The Graph 入門

yarn add -D @graphprotocol/graph-cli
yarn graph init --studio test

yarn graph auth
cd test
yarn codegen
yarn build
yarn deploy

specVersion: 0.0.2
schema:
  file: ./schema.graphql
dataSources:
  - kind: ethereum/contract
    name: Loot
    network: mainnet
    source:
      address: "0xff9c1b15b16263c61d017ee9f65c50e4ae0113d7"
      abi: Loot
    mapping:
      kind: ethereum/events
      apiVersion: 0.0.4
      language: wasm/assemblyscript
      entities:
        - Approval
        - ApprovalForAll
        - OwnershipTransferred
        - Transfer
      abis:
        - name: Loot
          file: ./abis/Loot.json
      eventHandlers:
        - event: Approval(indexed address,indexed address,indexed uint256)
          handler: handleApproval
        - event: ApprovalForAll(indexed address,indexed address,bool)
          handler: handleApprovalForAll
        - event: OwnershipTransferred(indexed address,indexed address)
          handler: handleOwnershipTransferred
        - event: Transfer(indexed address,indexed address,indexed uint256)
          handler: handleTransfer
      file: ./src/mapping.ts

import { BigInt } from "@graphprotocol/graph-ts";
import {
  Loot,
  Approval,
  ApprovalForAll,
  OwnershipTransferred,
  Transfer,
} from "../generated/Loot/Loot";
import { ExampleEntity } from "../generated/schema";

export function handleApproval(event: Approval): void {
  // Entities can be loaded from the store using a string ID; this ID
  // needs to be unique across all entities of the same type
  let entity = ExampleEntity.load(event.transaction.from.toHex());

  // Entities only exist after they have been saved to the store;
  // `null` checks allow to create entities on demand
  if (entity == null) {
    entity = new ExampleEntity(event.transaction.from.toHex());

    // Entity fields can be set using simple assignments
    entity.count = BigInt.fromI32(0);
  }

  // BigInt and BigDecimal math are supported
  entity.count = entity.count + BigInt.fromI32(1);

  // Entity fields can be set based on event parameters
  entity.owner = event.params.owner;
  entity.approved = event.params.approved;

  // Entities can be written to the store with `.save()`
  entity.save();

  // Note: If a handler doesn't require existing field values, it is faster
  // _not_ to load the entity from the store. Instead, create it fresh with
  // `new Entity(...)`, set the fields that should be updated and save the
  // entity back to the store. Fields that were not set or unset remain
  // unchanged, allowing for partial updates to be applied.

  // It is also possible to access smart contracts from mappings. For
  // example, the contract that has emitted the event can be connected to
  // with:
  //
  // let contract = Contract.bind(event.address)
  //
  // The following functions can then be called on this contract to access
  // state variables and other data:
  //
  // - contract.balanceOf(...)
  // - contract.getApproved(...)
  // - contract.getChest(...)
  // - contract.getFoot(...)
  // - contract.getHand(...)
  // - contract.getHead(...)
  // - contract.getNeck(...)
  // - contract.getRing(...)
  // - contract.getWaist(...)
  // - contract.getWeapon(...)
  // - contract.isApprovedForAll(...)
  // - contract.name(...)
  // - contract.owner(...)
  // - contract.ownerOf(...)
  // - contract.supportsInterface(...)
  // - contract.symbol(...)
  // - contract.tokenByIndex(...)
  // - contract.tokenOfOwnerByIndex(...)
  // - contract.tokenURI(...)
  // - contract.totalSupply(...)
}

export function handleApprovalForAll(event: ApprovalForAll): void {}

export function handleOwnershipTransferred(event: OwnershipTransferred): void {}

export function handleTransfer(event: Transfer): void {}

const loot = Loot.bind(event.address)
loot.balanceOf(...)