FGameplayTagQuery | Unreal Engine 5.7 Documentation

API > API/Runtime > API/Runtime/GameplayTags

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.


Name	FGameplayTagQuery
Type	struct
Header File	/Engine/Source/Runtime/GameplayTags/Classes/GameplayTagContainer.h
Include Path	#include "GameplayTagContainer.h"

Syntax

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

Constructors

Name	Remarks	Include Path	Unreal Specifiers
FGameplayTagQuery ( FGameplayTagQuery&& Other )		GameplayTagContainer.h
FGameplayTagQuery ( FGameplayTagQuery const& Other )		GameplayTagContainer.h
FGameplayTagQuery ()		GameplayTagContainer.h

Constants

Name	Type	Remarks	Include Path
EmptyQuery	const FGameplayTagQuery		GameplayTagContainer.h

Variables

Protected

Name	Type	Remarks	Include Path	Unreal Specifiers
AutoDescription	FString	Auto-generated string describing the query	GameplayTagContainer.h	EditAnywhere Category=Hidden
QueryTokenStream	TArray< uint8 >	Stream representation of the actual hierarchical query	GameplayTagContainer.h	EditAnywhere Category=Hidden
TagDictionary	TArray< FGameplayTag >	List of tags referenced by this entire query. Token stream stored indices into this list.	GameplayTagContainer.h	EditAnywhere Category=Hidden
TokenStreamVersion	int32	Versioning for future token stream protocol changes. See EGameplayTagQueryStreamVersion.	GameplayTagContainer.h	EditAnywhere Category=Hidden
UserDescription	FString	User-provided string describing the query	GameplayTagContainer.h	EditAnywhere Category=Hidden

Functions

Public

Name	Remarks	Include Path
void Build ( FGameplayTagQueryExpression& RootQueryExpr, FString InUserDescription )	Creates this query with the given root expression.	GameplayTagContainer.h
void BuildFromEditableQuery ( UEditableGameplayTagQuery& EditableQuery )	Creates this query based on the given EditableQuery object	GameplayTagContainer.h
void Clear()	Resets this query to its default empty state.	GameplayTagContainer.h
UEditableGameplayTagQuery * CreateEditableQuery()	Creates editable query object tree based on this query	GameplayTagContainer.h
const FString & GetDescription()	Returns description string.	GameplayTagContainer.h
void GetGameplayTagArray ( TArray< FGameplayTag >& OutGameplayTags ) const	Gets the explicit list of all unique gameplay tags referenced by the query.	GameplayTagContainer.h
const TArray< FGameplayTag > & GetGameplayTagArray ()	Gets the explicit list of all unique gameplay tags referenced by the query.	GameplayTagContainer.h
void GetQueryExpr ( FGameplayTagQueryExpression& OutExpr ) const	Builds a FGameplayTagQueryExpression from this query.	GameplayTagContainer.h
bool IsEmpty()	Returns true if this query is empty, false otherwise.	GameplayTagContainer.h
bool Matches ( FGameplayTagContainer const& Tags ) const	Returns true if the given tags match this query, or false otherwise.	GameplayTagContainer.h
void ReplaceTagFast ( FGameplayTag const& Tag )	Replaces existing tags with passed in tag.	GameplayTagContainer.h
void ReplaceTagsFast ( FGameplayTagContainer const& Tags )	Replaces existing tags with passed in tags.	GameplayTagContainer.h
void Serialize ( FArchive& Ar )	Serialize the tag query	GameplayTagContainer.h
void SetUserDescription ( const FString& InUserDescription )	Sets the user-specified description of this query.	GameplayTagContainer.h

Static

Name	Remarks	Include Path
static FGameplayTagQuery BuildQuery ( FGameplayTagQueryExpression& RootQueryExpr, FString InDescription )	Static function to assemble and return a query.	GameplayTagContainer.h
static FGameplayTagQuery MakeQuery_ExactMatchAllTags ( FGameplayTagContainer const& InTags )		GameplayTagContainer.h
static FGameplayTagQuery MakeQuery_ExactMatchAnyTags ( FGameplayTagContainer const& InTags )		GameplayTagContainer.h
static FGameplayTagQuery MakeQuery_MatchAllTags ( FGameplayTagContainer const& InTags )		GameplayTagContainer.h
static 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.	GameplayTagContainer.h
static FGameplayTagQuery MakeQuery_MatchNoTags ( FGameplayTagContainer const& InTags )		GameplayTagContainer.h
static FGameplayTagQuery MakeQuery_MatchTag ( FGameplayTag const& InTag )		GameplayTagContainer.h

Operators

Name	Remarks	Include Path
bool operator!= ( const FGameplayTagQuery& Other ) const		GameplayTagContainer.h
FGameplayTagQuery & operator= ( FGameplayTagQuery const& Other )	Assignment/Equality operators	GameplayTagContainer.h
FGameplayTagQuery & operator= ( FGameplayTagQuery&& Other )		GameplayTagContainer.h
bool operator== ( const FGameplayTagQuery& Other ) const		GameplayTagContainer.h

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