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, Two autorizers
    • Multiple Parties, Multiple Signatures
  • User Signature

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.

make create-account

Add Account Key

Add a key to an existing account.

make add-account-key

Deploy Contract

Deploy a Cadence smart contract.

make deploy-contract

Query Events

Query events emitted by transactions.

make query-events

Transaction Arguments

Submit a transaction with Cadence arguments.

make transaction-arguments

Transaction Signing

Single Party, Single Signature

Sign a transaction with a single account.

make single-party

Single Party, Multiple Signatures

Sign a transaction with a single account using multiple signatures.

make single-party-multisig

Multiple Parties

Sign a transaction with multiple accounts.

make multi-party

Multiple Parties, Two autorizers

Sign a transaction with multiple accounts and authorize for both of them.

make multi-party-two-authorizers

Multiple Parties, Multiple Signatures

Sign a transaction with multiple accounts using multiple signatures.

make multi-party-multisig

User Signature

Sign an arbitrary user message.

make user-signature

Documentation

Index

• func CreateAccount(flowClient *client.Client, publicKeys []*flow.AccountKey) *flow.Account
• func CreateAccountWithContracts(flowClient *client.Client, publicKeys []*flow.AccountKey, ...) *flow.Account
• func FundAccountInEmulator(flowClient *client.Client, address flow.Address, amount float64)
• func GetReferenceBlockId(flowClient *client.Client) flow.Identifier
• func Handle(err error)
• func RandomAccount(flowClient *client.Client) (flow.Address, *flow.AccountKey, crypto.Signer)
• func RandomPrivateKey() crypto.PrivateKey
• func ReadFile(path string) string
• 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) *flow.Account

func CreateAccountWithContracts

func CreateAccountWithContracts(flowClient *client.Client, publicKeys []*flow.AccountKey, contracts []templates.Contract) *flow.Account

func FundAccountInEmulator

func FundAccountInEmulator(flowClient *client.Client, address flow.Address, amount float64)

*

• FundAccountInEmulator Mints FLOW to an account. Minting only works in an emulator environment.

func GetReferenceBlockId

func GetReferenceBlockId(flowClient *client.Client) flow.Identifier

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) string

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