https://github.com/dabit3/building-a-subgraph-workshop
In this workshop you'll learn how to build an NFT Subgraph using any smart contract or smart contracts.
https://github.com/dabit3/building-a-subgraph-workshop
blockchain ethereum graph-protocol nft solidity
Last synced: 5 months ago
JSON representation
In this workshop you'll learn how to build an NFT Subgraph using any smart contract or smart contracts.
- Host: GitHub
- URL: https://github.com/dabit3/building-a-subgraph-workshop
- Owner: dabit3
- Created: 2021-04-17T22:58:25.000Z (about 4 years ago)
- Default Branch: main
- Last Pushed: 2022-04-18T21:19:55.000Z (about 3 years ago)
- Last Synced: 2024-12-16T05:38:36.288Z (5 months ago)
- Topics: blockchain, ethereum, graph-protocol, nft, solidity
- Language: TypeScript
- Homepage:
- Size: 25.4 MB
- Stars: 163
- Watchers: 5
- Forks: 57
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
## The Graph - Subgraph Workshop
Learn how to build a GraphQL API on top of the Ethereum blockchain to query data from [Foundation](https://foundation.app/).
In this workshop you'll learn how to build and deploy a subgraph using the [Foundation NFT](https://foundation.app/) smart contract.
### Prerequisites
To be successful in this workshop, you should have [Node.js](https://github.com/nvm-sh/nvm#node-version-manager---) installed on your machine.
## Getting started
To get started, open [The Graph Hosted Service](https://thegraph.com/hosted-service/dashboard) and either sign in or create a new account.
Next, go to the [dashboard](https://thegraph.com/hosted-service/dashboard) and click on __Add Subgraph__ to create a new subgraph.
Configure your subgraph with the following properties:
- Subgraph Name - __Foundationsubgraph__
- Subtitle - __A subgraph for querying NFTs__
- Optional - Fill the description and GITHUB URL properties
Once the subgraph is created, we will initialize the subgraph locally using the Graph CLI.
### Initializing a new subgraph using the Graph CLI
Next, install the Graph CLI:
```sh
npm install -g @graphprotocol/graph-cli
# or
yarn global add @graphprotocol/graph-cli
```
Once the Graph CLI has been installed you can initialize a new subgraph with the Graph CLI `init` command.
There are two ways to initialize a new subgraph:
1 - From an example subgraph (example command, do not run)
```sh
graph init --from-example / []
```
2 - From an existing smart contract (example command, do not run)
If you already have a smart contract deployed to Ethereum mainnet or one of the testnets, initializing a new subgraph from this contract is an easy way to get up and running.
```sh
graph init --from-contract \
[--network ] \
[--abi ] \
/ []
```
In our case we'll be starting with the [Foundation proxy contract](https://etherscan.io/address/0xc9fe4ffc4be41d93a1a7189975cd360504ee361a#code) so we can initialize from that contract address by passing in the contract address using the `--from-contract` flag.
__Run the following command:__
```sh
graph init --from-contract 0xc9fe4ffc4be41d93a1a7189975cd360504ee361a --protocol ethereum \
--network mainnet --contract-name Token --index-events
? Product for which to initialize › hosted-service
? Subgraph name › your-username/Foundationsubgraph
? Directory to create the subgraph in › Foundationsubgraph
? Ethereum network › Mainnet
? Contract address › 0xc9fe4ffc4be41d93a1a7189975cd360504ee361a
? Contract Name · Token
```
This command will generate a basic subgraph based off of the contract address passed in as the argument to `--from-contract`. By using this contract address, the CLI will initialize a few things in your project to get you started (including fetching the `abis` and saving them in the __abis__ directory).
> By passing in `--index-events` the CLI will automatically populate some code for us both in __schema.graphql__ as well as __src/mapping.ts__ based on the events emitted from the contract.
The main configuration and definition for the subgraph lives in the __subgraph.yaml__ file. The subgraph codebase consists of a few files:
- __subgraph.yaml__: a YAML file containing the subgraph manifest
- __schema.graphql__: a GraphQL schema that defines what data is stored for your subgraph, and how to query it via GraphQL
- __AssemblyScript Mappings__: AssemblyScript code that translates from the event data in Ethereum to the entities defined in your schema (e.g. mapping.ts in this tutorial)
The entries in __subgraph.yaml__ that we will be working with are:
- `description` (optional): a human-readable description of what the subgraph is. This description is displayed by the Graph Explorer when the subgraph is deployed to the Hosted Service.
- `repository` (optional): the URL of the repository where the subgraph manifest can be found. This is also displayed by the Graph Explorer.
- `dataSources.source`: the address of the smart contract the subgraph sources, and the abi of the smart contract to use. The address is optional; omitting it allows to index matching events from all contracts.
- `dataSources.source.startBlock` (optional): the number of the block that the data source starts indexing from. In most cases we suggest using the block in which the contract was created.
- `dataSources.mapping.entities` : the entities that the data source writes to the store. The schema for each entity is defined in the the schema.graphql file.
- `dataSources.mapping.abis`: one or more named ABI files for the source contract as well as any other smart contracts that you interact with from within the mappings.
- `dataSources.mapping.eventHandlers`: lists the smart contract events this subgraph reacts to and the handlers in the mapping — __./src/mapping.ts__ in the example — that transform these events into entities in the store.
### Defining the entities
With The Graph, you define entity types in __schema.graphql__, and Graph Node will generate top level fields for querying single instances and collections of that entity type. Each type that should be an entity is required to be annotated with an `@entity` directive.
The entities / data we will be indexing are the `Token` and `User`. This way we can index the Tokens created by the users as well as the users themselves.
To do this, update __schema.graphql__ with the following code:
```graphql
type Token @entity {
id: ID!
tokenID: BigInt!
contentURI: String
tokenIPFSPath: String
name: String!
createdAtTimestamp: BigInt!
creator: User!
owner: User!
}
type User @entity {
id: ID!
tokens: [Token!]! @derivedFrom(field: "owner")
created: [Token!]! @derivedFrom(field: "creator")
}
```
### On Relationships via `@derivedFrom` (from the docs):
Reverse lookups can be defined on an entity through the `@derivedFrom` field. This creates a virtual field on the entity that may be queried but cannot be set manually through the mappings API. Rather, it is derived from the relationship defined on the other entity. For such relationships, it rarely makes sense to store both sides of the relationship, and both indexing and query performance will be better when only one side is stored and the other is derived.
For one-to-many relationships, the relationship should always be stored on the 'one' side, and the 'many' side should always be derived. Storing the relationship this way, rather than storing an array of entities on the 'many' side, will result in dramatically better performance for both indexing and querying the subgraph. In general, storing arrays of entities should be avoided as much as is practical.
Now that we have created the GraphQL schema for our app, we can generate the entities locally to start using in the `mappings` created by the CLI:
```sh
graph codegen
```
In order to make working smart contracts, events and entities easy and type-safe, the Graph CLI generates AssemblyScript types from a combination of the subgraph's GraphQL schema and the contract ABIs included in the data sources.
## Updating the subgraph with the entities and mappings
Now we can configure the __subgraph.yaml__ to use the entities that we have just created and configure their mappings.
To do so, first update the `dataSources.mapping.entities` field with the `User` and `Token` entities:
```yaml
entities:
- Token
- User
```
Next, update the `dataSources.mapping.eventHandlers` to include only the following three event handlers:
```yaml
- event: TokenIPFSPathUpdated(indexed uint256,indexed string,string)
handler: handleTokenIPFSPathUpdated
- event: Transfer(indexed address,indexed address,indexed uint256)
handler: handleTransfer
```
Finally, update the configuration to add the startBlock and change the contract `address` to the [main contract](https://etherscan.io/address/0x3B3ee1931Dc30C1957379FAc9aba94D1C48a5405) address:
```yaml
source:
address: "0x3B3ee1931Dc30C1957379FAc9aba94D1C48a5405"
abi: Token
startBlock: 11565020
```
## Assemblyscript mappings
Next, open __src/mappings.ts__ to write the mappings that we defined in our subgraph subgraph `eventHandlers`.
Update the file with the following code:
```typescript
import {
TokenIPFSPathUpdated as TokenIPFSPathUpdatedEvent,
Transfer as TransferEvent,
Token as TokenContract,
} from "../generated/Token/Token"
import {
Token, User
} from '../generated/schema'
export function handleTransfer(event: TransferEvent): void {
let token = Token.load(event.params.tokenId.toString());
if (!token) {
token = new Token(event.params.tokenId.toString());
token.creator = event.params.to.toHexString();
token.tokenID = event.params.tokenId;
let tokenContract = TokenContract.bind(event.address);
token.contentURI = tokenContract.tokenURI(event.params.tokenId);
token.tokenIPFSPath = tokenContract.getTokenIPFSPath(event.params.tokenId);
token.name = tokenContract.name();
token.createdAtTimestamp = event.block.timestamp;
}
token.owner = event.params.to.toHexString();
token.save();
let user = User.load(event.params.to.toHexString());
if (!user) {
user = new User(event.params.to.toHexString());
user.save();
}
}
export function handleTokenURIUpdated(event: TokenIPFSPathUpdatedEvent): void {
let token = Token.load(event.params.tokenId.toString());
if (!token) return
token.tokenIPFSPath = event.params.tokenIPFSPath;
token.save();
}
```
These mappings will handle events for when a new token is created, transferred, or updated. When these events fire, the mappings will save the data into the subgraph.
### Running a build
Next, let's run a build to make sure that everything is configured properly. To do so, run the `build` command:
```sh
graph build
```
If the build is successful, you should see a new __build__ folder generated in your root directory.
## Deploying the subgraph
To deploy, we can run the `deploy` command using the Graph CLI. To deploy, you will first need to copy the __Access token__ for your account, available in the [Graph Explorer](https://thegraph.com/explorer/dashboard):
Next, run the following command:
```sh
$ graph auth
✔ Product for which to initialize · hosted-service
✔ Deploy key · ********************************
yarn deploy
```
Once the subgraph is deployed, you should see it show up in your dashboard:
When you click on the subgraph, it should open the Graph explorer:
## Querying for data
Now that we are in the dashboard, we should be able to start querying for data. Run the following query to get a list of tokens and their metadata:
```graphql
{
tokens {
id
tokenID
contentURI
tokenIPFSPath
}
}
```
We can also configure the order direction:
```graphql
{
tokens(
orderBy:id,
orderDirection: desc
) {
id
tokenID
contentURI
tokenIPFSPath
}
}
```
Or choose to skip forward a certain number of results to implement some basic pagination:
```graphql
{
tokens(
skip: 100,
orderBy:id,
orderDirection: desc
) {
id
tokenID
contentURI
tokenIPFSPath
}
}
```
Or query for users and their associated content:
```graphql
{
users {
id
tokens {
id
contentURI
}
}
}
```
We can also query by timestamp to view the most recently created NFTS:
```graphql
{
tokens(
orderBy: createdAtTimestamp,
orderDirection: desc
) {
id
tokenID
contentURI
}
}
```
> The codebase for this project is located [here](https://github.com/dabit3/building-a-subgraph-workshop/tree/main/Foundationsubgraph)
## Next steps
If you are interested in learning more about Web3, building Dapps, or building subgraphs, check out the following resources:
The Graph on Twitter - [@graphprotocol](https://twitter.com/graphprotocol)
[The Complete Guide to Full Stack Ethereum Development](https://dev.to/dabit3/the-complete-guide-to-full-stack-ethereum-development-3j13)
[The Graph Discord](thegraph.com/discord)
[Solidity Docs](https://docs.soliditylang.org/)
[Ethereum Developer Documentation](https://ethereum.org/en/developers/docs/)
Austin Griffith on Twitter [@austingriffith](https://twitter.com/austingriffith) & [Scaffold Eth](https://github.com/austintgriffith/scaffold-eth)
[Crypto Zombies](https://cryptozombies.io/)