cppcms::json::value Class Reference

This class is central representation of json objects. More...

#include <cppcms/json.h>

Public Member Functions
json_type	type () const
bool	is_undefined () const
bool	is_null () const
bool const &	boolean () const
double const &	number () const
std::string const &	str () const
json::object const &	object () const
json::array const &	array () const
bool &	boolean ()
double &	number ()
std::string &	str ()
json::object &	object ()
json::array &	array ()
void	undefined ()
void	null ()
void	boolean (bool)
void	number (double)
void	str (std::string const &)
void	object (json::object const &)
void	array (json::array const &)
template<typename T >
T	get_value () const
template<typename T >
void	set_value (T const &v)
value const &	find (std::string const &path) const
value const &	find (char const *path) const
value const &	at (std::string const &path) const
value const &	at (char const *path) const
value &	at (std::string const &path)
value &	at (char const *path)
void	at (std::string const &path, value const &v)
void	at (char const *path, value const &v)
template<typename T >
	value (T const &v)
json_type	type (std::string const &path) const
json_type	type (char const *path) const
template<typename T >
void	set (std::string const &path, T const &v)
template<typename T >
void	set (char const *path, T const &v)
std::string	get (std::string const &path, char const *def) const
std::string	get (char const *path, char const *def) const
template<typename T >
T	get (std::string const &path) const
template<typename T >
T	get (char const *path) const
template<typename T >
T	get (char const *path, T const &def) const
template<typename T >
T	get (std::string const &path, T const &def) const
value &	operator[] (std::string const &name)
value const &	operator[] (std::string const &name) const
value &	operator[] (size_t n)
value const &	operator[] (size_t n) const
std::string	save (int how=compact) const
void	save (std::ostream &out, int how=compact) const
bool	load (std::istream &in, bool full, int *line_number=0)
bool	load (char const *&begin, char const *end, bool full, int *line_number=0)
bool	operator== (value const &other) const
bool	operator!= (value const &other) const
	value (value const &other)
value const &	operator= (value const &other)
	value ()
	~value ()
void	swap (value &other)

Friends
struct	copyable

Detailed Description

This class is central representation of json objects.

It can be a value from any type including scalar, object, array and undefined

Constructor & Destructor Documentation

template<typename T >

cppcms::json::value::value ( T const &  v )

inline

Creates a value from and object v of type T

cppcms::json::value::value ( value const &  other )

inline

Copy constructor

cppcms::json::value::value ( )

inline

Default value - creates a value of undefined type

cppcms::json::value::~value ( )

inline

Destructor

Member Function Documentation

json::array const& cppcms::json::value::array

(

)

const

Convert value to json::array, throws bad_value_cast if value's type is not array

Referenced by swap().

json::array& cppcms::json::value::array

(

)

Get reference to array variable that represents this value, throws bad_value_cast if type is invalid

void cppcms::json::value::array

(

json::array const &

)

Set value to array type and assign it

value const& cppcms::json::value::at

(

std::string const &

path

)

const

Searches a value in the path path, if not found throw bad_value_cast.

For example if the json::value represents { "x" : { "y" : 10 } }, then find("x.y") would return a reference to value that hold a number 10, find("x") returns a reference to a value that holds an object { "y" : 10 } and find("foo") throws

value const& cppcms::json::value::at

(

char const *

path

)

const

Searches a value in the path path, if not found throw bad_value_cast.

For example if the json::value represents { "x" : { "y" : 10 } }, then find("x.y") would return a reference to value that hold a number 10, find("x") returns a reference to a value that holds an object { "y" : 10 } and find("foo") throws

value& cppcms::json::value::at

(

std::string const &

path

)

Searches a value in the path path, if not found throw bad_value_cast.

For example if the json::value represents { "x" : { "y" : 10 } }, then find("x.y") would return a reference to value that hold a number 10, find("x") returns a reference to a value that holds an object { "y" : 10 } and find("foo") throws

value& cppcms::json::value::at

(

char const *

path

)

Searches a value in the path path, if not found throw bad_value_cast.

For example if the json::value represents { "x" : { "y" : 10 } }, then find("x.y") would return a reference to value that hold a number 10, find("x") returns a reference to a value that holds an object { "y" : 10 } and find("foo") throws

void cppcms::json::value::at	(	std::string const &	path,
		value const &	v
	)

Sets the value v at the path path, if the path invalid, creates it.

void cppcms::json::value::at	(	char const *	path,
		value const &	v
	)

Sets the value v at the path path, if the path invalid, creates it.

bool const& cppcms::json::value::boolean

(

)

const

Convert value to boolean, throws bad_value_cast if value's type is not boolean

bool& cppcms::json::value::boolean

(

)

Get reference to bool variable that represents this value, throws bad_value_cast if type is invalid

void cppcms::json::value::boolean

(

bool

)

Set value to boolean type and assign it

value const& cppcms::json::value::find

(

std::string const &

path

)

const

Searches a value in the path path

For example if the json::value represents { "x" : { "y" : 10 } }, then find("x.y") would return a reference to value that hold a number 10, find("x") returns a reference to a value that holds an object { "y" : 10 } and find("foo") would return value of undefined type.

value const& cppcms::json::value::find

(

char const *

path

)

const

Searches a value in the path path

For example if the json::value represents { "x" : { "y" : 10 } }, then find("x.y") would return a reference to value that hold a number 10, find("x") returns a reference to a value that holds an object { "y" : 10 } and find("foo") would return value of undefined type.

std::string cppcms::json::value::get ( std::string const &  path, char const *  def  ) const

inline

Get a string value from a path path. If the path is not invalid or the object is not of type string at this path, returns def instead

References get_value(), and is_undefined().

std::string cppcms::json::value::get ( char const *  path, char const *  def  ) const

inline

Get a string value from a path path. If the path is not invalid or the object is not of type string at this path, returns def instead

References get_value(), and is_undefined().

template<typename T >

T cppcms::json::value::get ( std::string const &  path ) const

inline

Get an object of type T from the path path. Throws bad_value_cast if such path does not exists of conversion can't be done

template<typename T >

T cppcms::json::value::get ( char const *  path ) const

inline

Get an object of type T from the path path. Throws bad_value_cast if such path does not exists of conversion can't be done

template<typename T >

T cppcms::json::value::get ( char const *  path, T const &  def  ) const

inline

Get an object of type T from the path path. Returns def if such path does not exists of conversion can't be done

References get_value(), and is_undefined().

template<typename T >

T cppcms::json::value::get ( std::string const &  path, T const &  def  ) const

inline

Get an object of type T from the path path. Returns def if such path does not exists of conversion can't be done

References cppcms::json::compact, get_value(), and is_undefined().

template<typename T >

T cppcms::json::value::get_value ( ) const

inline

Convert the value to type T, using json::traits, throws bad_value_cast if conversion is not possible

References cppcms::json::traits< T >::get().

Referenced by get(), and swap().

bool cppcms::json::value::is_null

(

)

const

Returns true if type()==json::is_null

bool cppcms::json::value::is_undefined

(

)

const

Returns true if type()==json::is_undefined

Referenced by get().

bool cppcms::json::value::load	(	std::istream &	in,
		bool	full,
		int *	line_number = 0
	)

Read a value from std::istream.

Note: only JSON object and JSON array are considered valid values

Parameters

in	the std::istream used to read the data
full	require EOF once the object is read, otherwise consider it as syntax error
line_number	return a number of the line where syntax error occurred

Returns

returns true if the value was read successfully, otherwise returns false to indicate a syntax error.

bool cppcms::json::value::load	(	char const *&	begin,
		char const *	end,
		bool	full,
		int *	line_number = 0
	)

Read a value from character range

Note: only JSON object and JSON array are considered valid values

Parameters

begin	- begin of the text range, at the end points to the end of parsed range
end	- end of the text range
full	require EOF once the object is read, otherwise consider it as syntax error
line_number	return a number of the line where syntax error occurred

Returns

returns true if the value was read successfully, otherwise returns false to indicate a syntax error.

New in CppCMS 1.2

void cppcms::json::value::null

(

)

Set value to null type

double const& cppcms::json::value::number

(

)

const

Convert value to double, throws bad_value_cast if value's type is not number

Referenced by swap().

double& cppcms::json::value::number

(

)

Get reference to double variable that represents this value, throws bad_value_cast if type is invalid

void cppcms::json::value::number

(

double

)

Set value to numeric type and assign it

json::object const& cppcms::json::value::object

(

)

const

Convert value to json::object, throws bad_value_cast if value's type is not object

Referenced by swap().

json::object& cppcms::json::value::object

(

)

Get reference to object variable that represents this value, throws bad_value_cast if type is invalid

void cppcms::json::value::object

(

json::object const &

)

Set value to object type and assign it

bool cppcms::json::value::operator!=

(

value const &

other

)

const

Compare two values objects, return false if they are same

value const& cppcms::json::value::operator= ( value const &  other )

inline

Assignment operator

bool cppcms::json::value::operator==

(

value const &

other

)

const

Compare two values objects, return true if they are same

value& cppcms::json::value::operator[]

(

std::string const &

name

)

Returns a reference to the node name of the value. For value = {"x",10} and name == "x" return a value that holds 10.

If value is not object it's type set to object. If such node does not exits, it is created with undefined value

value const& cppcms::json::value::operator[]

(

std::string const &

name

)

const

Returns reference to the node name of the value. For value = {"x",10} and name == "x" return a value that holds 10.

If value is not object or such node does not exits, throws bad_value_cast

value& cppcms::json::value::operator[]

(

size_t

n

)

Returns a reference to n 'th entry of the array. If the value is not an array it is reset to array, of the array is too small it is resized to size of at least n+1

value const& cppcms::json::value::operator[]

(

size_t

n

)

const

Returns a reference to n 'th entry of array, if the value is not array or n is too big, throws bad_value_cast

std::string cppcms::json::value::save

(

int

how = compact

)

const

Convert a value to std::string, if how has value readable it is converted with indentation

void cppcms::json::value::save	(	std::ostream &	out,
		int	how = compact
	)		const

Write a value to std::ostream, if how has value readable it is converted with indentation

template<typename T >

void cppcms::json::value::set ( std::string const &  path, T const &  v  )

inline

Convert an object v of type T to a value at specific path, same as at(path,value(v))

template<typename T >

void cppcms::json::value::set ( char const *  path, T const &  v  )

inline

Convert an object v of type T to a value at specific path, same as at(path,value(v))

template<typename T >

void cppcms::json::value::set_value ( T const &  v )

inline

Convert the object v of type T to the value

References cppcms::json::traits< T >::set().

std::string const& cppcms::json::value::str

(

)

const

Convert value to strng, throws bad_value_cast if value's type is not string

std::string& cppcms::json::value::str

(

)

Get reference to string variable that represents this value, throws bad_value_cast if type is invalid

void cppcms::json::value::str

(

std::string const &

)

Set value to string type and assign it

void cppcms::json::value::swap ( value &  other )

inline

Swaps two values, does not throw.

References array(), get_value(), number(), booster::locale::as::number(), object(), and cppcms::json::to_json().

json_type cppcms::json::value::type

(

)

const

Get the type of the value

Referenced by type().

json_type cppcms::json::value::type ( std::string const &  path ) const

inline

Returns the type of variable in path, if not found returns undefined

Same as find(path).type()

References type().

json_type cppcms::json::value::type ( char const *  path ) const

inline

Returns the type of variable in path, if not found returns undefined

Same as find(path).type()

References type().

void cppcms::json::value::undefined

(

)

Set value to undefined type

---

The documentation for this class was generated from the following file:

• cppcms/json.h