use token listing event

config/ganache.json

@@ -1,5 +1,4 @@
 {
   "network": "mainnet",
-  "address": "0x9561C133DD8580860B6b7E504bC5Aa500f0f06a7",
-  "indexCalls": false
+  "address": "0x9561C133DD8580860B6b7E504bC5Aa500f0f06a7"
 }

config/mainnet.json

@@ -1,6 +1,5 @@
 {
   "network": "mainnet",
   "address": "0x6F400810b62df8E13fded51bE75fF5393eaa841F",
-  "startBlock": 9340147,
-  "indexCalls": true
+  "startBlock": 9340147
 }

config/rinkeby.json

@@ -1,6 +1,5 @@
 {
   "network": "rinkeby",
   "address": "0xC576eA7bd102F7E476368a5E98FA455d1Ea34dE2",
-  "startBlock": 5844678,
-  "indexCalls": false
+  "startBlock": 5844678
 }

config/xdai.json

@@ -1,6 +1,5 @@
 {
   "network": "xdai",
   "address": "0x25B06305CC4ec6AfCF3E7c0b673da1EF8ae26313",
-  "startBlock": 11948310,
-  "indexCalls": false
+  "startBlock": 11948310
 }

src/mappings/index.ts

@@ -1,4 +1,4 @@
-export { onAddToken } from './tokens'
+export { onTokenListing } from './tokens'
 export { onOrderPlacement, onOrderCancellation, onOrderDeletion } from './orders'
 export { onTrade, onTradeReversion } from './trades'
 export { onDeposit } from './deposits'

src/mappings/orders.ts

@@ -6,7 +6,7 @@ import {
 } from '../../generated/BatchExchange/BatchExchange'
 import { Order, Token, Trade, User } from '../../generated/schema'
 import { toOrderId, batchIdToEpoch, getBatchId } from '../utils'
-import { createTokenIfNotCreated } from './tokens'
+import { getTokenById } from './tokens'
 import { createUserIfNotCreated } from './users'
 
 export function onOrderPlacement(event: OrderPlacementEvent): void {
@@ -15,9 +15,10 @@ export function onOrderPlacement(event: OrderPlacementEvent): void {
   // Crete user if doesn't exist
   let owner = createUserIfNotCreated(params.owner, event)
 
-  // Crete tokens if they don't exist
-  let sellToken = createTokenIfNotCreated(params.sellToken, event)
-  let buyToken = createTokenIfNotCreated(params.buyToken, event)
+  // Get existing token entities - the `BatchExchange` contract requires token
+  // IDs to be valid to place orders.
+  let sellToken = getTokenById(params.sellToken)
+  let buyToken = getTokenById(params.buyToken)
 
   // Create order
   _createOrder(event, owner, sellToken, buyToken)

src/mappings/tokens.ts

@@ -1,62 +1,21 @@
-import { log, Address, BigInt, Bytes, ethereum } from '@graphprotocol/graph-ts'
+import { log, BigInt } from '@graphprotocol/graph-ts'
 import { Token } from '../../generated/schema'
-import { AddTokenCall, BatchExchange } from '../../generated/BatchExchange/BatchExchange'
+import { TokenListing as TokenListingEvent } from '../../generated/BatchExchange/BatchExchange'
 import { Erc20 } from '../../generated/BatchExchange/Erc20'
 import { epochToBatchId } from '../utils'
 
-export function onAddToken(call: AddTokenCall): void {
-  let address = call.inputs.token
-  let timestamp = call.block.timestamp
-  let txHash = call.transaction.hash
+export function onTokenListing(event: TokenListingEvent): void {
+  let params = event.params
 
   // Get token id
-  let batchExchange = BatchExchange.bind(call.to)
-  let tokenId = batchExchange.tokenAddressToIdMap(address)
-  log.info('[onAddToken] Add token {} with address', [BigInt.fromI32(tokenId).toString(), address.toHex()])
-
-  // Create token
-  let id = BigInt.fromI32(tokenId).toString()
-  _createToken(id, address, timestamp, txHash)
-
-  // It's possible, that there was already some deposits
-  // TODO: Update balances (once balances are implemented)
-}
-
-export function createTokenIfNotCreated(tokenId: u32, event: ethereum.Event): Token {
-  let id = BigInt.fromI32(tokenId).toString()
-  let token = Token.load(id)
-  log.info('[createTokenIfNotCreated] Make sure token {} is created', [id])
-
-  if (token == null) {
-    let batchExchange = BatchExchange.bind(event.address)
-    let address = batchExchange.tokenIdToAddressMap(tokenId)
-
-    let timestamp = event.block.timestamp
-    let txHash = event.transaction.hash
-
-    // Create token if not created
-    token = _createToken(id, address, timestamp, txHash)
-  }
-
-  return token!
-}
-
-export function getTokenById(tokenId: i32): Token {
-  let id = BigInt.fromI32(tokenId).toString()
-  let tokenOpt = Token.load(id)
-  if (!tokenOpt) {
-    throw new Error("Order doesn't exist: " + id)
-  }
-  return tokenOpt!
-}
-
-export function _createToken(id: string, address: Address, timestamp: BigInt, txHash: Bytes): Token {
-  log.info('[createToken] Create Token {} with address {}', [id, address.toHex()])
+  let id = BigInt.fromI32(params.id).toString()
+  let address = params.token
+  log.info('[onTokenListing] Add token {} with address {}', [id, address.toHex()])
 
   // Create token
   let token = new Token(id)
   token.address = address
-  token.fromBatchId = epochToBatchId(timestamp)
+  token.fromBatchId = epochToBatchId(event.block.timestamp)
 
   // Add symbol (optional)
   let erc20 = Erc20.bind(address)
@@ -87,11 +46,19 @@ export function _createToken(id: string, address: Address, timestamp: BigInt, tx
   }
 
   // Audit dates
-  token.createEpoch = timestamp
+  token.createEpoch = event.block.timestamp
 
   // Transaction
-  token.txHash = txHash
+  token.txHash = event.transaction.hash
 
   token.save()
-  return token
+}
+
+export function getTokenById(tokenId: i32): Token {
+  let id = BigInt.fromI32(tokenId).toString()
+  let tokenOpt = Token.load(id)
+  if (!tokenOpt) {
+    throw new Error("Token doesn't exist: " + id)
+  }
+  return tokenOpt!
 }

subgraph.yaml.mustache

@@ -38,13 +38,11 @@ dataSources:
           file: ./abis/BatchExchange.json
         - name: Erc20
           file: ./abis/Erc20.json
-{{#indexCalls}}
-      callHandlers:
-        # Tokens
-        - function: addToken(address)
-          handler: onAddToken
-{{/indexCalls}}
       eventHandlers:
+        # Tokens
+        - event: TokenListing(address,uint16)
+          handler: onTokenListing
+
         # Deposits
         - event: Deposit(indexed address,indexed address,uint256,uint32)
           handler: onDeposit