feat: Hooks for Memberships Managers! (#31)

* feat(fc-traits-memberships): change autoimplementation of `T` for traits in favour of `NonFungiblesMemberships` structure.

* feat(fc-traits-memberships): define `WithHooks` to extend managers and support hooks.

traits/memberships/src/hooks.rs

@@ -0,0 +1,66 @@
+use super::*;
+use frame_support::dispatch::DispatchResult;
+
+/// Triggers an action when a membership has been assigned
+pub trait OnMembershipAssigned<AccountId: Clone, Group: Clone, Membership: Clone> {
+    fn on_membership_assigned(
+        &self,
+        who: AccountId,
+        group: Group,
+        membership: Membership,
+    ) -> DispatchResult;
+}
+
+impl<A: Clone, G: Clone, M: Clone> OnMembershipAssigned<A, G, M> for () {
+    fn on_membership_assigned(&self, _: A, _: G, _: M) -> DispatchResult {
+        Ok(())
+    }
+}
+
+impl<T, A: Clone, G: Clone, M: Clone> OnMembershipAssigned<A, G, M> for T
+where
+    T: Fn(A, G, M) -> DispatchResult,
+{
+    fn on_membership_assigned(&self, who: A, group: G, membership: M) -> DispatchResult {
+        self(who, group, membership)
+    }
+}
+
+/// Triggers an action when a membership has been released
+pub trait OnMembershipReleased<Group: Clone, Membership: Clone> {
+    fn on_membership_released(&self, group: Group, membership: Membership) -> DispatchResult;
+}
+
+impl<T, G: Clone, M: Clone> OnMembershipReleased<G, M> for T
+where
+    T: Fn(G, M) -> DispatchResult,
+{
+    fn on_membership_released(&self, group: G, membership: M) -> DispatchResult {
+        self(group, membership)
+    }
+}
+
+impl<G: Clone, M: Clone> OnMembershipReleased<G, M> for () {
+    fn on_membership_released(&self, _: G, _: M) -> DispatchResult {
+        Ok(())
+    }
+}
+
+/// Triggers an action when a rank has been set for a membership
+pub trait OnRankSet<Group: Clone, Membership: Clone, Rank: Clone = GenericRank> {
+    fn on_rank_set(&self, group: Group, membership: Membership, rank: Rank) -> DispatchResult;
+}
+impl<G: Clone, M: Clone, R: Clone> OnRankSet<G, M, R> for () {
+    fn on_rank_set(&self, _: G, _: M, _: R) -> DispatchResult {
+        Ok(())
+    }
+}
+
+impl<T, G: Clone, M: Clone, R: Clone> OnRankSet<G, M, R> for T
+where
+    T: Fn(G, M, R) -> DispatchResult,
+{
+    fn on_rank_set(&self, group: G, membership: M, rank: R) -> DispatchResult {
+        self(group, membership, rank)
+    }
+}

traits/memberships/src/impl_nonfungibles.rs

@@ -1,4 +1,5 @@
 use crate::*;
+use core::marker::PhantomData;
 use frame_support::{
     pallet_prelude::DispatchError,
     sp_runtime::{str_array, traits::Zero},
@@ -11,7 +12,9 @@ const ATTR_MEMBER_RANK_TOTAL: &[u8] = b"membership_rank_total";
 
 pub const ASSIGNED_MEMBERSHIPS_ACCOUNT: [u8; 32] = str_array("memberships/assigned_memberships");
 
-impl<T, AccountId> Inspect<AccountId> for T
+pub struct NonFungiblesMemberships<T>(PhantomData<T>);
+
+impl<T, AccountId> Inspect<AccountId> for NonFungiblesMemberships<T>
 where
     T: nonfungibles::Inspect<AccountId> + nonfungibles::InspectEnumerable<AccountId>,
     T::OwnedInCollectionIterator: 'static,
@@ -41,7 +44,7 @@ where
     }
 }
 
-impl<T, AccountId, ItemConfig> Manager<AccountId, ItemConfig> for T
+impl<T, AccountId, ItemConfig> Manager<AccountId, ItemConfig> for NonFungiblesMemberships<T>
 where
     T: nonfungibles::Mutate<AccountId, ItemConfig>
         + nonfungibles::Inspect<AccountId>
@@ -80,7 +83,7 @@ where
     }
 }
 
-impl<T, AccountId, ItemConfig> Rank<AccountId, ItemConfig> for T
+impl<T, AccountId, ItemConfig> Rank<AccountId, ItemConfig> for NonFungiblesMemberships<T>
 where
     T: nonfungibles::Mutate<AccountId, ItemConfig>
         + nonfungibles::Inspect<AccountId>

traits/memberships/src/impls.rs

@@ -0,0 +1,89 @@
+use super::*;
+use core::marker::PhantomData;
+use frame_support::traits::Get;
+
+/// Extends a structure that already implements [`Manager`], and [`Rank`] to support
+/// hooks that are triggered after changes in memberships or ranks happen.
+pub struct WithHooks<T, OnMembershipAssigned = (), OnMembershipReleased = (), OnRankSet = ()>(
+    PhantomData<(T, OnMembershipAssigned, OnMembershipReleased, OnRankSet)>,
+);
+
+impl<T, MA, MR, RS, AccountId> Inspect<AccountId> for WithHooks<T, MA, MR, RS>
+where
+    T: Inspect<AccountId>,
+{
+    type Group = T::Group;
+    type Membership = T::Membership;
+
+    fn user_memberships(
+        who: &AccountId,
+        maybe_group: Option<Self::Group>,
+    ) -> Box<dyn Iterator<Item = (Self::Group, Self::Membership)>> {
+        T::user_memberships(who, maybe_group)
+    }
+
+    fn is_member_of(group: &Self::Group, who: &AccountId) -> bool {
+        T::is_member_of(group, who)
+    }
+
+    fn check_membership(who: &AccountId, m: &Self::Membership) -> Option<Self::Group> {
+        T::check_membership(who, m)
+    }
+
+    fn members_total(group: &Self::Group) -> u32 {
+        T::members_total(group)
+    }
+}
+
+impl<T, MA, MR, RS, AccountId, ItemConfig> Manager<AccountId, ItemConfig>
+    for WithHooks<T, MA, MR, RS>
+where
+    AccountId: Clone,
+    T: Manager<AccountId, ItemConfig>,
+    MA: Get<Box<dyn OnMembershipAssigned<AccountId, T::Group, T::Membership>>>,
+    MR: Get<Box<dyn OnMembershipReleased<T::Group, T::Membership>>>,
+{
+    fn assign(
+        group: &Self::Group,
+        m: &Self::Membership,
+        who: &AccountId,
+    ) -> Result<(), DispatchError> {
+        T::assign(group, m, who)?;
+        MA::get().on_membership_assigned(who.clone(), group.clone(), m.clone())?;
+        Ok(())
+    }
+
+    fn release(group: &Self::Group, m: &Self::Membership) -> Result<(), DispatchError> {
+        T::release(group, m)?;
+        MR::get().on_membership_released(group.clone(), m.clone())?;
+        Ok(())
+    }
+}
+
+impl<T, MA, MR, RS, R, AccountId, ItemConfig> Rank<AccountId, ItemConfig, R>
+    for WithHooks<T, MA, MR, RS>
+where
+    AccountId: Clone,
+    R: Ord + Clone,
+    T: Rank<AccountId, ItemConfig, R>,
+    RS: Get<Box<dyn OnRankSet<T::Group, T::Membership, R>>>,
+{
+    fn rank_of(group: &Self::Group, m: &Self::Membership) -> Option<R> {
+        T::rank_of(group, m)
+    }
+
+    fn set_rank(
+        group: &Self::Group,
+        m: &Self::Membership,
+        rank: impl Into<R>,
+    ) -> Result<(), DispatchError> {
+        let rank = rank.into();
+        T::set_rank(group, m, rank.clone())?;
+        RS::get().on_rank_set(group.clone(), m.clone(), rank)?;
+        Ok(())
+    }
+
+    fn ranks_total(group: &Self::Group) -> u32 {
+        T::ranks_total(group)
+    }
+}

traits/memberships/src/lib.rs

@@ -12,6 +12,13 @@ use core::{
 use frame_support::{sp_runtime::DispatchError, Parameter};
 
 mod impl_nonfungibles;
+pub use impl_nonfungibles::NonFungiblesMemberships;
+
+mod hooks;
+mod impls;
+
+pub use hooks::*;
+pub use impls::WithHooks;
 
 pub trait Manager<AccountId, ItemConfig>: Inspect<AccountId> {
     /// Transfers ownership of an unclaimed membership in the manager group to an account in the given group and activates it.

traits/memberships/src/tests.rs

@@ -51,6 +51,9 @@ impl pallet_balances::Config for Test {
     type RuntimeFreezeReason = RuntimeFreezeReason;
 }
 
+type CollectionId = <Test as pallet_nfts::Config>::CollectionId;
+type ItemId = <Test as pallet_nfts::Config>::ItemId;
+
 impl pallet_nfts::Config for Test {
     type ApprovalsLimit = ();
     type AttributeDepositBase = ();
@@ -119,29 +122,129 @@ pub(crate) fn new_test_ext() -> sp_io::TestExternalities {
 }
 
 mod manager {
+    use super::{new_test_ext, Memberships};
+    use super::{GroupOwner, Member, GROUP, MEMBERSHIP, MEMBERSHIPS_MANAGER_GROUP};
+    use crate::{impl_nonfungibles, Manager, NonFungiblesMemberships};
     use frame_support::assert_ok;
 
-    use crate::{
-        impl_nonfungibles,
-        tests::{GroupOwner, Member, Memberships, GROUP, MEMBERSHIP, MEMBERSHIPS_MANAGER_GROUP},
-        Manager,
-    };
-
-    use super::new_test_ext;
+    type MembershipsManager = NonFungiblesMemberships<Memberships>;
 
     #[test]
     fn assigning_and_releasing_moves_membership_to_special_account() {
         new_test_ext().execute_with(|| {
-            assert_ok!(Memberships::assign(&GROUP, &MEMBERSHIP, &Member::get()));
+            assert_ok!(MembershipsManager::assign(
+                &GROUP,
+                &MEMBERSHIP,
+                &Member::get()
+            ));
             assert_eq!(
                 Memberships::owner(MEMBERSHIPS_MANAGER_GROUP, MEMBERSHIP),
                 Some(impl_nonfungibles::ASSIGNED_MEMBERSHIPS_ACCOUNT.into())
             );
-            assert_ok!(Memberships::release(&GROUP, &MEMBERSHIP));
+            assert_ok!(MembershipsManager::release(&GROUP, &MEMBERSHIP));
             assert_eq!(
                 Memberships::owner(MEMBERSHIPS_MANAGER_GROUP, MEMBERSHIP),
                 Some(GroupOwner::get())
             );
         });
     }
 }
+
+mod with_hooks {
+    use super::{new_test_ext, Memberships};
+    use super::{AccountId, CollectionId, ItemId, Member, GROUP, MEMBERSHIP};
+    use crate::{
+        GenericRank, Manager, NonFungiblesMemberships, OnMembershipAssigned, OnMembershipReleased,
+        OnRankSet, Rank, WithHooks,
+    };
+    use codec::{Decode, Encode};
+    use frame_support::pallet_prelude::ValueQuery;
+    use frame_support::{assert_ok, parameter_types, storage_alias};
+    use sp_runtime::{traits::ConstU32, BoundedVec, DispatchError};
+
+    #[derive(Debug, Encode, Decode, PartialEq)]
+    enum Hook {
+        MembershipAssigned(AccountId, CollectionId, ItemId),
+        MembershipReleased(CollectionId, ItemId),
+        RankSet(CollectionId, ItemId, GenericRank),
+    }
+
+    #[storage_alias]
+    pub type Hooks = StorageValue<Prefix, BoundedVec<Hook, ConstU32<4>>, ValueQuery>;
+
+    parameter_types! {
+        pub AddMembershipAssignedHook: Box<dyn OnMembershipAssigned<AccountId, CollectionId, ItemId>> = Box::new(
+            |who, g, m| {
+                Hooks::try_append(Hook::MembershipAssigned(who, g, m)).map_err(|_| DispatchError::Other("MaxHooks"))
+            }
+        );
+        pub AddMembershipReleasedHook: Box<dyn OnMembershipReleased<CollectionId, ItemId>> = Box::new(
+            |g, m| Hooks::try_append(Hook::MembershipReleased(g, m)).map_err(|_| DispatchError::Other("MaxHooks"))
+        );
+        pub AddRankSetHook: Box<dyn OnRankSet<CollectionId, ItemId>> = Box::new(
+            |g, m, r| Hooks::try_append(Hook::RankSet(g, m, r)).map_err(|_| DispatchError::Other("MaxHooks"))
+        );
+    }
+
+    type MembershipsManager = WithHooks<
+        NonFungiblesMemberships<Memberships>,
+        AddMembershipAssignedHook,
+        AddMembershipReleasedHook,
+        AddRankSetHook,
+    >;
+
+    #[test]
+    fn assigning_and_releasing_calls_hooks() {
+        new_test_ext().execute_with(|| {
+            assert_ok!(MembershipsManager::assign(
+                &GROUP,
+                &MEMBERSHIP,
+                &Member::get()
+            ));
+
+            assert_eq!(
+                Hooks::get(),
+                BoundedVec::<Hook, ConstU32<4>>::truncate_from(vec![Hook::MembershipAssigned(
+                    Member::get(),
+                    GROUP,
+                    MEMBERSHIP
+                )])
+            );
+
+            assert_ok!(MembershipsManager::release(&GROUP, &MEMBERSHIP,));
+
+            assert_eq!(
+                Hooks::get(),
+                BoundedVec::<Hook, ConstU32<4>>::truncate_from(vec![
+                    Hook::MembershipAssigned(Member::get(), GROUP, MEMBERSHIP),
+                    Hook::MembershipReleased(GROUP, MEMBERSHIP)
+                ])
+            );
+        });
+    }
+
+    #[test]
+    fn setting_rank_calls_hooks() {
+        new_test_ext().execute_with(|| {
+            assert_ok!(MembershipsManager::assign(
+                &GROUP,
+                &MEMBERSHIP,
+                &Member::get()
+            ));
+
+            assert_ok!(MembershipsManager::set_rank(
+                &GROUP,
+                &MEMBERSHIP,
+                GenericRank(1)
+            ));
+
+            assert_eq!(
+                Hooks::get(),
+                BoundedVec::<Hook, ConstU32<4>>::truncate_from(vec![
+                    Hook::MembershipAssigned(Member::get(), GROUP, MEMBERSHIP),
+                    Hook::RankSet(GROUP, MEMBERSHIP, GenericRank(1))
+                ])
+            );
+        })
+    }
+}