new: storing nft owner address i.e. validator id owner address in val…

…idator entity

root/schema.graphql

@@ -74,18 +74,7 @@ type TokenMapping @entity {
 type Validator @entity {
   id: ID!
   validatorId: BigInt!
-  # Below could be added, but that causes one
-  # issue : In handler function how should we be able to
-  # understand which chain we're currently working with ?
-  #
-  # Because that affects our which contract should be called
-  # for checking ownership of NFT contract
-  #
-  # It's better done offline, before serving request, backend can
-  # query blockchain node for this piece of data using standard `ownerOf`
-  # function call of standard ERC721, where parameter should be passed `validatorId`
-  #
-  # owner: Bytes!
+  owner: Bytes!
   signer: Bytes!
   signerPubKey: Bytes!
   liquidatedRewards: BigInt!

root/src/mappings/staking-info.ts

@@ -30,6 +30,14 @@ import {
   ConfirmAuction,
 } from '../../generated/StakingInfo/StakingInfo'
 
+// using network address from config file
+// to be passed to client when creating instance
+// of contract, StakingNft, for calling `ownerOf` function
+import NetworkConfig from '../network.json'
+
+// This is the contract we're going to interact with when `Staked` event is emitted
+import {StakingNft} from '../../generated/StakingNft/StakingNft'
+
 const STAKING_PARAMS_ID = 'staking:params'
 
 
@@ -65,6 +73,11 @@ export function handleStaked(event: Staked): void {
   validator.signer = event.params.signer
   validator.activationEpoch = event.params.activationEpoch
 
+  // Keeping NFT owner address, to be helpful while responding
+  // client queries in staking API
+  let nft = StakingNft.bind(Address.fromString(NetworkConfig.stakingNft.address))
+  validator.owner = nft.ownerOf(event.params.validatorId)
+
   validator.totalStaked = event.params.total
   validator.selfStake = event.params.amount