FGameplayTagQuery | Unreal Engine 5.5 Documentation

Unreal Engine C++ API Reference > Runtime > GameplayTags

References


Module	GameplayTags
Header	/Engine/Source/Runtime/GameplayTags/Classes/GameplayTagContainer.h
Include	#include "GameplayTagContainer.h"

Syntax

USTRUCT (BlueprintType ,  
        Meta=(HasNativeMake="/Script/GameplayTags.BlueprintGameplayTagLibrary.MakeGameplayTagQuery"))  
struct FGameplayTagQuery

Remarks

An FGameplayTagQuery is a logical query that can be run against an FGameplayTagContainer. A query that succeeds is said to "match". Queries are logical expressions that can test the intersection properties of another tag container (all, any, or none), or the matching state of a set of sub-expressions (all, any, or none). This allows queries to be arbitrarily recursive and very expressive. For instance, if you wanted to test if a given tag container contained tags ((A && B) || (C)) && (!D), you would construct your query in the form ALL( ANY( ALL(A,B), ALL(C) ), NONE(D) )

You can expose the query structs to Blueprints and edit them with a custom editor, or you can construct them natively in code.

Example of how to build a query via code: FGameplayTagQuery Q; Q.BuildQuery( FGameplayTagQueryExpression() .AllTagsMatch() .AddTag(FGameplayTag::RequestGameplayTag(FName(TEXT("Animal.Mammal.Dog.Corgi")))) .AddTag(FGameplayTag::RequestGameplayTag(FName(TEXT("Plant.Tree.Spruce")))) );

Queries are internally represented as a byte stream that is memory-efficient and can be evaluated quickly at runtime. Note: these have an extensive details and graph pin customization for editing, so there is no need to expose the internals to Blueprints.

Constructors

	Type	Name	Description
		FGameplayTagQuery ()
		FGameplayTagQuery ( FGameplayTagQuery const& Other )
		FGameplayTagQuery ( FGameplayTagQuery&& Other )

Functions

Type	Name	Description
void	Build ( FGameplayTagQueryExpression& RootQueryExpr, FString InUserDescription )	Creates this query with the given root expression.
void	BuildFromEditableQuery ( UEditableGameplayTagQuery& EditableQuery )	Creates this query based on the given EditableQuery object
FGameplayTagQuery	BuildQuery ( FGameplayTagQueryExpression& RootQueryExpr, FString InDescription )	Static function to assemble and return a query.
void	Clear ()	Resets this query to its default empty state.
UEditableGameplayTagQuery *	CreateEditableQuery ()	Creates editable query object tree based on this query
const FString &	GetDescription ()	Returns description string.
void	GetGameplayTagArray ( TArray< FGameplayTag >& OutGameplayTags )	Gets the explicit list of all unique gameplay tags referenced by the query.
const TArray< FGameplayTag > &	GetGameplayTagArray ()	Gets the explicit list of all unique gameplay tags referenced by the query.
void	GetQueryExpr ( FGameplayTagQueryExpression& OutExpr )	Builds a FGameplayTagQueryExpression from this query.
bool	IsEmpty ()	Returns true if this query is empty, false otherwise.
FGameplayTagQuery	MakeQuery_MatchAllTags ( FGameplayTagContainer const& InTags )
FGameplayTagQuery	MakeQuery_MatchAnyTags ( FGameplayTagContainer const& InTags )	Shortcuts for easily creating common query types Creates a tag query that will match if there are any common tags between the given tags and the tags being queries against.
FGameplayTagQuery	MakeQuery_MatchNoTags ( FGameplayTagContainer const& InTags )
FGameplayTagQuery	MakeQuery_MatchTag ( FGameplayTag const& InTag )
bool	Matches ( FGameplayTagContainer const& Tags )	Returns true if the given tags match this query, or false otherwise.
void	ReplaceTagFast ( FGameplayTag const& Tag )	Replaces existing tags with passed in tag.
void	ReplaceTagsFast ( FGameplayTagContainer const& Tags )	Replaces existing tags with passed in tags.
void	Serialize ( FArchive& Ar )	Serialize the tag query
void	SetUserDescription ( const FString& InUserDescription )	Sets the user-specified description of this query.

Operators

Type	Name	Description
bool	operator!= ( const FGameplayTagQuery& Other )
FGameplayTagQuery &	operator= ( FGameplayTagQuery const& Other )	Assignment/Equality operators
FGameplayTagQuery &	operator= ( FGameplayTagQuery&& Other )
bool	operator== ( const FGameplayTagQuery& Other )

Constants

Name	Description
EmptyQuery

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