examples

README

Emulator Examples

This package contains code samples that interact with the Flow Emulator.

• Running the emulator with the Flow CLI
  • Installation
  • Starting the server
• Running the examples
  • Create Account
  • Add Account Key
  • Deploy Contract
  • Query Events
  • Transaction Arguments
  • Transaction Signing
    • Single Party, Single Signature
    • Single Party, Multiple Signatures
    • Multiple Parties
    • Multiple Parties, Multiple Signatures

Running the emulator with the Flow CLI

The emulator is bundled with the Flow CLI, a command-line interface for working with Flow.

Installation

Follow these steps to install the Flow CLI.

Starting the server

Start the emulator by running the following command in this directory:

flow emulator start -v

The -v flag enables verbose log output, which is useful for testing

Running the examples

In a separate process, run any of the example programs below. Watch the emulator logs to see transaction output.

Create Account

Create a new account on Flow.

go run ./create_account/main.go

Add Account Key

Add a key to an existing account.

go run ./add_account_key/main.go

Deploy Contract

Deploy a Cadence smart contract.

go run ./deploy_contract/main.go

Query Events

Query events emitted by transactions.

go run ./query_events/main.go

Transaction Arguments

Submit a transaction with Cadence arguments:

go run ./transaction_arguments/main.go

Transaction Signing

Single Party, Single Signature

Sign a transaction with a single account.

go run ./transaction_signing/single_party/main.go

Single Party, Multiple Signatures

Sign a transaction with a single account using multiple signatures.

go run ./transaction_signing/single_party_multisig/main.go

Multiple Parties

Sign a transaction with multiple accounts.

go run ./transaction_signing/multi_party/main.go

Multiple Parties, Multiple Signatures

Sign a transaction with multiple accounts using multiple signatures.

go run ./transaction_signing/multi_party_multisig/main.go

Documentation

Index

• func CreateAccount(flowClient *client.Client, publicKeys []*flow.AccountKey, code []byte) *flow.Account
• func DeployContract(flowClient *client.Client, code []byte) flow.Address
• func Handle(err error)
• func RandomAccount(flowClient *client.Client) (flow.Address, *flow.AccountKey, crypto.Signer)
• func RandomPrivateKey() crypto.PrivateKey
• func ReadFile(path string) []byte
• func ServiceAccount(flowClient *client.Client) (flow.Address, *flow.AccountKey, crypto.Signer)
• func WaitForSeal(ctx context.Context, c *client.Client, id flow.Identifier) *flow.TransactionResult

Functions

func CreateAccount

func CreateAccount(flowClient *client.Client, publicKeys []*flow.AccountKey, code []byte) *flow.Account

func DeployContract

func DeployContract(flowClient *client.Client, code []byte) flow.Address

func Handle

func Handle(err error)

func RandomAccount

func RandomAccount(flowClient *client.Client) (flow.Address, *flow.AccountKey, crypto.Signer)

func RandomPrivateKey

func RandomPrivateKey() crypto.PrivateKey

RandomPrivateKey returns a randomly generated ECDSA P-256 private key.

func ReadFile

func ReadFile(path string) []byte

ReadFile reads a file from the file system.

func ServiceAccount

func ServiceAccount(flowClient *client.Client) (flow.Address, *flow.AccountKey, crypto.Signer)

func WaitForSeal

func WaitForSeal(ctx context.Context, c *client.Client, id flow.Identifier) *flow.TransactionResult