UFWVendorComponent¶

Header: FWVendorComponent.h | Parent: UActorComponent

Provides NPC vendor functionality including a configurable shop inventory, buy/sell transactions with price calculation, a buyback buffer for recent sales, and currency validation. Placed on NPC actors that serve as merchants.

Class Declaration¶

UCLASS(ClassGroup = (FrostWeb), meta = (BlueprintSpawnableComponent))
class FWINVENTORYSYSTEM_API UFWVendorComponent : public UActorComponent
{
    GENERATED_BODY()

public:
    UFWVendorComponent();

    // --- Transactions ---
    UFUNCTION(BlueprintCallable, Category = "Vendor")
    bool BuyItem(UFWInventoryComponent* BuyerInventory,
        int32 VendorSlotIndex, int32 Quantity = 1);

    UFUNCTION(BlueprintCallable, Category = "Vendor")
    bool SellItem(UFWInventoryComponent* SellerInventory,
        const FGuid& ItemInstanceId, int32 Quantity = 1);

    UFUNCTION(BlueprintCallable, Category = "Vendor")
    bool BuybackItem(UFWInventoryComponent* BuyerInventory,
        int32 BuybackSlotIndex);

    // --- Price Queries ---
    UFUNCTION(BlueprintPure, Category = "Vendor")
    int32 GetBuyPrice(int32 VendorSlotIndex) const;

    UFUNCTION(BlueprintPure, Category = "Vendor")
    int32 GetSellPrice(const FFWItemInstance& Item) const;

    // --- Vendor Inventory ---
    UFUNCTION(BlueprintPure, Category = "Vendor")
    const TArray<FFWItemInstance>& GetVendorInventory() const;

    UFUNCTION(BlueprintPure, Category = "Vendor")
    const TArray<FFWItemInstance>& GetBuybackInventory() const;

    UFUNCTION(BlueprintCallable, Category = "Vendor")
    void RefreshVendorInventory();

    // --- Configuration ---
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Vendor|Config")
    TArray<UFWItemDefinition*> StockDefinitions;

    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Vendor|Config")
    float BuyPriceMultiplier = 1.0f;

    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Vendor|Config")
    float SellPriceMultiplier = 0.25f;

    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Vendor|Config")
    int32 MaxBuybackSlots = 12;

    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Vendor|Config")
    bool bHasLimitedStock = false;

    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Vendor|Config",
        Meta = (EditCondition = "bHasLimitedStock"))
    float RestockIntervalSeconds = 3600.0f;

    // --- Delegates ---
    UPROPERTY(BlueprintAssignable, Category = "Vendor|Events")
    FOnItemPurchased OnItemPurchased;

    UPROPERTY(BlueprintAssignable, Category = "Vendor|Events")
    FOnItemSold OnItemSold;

    UPROPERTY(BlueprintAssignable, Category = "Vendor|Events")
    FOnTransactionFailed OnTransactionFailed;

    UPROPERTY(BlueprintAssignable, Category = "Vendor|Events")
    FOnVendorInventoryRefreshed OnVendorInventoryRefreshed;
};

Functions¶

BuyItem¶

UFUNCTION(BlueprintCallable, Category = "Vendor")
bool BuyItem(UFWInventoryComponent* BuyerInventory,
    int32 VendorSlotIndex, int32 Quantity = 1);

Purchases an item from the vendor. Deducts currency from the buyer's inventory and adds the purchased item.

Parameter	Type	Default	Description
`BuyerInventory`	`UFWInventoryComponent*`		The buyer's inventory component.
`VendorSlotIndex`	`int32`		Index in the vendor's stock list.
`Quantity`	`int32`	`1`	Number to purchase.

Returns: true if the transaction succeeded.

Validation:

Vendor slot index is valid.
Buyer has enough currency.
Buyer has inventory space.
If bHasLimitedStock, vendor has sufficient quantity.

SellItem¶

UFUNCTION(BlueprintCallable, Category = "Vendor")
bool SellItem(UFWInventoryComponent* SellerInventory,
    const FGuid& ItemInstanceId, int32 Quantity = 1);

Sells an item from the player's inventory to the vendor. Removes the item, adds currency, and places the item in the buyback buffer.

Parameter	Type	Default	Description
`SellerInventory`	`UFWInventoryComponent*`		The seller's inventory component.
`ItemInstanceId`	`FGuid`		Instance ID of the item to sell.
`Quantity`	`int32`	`1`	Number to sell from the stack.

Bound Items

Items with EFWItemBinding::BindOnPickup or EFWItemBinding::AccountBound cannot be sold. The transaction will fail with OnTransactionFailed.

BuybackItem¶

UFUNCTION(BlueprintCallable, Category = "Vendor")
bool BuybackItem(UFWInventoryComponent* BuyerInventory,
    int32 BuybackSlotIndex);

Repurchases an item from the buyback buffer at the original sell price.

Parameter	Type	Description
`BuyerInventory`	`UFWInventoryComponent*`	The buyer's inventory component.
`BuybackSlotIndex`	`int32`	Index in the buyback buffer.

Price Calculation¶

UFUNCTION(BlueprintPure, Category = "Vendor")
int32 GetBuyPrice(int32 VendorSlotIndex) const;

UFUNCTION(BlueprintPure, Category = "Vendor")
int32 GetSellPrice(const FFWItemInstance& Item) const;

Prices are calculated based on the item definition's BasePrice and the vendor's multipliers:

Buy price: BasePrice * BuyPriceMultiplier * QualityMultiplier
Sell price: BasePrice * SellPriceMultiplier * QualityMultiplier * DurabilityFactor

Quality multipliers by EFWItemQuality:

Quality	Multiplier
Poor	0.5
Common	1.0
Uncommon	1.5
Rare	2.5
Epic	5.0
Legendary	10.0
Mythic	25.0
Artifact	50.0

Configuration Properties¶

Property	Type	Default	Description
`StockDefinitions`	`TArray<UFWItemDefinition*>`	`[]`	Item definitions this vendor sells. Set in the editor.
`BuyPriceMultiplier`	`float`	`1.0`	Multiplier applied to base price for purchases.
`SellPriceMultiplier`	`float`	`0.25`	Multiplier applied to base price for sales. Players get 25% by default.
`MaxBuybackSlots`	`int32`	`12`	Maximum items in the buyback buffer. Oldest are evicted when full.
`bHasLimitedStock`	`bool`	`false`	Whether the vendor has finite stock quantities.
`RestockIntervalSeconds`	`float`	`3600.0`	Time between automatic restocks (only if `bHasLimitedStock`).

Delegates¶

OnItemPurchased¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_ThreeParams(
    FOnItemPurchased,
    const FFWItemInstance&, Item,
    int32, Price,
    int32, Quantity);

OnItemSold¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_ThreeParams(
    FOnItemSold,
    const FFWItemInstance&, Item,
    int32, Price,
    int32, Quantity);

OnTransactionFailed¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(
    FOnTransactionFailed,
    const FString&, Reason);

OnVendorInventoryRefreshed¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE(FOnVendorInventoryRefreshed);

Fires when the vendor's stock is refreshed (restocked or manually refreshed).

Usage Example¶

C++Blueprint

void AMyNPCVendor::BeginPlay()
{
    Super::BeginPlay();

    VendorComp = FindComponentByClass<UFWVendorComponent>();
    VendorComp->BuyPriceMultiplier = 1.2f;    // 20% markup
    VendorComp->SellPriceMultiplier = 0.30f;   // 30% return
    VendorComp->MaxBuybackSlots = 8;
}

void AMyNPCVendor::OnPlayerInteract(AMyCharacter* Player)
{
    UFWInventoryComponent* PlayerInventory =
        Player->FindComponentByClass<UFWInventoryComponent>();

    // Open vendor UI with vendor and player inventory references
    UVendorWidget* Widget = CreateWidget<UVendorWidget>(
        Player->GetController<APlayerController>(), VendorWidgetClass);
    Widget->Initialize(VendorComp, PlayerInventory);
    Widget->AddToViewport();
}

Add FW Vendor Component to your NPC actor.
In the Details panel, add item definitions to the Stock Definitions array.
Set Buy Price Multiplier and Sell Price Multiplier as desired.
On player interaction, open a vendor UI widget that references the vendor component.
Bind On Transaction Failed to show error messages.