueType::Object. Another Value can then be set to this one by assignment. This is useful since clear() and resize() will not alter types.

   Examples:

json::Value null_value; // null
json::Value arr_value(json::ValueType::Array); // []
json::Value obj_value(json::ValueType::Object); // {}

Definition at line 182 of file json_value.cpp.

◆ Value() [2/11]

json::Value::Value ( Int value )

Definition at line 218 of file json_value.cpp.

◆ Value() [3/11]

json::Value::Value ( UInt value )

Definition at line 223 of file json_value.cpp.

◆ Value() [4/11]

json::Value::Value ( double value )

Definition at line 228 of file json_value.cpp.

◆ Value() [5/11]

json::Value::Value ( char const * value )

Definition at line 233 of file json_value.cpp.

◆ Value() [6/11]

json::Value::Value ( xrpl::Number const & value )

Definition at line 238 of file json_value.cpp.

◆ Value() [7/11]

json::Value::Value ( StaticString const & value )

Constructs a value from a static string.

Like other value string constructor but do not duplicate the string for internal storage. The given string must remain alive after the call to this constructor. Example of usage:

json::Value aValue( StaticString("some text") );

json::StaticString

Lightweight wrapper to tag static string.

Definition json_value.h:48

Definition at line 250 of file json_value.cpp.

◆ Value() [8/11]

json::Value::Value ( std::string const & value )

Definition at line 244 of file json_value.cpp.

◆ Value() [9/11]

json::Value::Value ( bool value )

Definition at line 256 of file json_value.cpp.

◆ Value() [10/11]

json::Value::Value ( Value const & other )

Definition at line 261 of file json_value.cpp.

◆ ~Value()

json::Value::~Value ( )

Definition at line 298 of file json_value.cpp.

◆ Value() [11/11]

json::Value::Value ( Value && other )

noexcept

Definition at line 335 of file json_value.cpp.

Member Function Documentation

◆ operator=() [1/2]

Value & json::Value::operator= ( Value const & other )

Definition at line 328 of file json_value.cpp.

◆ operator=() [2/2]

Value & json::Value::operator= ( Value && other )

Definition at line 343 of file json_value.cpp.

◆ swap()

void json::Value::swap ( Value & other )

noexcept

Swap values.

Definition at line 351 of file json_value.cpp.

◆ type()

ValueType json::Value::type ( ) const

nodiscard

Definition at line 365 of file json_value.cpp.

◆ asCString()

char const * json::Value::asCString ( ) const

nodiscard

Definition at line 487 of file json_value.cpp.

◆ asString()

std::string json::Value::asString ( ) const

nodiscard

Returns the unquoted string value.

Definition at line 494 of file json_value.cpp.

◆ asInt()

Value::Int json::Value::asInt ( ) const

nodiscard

Definition at line 530 of file json_value.cpp.

◆ asUInt()

Value::UInt json::Value::asUInt ( ) const

nodiscard

Definition at line 631 of file json_value.cpp.

◆ asDouble()

double json::Value::asDouble ( ) const

nodiscard

Definition at line 674 of file json_value.cpp.

◆ asBool()

bool json::Value::asBool ( ) const

nodiscard

Definition at line 708 of file json_value.cpp.

◆ asAbsUInt()

UInt json::Value::asAbsUInt ( ) const

nodiscard

Correct absolute value from int or unsigned int.

Definition at line 573 of file json_value.cpp.

◆ isNull()

bool json::Value::isNull ( ) const

nodiscard

isNull() tests to see if this field is null.

Don't use this method to test for emptiness: use empty().

Definition at line 1092 of file json_value.cpp.

◆ isBool()

bool json::Value::isBool ( ) const

nodiscard

Definition at line 1098 of file json_value.cpp.

◆ isInt()

bool json::Value::isInt ( ) const

nodiscard

Definition at line 1104 of file json_value.cpp.

◆ isUInt()

bool json::Value::isUInt ( ) const

nodiscard

Definition at line 1110 of file json_value.cpp.

◆ isIntegral()

bool json::Value::isIntegral ( ) const

nodiscard

Definition at line 1116 of file json_value.cpp.

◆ isDouble()

bool json::Value::isDouble ( ) const

nodiscard

Definition at line 1122 of file json_value.cpp.

◆ isNumeric()

bool json::Value::isNumeric ( ) const

nodiscard

Definition at line 1128 of file json_value.cpp.

◆ isString()

bool json::Value::isString ( ) const

nodiscard

Definition at line 1134 of file json_value.cpp.

◆ isArray()

bool json::Value::isArray ( ) const

nodiscard

Definition at line 1140 of file json_value.cpp.

◆ isArrayOrNull()

bool json::Value::isArrayOrNull ( ) const

nodiscard

Definition at line 1146 of file json_value.cpp.

◆ isObject()

bool json::Value::isObject ( ) const

nodiscard

Definition at line 1152 of file json_value.cpp.

◆ isObjectOrNull()

bool json::Value::isObjectOrNull ( ) const

nodiscard

Definition at line 1158 of file json_value.cpp.

◆ isConvertibleTo()

bool json::Value::isConvertibleTo ( ValueType other ) const

nodiscard

Definition at line 742 of file json_value.cpp.

◆ size()

Value::UInt json::Value::size ( ) const

nodiscard

Number of values in array or object.

Definition at line 801 of file json_value.cpp.

◆ operator bool()

json::Value::operator bool ( ) const

explicit

Returns false if this is an empty array, empty object, empty string, or null.

Definition at line 835 of file json_value.cpp.

◆ clear()

void json::Value::clear ( )

Remove all object members and array elements.

Precondition: type() is ValueType::Array, ValueType::Object, or ValueType::Null

Postcondition: type() is unchanged

Definition at line 851 of file json_value.cpp.

◆ operator[]() [1/8]

Value & json::Value::operator[] ( UInt index )

Access an array element (zero based index ).

If the array contains less than index element, then null value are inserted in the array so that its size is index+1. (You may need to say 'value[0u]' to get your compiler to distinguish this from the operator[] which takes a string.)

Definition at line 870 of file json_value.cpp.

◆ operator[]() [2/8]

Value const & json::Value::operator[] ( UInt index ) const

Access an array element (zero based index ) (You may need to say 'value[0u]' to get your compiler to distinguish this from the operator[] which takes a string.).

Definition at line 891 of file json_value.cpp.

◆ get() [1/3]

Value json::Value::get	(	UInt	index,
		Value const &	defaultValue ) const

nodiscard

If the array contains at least index+1 elements, returns the element value, otherwise returns defaultValue.

Definition at line 941 of file json_value.cpp.

◆ isValidIndex()

bool json::Value::isValidIndex ( UInt index ) const

nodiscard

Return true if index < size().

Definition at line 948 of file json_value.cpp.

◆ append() [1/2]

Value & json::Value::append ( Value const & value )

Append value to array at the end.

Equivalent to jsonvalue[jsonvalue.size()] = value;

Definition at line 997 of file json_value.cpp.

◆ append() [2/2]

Value & json::Value::append ( Value && value )

Definition at line 1003 of file json_value.cpp.

◆ operator[]() [3/8]

Value & json::Value::operator[] ( char const * key )

Access an object value by name, create a null member if it does not exist.

Definition at line 910 of file json_value.cpp.

◆ operator[]() [4/8]

Value const & json::Value::operator[] ( char const * key ) const

Access an object value by name, returns null if there is no member with that name.

Definition at line 954 of file json_value.cpp.

◆ operator[]() [5/8]

Value & json::Value::operator[] ( std::string const & key )

Access an object value by name, create a null member if it does not exist.

Definition at line 973 of file json_value.cpp.

◆ operator[]() [6/8]

Value const & json::Value::operator[] ( std::string const & key ) const

Access an object value by name, returns null if there is no member with that name.

Definition at line 979 of file json_value.cpp.

◆ operator[]() [7/8]

Value & json::Value::operator[] ( StaticString const & key )

Access an object value by name, create a null member if it does not exist.

If the object as no entry for that name, then the member name used to store the new entry is not duplicated. Example of use:

json::Value object;
static const StaticString code("code");
object[code] = 1234;

Definition at line 985 of file json_value.cpp.

◆ operator[]() [8/8]

Value const & json::Value::operator[] ( StaticString const & key ) const

Definition at line 991 of file json_value.cpp.

◆ get() [2/3]

Value json::Value::get	(	char const *	key,
		Value const &	defaultValue ) const

Return the member named key if it exist, defaultValue otherwise.

Definition at line 1009 of file json_value.cpp.

◆ get() [3/3]

Value json::Value::get	(	std::string const &	key,
		Value const &	defaultValue ) const

nodiscard

Return the member named key if it exist, defaultValue otherwise.

Definition at line 1016 of file json_value.cpp.

◆ removeMember() [1/2]

Value json::Value::removeMember ( char const * key )

Remove and return the named member.

Do nothing if it did not exist.

Returns: the removed Value, or null.

Precondition: type() is ValueType::Object or ValueType::Null

Postcondition: type() is unchanged

Definition at line 1022 of file json_value.cpp.

◆ removeMember() [2/2]

Value json::Value::removeMember ( std::string const & key )

Same as removeMember(const char*).

Definition at line 1043 of file json_value.cpp.

◆ isMember() [1/3]

bool json::Value::isMember ( char const * key ) const

Return true if the object has a member named key.

Definition at line 1049 of file json_value.cpp.

◆ isMember() [2/3]

bool json::Value::isMember ( std::string const & key ) const

nodiscard

Return true if the object has a member named key.

Definition at line 1059 of file json_value.cpp.

◆ isMember() [3/3]

bool json::Value::isMember ( StaticString const & key ) const

nodiscard

Return true if the object has a member named key.

Definition at line 1065 of file json_value.cpp.

◆ getMemberNames()

Value::Members json::Value::getMemberNames ( ) const

nodiscard

Return a list of the member names.

If null, return an empty list.

Precondition: type() is ValueType::Object or ValueType::Null

Postcondition: if type() was ValueType::Null, it remains ValueType::Null

Definition at line 1071 of file json_value.cpp.

◆ toStyledString()

std::string json::Value::toStyledString ( ) const

nodiscard

Definition at line 1164 of file json_value.cpp.

◆ begin() [1/2]

Value::const_iterator json::Value::begin ( ) const

nodiscard

Definition at line 1171 of file json_value.cpp.

◆ end() [1/2]

Value::const_iterator json::Value::end ( ) const

nodiscard

Definition at line 1189 of file json_value.cpp.

◆ begin() [2/2]

Value::iterator json::Value::begin ( )

Definition at line 1207 of file json_value.cpp.

◆ end() [2/2]

Value::iterator json::Value::end ( )

Definition at line 1224 of file json_value.cpp.

◆ resolveReference()

Value & json::Value::resolveReference	(	char const *	key,
		bool	isStatic )

private

Definition at line 916 of file json_value.cpp.

◆ ValueIteratorBase

friend class ValueIteratorBase

friend

Definition at line 118 of file json_value.h.

◆ operator==

bool operator==	(	Value const &	x,
		Value const &	y )

friend

Definition at line 439 of file json_value.cpp.

◆ operator<

bool operator<	(	Value const &	x,
		Value const &	y )

friend

Definition at line 383 of file json_value.cpp.

Member Data Documentation

◆ kNull

Value const json::Value::kNull

static

Definition at line 128 of file json_value.h.

◆ kMinInt

Int json::Value::kMinInt = std::numeric_limits<Int>::min()

staticconstexpr

Definition at line 129 of file json_value.h.

◆ kMaxInt

Int json::Value::kMaxInt = std::numeric_limits<Int>::max()

staticconstexpr

Definition at line 130 of file json_value.h.

◆ kMaxUInt

UInt json::Value::kMaxUInt = std::numeric_limits<UInt>::max()

staticconstexpr

Definition at line 131 of file json_value.h.

◆ value_

union json::Value::ValueHolder json::Value::value_

private

◆ type_

ValueType json::Value::type_

private

Definition at line 462 of file json_value.h.

◆ allocated_

int json::Value::allocated_

private

Definition at line 463 of file json_value.h.

Classes

Public Types

Public Member Functions

Static Public Attributes

Private Member Functions

Private Attributes

Friends

Detailed Description

Member Typedef Documentation

◆ Members

◆ iterator

◆ const_iterator

◆ UInt

◆ Int

◆ ArrayIndex

◆ ObjectValues

Constructor & Destructor Documentation

◆ Value() [1/11]

◆ Value() [2/11]

◆ Value() [3/11]

◆ Value() [4/11]

◆ Value() [5/11]

◆ Value() [6/11]

◆ Value() [7/11]

◆ Value() [8/11]

◆ Value() [9/11]

◆ Value() [10/11]

◆ ~Value()

◆ Value() [11/11]

Member Function Documentation

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ swap()

◆ type()

◆ asCString()

◆ asString()

◆ asInt()

◆ asUInt()

◆ asDouble()

◆ asBool()

◆ asAbsUInt()

◆ isNull()

◆ isBool()

◆ isInt()

◆ isUInt()

◆ isIntegral()

◆ isDouble()

◆ isNumeric()

◆ isString()

◆ isArray()

◆ isArrayOrNull()

◆ isObject()

◆ isObjectOrNull()

◆ isConvertibleTo()

◆ size()

◆ operator bool()

◆ clear()

◆ operator[]() [1/8]

◆ operator[]() [2/8]

◆ get() [1/3]

◆ isValidIndex()

◆ append() [1/2]

◆ append() [2/2]

◆ operator[]() [3/8]

◆ operator[]() [4/8]

◆ operator[]() [5/8]

◆ operator[]() [6/8]

◆ operator[]() [7/8]

◆ operator[]() [8/8]

◆ get() [2/3]

◆ get() [3/3]

◆ removeMember() [1/2]

◆ removeMember() [2/2]

◆ isMember() [1/3]

◆ isMember() [2/3]

◆ isMember() [3/3]

◆ getMemberNames()

◆ toStyledString()

◆ begin() [1/2]

◆ end() [1/2]