eth-dagger

eth-dagger is library for dagger project written in node.js and browser. It uses dagger server to get realtime updates from Ethereum Network.

About dagger

Dagger helps users to develop faster and better Ethereum DApps. For more information:

• Installation
• Example
• Network
• Events
• API
• Examples
• Support
• License

Installation

NPM

# Using Yarn
yarn add eth-dagger

# Using NPM
npm install eth-dagger --save

Direct <script> Include

Simply download lib/eth-dagger.min.js and include with a script tag. Dagger will be registered as a global variable.

Usage:

var Dagger = window.Dagger

CDN

<script src="https://cdn.jsdelivr.net/npm/eth-dagger/lib/eth-dagger.min.js"></script>

Matic is also available on unpkg

Network

Mainnet

Websocket: wss://mainnet.dagger.matic.network
Socket: mqtts://mainnet.dagger.matic.network (You can also use `ssl://` protocol)

Kovan

Websocket: wss://kovan.dagger.matic.network
Socket: mqtts://kovan.dagger.matic.network (You can also use `ssl://` protocol)

Ropsten

Websocket: wss://ropsten.dagger.matic.network
Socket: mqtts://ropsten.dagger.matic.network (You can also use `ssl://` protocol)

Example

var Dagger = require("eth-dagger");

// connect to Dagger ETH main network (network id: 1) over web socket
var dagger = new Dagger("wss://mainnet.dagger.matic.network"); // dagger server

// Use mqtt protocol for node (socket)
// var dagger = new Dagger('mqtts://mainnet.dagger.matic.network'); // dagger server

// get new block as soon as it gets created
dagger.on("latest:block", function(result) {
  console.log("New block created: ", result);
});

// get only block number (as it gets created)
dagger.on("latest:block.number", function(result) {
  console.log("Current block number: ", result);
});

Test dagger server

This library consists woodendagger executable which is test dagger server on your local machine. So you can test with TestRPC.

Please do not use woodendagger in production. It's only for development purpose. It doesn't support removed flag.

$ woodendagger --url=https://mainnet.infura.io # or http://localhost:8545 for local json-rpc

# If you want to start dagger server on different ports,
# sockport: socket port for backend connection over TCP
# wsport: websocket port for frontend connection over websocket
$ woodendagger --url=http://localhost:8545 --sockport=1883 --wsport=1884

# To connect from dagger:
var dagger = new Dagger('mqtt://localhost:1883')

Events

Ethereum events

Every ethereum event has room, and there are two rooms: latest and confirmed. latest events are fired immediately block included in chain. confirmed events are fired after 12 confirmations.

If you want to show updates on UI in your DApp, use latest events. It will help to make UI/UX better and user friendly.

Use confirmed events for irreversible tasks from server or on UI. Like sending email, notifications or allow user to do subsequent task on UI after one transaction gets confirmed.

Every event has to start with room:

// latest block number
dagger.on("latest:block.number", function(result) {
  console.log("Current block number: ", result.data);
});

// confirmed (irreversible) incoming transaction
dagger.on("confirmed:addr/0xa7447.../tx/in", function(result) {
  // send email to user about new transaction she received
});

// confirmed (irreversible) contract deployment
dagger.on("confirmed:tx/0xd66169d..../receipt", function(result) {
  // send notification to user saying - her contract has been deployed successfully
});

You can use wildcard for events too. There are two type of wildcards: + (for single) and # (for multiple). Use with caution as it will fetch more data then you need, and can bombard with data to your DApp.

// Listen for every outgoing transaction for any address
dagger.on('latest:addr/+/tx/out', ...)

// Triggers when 1 GNT (Golem token) get transferred to Golem multisig wallet
dagger.on('latest:log/0xa74476443119a942de498590fe1f2454d7d4ac0d/filter/0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef/+/0x7da82c7ab4771ff031b66538d2fb9b0b047f6cf9/#', ...)

// Triggers when any amount of GNT (Golem token) get sent from Golem multisig wallet
dagger.on('latest:log/0xa74476443119a942de498590fe1f2454d7d4ac0d/filter/0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef/0x7da82c7ab4771ff031b66538d2fb9b0b047f6cf9/#', ...)

// Listen for every Golem token transfer (notice `#` at the end)
dagger.on('latest:log/0xa74476443119a942de498590fe1f2454d7d4ac0d/filter/0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef/#', ...)

| Ethereum event | When? | removed flag | | ---------------------------------------------- | ----------------------------------------------------------------------- | -------------- | | block.number | For every new block number created | | | block.hash | For every new block hash created | Yes | | block | For every new block created | Yes | | block/number | When particular block in future included in chain | Yes | | addr/address/tx | On every new transaction for address | Yes | | addr/address/tx/out | On every new outgoing transaction for address | Yes | | addr/address/tx/in | On every new incoming transaction for address | Yes | | tx/txId | When given txId included in block | Yes | | tx/txId/success | When tx status is success (included in block) for txId | Yes | | tx/txId/fail | When tx fails (included in block) for txId | Yes | | tx/txId/receipt | When receipt is generated (included in block) for txId | Yes | | addr/contractAddress/deployed | When new contractAddress included in block | Yes | | log/contractAddress | When new log generated for contractAddress | Yes | | log/contractAddress/filter/topic0/topic1 | When new log with topic0 and topic1 generated for contractAddress | Yes |

Dagger events

| Dagger event | When? | args | | ----------------- | ------------------------------ | -------------- | | connection.status | When connection status changes | value: Boolean |

Event names are case-sensitive. address, txId and topics must be in lowercase.

API

• Dagger.connect()
• dagger.on()
• dagger.once()
• dagger.off()
• dagger.of()
• dagger.end()
• dagger.contract()

Dagger.connect(url, options)

Connects to the dagger specified by the given url and options. It returns a Dagger object.

dagger.on(event, fn)

Subscribe to a topic

• event is a String topic to subscribe to. event wildcard characters are supported (+ - for single level and # - for multi level)
• fn - function (data, removed) fn will be executed when event occurred:
  • data data from event
  • removed flag saying if data is removed from blockchain due to re-organization.

dagger.once(event, fn)

Same as on but will be fired only once.

dagger.off(event, fn)

Unsubscribe from a topic

• event is a String topic to unsubscribe from
• fn - function (data, removed)

dagger.of(room)

Create room out of dagger. room has to be one out of two values: latest and confirmed

• room object has following methods:
  • on same as dagger on
  • once same as dagger once
  • off same as dagger off

dagger.end([force])

Close the dagger, accepts the following options:

• force: passing it to true will close the dagger right away. This parameter is optional.

dagger.contract(web3Contract)

Creates web3 contract wrapper to support dagger.

• web3Contract: contract object web3. Example: new web3.eth.Contract(abi, address)

  // web3 contract
  var web3Contract = new web3.eth.Contract(abi, address);
  
  // dagger contract
  var contract = dagger.contract(web3Contract);
  var filter = contract.events.Transfer({
    filter: { from: "0x123456..." },
    room: "latest"
  });
  // watch
  filter.watch(function(data, removed) {
    // data.returnValues.to : address to which it has been transferred to
    // data.returnValues.value : value which has been transferred
  });
  // watch only once
  filter.watchOnce(function(data, removed) {
    // data.returnValues.to : address to which it has been transferred to
    // data.returnValues.value : value which has been transferred
  });
  // stop watching
  filter.stopWatching();

Examples

To listen ERC20 transfer event

Use following topic to listen ERC20 transfer event. Use + instead of or or if you want to listen for any value.

For latest events:

latest:log/<contract-address>/filter/0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef/<from-address>/<to-address>

For confirmed events:

confirmed:log/<contract-address>/filter/0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef/<from-address>/<to-address>

Support

If you have any queries, feedback or feature requests, feel free to reach out to us on telegram: https://t.me/maticnetwork

License

MIT