lemo-core-sdk v0.12.1

LemoChain Core SDK

This is the LemoChain Core node SDK which implements the Generic JSON RPC.

You need to run a local LemoChain Core node with flag --rpc or connect to a remote LemoChain Core node to use this library.

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Installing

Using Yarn

yarn add lemo-core-sdk

As Browser module

• Include lemo-core-sdk.min.js in your html file.
• Use the LemoCore object directly from global namespace

Example

const LemoCore = require('lemo-core-sdk')
const lemo = new LemoCore({
    host: 'http://127.0.0.1:8001'
})

lemo.chain.getBlockByNumber(0).then(function(block) {
    console.log(block)
})

LemoChain Core API

Almost every API returns a promise object, except watchXXX, stopWatch and so on
All API available in the console of LemoChain core. But some APIs are not available over remote connection such as http, websocket

Protocol

Send and receive data by json format, use JSON-RPC2.0 standard.
For convenient, all numbers will be convert to string. So the numbers will never overflow.

POST request

{
    "jsonrpc": "2.0",
    "method": "chain_getBlockByHeight",
    "params": [1, false],
    "id": 1
}

• jsonrpc - (string) Always 2.0
• method - (string) API module name and method name connected by _
• params - (Array) API method parameters, object is available
• id - (number) Increasing request id

Success response

{
    "jsonrpc": "2.0",
    "result": {...},
    "id": 1
}

• jsonrpc - (string) Always 2.0
• result - (*) The result could be any type
• id - (number) The id in request

Error response

{
    "jsonrpc": "2.0",
    "error": {"code": -32601, "message": "Method not found"},
    "id": 1
}

• jsonrpc - (string) Always 2.0
• error - (object) The error detail. It contains a negtive number code and a string message.
• id - (number) The id in request

Data structure

block

{
    "header": {},
    "transactions": [],
    "changeLogs": [],
    "confirms": [],
    "events": [],
    "deputyNodes": []
}

• header The header of block
• transactions All Transactions in block
• changeLogs The account data changeLogs by transactions in block
• confirms The signatures from deputies after they verified the block
• events The contract events from transactions in block
• deputyNodes New deputy nodes information If the block is snapshot block, or else it is empty

header

The header of block

{
    "hash": "0x11d9153b14adb92a14c16b66c3524d62b4742c0e7d375025525e2f131de37a8b",
    "height": "0",
    "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "miner": "Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG",
    "signData": "0x",
    "timestamp": "1535630400",
    "gasLimit": "105000000",
    "gasUsed": "0",
    "eventBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
    "changeLogRoot": "0x93273cebb4f0728991811d5d7c57ae8f88a83524eedb0af48b3061ed2e8017b8",
    "deputyRoot": "0x49b613bbdf76be3fe761fd60d1ade6d2835315047c53d6e8199737898b8d9b47",
    "eventRoot": "0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470",
    "transactionRoot": "0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470",
    "versionRoot": "0x1e78c4779248d3d8d3cd9b77bf7b67b4c759ec87d45d52a3e79c928290773f4c",
    "extraData": ""
}

• hash Block hash
• height Block height
• parentHash Previous block hash
• miner Address of the account who produce this block
• signData Miner's signatue of the block hash
• timestamp The time of block creation in seconds
• gasLimit Max gas limit for all transactions in block
• gasUsed Used gas of all transactions in block
• eventBloom The bloom filter for speed up contract events query. Calculated by events in block
• changeLogRoot The root hash of block's changeLogs Merkle Trie
• deputyRoot The root hash of block's deputyNodes Merkle Trie
• eventRoot The root hash of block's events Merkle Trie
• transactionRoot The root hash of block's transactions Merkle Trie
• versionRoot The root hash of global versions Merkle Patricia Trie. This trie is storing all accounts' newest version
• extraData (optional) The custom data from miner

transaction

Signed transaction

{
    "type": "1",
    "chainID": "1",
    "version": "1",
    "from": "Lemo836BQKCBZ8Z7B7N4G4N4SNGBT24ZZSJQD24D",
    "to": "Lemo83JW7TBPA7P2P6AR9ZC2WCQJYRNHZ4NJD4CY",
    "gasPayer": "",
    "toName": "",
    "amount": "100",
    "data": "0x",
    "expirationTime": 1541566996,
    "gasLimit": 2000000,
    "gasPrice": "3000000000",
    "hash": "0x6d3062a9f5d4400b2002b436bc69485449891c83e23bf9e27229234da5b25dcf",
    "message": "",
    "sigs": ["0xd9a9f9f41ea020185a6480fe6938d776f0a675d89057c071fc890e09742a4dd96edb9d48c9978c2f12fbde0d0445f2ff5f08a448b91469511c663567d0b015f601"],
    "gasPayerSigs": ["0x800be6a0cf31ab9e86d547fb8cf964339276233a2b260ad8a4b4c93b39a48d6b1761e125f601bc6953e30eaad3e698c12add332a5740f1618915c12432dc610601"]
}

• type The type of transaction
• chainID The LemoChain ID
• version Current transaction version, Between 0 and 128
• from Sender address.
• to Recipient address
• gasPayer Account address of gas reimbursement agent
• toName (optional) Recipient name. It will be checked with to for safe. The max limit of length is 100.
• amount Amount in mo. It is a BigNumber object. 1LEMO=1000000000000000000mo=1e18mo
• data (optional) The extra data. It usually using for calling smart contract. It depends on type that how to using this field
• expirationTime The expiration time of transaction in seconds. If a transaction's expiration time is more than half hour from now, it may not be packaged in block. It depends on the transactions picking logic from miner
• gasLimit Max gas limit of transaction. The transaction will be fail if it cost more gas than gasLimit. And the gas will not be refunded
• gasPrice Price of every gas in mo. It is a BigNumber object. The more gas price the more priority
• hash Transaction hash
• message (optional) Extra text message from sender. The max limit of length is 1024.
• sigs Transaction signature array, each field length is 65 bytes
• gasPayerSigs An array of paid gas transaction signature data, each field length is 65 bytes

changeLog

The modification record of data on chain

{
    "address": "Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG",
    "extra": "",
    "newValue": "0x8c052b7d2dcc80cd2e40000000",
    "type": "BalanceLog",
    "version": 1
}

• address The address of account which data is changed
• version The version of account data. Every type data has its own version
• Depends on different type, the newValue and extra have different functions

confirm

The signature of block hash from a deputy node after him verified the block

0x1234

event

Smart contract event

{
    "address": "Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG"
}

deputyNode

Deputy node information

{
    "minerAddress": "Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG",
    "nodeID": "0x5e3600755f9b512a65603b38e30885c98cbac70259c3235c9b3f42ee563b480edea351ba0ff5748a638fe0aeff5d845bf37a3b437831871b48fd32f33cd9a3c0",
    "host": "127.0.0.1",
    "port": "7001",
    "votes": "50000"
}

• minerAddress The account address to receive mining benefit
• nodeID The LemoChain node ID, it is from the public key whose private key is using for sign blocks. The length should be 130 characters with 0x
• host Deputy node IP address or domain. The max limit of length is 128.
• port The port to connect other nodes
• votes The votes count

account

Account information

{
    "address": "Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG",
    "assetCodeRoot": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "assetIdRoot": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "balance": "1599999999999999999999999900",
    "records": {
        "BalanceLog": {
            "version": 3,
            "height": 1
        }
    },
    "codeHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "equityRoot": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "root": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "txCount": 0,
    "voteFor": "Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG",
    "candidate": {
        "votes": "1599999000",
        "profile": {
            "host": "www.lemochain.com",
            "isCandidate": "true",
            "minerAddress": "Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG",
            "nodeID": "0x5e3600755f9b512a65603b38e30885c98cbac70259c3235c9b3f42ee563b480edea351ba0ff5748a638fe0aeff5d845bf37a3b437831871b48fd32f33cd9a3c0",
            "port": "7001"
        }
    },
    "signers": [{"address": "Lemo83JW7TBPA7P2P6AR9ZC2WCQJYRNHZ4NJD4CY","weight": "60"}, {"address": "Lemo842BJZ4DKCC764C63Y6A943775JH6NQ3Z33Y", "weight":  "50"}]
}

• address Account address
• assetCodeRoot The hash of created assets MPT root
• assetIdRoot The hash of issued assets MPT root
• balance Account balance. It is a modified BigNumber object. It has a method toMoney() to output formatted balance
• records Modification record object of account. The key is type of ChangeLog, value is the newest ChangeLog's version and height of the block which contains this newest ChangeLog
• codeHash Hash of contract code
• equityRoot The hash of asset equities MPT root
• root The hash of contract storage MPT root
• txCount Transactions count from or to this account
• voteFor Vote target address of this account
• candidate If this account is a consensus candidate, then this property exist
  • votes Received votes count for a candidate account
  • profile Candidate account profile
    • host IP or domain of the candidate node server
    • isCandidate This account is or isn't a candidate. It is used to cancel candidate
    • minerAddress The address of miner account who receive miner benefit
    • nodeID The LemoChain node ID, it is from the public key whose private key is using for sign blocks. The length should be 130 characters with 0x
    • port Port of the candidate node server
• signers The signers for a multi-sign account. It is necessary to collect over 100 weight to sign a transaction
  • address The signer's account address
  • weight Weight for the signer

Constructor

lemo = new LemoCore({
    chainID: 1, 
    host: 'http://127.0.0.1:8001'
})

• chainID The ID of LemoChain. Default value is 1, it represents main net
• host LemoChain node's HTTP listening address. The default value is http://127.0.0.1:8001

  NOTE: If the cross domain issue appear. Try to use flag --rpccorsdomain http://[domain of the web page]:[port] to restart LemoChain node.

chain API

lemo.getBlock

lemo.getBlock(heightOrHash [, withBody])

Get block by height or block hash

Parameters

1. number|string - Block height or block hash. If it is block height, only stable blocks will be retrived which confirmed by most deputy nodes
2. boolean - (optional) Enable to get block body such as transactions. Default value is false

Returns

Promise - Call then method to get block object

Example

lemo.getBlock(0).then(function(block) {
    console.log(block.header.hash) // "0x11d9153b14adb92a14c16b66c3524d62b4742c0e7d375025525e2f131de37a8b"
})

lemo.getNewestBlock

lemo.getNewestBlock([withBody])

Get the newest block

Parameters

1. boolean - (optional) Enable to get block body such as transactions. Default value is false

Returns

Promise - Call then method to get block object

Example

lemo.getNewestBlock(true).then(function(block) {
    console.log(block.header.miner) // "Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG"
})

lemo.getNewestUnstableBlock

lemo.getNewestUnstableBlock()

Get the newest unstable block which may not has enough confirms by deputy nodes

Parameters

None

Returns

Promise - Call then method to get block object with body

Example

lemo.getNewestUnstableBlock().then(function(block) {
    console.log(block.header.miner) // "Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG"
})

lemo.getNewestHeight

lemo.getNewestHeight()

Get the newest block height

Parameters

None

Returns

Promise - Call then method to get height string

Example

lemo.getNewestHeight().then(function(height) {
    console.log(height) // "100"
})

lemo.getNewestUnstableHeight

lemo.getNewestUnstableHeight()

Get the newest unstable block height

Parameters

None

Returns

Promise - Call then method to get height string

Example

lemo.getNewestUnstableHeight().then(function(height) {
    console.log(height) // "100"
})

lemo.getGenesis

lemo.getGenesis()

Get the first block

Parameters

None

Returns

Promise - Call then method to get block object

Example

lemo.getGenesis().then(function(block) {
    console.log(block.header.parentHash) // "0x0000000000000000000000000000000000000000000000000000000000000000"
})

lemo.getChainID

lemo.getChainID()

Get the chain ID from current connected LemoChain node

Parameters

None

Returns

Promise - Call then method to get chainID string

Example

lemo.getChainID().then(function(chainID) {
    console.log(chainID) // "1"
})

lemo.getCandidateTop30

lemo.getCandidateTop30()

Get top 30 candidates information

Parameters

None

Returns

Promise - Call then method to get a candidate information list. The item in list is very similar with candidate in account. There is an account address field in every candidate item

Example

lemo.getCandidateTop30().then(function(candidateList) {
    console.log(candidateList.length) // 1
    console.log(candidateList[0].address) // Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG
    console.log(JSON.stringify(candidateList)) // [{"address":"Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG","profile":{"host":"127.0.0.1","isCandidate":true,"minerAddress":"Lemobw","nodeID":"0x5e3600755f9b512a65603b38e30885c98cbac70259c3235c9b3f42ee563b480edea351ba0ff5748a638fe0aeff5d845bf37a3b437831871b48fd32f33cd9a3c0","port":7001},"votes":"1599999000"}]
})

lemo.getDeputyNodeList

lemo.getDeputyNodeList(onlyBlockSigner)

Get information of current deputy nodes

Parameters

1. boolean - (Optional) If true it returns deputy node information of who can currently sign blocks, false returns who has become deputy node from candidate in current stable state.

Returns

Promise - Call then method to get the information list of current deputy nodes
minerAddress - (string)The address of miner account who receive miner benefit incomeAddress - (string)Nodal incomeAddress nodeID - (string)The LemoChain node ID, it is from the public key whose private key is using for sign blocks. The length should be 130 characters with 0x rank - (string)The rank of the outgoing node votes - (string)Node votes host - (string)Domain or IP of the candidate node server port - (string)Port of the candidate node server depositAmount - (string)deposit amount introduction - (string)Introduction of node p2pUri - (string)Connection uri of a LemoChain node. The address can be used to connect LemoChain node.

Example

lemo.getDeputyNodeList(true).then(function(nodeList) {
    console.log(nodeList.length) // 1
    console.log(JSON.stringify(nodeList[0]))
// "{"minerAddress":"Lemo83DZ5J99JSK5ZH89TCW7T6ZZCWJ8H7FDGA7W","incomeAddress":"Lemo83DZ5J99JSK5ZH89TCW7T6ZZCWJ8H7FDGA7W","nodeID":"0x0e7dcd418dbe7717eb0e83162f8810a3c7725e0d386b324dc5f3ef5a27a2a83e393a193f6ab53d3a51b490adeee362357676f50eed3d188824ef1fb3af02b2d0","rank":0,"votes":"50000","host":"127.0.0.1","port":8080,"depositAmount":"5000000000000000000000000","introduction":"ddf","p2pUri":"0e7dcd418dbe7717eb0e83162f8810a3c7725e0d386b324dc5f3ef5a27a2a83e393a193f6ab53d3a51b490adeee362357676f50eed3d188824ef1fb3af02b2d0@127.0.0.1:8080"}"
    lemo.net.connect(nodeList[0].p2pUri)
})

lemo.getTermReward

lemo.getTermReward(height)

Get miners' reward in current term

Parameters

1. number - the height of block which used to find the term reward block in same term

Returns

object - Term reward information，includes： term - (number)Term index, starting from 0 value - (string)The total amount of reward for all miners, The unit is mo rewardHeight - (number)The height of reward block

Example

lemo.getTermReward(1001).then(function(result){
console.log(JSON.stringify(result)) // {"term":0,"value":"1000000000","rewardHeight":10001}
})

lemo.getAllRewardValue

lemo.getAllRewardValue()

Get all miners' award information for the chain

Parameters

None

Returns

object - Miners' award information，includes： term - (number)Terms index, starting at 0 value - (string)The total amount of awards given times - (number)Updated times，times must be 1 or 2

Example

lemo.getAllRewardValue().then(function(result){
console.log(result) // { 0: { term: '1', value: '1000000001', times: '1' } }
})

lemo.getNodeVersion

lemo.getNodeVersion()

Get the version of LemoChain node

Parameters

None

Returns

Promise - Call then method to get version string

Example

lemo.getNodeVersion().then(function(version) {
    console.log(version) // "1.0.0"
})

lemo.watchBlock

lemo.watchBlock(withBody, callback)

Listen for new block. The callback function will be called at the beginning and every times a new stable block produced.

Parameters

1. boolean - Enable to get block body such as transactions. Default value is false
2. Function - Used to receive block object

Returns

number - subscribeId, it is used to stop watching

Example

lemo.watchBlock(true, function(block) {
    const d = new Date(1000 * parseInt(block.header.timestamp, 10))
    console.log(d.toUTCString()) // "Thu, 30 Aug 2018 12:00:00 GMT"
})

lemo.stopWatchBlock

lemo.stopWatchBlock(subscribeId)

Stop watching and filtering transactions of block

Parameters

1. number - The subscribeId from watchBlock

Returns

None

Example

const subscribeId = lemo.watchBlock(false, function(newBlock) {
    console.log(newBlock)
})
lemo.stopWatchBlock(subscribeId)

net API

lemo.net.connect

lemo.net.connect(nodeAddr)

Connect to a LemoChain node

Parameters

1. string - Node ID and IP address

Returns

Promise - No data input in then function

Example

lemo.net.connect('5e3600755f9b512a65603b38e30885c98cbac70259c3235c9b3f42ee563b480edea351ba0ff5748a638fe0aeff5d845bf37a3b437831871b48fd32f33cd9a3c0@127.0.0.1:60002')

lemo.net.disconnect

lemo.net.disconnect(nodeAddr)

Disconnect to a LemoChain node

Parameters

1. string - ip address

Returns

Promise - Call then method to get boolean

Example

lemo.net.disconnect('127.0.0.1:60002').then(function(success) {
    console.log(sucess ? 'success' : 'fail')
})

lemo.net.getConnections

lemo.net.getConnections()

Get the information of connections

Parameters

None

Returns

Promise - Call then method to get connection information list

Example

lemo.net.getConnections().then(function(connections) {
    console.log(connections)
    // [{
    //   localAddress: "127.0.0.1:50825",
    //   nodeID: "0xddb5fc36c415799e4c0cf7046ddde04aad6de8395d777db4f46ebdf258e55ee1d698fdd6f81a950f00b78bb0ea562e4f7de38cb0adf475c5026bb885ce74afb0",
    //   remoteAddress: "127.0.0.1:60002"
    // }]
})

lemo.net.getConnectionsCount

lemo.net.getConnectionsCount()

Get the count of connections

Parameters

None

Returns

Promise - Call then method to get connection count

Example

lemo.net.getConnectionsCount().then(function(count) {
    console.log(count) // "1"
})

lemo.net.getInfo

lemo.net.getInfo()

Get current node information

Parameters

None

Returns

Promise - Call then method to get node information

Example

lemo.net.getInfo().then(function(info) {
    console.log(info.nodeName) // "Lemo"
    console.log(info.nodeVersion) // "1.0.0"
    console.log(info.os) // "windows-amd64"
    console.log(info.port) // "60001"
    console.log(info.runtime) // "go1.10.1"
})

lemo.net.getNodeID

lemo.net.getNodeID()

Get the nodeID of the current node

Parameters

None

Returns

Promise - Call then method to get the nodeID of the current node

Example

lemo.net.getNodeID().then(function(info) {
    console.log(info) // "0x0e7dcd418dbe7717eb0e83162f8810a3c7725e0d386b324dc5f3ef5a27a2a83e393a193f6ab53d3a51b490adeee362357676f50eed3d188824ef1fb3af02b2d0"
})

lemo.net.broadcastConfirm

lemo.net.broadcastConfirm(hash)

broadcast confirms of a block

Parameters

1. string - block hash

Returns

None

Example

lemo.net.broadcastConfirm('0x6d3062a9f5d4400b2002b436bc69485449891c83e23bf9e27229234da5b25dcf')

lemo.net.fetchConfirm

lemo.net.fetchConfirm(height)

Pulls the confirms (signatures from miners) of the specified height block

Parameters

1. number - Block Height

Returns

None

Example

lemo.net.fetchConfirm(1001)

mine API

lemo.mine.start

lemo.mine.start()

Start mining

Parameters

None

Returns

Promise - No data input in then function

Example

lemo.mine.start()

lemo.mine.stop

lemo.mine.stop()

Stop mining

Parameters

None

Returns

Promise - No data input in then function

Example

lemo.mine.stop()

lemo.mine.getMining

lemo.mine.getMining()

True if current LemoChain node is mining

Parameters

None

Returns

Promise - Call then method to get boolean

Example

lemo.mine.getMining().then(function(isMining) {
    console.log(isMining ? 'mining' : 'not mining')
})

lemo.mine.getMiner

lemo.mine.getMiner()

Get the account address to receive mining benefit

Parameters

None

Returns

Promise - Call then method to get account address

Example

lemo.mine.getMiner().then(function(miner) {
    console.log(miner) // "Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG"
})

account API

lemo.account.newKeyPair

lemo.account.newKeyPair()

Create a private key and account address

Parameters

None

Returns

Promise - Call then method to get account key object

Example

const result = lemo.account.newKeyPair()
console.log(result.privateKey) // "0xfdbd9978910ce9e1ed276a75132aacb0a12e6c517d9bd0311a736c57a228ee52"
console.log(result.address) // "Lemo83BYKZJ4RN4TKC9C78RFW7YHW6S87TPRSH34"

lemo.account.getBalance

lemo.account.getBalance(address)

Get the balance of an account

Parameters

1. string - account address

Returns

Promise - Call then method to get balance BigNumber object

Example

lemo.account.getBalance('Lemo83BYKZJ4RN4TKC9C78RFW7YHW6S87TPRSH34').then(function(balance) {
    console.log(balance.toString(10)) // "1600000000000000000000000000"
})

lemo.account.getAccount

lemo.account.getAccount(address)

Get the information of an account

Parameters

1. string - account address

Returns

Promise - Call then method to get account information

Example

lemo.account.getAccount('Lemo83BYKZJ4RN4TKC9C78RFW7YHW6S87TPRSH34').then(function(account) {
    console.log(account.balance.toMoney()) // "1600000000 LEMO"
})

lemo.account.getCandidateInfo

lemo.account.getCandidateInfo(address)

Get the information of an candidate

Parameters

1. string - candidate account address

Returns

Promise - Call then method to get candidate information. It is same with candidate in account

Example

lemo.account.getCandidateInfo('Lemo83BYKZJ4RN4TKC9C78RFW7YHW6S87TPRSH34')
    .then(function(candidate) {
        console.log(candidate.votes); // "1599999000"
    })

lemo.account.getVoteFor

lemo.account.getVoteFor(address)

Get voting information from account

Parameters

1. string - lemo address

Returns

promise - return a vote target address

Example

lemo.account.getVoteFor('Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG')
    .then(function(info) {
        console.log(info); // "Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG"
    })

lemo.account.getEquity

lemo.account.getEquity(address, assetId)

Get the balance of asset from account

Parameters

1. string - The account address
2. string - asset id

Returns

Promise - Call then method to get the balance of asset from account, includes: assetCode - (string) asset code assetId - (string) asset id equity - (string) amount of asset

Example

lemo.account.getEquity('Lemo836BQKCBZ8Z7B7N4G4N4SNGBT24ZZSJQD24D', '0x34b04e018488f37f449193af2f24feb3b034c994cde95d30e3181403ac76528a')
    .then(function(info) {
        console.log(info.assetCode); // "0xd0befd3850c574b7f6ad6f7943fe19b212affb90162978adc2193a035ced8884"
    })

lemo.account.createTempAddress

lemo.account.createTempAddress(from, userId)

create a temp account

Parameters

1. string - account address
2. string - customized user id, which's length should be 10 bytes in hexadecimal at most

Returns

string - Temporary account address

Example

const userId = '1110000000000000000'
const result = lemo.account.createTempAddress('Lemo836BQKCBZ8Z7B7N4G4N4SNGBT24ZZSJQD24D', userId)
console.log(result) // Lemo85SY56SGRTQQ63A2Y43KYA8C7QAZB37P3KY5

lemo.account.isTempAddress

lemo.account.isTempAddress(address)

Test whether the specific address is a temporary account or not

Parameters

1. string - Account address

Returns

boolean - True if the current address is a temporary account

Example

const result = lemo.account.isTempAddress('Lemo85SY56SGRTQQ63A2Y43KYA8C7QAZB37P3KY5')
console.log(result) // true

lemo.account.isContractAddress

lemo.account.isContractAddress(address)

Test whether the specific address is a contract account or not

Parameters

1. string - Account address

Returns

boolean - True if the current address is a contract account

Example

const result = lemo.account.isContractAddress('Lemo836BQKCBZ8Z7B7N4G4N4SNGBT24ZZSJQD24D')
console.log(result) // false

tx API

lemo.tx.send

lemo.tx.send(txConfig, privateKey)

Send a transaction

Parameters

1. LemoTx|object|string - Signed or unsigned transaction information. Or a LemoTx object or json string.
2. string - (optional) Account private key, it will be used to sign if exist

Returns

Promise - Call then method to get transaction hash

Example

const txConfig = {from: 'Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG', to: 'Lemo83BYKZJ4RN4TKC9C78RFW7YHW6S87TPRSH34', amount: 100}
lemo.tx.send(txConfig, '0xc21b6b2fbf230f665b936194d14da67187732bf9d28768aef1a3cbb26608f8aa').then(function(txHash) {
    console.log(txHash) // 0x03fea27a8d140574dc648e1cb1a198f5ade450a347095cff7f3d961a11dac505
})

const tx = new LemoTx({chainID: 100, from: 'Lemo83GN72GYH2NZ8BA729Z9TCT7KQ5FC3CR6DJG', to: 'Lemo83BYKZJ4RN4TKC9C78RFW7YHW6S87TPRSH34', amount: 100})
tx.signWith('0xc21b6b2fbf230f665b936194d14da67187732bf9d28768aef1a3cbb26608f8aa')
lemo.tx.send(tx).then(function(txHash) {
    console.log(txHash) // 0x03fea27a8d140574dc648e1cb1a198f5ade450a347095cff7f3d961a11dac505
})

lemo.tx.waitConfirm

lemo.tx.waitConfirm(txHash)

wait for the transaction to be confirmed

Parameters

1. string - transaction hash

Returns

Promise - Call then method to get transaction hash

Example

lemo.tx.waitConfirm(0xe71cd6d98b1e48ddccf36ed655700478971a8514abf7c4d2173512201222c6c0).then(function(result) {
  console.log(JSON.stringify(result))
  // {"blockHash":"0x425f4ca99da879aa97bd6feaef0d491096ff3437934a139f423fecf06f9fd5ab","height":"100","time":"1541649535","tx":{"chainID":200,"version":"1","type":"0","to":"Lemo846Q4NQCKJ2YWY6GHTSQHC7K24JDC7CPCWYH","toName":"aa","gasPrice":"2","gasLimit":"100","amount":"1","data":"0x0c","expirationTime":"1544584596","message":"aaa","from":"Lemo836BQKCBZ8Z7B7N4G4N4SNGBT24ZZSJQD24D","sigs":["0x8c0499083cb3d27bead4f21994aeebf8e75fa11df6bfe01c71cad583fc9a3c70778a437607d072540719a866adb630001fabbfb6b032d1a8dfbffac7daed8f0201"]}}
})

lemo.tx.watchTx

lemo.tx.watchTx(filterTxConfig, callback)

Listen for transactions of block. Returns an array with transactions from block body, and the value of the subscribeId

Parameters

1. object - This is the condition used to filter the transactions, can enter multiple attributes
2. function - Used to receive transaction list

Returns

number - subscribeId, it is used to stop watching

Example

lemo.tx.watchTx({to:'Lemo83JW7TBPA7P2P6AR9ZC2WCQJYRNHZ4NJD4CY'}, function(transaction) {
    console.log(transaction[0].version)
}); //"1"

lemo.tx.watchTx({to:'Lemo83JW7TBPA7P2P6AR9ZC2WCQJYRNHZ4NJD4CY', from:'Lemo836BQKCBZ8Z7B7N4G4N4SNGBT24ZZSJQD24D'}, function(transactions) {
    console.log(transactions[0].version)
}); //"1"

lemo.tx.stopWatchTx

lemo.tx.stopWatchTx(subscribeId)

Stop watching and filtering transactions of block

Parameters

1. number - The subscribeId from watchTx

Returns

None

Example

const subscribeId = lemo.tx.watchTx({to:'Lemo83JW7TBPA7P2P6AR9ZC2WCQJYRNHZ4NJD4CY'}, function(transactions) {
    console.log(transactions[0].version)
}); 
lemo.tx.stopWatchTx(subscribeId)

lemo.stopWatch

lemo.stopWatch()

Stop all listening

Parameters

None

Returns

None

Example

lemo.stopWatch()

lemo.isWatching

lemo.isWatching()

True if is listening

Parameters

None

Returns

boolean - True if is listening

Example

console.log(lemo.isWatching() ? 'watching' : 'not watching')

Class Properties

LemoCore.SDK_VERSION

LemoCore.SDK_VERSION

string - The version of SDK

Example

console.log(LemoCore.SDK_VERSION) // "1.0.0"

LemoCore.TxType

LemoCore.TxType

Enum of transaction type, the value is number type

Example

console.log(LemoCore.TxType.VOTE) // 1

LemoCore.ChangeLogType

LemoCore.ChangeLogType

Enum of change log type, the value is number type

Example

console.log(LemoCore.ChangeLogType.BalanceLog) // 1

Developing

Requirements

• Node.js
• yarn

sudo apt-get update
sudo apt-get install nodejs
sudo apt-get install yarn

Building

yarn build

Testing

yarn test

Licensing

LGPL-3.0