Nfts: minor fixes (#13576)

* Rename owner_of_item to owned_item

* Move AttributeNamespace into the types file

substrate/frame/nfts/src/lib.rs

@@ -45,9 +45,7 @@ pub mod weights;
 
 use codec::{Decode, Encode};
 use frame_support::traits::{
-	tokens::{AttributeNamespace, Locker},
-	BalanceStatus::Reserved,
-	Currency, EnsureOriginWithArg, ReservableCurrency,
+	tokens::Locker, BalanceStatus::Reserved, Currency, EnsureOriginWithArg, ReservableCurrency,
 };
 use frame_system::Config as SystemConfig;
 use sp_runtime::{
@@ -809,13 +807,13 @@ pub mod pallet {
 					match mint_settings.mint_type {
 						MintType::Issuer => return Err(Error::<T, I>::NoPermission.into()),
 						MintType::HolderOf(collection_id) => {
-							let MintWitness { owner_of_item } =
+							let MintWitness { owned_item } =
 								witness_data.ok_or(Error::<T, I>::BadWitness)?;
 
 							let owns_item = Account::<T, I>::contains_key((
 								&caller,
 								&collection_id,
-								&owner_of_item,
+								&owned_item,
 							));
 							ensure!(owns_item, Error::<T, I>::BadWitness);
 
@@ -824,7 +822,7 @@ pub mod pallet {
 
 							let key = (
 								&collection_id,
-								Some(owner_of_item),
+								Some(owned_item),
 								AttributeNamespace::Pallet,
 								&Self::construct_attribute_key(pallet_attribute.encode())?,
 							);

substrate/frame/nfts/src/tests.rs

@@ -335,7 +335,7 @@ fn mint_should_work() {
 				1,
 				42,
 				account(2),
-				Some(MintWitness { owner_of_item: 42 })
+				Some(MintWitness { owned_item: 42 })
 			),
 			Error::<Test>::BadWitness
 		);
@@ -344,7 +344,7 @@ fn mint_should_work() {
 			1,
 			42,
 			account(2),
-			Some(MintWitness { owner_of_item: 43 })
+			Some(MintWitness { owned_item: 43 })
 		));
 
 		// can't mint twice
@@ -354,7 +354,7 @@ fn mint_should_work() {
 				1,
 				46,
 				account(2),
-				Some(MintWitness { owner_of_item: 43 })
+				Some(MintWitness { owned_item: 43 })
 			),
 			Error::<Test>::AlreadyClaimed
 		);

substrate/frame/nfts/src/types.rs

@@ -124,7 +124,7 @@ impl<AccountId, DepositBalance> CollectionDetails<AccountId, DepositBalance> {
 #[derive(Clone, Encode, Decode, Eq, PartialEq, RuntimeDebug, TypeInfo)]
 pub struct MintWitness<ItemId> {
 	/// Provide the id of the item in a required collection.
-	pub owner_of_item: ItemId,
+	pub owned_item: ItemId,
 }
 
 /// Information concerning the ownership of a single unique item.
@@ -317,6 +317,21 @@ impl<Price, BlockNumber, CollectionId> Default for MintSettings<Price, BlockNumb
 	}
 }
 
+/// Attribute namespaces for non-fungible tokens.
+#[derive(
+	Clone, Encode, Decode, Eq, PartialEq, RuntimeDebug, scale_info::TypeInfo, MaxEncodedLen,
+)]
+pub enum AttributeNamespace<AccountId> {
+	/// An attribute was set by the pallet.
+	Pallet,
+	/// An attribute was set by collection's owner.
+	CollectionOwner,
+	/// An attribute was set by item's owner.
+	ItemOwner,
+	/// An attribute was set by pre-approved account.
+	Account(AccountId),
+}
+
 /// A witness data to cancel attributes approval operation.
 #[derive(Clone, Encode, Decode, Eq, PartialEq, RuntimeDebug, TypeInfo)]
 pub struct CancelAttributesApprovalWitness {