gochain/flutter_web3_provider

An easy to use wrapper for Flutter web apps that want to use metamask and other Dapp wallets.

GoChain

Official golang implementation of the GoChain protocol.

Mainnet: Live Stats | Block Explorer | Public RPC Endpoint

General Documentation

If you are looking to build DApps, deploy smart contracts, setup a private network or run a node, please see our Documentation Repository, it will be much more useful to you.

If you plan on working on the GoChain core code, then read on.

Building the source

Building gochain requires both a Go (version 1.12 or later) and a C compiler. You can install them using your favourite package manager. Once the dependencies are installed, run:

# build gochain
make gochain

or, to build the full suite of utilities:

make all

Executables

The GoChain project comes with several wrappers/executables found in the cmd directory.

Command	Description
gochain	Our main GoChain CLI client. It is the entry point into the GoChain network (main-, test- or private net), capable of running as a full node (default) archive node (retaining all historical state) or a light node (retrieving data live). It can be used by other processes as a gateway into the GoChain network via JSON RPC endpoints exposed on top of HTTP, WebSocket and/or IPC transports. gochain --help and the CLI Wiki page for command line options.
abigen	Source code generator to convert GoChain contract definitions into easy to use, compile-time type-safe Go packages. It operates on plain Ethereum contract ABIs with expanded functionality if the contract bytecode is also available. However it also accepts Solidity source files, making development much more streamlined. Please see our Native DApps wiki page for details.
bootnode	Stripped down version of our GoChain client implementation that only takes part in the network node discovery protocol, but does not run any of the higher level application protocols. It can be used as a lightweight bootstrap node to aid in finding peers in private networks.
evm	Developer utility version of the EVM (Ethereum Virtual Machine) that is capable of running bytecode snippets within a configurable environment and execution mode. Its purpose is to allow isolated, fine-grained debugging of EVM opcodes (e.g. evm --code 60ff60ff --debug).
gethrpctest	Developer utility tool to support our ethereum/rpc-test test suite which validates baseline conformity to the Ethereum JSON RPC specs. Please see the test suite's readme for details.
rlpdump	Developer utility tool to convert binary RLP (Recursive Length Prefix) dumps (data encoding used by the Ethereum protocol both network as well as consensus wise) to user friendlier hierarchical representation (e.g. rlpdump --hex CE0183FFFFFFC4C304050583616263).
swarm	swarm daemon and tools. This is the entrypoint for the swarm network. swarm --help for command line options and subcommands. See https://swarm-guide.readthedocs.io for swarm documentation.

Running GoChain

Full node on the main GoChain network

By far the most common scenario is people wanting to simply interact with the GoChain network: create accounts; transfer funds; deploy and interact with contracts. For this particular use-case the user doesn't care about years-old historical data, so we can fast-sync quickly to the current state of the network. To do so:

$ gochain console

This command will:

• Start GoChain in fast sync mode (default, can be changed with the --syncmode flag), causing it to download more data in exchange for avoiding processing the entire history of the GoChain network, which is very CPU intensive.
• Start up GoChain's built-in interactive JavaScript console, (via the trailing console subcommand) through which you can invoke all official web3 methods as well as GoChain's own management APIs. This too is optional and if you leave it out you can always attach to an already running GoChain instance with gochain attach.

Full node on the GoChain test network

Transitioning towards developers, if you'd like to play around with creating GoChain contracts, you almost certainly would like to do that without any real money involved until you get the hang of the entire system. In other words, instead of attaching to the main network, you want to join the test network with your node, which is fully equivalent to the main network, but with play-GOC only.

$ gochain --testnet console

The console subcommand have the exact same meaning as above and they are equally useful on the testnet too. Please see above for their explanations if you've skipped to here.

Specifying the --testnet flag however will reconfigure your GoChain instance a bit:

• Instead of using the default data directory (~/.gochain on Linux for example), GoChain will nest itself one level deeper into a testnet subfolder (~/.gochain/testnet on Linux). Note, on OSX and Linux this also means that attaching to a running testnet node requires the use of a custom endpoint since gochain attach will try to attach to a production node endpoint by default. E.g. gochain attach <datadir>/testnet/gochain.ipc. Windows users are not affected by this.
• Instead of connecting the main GoChain network, the client will connect to the test network, which uses different P2P bootnodes, different network IDs and genesis states.

Note: Although there are some internal protective measures to prevent transactions from crossing over between the main network and test network, you should make sure to always use separate accounts for play-money and real-money. Unless you manually move accounts, GoChain will by default correctly separate the two networks and will not make any accounts available between them.

Configuration

As an alternative to passing the numerous flags to the gochain binary, you can also pass a configuration file via:

$ gochain --config /path/to/your_config.toml

To get an idea how the file should look like you can use the dumpconfig subcommand to export your existing configuration:

$ gochain --your-favourite-flags dumpconfig

Docker quick start

One of the quickest ways to get GoChain up and running on your machine is by using Docker:

docker run -d --name gochain-node -v /Users/alice/GoChain:/root \
           -p 8545:8545 -p 30303:30303 \
           ghcr.io/gochain/gochain

This will start GoChain in fast-sync mode with a DB memory allowance of 1GB just as the above command does. It will also create a persistent volume in your home directory for saving your blockchain as well as map the default ports.

Do not forget --rpcaddr 0.0.0.0, if you want to access RPC from other containers and/or hosts. By default, gochain binds to the local interface and RPC endpoints is not accessible from the outside.

Programatically interfacing GoChain nodes

As a developer, sooner rather than later you'll want to start interacting with GoChain network via your own programs and not manually through the console. To aid this, GoChain has built in support for a JSON-RPC based APIs (standard APIs and GoChain specific APIs). These can be exposed via HTTP, WebSockets and IPC (unix sockets on unix based platforms, and named pipes on Windows).

The IPC interface is enabled by default and exposes all the APIs supported by GoChain, whereas the HTTP and WS interfaces need to manually be enabled and only expose a subset of APIs due to security reasons. These can be turned on/off and configured as you'd expect.

HTTP based JSON-RPC API options:

• --rpc Enable the HTTP-RPC server
• --rpcaddr HTTP-RPC server listening interface (default: "localhost")
• --rpcport HTTP-RPC server listening port (default: 8545)
• --rpcapi API's offered over the HTTP-RPC interface (default: "eth,net,web3")
• --rpccorsdomain Comma separated list of domains from which to accept cross origin requests (browser enforced)
• --ws Enable the WS-RPC server
• --wsaddr WS-RPC server listening interface (default: "localhost")
• --wsport WS-RPC server listening port (default: 8546)
• --wsapi API's offered over the WS-RPC interface (default: "eth,net,web3")
• --wsorigins Origins from which to accept websockets requests
• --ipcdisable Disable the IPC-RPC server
• --ipcapi API's offered over the IPC-RPC interface (default: "admin,debug,eth,miner,net,personal,shh,txpool,web3")
• --ipcpath Filename for IPC socket/pipe within the datadir (explicit paths escape it)

You'll need to use your own programming environments' capabilities (libraries, tools, etc) to connect via HTTP, WS or IPC to a GoChain node configured with the above flags and you'll need to speak JSON-RPC on all transports. You can reuse the same connection for multiple requests!

Note: Please understand the security implications of opening up an HTTP/WS based transport before doing so! Hackers on the internet are actively trying to subvert GoChain nodes with exposed APIs! Further, all browser tabs can access locally running webservers, so malicious webpages could try to subvert locally available APIs!

Operating a private network

See: https://github.com/gochain/docs/tree/master/nodes/custom

Contribution

Thank you for considering to help out with the source code! We welcome contributions from anyone on the internet, and are grateful for even the smallest of fixes!

If you'd like to contribute to GoChain, please fork, fix, commit and send a pull request for the maintainers to review and merge into the main code base.

Please make sure your contributions adhere to our coding guidelines:

• Code must adhere to the official Go formatting guidelines (i.e. uses gofmt).
• Code must be documented adhering to the official Go commentary guidelines.
• Pull requests need to be based on and opened against the master branch.
• Commit messages should be prefixed with the package(s) they modify.
  • E.g. "gochain, rpc: make trace configs optional"

License

The gochain library (i.e. all code outside of the cmd directory) is licensed under the GNU Lesser General Public License v3.0, also included in our repository in the COPYING.LESSER file.

The gochain binaries (i.e. all code inside of the cmd directory) is licensed under the GNU General Public License v3.0, also included in our repository in the COPYING file.

flutter_web3_provider's Issues

Notify transaction state

I'm trying to call functions in a smart contract sequentially and they need to finish executing between calls. Is there a way to know when a transaction went through?

Help on read response value

I'm a flutter beginner and try using this lib, I'm follow the example, it works well. There's a bit I need your help, to convert response into Dart value, say

var res =
    await promiseToFuture(callMethod(contract, "transfer", [
    '0x39C5190c09ec04cF09C782bA4311C469473Ffe83',
    "0x" + amount.toString()).toRadixString(16)
    ]));

1. res is an object, I don't know how to read tx from it?
2. when above call raise exception, again I receive an object with catch, how do I read message in it?

Thank you!

Getting chain id

Great library, thank you!

How can we get the chainid? Can we use that to check if wallet's on mainnet?

insert more example

insert more example please
first smart contract solidity source code insert on the repo please
second add more example please
insert example like Deposit and withdrawal

thank you

How to include another contract as dependency?

Is there a way to deploy in a Parent/Child type of situation? How would you specify another contract in the List object that you use to declare the contract you want to call?
Here's the issue in more details https://stackoverflow.com/questions/66891008/how-to-include-another-contract-as-dependency

Trust Wallet Connect Wallet problem

on the Trust Wallet Connect Wallet button example do not work
but sign and verify is ok and dont have any problem

Null safety migration

Hi,

would be cool to seen this plugin with null safety support^^

dart.global.ethers is undefined

despite having the same syntax as in the example, I get the error in the title

`final Web3Provider provider = Web3Provider(ethereum!);

final Signer signer = provider.getSigner();

final Contract contract =
Contract(deployedNftContractAddress, tideNftAbiListed, provider);

final symbol = await contract.symbol();`

when running final Web3Provider provider = Web3Provider(ethereum!);
I get the error dart.global.ethers is undefined.
Below I put all the imports of the file containing this code:

`import 'package:flutter_web3_provider/ethers.dart';

import 'package:http/http.dart' as http;

import 'package:flutter_web3_provider/ethereum.dart';

import 'dart:convert';`

Read Only Provider

How can I use a read only provider to call a method (from mobile browser for example).
I tried:
var readProvider = new JsonRpcProvider("https://rpc.gochain.io");
contract = Contract(contractAddress, abi, readProvider);
data = promiseToFuture(callMethod(contract, "getData", []));

But I get a "call revert exception". The call works well with web3 provider.

Thank you!

Verify message function gives error. [Uncaught (in promise) TypeError: jsPromise.then is not a function]

Load abi from json file

I see you can load the abi from a list of strings, but it would be useful to actually get it from a json file, since that's how Remix is exporting the abi.

Please add support for AbiCoder utility

abiCoder.encode( types , values ) ⇒ string< DataHexString >source
Encode the array values according to the array of types, each of which may be a string or a ParamType.

abiCoder.decode( types , data ) ⇒ Resultsource
Decode the data according to the array of types, each of which may be a string or ParamType.

How to implement this?

https://docs.ethers.io/v5/api/utils/abi/coder/

Listen to contract events

How can i listen to a contract event that the contract emits?

Help Needed. How to add a API like Biconomy to web3Provider?

Is it possible to add an API like Biconomy to Web3Provider.

// Install Biconomy
<script src="https://cdn.jsdelivr.net/npm/@biconomy/mexa@latest/dist/mexa.js"></script>

// Import Biconomy
let Biconomy = window.Biconomy.default;

const biconomy = new Biconomy(<web3 provider>,{apiKey: <API Key>, debug: true});

let ethersProvider = new ethers.providers.Web3Provider(biconomy);

biconomy.onEvent(biconomy.READY, () => {
  // Initialize your dapp here like getting user accounts etc
}).onEvent(biconomy.ERROR, (error, message) => {
  // Handle error while initializing mexa
});

This is how it's supposed to be in JS.

Exception caught by widgets library

Face this error while running the example in android studio
Error:
No top-level getter 'ethereum' declared.
Receiver: top-level
Tried calling: ethereum

Listent to request new connection from dapp

you can make func listen request new connection from dapp ?

[Not issue] install metamask on chrome debug mode

Hi, I run example code on chrome. But application run on chrome debug mode, so I cannot install metamask there to connect to wallet. Could you please give me a solution to fix this?

Support for encodeFunctionData or equivalent?

how to implement function encoder?

interface.encodeFunctionData( fragment [ , values ] ) ⇒ string< DataHexString >

or is there a way to achieve the same with [defaultAbiCoder]

get balance

how can get balance from metamask ? (get balance from wallet address connected)

Passing gas and value to metamask

Can you give an example of how to call a payable function; passing the gaslimit, gasprice, value, data.

Will you guys do any more update with this package?

If more update, what features are going to be included?

Web3Provider(ethereum) -> Cannot read property 'providers' of undefined

I am having a similar problem to issues #5 .
Basically I am getting the same error (TypeError: Cannot read property 'providers' of undefined) when I try to do "Web3Provider(ethereum)" called within onPressed function.
Notes :

• Web3Provider web3 = Web3Provider(ethereum); is the only thing that is currently in the function (to eliminate the possibility of something else causing the problem)
• The connection to metamask is fine since eth_requestAccounts method works perfectly fine.
• Function is being called from StatelessWidget Button onPressed operation (that is the difference I noticed comparing it to the example, although I do not see how that could affect things)

Any idea what causes this and how I can fix it ?

Packages version mismatch

If you try to clone the repo and run it as is, you get

Because flutter_web3_provider requires SDK version >=2.12.0 <3.0.0, version solving failed.
pub get failed (1; Because flutter_web3_provider requires SDK version >=2.12.0 <3.0.0, version solving failed.)
exit code 1

Even when you manually set the sdk to >=2.12.0 <3.0.0 , it still fails to get the packages.

Example app doesn't run - TypeError: Cannot read property 'providers' of undefined

If you run it using the Chrome driver it will start an incognito window that does not have plugins so you can't connect your MetaMask to it. But it does show the page, complete with the message "Dapp Browser not found"

If you run it in a web server using flutter run -d web-server, it allows you to connect to it from a regular browser window, but it just goes into "TypeError: Cannot read property 'providers' of undefined" on the red background. No line number indicated or anything like that.

Any help would be super valued.