FUniversalObjectLocatorFragment Struct Reference

#include <UniversalObjectLocatorFragment.h>

Inheritance diagram for FUniversalObjectLocatorFragment:

Classes
struct	FAllocatedPayload

Public Types
using	FParseStringResult = UE::UniversalObjectLocator::FParseStringResult
using	FParseStringParams = UE::UniversalObjectLocator::FParseStringParams

Public Member Functions
template<typename T , typename ... ArgTypes>
	FUniversalObjectLocatorFragment (UE::UniversalObjectLocator::TFragmentTypeHandle< T > InHandle, ArgTypes &&...InArgs)
UNIVERSALOBJECTLOCATOR_API	FUniversalObjectLocatorFragment (const UE::UniversalObjectLocator::FFragmentType &InFragmentType)
UNIVERSALOBJECTLOCATOR_API	FUniversalObjectLocatorFragment (const UObject *InObject, UObject *Context)
UNIVERSALOBJECTLOCATOR_API	FUniversalObjectLocatorFragment ()
UNIVERSALOBJECTLOCATOR_API	~FUniversalObjectLocatorFragment ()
UNIVERSALOBJECTLOCATOR_API	FUniversalObjectLocatorFragment (const FUniversalObjectLocatorFragment &RHS)
UNIVERSALOBJECTLOCATOR_API FUniversalObjectLocatorFragment &	operator= (const FUniversalObjectLocatorFragment &RHS)
UNIVERSALOBJECTLOCATOR_API	FUniversalObjectLocatorFragment (FUniversalObjectLocatorFragment &&RHS)
UNIVERSALOBJECTLOCATOR_API FUniversalObjectLocatorFragment &	operator= (FUniversalObjectLocatorFragment &&RHS)
UNIVERSALOBJECTLOCATOR_API UE::UniversalObjectLocator::FResolveResult	Resolve (const UE::UniversalObjectLocator::FResolveParams &Params) const
bool	IsEmpty () const
UNIVERSALOBJECTLOCATOR_API void	Reset ()
UNIVERSALOBJECTLOCATOR_API void	Reset (const UObject *InObject, UObject *Context)
UNIVERSALOBJECTLOCATOR_API void	Reset (const UObject *InObject, UObject *Context, TFunctionRef< bool(UE::UniversalObjectLocator::FFragmentTypeHandle)> CanUseFragmentType)
UNIVERSALOBJECTLOCATOR_API void	ToString (FStringBuilderBase &OutString) const
UNIVERSALOBJECTLOCATOR_API FParseStringResult	TryParseString (FStringView InString, const FParseStringParams &InParams)
UNIVERSALOBJECTLOCATOR_API FParseStringResult	TryParseFragmentType (FStringView InString, const FParseStringParams &InParams)
UNIVERSALOBJECTLOCATOR_API FParseStringResult	TryParseFragmentPayload (FStringView InString, const FParseStringParams &InParams)
template<typename T >
T *	GetPayloadAs (UE::UniversalObjectLocator::TFragmentTypeHandle< T > InType)
template<typename T >
const T *	GetPayloadAs (UE::UniversalObjectLocator::TFragmentTypeHandle< T > InType) const
template<typename T >
bool	TryGetPayloadAs (UE::UniversalObjectLocator::TFragmentTypeHandle< T > InType, T *&OutData)
template<typename T >
bool	TryGetPayloadAs (UE::UniversalObjectLocator::TFragmentTypeHandle< T > InType, const T *&OutData) const
UNIVERSALOBJECTLOCATOR_API void *	GetPayload ()
UNIVERSALOBJECTLOCATOR_API const void *	GetPayload () const
UNIVERSALOBJECTLOCATOR_API const UE::UniversalObjectLocator::FFragmentType *	GetFragmentType () const
UNIVERSALOBJECTLOCATOR_API UScriptStruct *	GetFragmentStruct () const
UNIVERSALOBJECTLOCATOR_API UE::UniversalObjectLocator::FFragmentTypeHandle	GetFragmentTypeHandle () const
UNIVERSALOBJECTLOCATOR_API bool	Serialize (FArchive &Ar)
UNIVERSALOBJECTLOCATOR_API void	AddStructReferencedObjects (FReferenceCollector &Collector)
UNIVERSALOBJECTLOCATOR_API bool	ExportTextItem (FString &ValueStr, const FUniversalObjectLocatorFragment &DefaultValue, UObject *Parent, int32 PortFlags, UObject *ExportRootScope) const
UNIVERSALOBJECTLOCATOR_API bool	ImportTextItem (const TCHAR *&Buffer, int32 PortFlags, UObject *Parent, FOutputDevice *ErrorText, FArchive *InSerializingArchive=nullptr)
UNIVERSALOBJECTLOCATOR_API bool	SerializeFromMismatchedTag (const FPropertyTag &Tag, FStructuredArchive::FSlot Slot)
UNIVERSALOBJECTLOCATOR_API void	GetPreloadDependencies (TArray< UObject * > &OutDeps)

Static Public Attributes
static constexpr FAsciiSet	ValidFragmentTypeCharacters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-"
static constexpr FAsciiSet	ValidFragmentDelimiters = "%!$'()*+,;=/?:@.~"
static constexpr FAsciiSet	ValidFragmentPayloadCharacters = ValidFragmentTypeCharacters | ValidFragmentDelimiters
static constexpr SIZE_T	SizeInMemory = 32

Protected Member Functions
UNIVERSALOBJECTLOCATOR_API FAllocatedPayload	AllocatePayload (size_t Size, size_t Alignment)
void	DefaultConstructPayload (const UE::UniversalObjectLocator::FFragmentType &InFragmentType)
void	DestroyPayload ()

Static Protected Member Functions
static FORCEINLINE constexpr void	CheckPayloadType (void *TypeToCompare)

Friends
UNIVERSALOBJECTLOCATOR_API friend bool	operator== (const FUniversalObjectLocatorFragment &A, const FUniversalObjectLocatorFragment &B)
UNIVERSALOBJECTLOCATOR_API friend bool	operator!= (const FUniversalObjectLocatorFragment &A, const FUniversalObjectLocatorFragment &B)
UNIVERSALOBJECTLOCATOR_API friend uint32	GetTypeHash (const FUniversalObjectLocatorFragment &Fragment)

Detailed Description

Universal Object Locator (UOL) Fragments provide an extensible mechanism for referencing permanent, transient or dynamically created objects relative to an external context. UOLs comprise zero or more nested fragments.

Creation and resolution of a fragment requires a context to be provided; normally this will be the object on which the UOL exists as a property.

The way in which the object is referenced is defined by globally registered 'FragmentTypes' (See IUniversalObjectLocatorModule::RegisterFragmentType). Each FragmentType can be thought of as somewhat equivalent to a www URI fragment type, though the 'path' is not necessarily just a string, but includes support for the full set of Engine Property types.

The type is implemented as a type-erased payload block, a fragment type handle and some internal flags. Payloads will be allocated using the inline memory if alignment and size constraints allow, but will fall back to a heap allocation if necessary. Allocation should be avoided by keeping payload types small.

Aligned to 8 bytes, 32 (runtime) or 64 (editor) bytes big.

Member Typedef Documentation

FParseStringParams

using FUniversalObjectLocatorFragment::FParseStringParams = UE::UniversalObjectLocator::FParseStringParams

FParseStringResult

using FUniversalObjectLocatorFragment::FParseStringResult = UE::UniversalObjectLocator::FParseStringResult

Constructor & Destructor Documentation

FUniversalObjectLocatorFragment() [1/6]

template<typename T , typename ... ArgTypes>

FUniversalObjectLocatorFragment::FUniversalObjectLocatorFragment	(	UE::UniversalObjectLocator::TFragmentTypeHandle< T >	InHandle,
		ArgTypes &&...	InArgs
	)

Construct a new fragment with a specific fragment type and data. Used when a specific type of relative fragment is required.

Parameters

InHandle	A typed handle to the fragment type to use for construction. Retrieved from IUniversalObjectLocatorModule::RegisterFragmentType.
InArgs	(Optional) Payload construction arguments to be passed to T on construction. Omission implies default construction.

FUniversalObjectLocatorFragment() [2/6]

FUniversalObjectLocatorFragment::FUniversalObjectLocatorFragment

(

const UE::UniversalObjectLocator::FFragmentType &

InFragmentType

)

Construct a new fragment with a specific fragment type and default-constructed payload. Used when a specific type of relative fragment is required.

Parameters

InFragmentType

The fragment type to use with this fragment

FUniversalObjectLocatorFragment() [3/6]

FUniversalObjectLocatorFragment::FUniversalObjectLocatorFragment	(	const UObject *	InObject,
		UObject *	Context
	)

Construct this fragment by binding it to an object within a given context.

Note

: This constructor can 'fail' and result in an Empty fragment if no suitable fragment type could be found for the object

FUniversalObjectLocatorFragment() [4/6]

FUniversalObjectLocatorFragment::FUniversalObjectLocatorFragment

(

)

Default constructor: initializes to an empty fragment with no fragment type

~FUniversalObjectLocatorFragment()

FUniversalObjectLocatorFragment::~FUniversalObjectLocatorFragment

(

)

Destructor - destructs the payload, and frees any heap allocation as necessary

FUniversalObjectLocatorFragment() [5/6]

FUniversalObjectLocatorFragment::FUniversalObjectLocatorFragment

(

const FUniversalObjectLocatorFragment &

RHS

)

Copy construction/assignment

FUniversalObjectLocatorFragment() [6/6]

FUniversalObjectLocatorFragment::FUniversalObjectLocatorFragment

(

FUniversalObjectLocatorFragment &&

RHS

)

Move construction/assignment

Member Function Documentation

AddStructReferencedObjects()

void FUniversalObjectLocatorFragment::AddStructReferencedObjects

(

FReferenceCollector &

Collector

)

AllocatePayload()

FUniversalObjectLocatorFragment::FAllocatedPayload FUniversalObjectLocatorFragment::AllocatePayload ( size_t  Size, size_t  Alignment  )

protected

Allocate (but do not initialize) the fragment payload using the specified size and alignment, accounting for enough space to fit a debug vftable ptr whern UE_UNIVERSALOBJECTLOCATOR_DEBUG is enabled.

Returns

Structure identifying the payload

CheckPayloadType()

static FORCEINLINE constexpr void FUniversalObjectLocatorFragment::CheckPayloadType ( void *  TypeToCompare )

inlinestaticconstexprprotected

Runtime type-checking against specific struct types. Compiled out if checks are not enabled.

DefaultConstructPayload()

void FUniversalObjectLocatorFragment::DefaultConstructPayload ( const UE::UniversalObjectLocator::FFragmentType &  InFragmentType )

protected

Default-initialize the fragment payload using the specified type

DestroyPayload()

void FUniversalObjectLocatorFragment::DestroyPayload ( )

protected

Destroy the payload (if valid) by calling its destructor and freeing the memory (if necessary)

ExportTextItem()

bool FUniversalObjectLocatorFragment::ExportTextItem	(	FString &	ValueStr,
		const FUniversalObjectLocatorFragment &	DefaultValue,
		UObject *	Parent,
		int32	PortFlags,
		UObject *	ExportRootScope
	)		const

GetFragmentStruct()

UScriptStruct * FUniversalObjectLocatorFragment::GetFragmentStruct

(

)

const

Retrieve this fragment's fragment struct type

Returns

The fragment struct type or nullptr if this fragment is empty

GetFragmentType()

const UE::UniversalObjectLocator::FFragmentType * FUniversalObjectLocatorFragment::GetFragmentType

(

)

const

Retrieve this fragment's fragment type

Returns

The fragment type or nullptr if this fragment is empty

GetFragmentTypeHandle()

UE::UniversalObjectLocator::FFragmentTypeHandle FUniversalObjectLocatorFragment::GetFragmentTypeHandle

(

)

const

Retrieve this fragment's fragment type handle

Returns

The fragment type handle (possibly invalid if this fragment is empty)

GetPayload() [1/2]

void * FUniversalObjectLocatorFragment::GetPayload

(

)

Retrieve this fragment's payload data

Returns

The payload data or nullptr if this fragment is empty

GetPayload() [2/2]

const void * FUniversalObjectLocatorFragment::GetPayload

(

)

const

Retrieve this fragment's payload data

Returns

The payload data or nullptr if this fragment is empty

GetPayloadAs() [1/2]

template<typename T >

T * FUniversalObjectLocatorFragment::GetPayloadAs

(

UE::UniversalObjectLocator::TFragmentTypeHandle< T >

InType

)

Try and retrieve this fragment's payload as a specific type using its fragment type handle

Parameters

InType

The handle of the fragment type to this payload to. This is returned from IUniversalObjectLocatorModule::RegisterFragmentType on registration.

Returns

A mutable pointer to the payload, or nullptr if this fragment is empty or of a different type.

GetPayloadAs() [2/2]

template<typename T >

const T * FUniversalObjectLocatorFragment::GetPayloadAs

(

UE::UniversalObjectLocator::TFragmentTypeHandle< T >

InType

)

const

Try and retrieve this fragment's payload as a specific type using its fragment type handle

Parameters

InType

The handle of the fragment type to this payload to. This is returned from IUniversalObjectLocatorModule::RegisterFragmentType on registration.

Returns

A mutable pointer to the payload, or nullptr if this fragment is empty or of a different type.

GetPreloadDependencies()

void FUniversalObjectLocatorFragment::GetPreloadDependencies

(

TArray< UObject * > &

OutDeps

)

ImportTextItem()

bool FUniversalObjectLocatorFragment::ImportTextItem	(	const TCHAR *&	Buffer,
		int32	PortFlags,
		UObject *	Parent,
		FOutputDevice *	ErrorText,
		FArchive *	InSerializingArchive = nullptr
	)

IsEmpty()

bool FUniversalObjectLocatorFragment::IsEmpty ( ) const

inline

Check whether this reference is empty.

Note

: An empty fragment can never resolve to an object, but is distinct from, and not equal to, a populated fragment that does points to a non-existent or irretrievable object.

operator=() [1/2]

FUniversalObjectLocatorFragment & FUniversalObjectLocatorFragment::operator=

(

const FUniversalObjectLocatorFragment &

RHS

)

operator=() [2/2]

FUniversalObjectLocatorFragment & FUniversalObjectLocatorFragment::operator=

(

FUniversalObjectLocatorFragment &&

RHS

)

Reset() [1/3]

void FUniversalObjectLocatorFragment::Reset

(

)

Reset this fragment back to its default-constructed, empty state

Reset() [2/3]

void FUniversalObjectLocatorFragment::Reset	(	const UObject *	InObject,
		UObject *	Context
	)

Reset this fragment to point to a new object from the specified context

Note

: If no suitable fragment type could be found for the object and context, results in an Empty fragment

Reset() [3/3]

void FUniversalObjectLocatorFragment::Reset	(	const UObject *	InObject,
		UObject *	Context,
		TFunctionRef< bool(UE::UniversalObjectLocator::FFragmentTypeHandle)>	CanUseFragmentType
	)

Reset this fragment to point to a new object from the specified context using a filtered set of fragment types

Note

: If no suitable fragment type could be found for the object and context, results in an Empty fragment

Resolve()

UE::UniversalObjectLocator::FResolveResult FUniversalObjectLocatorFragment::Resolve

(

const UE::UniversalObjectLocator::FResolveParams &

Params

)

const

Attempt to resolve this fragment by invoking the payload's 'Resolve' function

Parameters

Params

Resolution parameters, defining the context to resolve within, and the type of resolution to perform

Returns

A result structure defining the resolved object pointer, and associated flags

Serialize()

bool FUniversalObjectLocatorFragment::Serialize

(

FArchive &

Ar

)

SerializeFromMismatchedTag()

bool FUniversalObjectLocatorFragment::SerializeFromMismatchedTag	(	const FPropertyTag &	Tag,
		FStructuredArchive::FSlot	Slot
	)

ToString()

void FUniversalObjectLocatorFragment::ToString

(

FStringBuilderBase &

OutString

)

const

Convert this fragment to a string of the form fragment-id[=fragment-payload]

Parameters

OutString

String builder to populate

TryGetPayloadAs() [1/2]

template<typename T >

bool FUniversalObjectLocatorFragment::TryGetPayloadAs	(	UE::UniversalObjectLocator::TFragmentTypeHandle< T >	InType,
		const T *&	OutData
	)		const

Try and retrieve this fragment's payload as a specific type using its fragment type handle

Parameters

InType	The handle of the fragment type to this payload to. This is returned from IUniversalObjectLocatorModule::RegisterFragmentType on registration.
OutData	Pointer to retrieve the resulting payload ptr

Returns

true on success, false if this fragment is empty or of a different type.

TryGetPayloadAs() [2/2]

template<typename T >

bool FUniversalObjectLocatorFragment::TryGetPayloadAs	(	UE::UniversalObjectLocator::TFragmentTypeHandle< T >	InType,
		T *&	OutData
	)

Try and retrieve this fragment's payload as a specific type using its fragment type handle

Parameters

InType	The handle of the fragment type to this payload to. This is returned from IUniversalObjectLocatorModule::RegisterFragmentType on registration.
OutData	Pointer to retrieve the resulting payload ptr

Returns

true on success, false if this fragment is empty or of a different type.

TryParseFragmentPayload()

UE::UniversalObjectLocator::FParseStringResult FUniversalObjectLocatorFragment::TryParseFragmentPayload	(	FStringView	InString,
		const FParseStringParams &	InParams
	)

Attempt to deserialize this fragment's payload from a string, based on its currently assigned type The state of this instance will not be changed if this function returns false.

Parameters

InString	The string to parse.
InParams	Additional string parameters

Returns

Parse result, specifying success or failure, and number of characters that were parsed

TryParseFragmentType()

UE::UniversalObjectLocator::FParseStringResult FUniversalObjectLocatorFragment::TryParseFragmentType	(	FStringView	InString,
		const FParseStringParams &	InParams
	)

Attempt to default initialize this fragment using a string that defines the type The state of this instance will not be changed if this function returns false.

Parameters

InString	The string to parse.
InParams	Additional string parameters

Returns

Parse result, specifying success or failure, and number of characters that were parsed

TryParseString()

UE::UniversalObjectLocator::FParseStringResult FUniversalObjectLocatorFragment::TryParseString	(	FStringView	InString,
		const FParseStringParams &	InParams
	)

Attempt to initialize this fragment from a string of the form fragment-type-id[=payload] The state of this instance will not be changed if this function returns false.

Parameters

InString	The string to parse.
InParams	Additional string parameters

Returns

Parse result, specifying success or failure, and number of characters that were parsed

Friends And Related Symbol Documentation

GetTypeHash

UNIVERSALOBJECTLOCATOR_API friend uint32 GetTypeHash ( const FUniversalObjectLocatorFragment &  Fragment )

friend

Type hashable

operator!=

UNIVERSALOBJECTLOCATOR_API friend bool operator!= ( const FUniversalObjectLocatorFragment &  A, const FUniversalObjectLocatorFragment &  B  )

friend

Inequality comparison. Compares the fragment type and payload data.

operator==

UNIVERSALOBJECTLOCATOR_API friend bool operator== ( const FUniversalObjectLocatorFragment &  A, const FUniversalObjectLocatorFragment &  B  )

friend

Equality comparison. Compares the fragment type and payload data.

Member Data Documentation

SizeInMemory

constexpr SIZE_T FUniversalObjectLocatorFragment::SizeInMemory = 32

staticconstexpr

Make our inline data buffer larger in-editor to support editor-only data without allocation

ValidFragmentDelimiters

constexpr FAsciiSet FUniversalObjectLocatorFragment::ValidFragmentDelimiters = "%!$'()*+,;=/?:@.~"

staticconstexpr

ValidFragmentPayloadCharacters

constexpr FAsciiSet FUniversalObjectLocatorFragment::ValidFragmentPayloadCharacters = ValidFragmentTypeCharacters | ValidFragmentDelimiters

staticconstexpr

ValidFragmentTypeCharacters

constexpr FAsciiSet FUniversalObjectLocatorFragment::ValidFragmentTypeCharacters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-"

staticconstexpr

---

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

• Engine/Source/Runtime/UniversalObjectLocator/Public/UniversalObjectLocatorFragment.h
• Engine/Source/Runtime/UniversalObjectLocator/Private/UniversalObjectLocatorFragment.cpp