Simple Trait to Inspect Metadata (#9893)

* simple trait to inspect metadata

* import vec

frame/assets/src/impl_fungibles.rs

@@ -60,6 +60,25 @@ impl<T: Config<I>, I: 'static> fungibles::Inspect<<T as SystemConfig>::AccountId
  }
 }
 
+impl<T: Config<I>, I: 'static> fungibles::InspectMetadata<<T as SystemConfig>::AccountId>
+ for Pallet<T, I>
+{
+ /// Return the name of an asset.
+ fn name(asset: &Self::AssetId) -> Vec<u8> {
+ Metadata::<T, I>::get(asset).name.to_vec()
+ }
+
+ /// Return the symbol of an asset.
+ fn symbol(asset: &Self::AssetId) -> Vec<u8> {
+ Metadata::<T, I>::get(asset).symbol.to_vec()
+ }
+
+ /// Return the decimals of an asset.
+ fn decimals(asset: &Self::AssetId) -> u8 {
+ Metadata::<T, I>::get(asset).decimals
+ }
+}
+
 impl<T: Config<I>, I: 'static> fungibles::Mutate<<T as SystemConfig>::AccountId> for Pallet<T, I> {
  fn mint_into(
  asset: Self::AssetId,

frame/support/src/traits/tokens/fungibles.rs

@@ -23,6 +23,7 @@ use super::{
 };
 use crate::dispatch::{DispatchError, DispatchResult};
 use sp_runtime::traits::Saturating;
+use sp_std::vec::Vec;
 
 mod balanced;
 pub use balanced::{Balanced, Unbalanced};
@@ -65,6 +66,18 @@ pub trait Inspect<AccountId> {
  ) -> WithdrawConsequence<Self::Balance>;
 }
 
+/// Trait for reading metadata from a fungible asset.
+pub trait InspectMetadata<AccountId>: Inspect<AccountId> {
+ /// Return the name of an asset.
+ fn name(asset: &Self::AssetId) -> Vec<u8>;
+
+ /// Return the symbol of an asset.
+ fn symbol(asset: &Self::AssetId) -> Vec<u8>;
+
+ /// Return the decimals of an asset.
+ fn decimals(asset: &Self::AssetId) -> u8;
+}
+
 /// Trait for providing a set of named fungible assets which can be created and destroyed.
 pub trait Mutate<AccountId>: Inspect<AccountId> {
  /// Attempt to increase the `asset` balance of `who` by `amount`.