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FTransaction

Base class for tracking transactions for undo/redo.

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MacOS

Linux

Inheritance Hierarchy

ITransaction

FTransaction

References

Module	UnrealEd
Header	/Engine/Source/Editor/UnrealEd/Classes/Editor/Transactor.h
Include	#include "Editor/Transactor.h"

Syntax

class FTransaction : public ITransaction

Remarks

Base class for tracking transactions for undo/redo. A single transaction, representing a set of serialized, undo-able changes to a set of objects.

warning: The undo buffer cannot be made persistent because of its dependence on offsets of arrays from their owning UObjects.

warning: UObject::Serialize implicitly assumes that class properties do not change in between transaction resets.

Variables

	Name	Description
bool	bFlip	If true, on apply flip the direction of iteration over object records.
TMap< UObject &...	ChangedObjects	Objects that will be changed directly by the transaction, empty when not transacting
FString	Context	A text string describing the context for the transaction.
FGuid	Id	Unique identifier for this transaction, used to track it during its lifetime
int32	Inc	Used to track direction to iterate over transaction's object records.
TMap< UObject &...	ObjectMap	Used to prevent objects from being serialized to a transaction more than once.
FGuid	OperationId	Unique identifier for the active operation on this transaction (if any).
UObject *	PrimaryObject	The key object being edited in this transaction. For example the blueprint object. Can be NULL
TIndirectArray<...	Records	Transaction variables.
FText	Title	Description of the transaction. Can be used by UI

Constructors

	Name	Description
	FTransaction ( const TCHAR* InContext, const FText& InTitle, bool bInFlip )	Constructor.

Destructors

	Name	Description
	~FTransaction()

Functions

	Name	Description
void	AddReferencedObjects ( FReferenceCollector& Collector )	Used by GC to collect referenced objects.
SIZE_T	DataSize()
void	DumpObjectMap ( FOutputDevice& Ar )	Outputs the contents of the ObjectMap to the specified output device.
FTransaction...	GenerateDiff()	Create a map that holds information about objects of a given transaction.
FGuid	GetId()	Returns the unique identifier for this transaction, used to track it during its lifetime
FGuid	GetOperationId()	Returns the unique identifier for the active operation on this transaction (if any)
const UObjec...	GetPrimaryObject()
int32	GetRecordCount()
FText	GetTitle()	Returns the descriptive text for the transaction
void	GetTransactionObjects ( TArray< UObject* >& Objects )	Get all the objects that are part of this transaction.
const TCHAR ...	GetTransactionType()	Returns a unique string to serve as a type ID for the FTranscationBase-derived type.
bool	HasExpired()
bool	IsObjectTransacting ( const UObject* Object )	Checks if a specific object is in the transaction currently underway
void	RemoveRecords ( int32 Count )

Overridden from ITransaction

	Name	Description
void	Apply()	Enacts the transaction.
void	BeginOperation()	BeginOperation should be called when a transaction or undo/redo starts
bool	ContainsPieObjects()
void	EndOperation()	EndOperation should be called when a transaction is finalized or canceled or undo/redo ends
void	Finalize()	Finalize the transaction (try and work out what's changed).
FTransaction...	GetContext()	Gets the full context for the transaction.
bool	IsTransient()	Report if a transaction should be put in the undo buffer.
void	SaveArray ( UObject* Object, FScriptArray* Array, int32 Index, int32 Count, int32 Oper, int32 ElementSize, STRUCT_DC DefaultConstructor, STRUCT_AR Serializer, STRUCT_DTOR Destructor )	Saves an array to the transaction.
void	SaveObject ( UObject* Object )	Saves an UObject to the transaction.
void	SetPrimaryObject ( UObject* Object )	Sets the transaction's primary object.
void	SnapshotObject ( UObject* Object, TArrayView< const FProperty* >... )	Snapshots a UObject within the transaction.
void	StoreUndo ( UObject* Object, TUniquePtr< FChange > CustomChange )	Stores a command that can be used to undo a change to the specified object.

Classes

	Name	Description
	FChangedObjectValue
	FObjectRecord	Record of an object.

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