GameObject Class Reference

The GameObject class is at the core of OpenAstra. More...

#include <gameobject.h>

Inheritance diagram for GameObject:

Public Types
using	undumpFactory = std::function<std::shared_ptr<GameObject>(ObjectId, const std::string &)>

Public Member Functions
nlohmann::json	toJson ()
	serialize the current object to JSON object
bool	writeToJsonFile ()
	Write to the storage folder a file (see _create_filename() below) containing the object in JSON format.
DataItem &	addDataItem (const std::string &dataItem)
	Add a dataItem, and return a reference to it.
bool	hasDataItem (const std::string &dataItem) const
	Check if a specific data item exist.
DataItem &	accessDataItem (const std::string &dataItem)
	get a reference to the dataItem
const DataItem &	accessDataItem (const std::string &dataItem) const
	get a const reference to the dataItem
void	dataItemsFromTemplate (const nlohmann::json &template_data)
	Initialize a list of dataitems from a JSON template.
const std::string &	category () const
	return the object category (starsystemobject, module, command...)
const std::string &	type () const
	return the type (ship_xxx, station_xxx, planet_xxx...)
ObjectId	id () const
	return the object unique ID
void	reparent (std::shared_ptr< GameObject > new_parent)
	reparent from the current parent, to a new one
void	lock ()
void	unlock ()
std::shared_ptr< GameObject >	getParent () const
	return pointer to this object parent
template<typename T>
std::shared_ptr< T >	getParent () const
	return pointer to this object parent
std::shared_ptr< GameObject >	getSibling (ObjectId id)
	get sibling with given ID
template<typename T>
std::shared_ptr< T >	getSibling (ObjectId id)
	get sibling with given ID
std::shared_ptr< GameObject >	getChild (ObjectId id)
	return the child to match the id
template<typename T>
std::shared_ptr< T >	getChild (ObjectId id)
	return the child to match the id
bool	hasChild (ObjectId id)
	check if current object has a child with this id
std::map< ObjectId, std::shared_ptr< GameObject > > &	childrenMap ()
	get a direct reference to the children map
virtual void	tick (double, double)

Static Public Member Functions
static bool	initialize (const std::string &storage_path)
	initialize the disk serialization process
static void	registerSubtype (const std::string &category, undumpFactory undumpCb)
	Static function that needs to be called for each derived class to create types autmatically while undumping from JSON.
template<typename T>
static std::shared_ptr< T >	createFromJsonFile (const std::string &category, ObjectId id)
	create a GameObject object from a JSON file

Static Public Attributes
static DataItem	invalidDataItem = DataItem()

Protected Member Functions
virtual void	_finalizeDump ()
	Gives the object an opportunity to perform some additional stuff after the object had been serialized to disk.
virtual void	_finalizeUndump (std::shared_ptr< GameObject >)
	Gives the object an opportunity to perform some cleanup/inizialization after the specific child has been deserialized from disk.
virtual void	_finalizeUndump ()
	Gives the object an opportunity to perform some cleanup/inizialization after the entire object has been deserialized from disk.
	GameObject (const std::string &category, ObjectId id, const std::string &type)
	Create a GameObject object.

Detailed Description

The GameObject class is at the core of OpenAstra.

This class implements the entire object management of the game.

The basic class contains data and child objects, allowing for an advanced and stackable object management.

Some of the features of GameObject objects:

• can be automatically serialized to JSON on disk and deserialized back from disk (save/restore)
• can contain any type of data (more or less) without requiring complex maintanance, see class DataItem.
• can express an hierarchy of objects, with all the above advantages
• offers a nice search interface to access child objects and data

Each object has "data" items, which are labels/value couples. Each object has "children", which are other GameObject instances.

Each GameObject instance is identified by three pieces of information:

• an unique ID (ID)
• a category (to identify which object family it is)
• a type (to identify which type inside the family it is)

Each object can have a list of data items. Each data item is defined by it's string label, which is unique for the object, and it's stored by the GameObject itself. You can access those references.

Constructor & Destructor Documentation

GameObject()

GameObject::GameObject ( const std::string & category, ObjectId id, const std::string & type )

protected

Create a GameObject object.

Parameters

item_category	object category (header)
item_id	object ID (header)
item_type	object type (header)

Member Function Documentation

_finalizeDump()

virtual void GameObject::_finalizeDump ( )

inlineprotectedvirtual

Gives the object an opportunity to perform some additional stuff after the object had been serialized to disk.

_finalizeUndump() [1/2]

virtual void GameObject::_finalizeUndump ( )

inlineprotectedvirtual

Gives the object an opportunity to perform some cleanup/inizialization after the entire object has been deserialized from disk.

Reimplemented in Player.

_finalizeUndump() [2/2]

virtual void GameObject::_finalizeUndump ( std::shared_ptr< GameObject > )

inlineprotectedvirtual

Gives the object an opportunity to perform some cleanup/inizialization after the specific child has been deserialized from disk.

accessDataItem() [1/2]

DataItem & GameObject::accessDataItem ( const std::string & dataItem )

inline

get a reference to the dataItem

Parameters

dataItem

Returns

reference to the dataItem

accessDataItem() [2/2]

const DataItem & GameObject::accessDataItem ( const std::string & dataItem ) const

inline

get a const reference to the dataItem

Parameters

dataItem

Returns

reference to the dataItem

addDataItem()

DataItem & GameObject::addDataItem ( const std::string & dataItem )

inline

Add a dataItem, and return a reference to it.

Parameters

dataItem

Returns

pointer to the dataItem (like accessDataItem())

category()

const std::string & GameObject::category ( ) const

inline

return the object category (starsystemobject, module, command...)

Returns

the object category

childrenMap()

std::map< ObjectId, std::shared_ptr< GameObject > > & GameObject::childrenMap ( )

inline

get a direct reference to the children map

Use this method where speed is of the essence. You will need to iterate the set yourself, but it will be faster than performing multiple calls to the getChildren() call.

Returns

a reference to the internal children map

createFromJsonFile()

template<typename T>

static std::shared_ptr< T > GameObject::createFromJsonFile ( const std::string & category, ObjectId id )

inlinestatic

create a GameObject object from a JSON file

This method will load a specific file (see _create_filename() below) and create a from it. it will use the registered types to call the respective factory functions.

Parameters

category	type of the object
id	unique id of the object

Returns

created object

dataItemsFromTemplate()

void GameObject::dataItemsFromTemplate

(

const nlohmann::json &

template_data

)

Initialize a list of dataitems from a JSON template.

Parameters

template_data

Returns

true if no error

getChild() [1/2]

std::shared_ptr< GameObject > GameObject::getChild ( ObjectId id )

inline

return the child to match the id

Parameters

id	the ID to match, required

Returns

the first matching child

getChild() [2/2]

template<typename T>

std::shared_ptr< T > GameObject::getChild ( ObjectId id )

inline

return the child to match the id

Parameters

id	the ID to match, required

Returns

the first matching child

getParent() [1/2]

std::shared_ptr< GameObject > GameObject::getParent ( ) const

inline

return pointer to this object parent

Returns

the object parent

getParent() [2/2]

template<typename T>

std::shared_ptr< T > GameObject::getParent ( ) const

inline

return pointer to this object parent

Returns

the object parent

getSibling() [1/2]

std::shared_ptr< GameObject > GameObject::getSibling ( ObjectId id )

inline

get sibling with given ID

Parameters

id

Returns

pointer to sibling

getSibling() [2/2]

template<typename T>

std::shared_ptr< T > GameObject::getSibling ( ObjectId id )

inline

get sibling with given ID

Parameters

id

Returns

pointer to sibling

hasChild()

bool GameObject::hasChild

(

ObjectId

id

)

check if current object has a child with this id

Parameters

ud

Returns

true if there is at least child

hasDataItem()

bool GameObject::hasDataItem ( const std::string & dataItem ) const

inline

Check if a specific data item exist.

Parameters

dataItem

data item to check

Returns

true if it exist

id()

ObjectId GameObject::id ( ) const

inline

return the object unique ID

Returns

the id

initialize()

bool GameObject::initialize ( const std::string & storage_path )

static

initialize the disk serialization process

Parameters

storage_path

path that will contain the saved files. Will be created if missing.

Returns

true if the folder exist or was created. False in case of error.

registerSubtype()

void GameObject::registerSubtype ( const std::string & category, undumpFactory undumpCb )

static

Static function that needs to be called for each derived class to create types autmatically while undumping from JSON.

Parameters

category	family of the object
undumpCb	callback that will be used to allocate a new instance of type category during deserialization

reparent()

void GameObject::reparent

(

std::shared_ptr< GameObject >

new_parent

)

reparent from the current parent, to a new one

Parameters

new_parent

the new parent

toJson()

nlohmann::json GameObject::toJson

(

)

serialize the current object to JSON object

Returns

JSON data struct

type()

const std::string & GameObject::type ( ) const

inline

return the type (ship_xxx, station_xxx, planet_xxx...)

Returns

the object type

writeToJsonFile()

bool GameObject::writeToJsonFile

(

)

Write to the storage folder a file (see _create_filename() below) containing the object in JSON format.

Returns

true if no error

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

• server/engine/gameobject.h
• server/engine/gameobject.cpp