#include <CUJSONReader.h>

Inheritance diagram for JSONReader:

Public Member Functions
void	setFile (std::string file)

std::string	getFile () const

bool	startJSON ()

bool	startJSON (std::string source)

void	endJSON ()

void	reset ()

std::string	getKey () const

bool	isNull () const

bool	isObject () const

bool	isArray () const

bool	isBool () const

bool	isNumber () const

bool	isString () const

bool	isVec2 () const

bool	isFloatArray () const

bool	exists (std::string key) const

bool	isNull (std::string key) const

bool	isObject (std::string key) const

bool	isArray (std::string key) const

bool	isBool (std::string key) const

bool	isNumber (std::string key) const

bool	isString (std::string key) const

bool	isVec2 (std::string key) const

bool	isFloatArray (std::string key) const

bool	getBool () const

float	getNumber () const

std::string	getString () const

Vec2	getVec2 () const

int	getFloatArray (float *buffer) const

bool	getBool (std::string key) const

float	getNumber (std::string key) const

std::string	getString (std::string key) const

Vec2	getVec2 (std::string key) const

int	getFloatArray (std::string key, float *buffer) const

bool	startObject (std::string key)

bool	startObject ()

void	endObject ()

int	getSize () const

int	getSize (std::string key) const

int	startArray (std::string key)

int	startArray ()

void	endArray ()

bool	advance ()

CC_CONSTRUCTOR_ACCESS	_json (nullptr)

CC_CONSTRUCTOR_ACCESS	_arraymode (false)

	~JSONReader ()

bool	init ()

bool	init (std::string file)

Static Public Member Functions
static JSONReader *	create ()

static JSONReader *	create (std::string file)

Public Attributes
CC_CONSTRUCTOR_ACCESS	__pad0__: JSONReader() : _root(nullptr)

Protected Attributes
Json *	_root

Json *	_json

std::string	_file

std::vector< Json * >	_stack

bool	_arraymode

std::vector< bool >	_states

Detailed Description

Class represents a simple DOM reader for parsing JSON

As most DOM readers, this uses a begin-end syntax to descend the document to tree. At any time, this reader has a cursor positioned at a particular node. You use methods to move this cursor. For example, to read the contents of an object, you must call startObject() to move the cursor to access its contents, and then must call endObject() when you are done. Similarly for arrays. Primitive types, such as bools, floats, and strings can all be access directly.

Objects and arrays are interchangeable. Any object can be treated as an array and traversed accordingly. Traversing an object as an array allows you to query both the keys and values of the object, instead of just the keys.

Elements of the JSON may be accessed without or without a name. If no name is given, it assumes that you are refering to the current node in the DOM tree. Otherwise, you are refering to a field of a given name. This is crucial for going back and forth between objects and arrays. For example, if you call startObject("foo"), it will descend the field "foo" from the current position. If you then call startArray() it will stay at the same position, but treat it as an array instead.

This reader tries to fail as little as possible. If a field or current position is treated as the wrong type, it will return a default value instead. This makes it easier to process missing data. If you really care about whether data is there or not, use the type-checking methods.

Constructor & Destructor Documentation

JSONReader::~JSONReader ( )

inline

Deletes the JSON reader, releasing all resources

Member Function Documentation

bool JSONReader::advance ( )

Advances the cursor to the next position in the array.

This method returns false if there are no more elements in the array. You must have called startArray() for this method to work.

Returns: true if there was an element to advance to

NS_CC_BEGIN JSONReader * JSONReader::create ( )

static

Creates a new JSONReader.

This constructor does not load any JSON, as there is no associate file. You can associate a file later with the setFile() method.

Returns: an autoreleased JSONReader object

JSONReader * JSONReader::create ( std::string file )

static

Creates a new JSONReader.

This constructor does load the JSON file; it only stores the file name. You start parsing with the startJSON() method.

Parameters

file	the file to read from

Returns: an autoreleased JSONReader object

void JSONReader::endArray ( )

Ends processing of the current array, returning the cursor to its parent

void JSONReader::endJSON ( )

Ends the current JSON parsing session, erasing the DOM tree.

Once this method is called of the JSON methods will fail until startJSON() – either version – is called again.

void JSONReader::endObject ( )

Ends processing of the current object, returning the cursor to its parent

bool JSONReader::exists ( std::string key ) const

Returns true if there is an entry for the given key.

Parameters

key	the field name to query

Returns: true if there is an entry for the given key.

bool JSONReader::getBool ( ) const

inline

Returns the boolean value for the current cursor position.

If the current position is not a boolean, it returns False as a default.

Returns: the boolean value for the current cursor position.

bool JSONReader::getBool ( std::string key ) const

Returns the boolean value for the given key.

If the key does not exist, or does not refer to a boolean, this method returns False as a default.

Parameters

key	the field name to query

Returns: the boolean value for the given key.

std::string JSONReader::getFile ( ) const

inline

Returns the file for this JSON reader.

If this value is "", then there is no file. Instead, the JSONReader is intended to be used directly on a string via the startJSON(string) method.

Parameters

file	for this JSON reader

int JSONReader::getFloatArray ( float * buffer ) const

Fills the buffer with the contents of the cursor position

This method assumes that the current cursor position is an array of floats (e.g. the children of the cursor are all float nodes), and writes these floats to the given buffer. The method returns the number of elements written. If the cursor is not a valid float array, nothing will be written.

The buffer must be sized large enough to recieve the float array. Use the method getSize() to determine the size of the array.

Parameters

buffer the buffer to store the float values

Returns: number of elements written to the buffer

int JSONReader::getFloatArray	(	std::string	key,
		float *	buffer
	)		const

Fills the buffer with the contents of the given key.

This method assumes that the key refers to an array of floats (e.g. the children of the key are all float nodes), and writes these floats to the given buffer. The method returns the number of elements written. If the key does not exist, or does not refer to a valid float array, nothing will be written.

The buffer must be sized large enough to recieve the float array. Use the method getSize() to determine the size of the array.

Parameters

buffer	the buffer to store the float values
key	the field name to query

Returns: number of elements written to the buffer

std::string JSONReader::getKey ( ) const

inline

Returns the key for the current cursor position in the DOM.

Returns: the key for the current cursor position in the DOM.

float JSONReader::getNumber ( ) const

inline

Returns the number for the current cursor position.

All numbers in JSON files are treated as floats. If the current position is not a number, it returns 0.0f as a default.

Returns: the number for the current cursor position.

float JSONReader::getNumber ( std::string key ) const

Returns the number for the given key.

If the key does not exist, or does not refer to a number, this method returns 0.0f as a default. All numbers in JSON files are treated as floats.

Parameters

key	the field name to query

Returns: the number for the given key.

int JSONReader::getSize ( ) const

inline

Returns the number of children for the cursor node

If the current cursor is an array, it returns the number of elements of the array. If it is an object, it returns the number of fields in the object.

Returns: the number of children for the cursor node

int JSONReader::getSize ( std::string key ) const

Returns the number of children for the given key

If the key refers to an array, it returns the number of elements of the array. If it refers to an object, it returns the number of fields in the object. If the key does not exist, it returns 0.

Parameters

key	the field name to query

Returns: the number of children for the given key

std::string JSONReader::getString ( ) const

inline

Returns the string for the current cursor position.

If the current position is not a string, it returns "" as a default.

Returns: the string for the current cursor position.

std::string JSONReader::getString ( std::string key ) const

Returns the string for the given key.

If the key does not exist, or does not refer to a string, this method returns "" as a default.

Parameters

key	the field name to query

Returns: the string for the given key.

Vec2 JSONReader::getVec2 ( ) const

Returns the Vec2 value for the current cursor position.

If the current position is not a Vec2, it returns Vec2::ZERO as a default.

Returns: the Vec2 value for the current cursor position.

Vec2 JSONReader::getVec2 ( std::string key ) const

Returns the Vec2 value for the given key.

If the key does not exist, or does not refer to a Vec2 value, this method returns Vec2::ZERO as a default.

Parameters

key	the field name to query

Returns: the Vec2 value for the given key.

bool JSONReader::init ( )

Initializes a new JSONReader.

This initializer does not load any JSON, as there is no associate file. You can associate a file later with the setFile() method.

Returns: true if the reader is initialized properly, false otherwise.

bool JSONReader::init ( std::string file )

Initializes a new JSONReader.

This initializer does load the JSON file; it only stores the file name. You start parsing with the startJSON() method.

Parameters

file	the file to read from

Returns: true if the reader is initialized properly, false otherwise.

bool JSONReader::isArray ( ) const

inline

Returns true if the current cursor position represents an array.

Returns: true if the current cursor position represents an array.

bool JSONReader::isArray ( std::string key ) const

Returns true if the entry for key exists and represents an array.

Parameters

key	the field name to query

Returns: true if the entry for key exists and represents an array.

bool JSONReader::isBool ( ) const

inline

Returns true if the current cursor position represents a boolean value

Returns: true if the current cursor position represents a boolean value

bool JSONReader::isBool ( std::string key ) const

Returns true if the entry for key exists and represents a boolean value

Parameters

key	the field name to query

Returns: true if the entry for key exists and represents a boolean value

bool JSONReader::isFloatArray ( ) const

Returns true if the current cursor position represents an array of floats

This method is just an additional type-check on top of isArray.

Returns: true if the current cursor position represents an array of floats

bool JSONReader::isFloatArray ( std::string key ) const

Returns true if the entry for key exists and represents an array of floats

This method is just an additional type-check on top of isArray.

Parameters

key	the field name to query

Returns: true if the entry for key exists and represents an array of floats

bool JSONReader::isNull ( ) const

inline

Returns true if the current cursor position has a nullptr value.

Returns: true if the current cursor position has a nullptr value.

bool JSONReader::isNull ( std::string key ) const

Returns true if the entry for key exists and has a nullptr value.

Parameters

key	the field name to query

Returns: true if the entry for key exists and has a nullptr value.

bool JSONReader::isNumber ( ) const

inline

Returns true if the current cursor position represents a number

All numbers in JSON files are treated as floats.

Returns: true if the current cursor position represents a number

bool JSONReader::isNumber ( std::string key ) const

Returns true if the entry for key exists and represents a number

All numbers in JSON files are treated as floats.

Parameters

key	the field name to query

Returns: true if the entry for key exists and represents a number

bool JSONReader::isObject ( ) const

inline

Returns true if the current cursor position represents an object.

Returns: true if the current cursor position represents an object.

bool JSONReader::isObject ( std::string key ) const

Returns true if the entry for key exists and represents an object.

Parameters

key	the field name to query

Returns: true if the entry for key exists and represents an object.

bool JSONReader::isString ( ) const

inline

Returns true if the current cursor position represents a string

Returns: true if the current cursor position represents a string

bool JSONReader::isString ( std::string key ) const

Returns true if the entry for key exists and represents a string

Parameters

key	the field name to query

Returns: true if the entry for key exists and represents a string

bool JSONReader::isVec2 ( ) const

Returns true if the current cursor position represents a Vec2 value

In a JSON file, a Vec2 is just a two-element array, whose elements are both numbers.

Returns: true if the current cursor position represents a Vec2 value

bool JSONReader::isVec2 ( std::string key ) const

Returns true if the entry for key exists and represents a Vec2 value

In a JSON file, a Vec2 is just a two-element array, whose elements are both numbers.

Parameters

key	the field name to query

Returns: true if the entry for key exists and represents a Vec2 value

void JSONReader::reset ( )

inline

Resets the JSON parser to the top of the DOM tree.

No information about the JSON is lost. This method simply resets the cursor position.

void JSONReader::setFile ( std::string file )

inline

Sets the file for this JSON reader.

This constructor does load the JSON file; it only stores the file name. You start parsing with the startJSON() method.

Parameters

file	for this JSON reader

int JSONReader::startArray ( std::string key )

Moves the cursor to begin processing the given key as an array

The cursor will move to the first position of the array. This method will return the number of elements in the array. This method returns 0 if the cursor does not refer to an array. However, the cursor always moves, so you must call endArray() to restore the cursor even if it fails.

Parameters

key	the field name to query

Returns: the number of elements in the array

int JSONReader::startArray ( )

Moves the cursor to begin processing the current cursor position as an array

The cursor will move to the first position of the array. This method will return the number of elements in the array. This method returns 0 if key does not exist, or its value is not an array. However, the cursor always moves, so you must call endArray() to restore the cursor even if it fails.

Returns: the number of elements in the array

bool JSONReader::startJSON ( )

Starts a JSON parser for the current file.

The parser will fail if the JSON is not well-formed. In that case, the method will return false. There are (unfortunately) no error messages for why parsing failed.

Returns: true if the file is a well-formed JSON file.

bool JSONReader::startJSON ( std::string source )

Starts a JSON parser for the given JSON string.

This method will ignore the associated file, and parse the provided string instead. The string should be an JSON string, not a file containing a JSON string.

The parser will fail if the JSON is not well-formed. In that case, the method will return false. There are (unfortunately) no error messages for why parsing failed.

Parameters

source the JSON source string

Returns: true if the file is a well-formed JSON file.

bool JSONReader::startObject ( std::string key )

Moves the cursor to the value for the given key, and treats it as an object.

This method returns false if the key does not exist, or its value is not an object. However, the cursor always moves, so you must call endObject() to restore the cursor even if it fails.

Parameters

key	the field name to query

Returns: true if the associated value is an object

bool JSONReader::startObject ( )

Treats the current cursor position as an object.

This method should be used when extracting an object while you are traversing an array (e.g. the object is an element inside the array). It changes the parsing state, but does not move the cursor.

This method returns false if the current cursor position is not an object. However, the state always changes, so you must call endObject() to restore the state even if it fails.

Returns: true if the cursor position is an object

Member Data Documentation

bool JSONReader::_arraymode

protected

Whether we are in object mode or array mode

std::string JSONReader::_file

protected

The file with the JSON source

Json* JSONReader::_json

protected

The current position in the DOM tree

Json* JSONReader::_root

protected

The root of the JSON DOM tree

std::vector<Json*> JSONReader::_stack

protected

A stack to allow us to traverse the tree

std::vector<bool> JSONReader::_states

protected

A stack to allow us to tracks states as we traverse the tree

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

/Users/wmwhite/Developer/cocos2d-cornell/cocos/cornell/CUJSONReader.h
/Users/wmwhite/Developer/cocos2d-cornell/cocos/cornell/CUJSONReader.cpp

Public Member Functions

Static Public Member Functions

Public Attributes

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation