For dApp developers we have a javascript sdk to help interact with the node's web API. Of course, you need to run an AELF node to use the sdk.
Get the full examples in the ./examples
directory
<!-- minified version with UMD module -->
<script src="https://unpkg.com/aelf-sdk@lastest/dist/aelf.umd.js"></script>
npm install aelf-sdk
yarn add aelf-sdk
In our dist directory, we supply two kinds of packages for different platforms, such as Node and Browser.
packages | usage |
---|---|
dist/aelf.cjs.js | built for node, remove node built-in modules such as crypto. |
dist/aelf.umd.js | built for browser, add some node built-in modules by webpack |
You can choose any packages based on your need, for examples:
if you are new to FrontEnd, you can use AElf-sdk
by add a script tag in your html files.
<!-- minified version with UMD module -->
<script src="https://unpkg.com/aelf-sdk@lastest/dist/aelf.umd.js"></script>
if you want to use a bundle system such as webpack or rollup, and build your applications for Node.js and Browsers, just import the specified version of package files.
Webpack:
module.exports = {
// ...
resolve: {
alias: {
'aelf-sdk$': 'aelf-sdk/dist/aelf.umd.js'
}
}
}
Rollup:
const alias = require('rollup-plugin-alias');
rollup({
// ...
plugins: [
alias({
'aelf-sdk': require.resolve('aelf-sdk/dist/aelf.umd.js')
})
]
})
Webpack:
module.exports = {
// ...
resolve: {
alias: {
'aelf-sdk$': 'aelf-sdk/dist/aelf.cjs.js'
}
}
}
Rollup:
const alias = require('rollup-plugin-alias');
rollup({
// ...
plugins: [
alias({
'aelf-sdk': require.resolve('aelf-sdk/dist/aelf.cjs.js')
})
]
})
You can also see full examples in ./examples
;
-
Create a new instance of AElf, connect to an AELF chain node.
import AElf from 'aelf-sdk'; // create a new instance of AElf const aelf = new AElf(new AElf.providers.HttpProvider('http://127.0.0.1:1235'));
-
Create or load a wallet with
AElf.wallet
// create a new wallet const newWallet = AElf.wallet.createNewWallet(); // load a wallet by private key const priviteKeyWallet = AElf.wallet.getWalletByPrivateKey('xxxxxxx'); // load a wallet by mnemonic const mnemonicWallet = AElf.wallet.getWalletByMnemonic('set kite ...');
-
Get a system contract address, take
AElf.ContractNames.Token
as an exampleconst tokenContractName = 'AElf.ContractNames.Token'; let tokenContractAddress; (async () => { // get chain status const chainStatus = await aelf.chain.getChainStatus(); // get genesis contract address const GenesisContractAddress = chainStatus.GenesisContractAddress; // get genesis contract instance const zeroContract = await aelf.chain.contractAt(GenesisContractAddress, newWallet); // Get contract address by the read only method `GetContractAddressByName` of genesis contract tokenContractAddress = await zeroContract.GetContractAddressByName.call(AElf.utils.sha256(tokenContractName)); })()
-
Get a contract instance by contract address
const wallet = AElf.wallet.createNewWallet(); let tokenContract; // Use token contract for examples to demonstrate how to get a contract instance in different ways // in async function (async () => { tokenContract = await aelf.chain.contractAt(tokenContractAddress, wallet) })(); // promise way aelf.chain.contractAt(tokenContractAddress, wallet) .then(result => { tokenContract = result; }); // callback way aelf.chain.contractAt(tokenContractAddress, wallet, (error, result) => {if (error) throw error; tokenContract = result;});
-
How to use contract instance
A contract instance consists of several contract methods and methods can be called in two ways: read-only and send transaction.
(async () => { // get the balance of an address, this would not send a transaction, // or store any data on the chain, or required any transaction fee, only get the balance // with `.call` method, `aelf-sdk` will only call read-only method const result = await tokenContract.GetBalance.call({ symbol: "ELF", owner: "7s4XoUHfPuqoZAwnTV7pHWZAaivMiL8aZrDSnY9brE1woa8vz" }); console.log(result); /** { "symbol": "ELF", "owner": "2661mQaaPnzLCoqXPeys3Vzf2wtGM1kSrqVBgNY4JUaGBxEsX8", "balance": "1000000000000" }*/ // with no `.call`, `aelf-sdk` will sign and send a transaction to the chain, and return a transaction id. // make sure you have enough transaction fee `ELF` in your wallet const transactionId = await tokenContract.Transfer({ symbol: "ELF", to: "7s4XoUHfPuqoZAwnTV7pHWZAaivMiL8aZrDSnY9brE1woa8vz", amount: "1000000000", memo: "transfer in demo" }); console.log(transactionId); /** { "TransactionId": "123123" } */ })()
-
Change the node endpoint by using
aelf.setProvider
import AElf from 'aelf-sdk'; const aelf = new AElf(new AElf.providers.HttpProvider('http://127.0.0.1:1235')); aelf.setProvider(new AElf.providers.HttpProvider('http://127.0.0.1:8000'));
You can see how the Web Api of the node works in {chainAddress}/swagger/index.html
tip: for an example, my local address: 'http://127.0.0.1:1235/swagger/index.html'
The usage of these methods is based on the AElf instance, so if you don't have one please create it:
import AElf from 'aelf-sdk';
// create a new instance of AElf, change the URL if needed
const aelf = new AElf(new AElf.providers.HttpProvider('http://127.0.0.1:1235'));
Get the current status of the block chain.
Web API path
/api/blockChain/chainStatus
Parameters
Empty
Returns
Object
ChainId - String
Branches - Object
NotLinkedBlocks - Object
LongestChainHeight - Number
LongestChainHash - String
GenesisBlockHash - String
GenesisContractAddress - String
LastIrreversibleBlockHash - String
LastIrreversibleBlockHeight - Number
BestChainHash - String
BestChainHeight - Number
Example
aelf.chain.getChainStatus()
.then(res => {
console.log(res);
})
Get the protobuf definitions related to a contract
Web API path
/api/blockChain/contractFileDescriptorSet
Parameters
contractAddress - String
address of a contract
Returns
String
Example
aelf.chain.getContractFileDescriptorSet(contractAddress)
.then(res => {
console.log(res);
})
Get current best height of the chain.
Web API path
/api/blockChain/blockHeight
Parameters
Empty
Returns
Number
Example
aelf.chain.getBlockHeight()
.then(res => {
console.log(res);
})
Get block information by block hash.
Web API path
/api/blockChain/block
Parameters
blockHash - String
includeTransactions - Boolean
:
true
require transaction ids list in the blockfalse
Doesn't require transaction ids list in the block
Returns
Object
BlockHash - String
Header - Object
PreviousBlockHash - String
MerkleTreeRootOfTransactions - String
MerkleTreeRootOfWorldState - String
Extra - Array
Height - Number
Time - google.protobuf.Timestamp
ChainId - String
Bloom - String
SignerPubkey - String
Body - Object
TransactionsCount - Number
Transactions - Array
transactionId - String
Example
aelf.chain.getBlock(blockHash, false)
.then(res => {
console.log(res);
})
Web API path
/api/blockChain/blockByHeight
Get block information by block height.
Parameters
blockHeight - Number
includeTransactions - Boolean
:
true
require transaction ids list in the blockfalse
Doesn't require transaction ids list in the block
Returns
Object
BlockHash - String
Header - Object
PreviousBlockHash - String
MerkleTreeRootOfTransactions - String
MerkleTreeRootOfWorldState - String
Extra - Array
Height - Number
Time - google.protobuf.Timestamp
ChainId - String
Bloom - String
SignerPubkey - String
Body - Object
TransactionsCount - Number
Transactions - Array
transactionId - String
Example
aelf.chain.getBlockByHeight(12, false)
.then(res => {
console.log(res);
})
Get the result of a transaction
Web API path
/api/blockChain/transactionResult
Parameters
transactionId - String
Returns
Object
TransactionId - String
Status - String
Logs - Array
Address - String
Name - String
Indexed - Array
NonIndexed - String
Bloom - String
BlockNumber - Number
Transaction - Object
From - String
To - String
RefBlockNumber - Number
RefBlockPrefix - String
MethodName - String
Params - Object
Signature - String
ReadableReturnValue - Object
Error - String
Example
aelf.chain.getTxResult(transactionId)
.then(res => {
console.log(res);
})
Get multiple transaction results in a block
Web API path
/api/blockChain/transactionResults
Parameters
blockHash - String
offset - Number
limit - Number
Returns
Array
- The array of method descriptions:
- the transaction result object
Example
aelf.chain.getTxResults(blockHash, 0, 2)
.then(res => {
console.log(res);
})
Get the transaction pool status.
Web API path
/api/blockChain/transactionPoolStatus
Parameters
Empty
Broadcast a transaction
Web API path
/api/blockChain/sendTransaction
POST
Parameters
Object
- Serialization of data into protobuf data, The object with the following structure :
RawTransaction - String
:
usually developers don't need to use this function directly, just get a contract method and send transaction by call contract method:
Broadcast multiple transactions
POST
Parameters
Object
- The object with the following structure :
RawTransaction - String
Call a read-only method on a contract.
POST
Parameters
Object
- The object with the following structure :
RawTransaction - String
Get peer info about the connected network nodes
Attempts to add a node to the connected network nodes
Attempts to remove a node from the connected network nodes
Get information about the node’s connection to the network
AElf.wallet
is a static property of AElf
.
Use the api to see detailed results
Returns
Object
mnemonic - String
: mnemonicBIP44Path - String
: m/purpose'/coin_type'/account'/change/address_indexchildWallet - Object
: HD WalletkeyPair - String
: The EC key pair generated by ellipticprivateKey - String
: private Keyaddress - String
: address
Example
import AElf from 'aelf-sdk';
const wallet = AElf.wallet.createNewWallet();
Parameters
mnemonic - String
: wallet's mnemonic
Returns
Object
: Complete wallet object.
Example
const wallet = AElf.wallet.getWalletByMnemonic(mnemonic);
Parameters
privateKey: String
: wallet's private key
Returns
Object
: Complete wallet object, with empty mnemonic
Example
const wallet = AElf.wallet.getWalletByPrivateKey(privateKey);
Use wallet keypair
to sign a transaction
Parameters
rawTxn - String
keyPair - String
Returns
Object
: The object with the following structure :
Example
const result = aelf.wallet.signTransaction(rawTxn, keyPair);
Encrypt a string by aes algorithm
Parameters
input - String
password - String
Returns
String
Decrypt by aes algorithm
Parameters
input - String
password - String
Returns
String
The reference to protobuf.js, read the documentation to see how to use.
Some basic format methods of aelf.
For more information, please see the code in src/utils/proto.js
. It is simple and easy to understand.
import AElf from 'aelf-sdk';
AElf.version // eg. 3.2.23
Read out contributing guide