@lemonneko/easi-gen NPM

Easinteraction For Cadence(WIP)

Easinteraction is a tool that help users to generate code for easier contract interaction.

This version is for Cadence(Flow Blockchain) and Golang.

Get Started

Installation

$ go install github.com/LemonNekoGH/easinteraction-for-cadence/cmd/easi-gen@latest
# or use brew if you do not have go installed
$ brew tap LemonNekoGH/tap
$ brew install easi-gen

Homebrew is a package manager for macOS.

Usage

$ easi-gen --source NekosMerge.cdc --output nekosmerge.go --pkg-name nekosmerge

Now easi-gen will read your Cadence code from NekosMerge.cdc, then parse the code, then generate Go code with package name nekosmerge and output to nekosmerge.go.

If no --pkg-name flag specified, it will use mypackage as default.
If no --source flag specified, it will read from standard input.
If no --output flag specified, it will output to standard output.

So you can also use it like this:

$ cat NekosMerge.cdc | easi-gen --pkg-name nekosmerge > nekosmerge.go

Result Preview

Cadence code:

pub contract UserProfiles {
    access(self) let usernames: {Address:String}

    pub fun setName(_ acc: AuthAccount, _ name: String) {
        self.usernames[acc.address] = name
    }

    pub fun getName(_ addr: Address): String {
        return self.usernames[addr] ?? ""
    }

    init() {
        self.usernames = {}
    }
}

Go code:

package mypackage

import (
	"context"
	"fmt"
	"github.com/LemonNekoGH/godence"
	"github.com/onflow/cadence"
	flowSdk "github.com/onflow/flow-go-sdk"
	flowGrpc "github.com/onflow/flow-go-sdk/access/grpc"
	flowCrypto "github.com/onflow/flow-go-sdk/crypto"
)

type ContractUserProfiles struct {
	address string
	flowCli *flowGrpc.Client
}

// NewUserProfilesContract construct a new ContractUserProfiles instance.
func NewUserProfilesContract(address string, flowCli *flowGrpc.Client) (*ContractUserProfiles, error) {
	// prepare script
	script := fmt.Sprintf(`import UserProfiles from %s
pub fun main(){}
`, address)
	// send a script to ensure contract address is correct
	_, err := flowCli.ExecuteScriptAtLatestBlock(context.Background(), []byte(script), nil)
	if err != nil {
		return nil, err
	}
	return &ContractUserProfiles{
		address: address,
		flowCli: flowCli,
	}, nil
}

// SetName will change Flow blockchain's state.
// Signature: pub fun setName(user acc: AuthAccount,to name: String)
func (c *ContractUserProfiles) SetName(
	arg1 string,
	authorizer0, payer, proposer flowSdk.Address,
	authorizerKeyIndex, payerKeyIndex, proposalKeyIndex int,
	authorizerSigner, payerSigner flowCrypto.Signer,
) (*flowSdk.Identifier, error) {
	// get reference id
	block, err := c.flowCli.GetLatestBlock(context.Background(), true)
	if err != nil {
		return nil, err
	}
	// get proposer sequence number
	propAcct, err := c.flowCli.GetAccount(context.Background(), proposer)
	if err != nil {
		return nil, err
	}
	// gen script
	script := fmt.Sprintf(`import UserProfiles from %s
transaction(arg1: String) {
    prepare(arg0: AuthAccount) {
        UserProfiles.setName(user:arg0,to:arg1)
    }
}
`, c.address)
	// construct tx
	tx := flowSdk.NewTransaction().
		SetScript([]byte(script)).
		AddAuthorizer(authorizer0).
		SetPayer(payer).
		SetProposalKey(proposer, proposalKeyIndex, propAcct.Keys[proposalKeyIndex].SequenceNumber).
		SetReferenceBlockID(block.ID).
		SetGasLimit(9999)
	// add argument
	argCdc1, err := godence.ToCadence(
		arg1,
	)
	if err != nil {
		return nil, err
	}
	err = tx.AddArgument(argCdc1)
	if err != nil {
		return nil, err
	}

	if authorizer0.String() != payer.String() {
		// sign payload
		err = tx.SignPayload(authorizer0, authorizerKeyIndex, authorizerSigner)
		if err != nil {
			return nil, err
		}
	}
	// sign envelop
	err = tx.SignEnvelope(payer, payerKeyIndex, payerSigner)
	if err != nil {
		return nil, err
	}
	// send
	err = c.flowCli.SendTransaction(context.Background(), *tx)
	if err != nil {
		return nil, err
	}
	id := tx.ID()
	return &id, nil
}

// GetName will query from Flow blockchain.
// Signature: pub fun getName(_ addr: Address): String
func (c *ContractUserProfiles) GetName(
	arg0 string,

) (*string, error) {
	// gen script
	script := fmt.Sprintf(`import UserProfiles from %s
pub fun main(arg0: Address): String{
    return UserProfiles.getName(arg0)
}
`, c.address)
	// prepare args
	args := []cadence.Value{}
	argCdc0, err := godence.ToCadence(
		godence.Address(arg0),
	)
	if err != nil {
		return nil, err
	}
	args = append(args, argCdc0)
	// send query
	result, err := c.flowCli.ExecuteScriptAtLatestBlock(context.Background(), []byte(script), args)
	if err != nil {
		return nil, err
	}

	// covert result
	var ret string
	err = godence.ToGo(result, &ret)
	if err != nil {
		return nil, err
	}
	return &ret, nil

}

Contributing

Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated.

If you have a suggestion that would make this better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement". Don't forget to give the project a star! Thanks again!