fetch limit order

here, we provide a simple example to fetch limit orders of iZiSwap from an user’s address

by calling fetchLimitOrderOfAccount()

The full example code of this chapter can be spotted here.

1. some imports

before we use function of fetchLimitOrderOfAccount(), we should import some corresponding function and data structure

1import {BaseChain, ChainId, initialChainTable } from 'iziswap-sdk/lib/base/types'
2import {privateKey} from '../../.secret'
3import Web3 from 'web3';
4import { fetchToken } from 'iziswap-sdk/lib/base/token/token';
5import { fetchLimitOrderOfAccount, getLimitOrderManagerContract } from 'iziswap-sdk/lib/limitOrder/view';

the detail of these imports can be viewed in following content

2. specify which chain, rpc url, web3, and account

1const chain:BaseChain = initialChainTable[ChainId.BSC]
2const rpc = 'https://bsc-dataseed2.defibit.io/'
3console.log('rpc: ', rpc)
4const web3 = new Web3(new Web3.providers.HttpProvider(rpc))
5const account =  web3.eth.accounts.privateKeyToAccount(privateKey)
6console.log('address: ', account.address)


BaseChain is a data structure to describe a chain, in this example we use bsc chain.

ChainId is an enum to describe chain id, value of the enum is equal to value of chain id

initialChainTable is a mapping from some most used ChainId to BaseChain, of course you can fill fields of BaseChain by yourself

privateKey is a string, which is your private key, and should be configured by your self

web3 package is a public package to interact with block chain

rpc is the rpc url on the chain you specified

3. get web3.eth.Contract object of LimitOrderManager

1const limitOrderAddress = '0x9Bf8399c9f5b777cbA2052F83E213ff59e51612B'
2const limitOrderManager = getLimitOrderManagerContract(limitOrderAddress, web3)

here, getLimitOrderManagerContract is an api provided by our sdk, which returns a web3.eth.Contract object of LimitOrderManager

4. cache some erc20 tokens to speed up fetching(optional)

the function fetchLimitOrderOfAccount() has a parameter called tokenList: TokenInfoFormatted[], which is a cache of list of TokenInfoFormatted

each returned liquidity will contain fields tokenX and tokenY which are both TokenInfoFormatted type

if we fill tokenList with most erc20 tokens involved by these liquidities in advance, we may speed up calling of fetchLiquiditiesOfAccount() and fetchLiquiditiesByTokenIds()

ofcourse, you can skip this section and just transfer [] to the tokenList parameter in next section

here, we cache 2 erc20 tokens testA and testB in advance

1const testAAddress = '0xCFD8A067e1fa03474e79Be646c5f6b6A27847399'
2const testBAddress = '0xAD1F11FBB288Cd13819cCB9397E59FAAB4Cdc16F'
4const testA = await fetchToken(testAAddress, chain, web3)
5const testB = await fetchToken(testBAddress, chain, web3)

5. fetch!

1const {activeOrders, deactiveOrders} = await fetchLimitOrderOfAccount(
2    chain, web3, limitOrderManager, account.address, [testA]
5console.log('active orders len: ', activeOrders.length)
6console.log('deactive orders len: ', deactiveOrders.length)


chain is BaseChain obj specified in 2

web3 is Web3 obj specified in 2

liquidityManagerContract is constructed in 3

account.address is generated from private key in 2

[testA, testB] is parameter tokenList which is cache of list of possible erc20 token info needed, of course we can fill tokenList with []

return of fetchLimitOrderOfAccount() is list of LimitOrder object, each has following fields

 1export interface LimitOrder {
 2    // slot idx of the limit in use's limit order set
 3    idx: string,
 4    lastAccEarn: string,
 5    // original undecimal amount of token on sale when this limit order created
 6    // if sellXEarnY is true, the token is tokenX, otherwise tokenY
 7    amount: string,
 8    // undecimal amount of saled
 9    filled: string,
10    // undecimal amount of
11    sellingRemain: string,
12    // undecimal amount of token on sale currently
13    sellingDec: string,
14    accSellingDec: string,
15    // undecimal amount of claimed earning token
16    // if sellXEarnY is true, the token is tokenY, otherwise tokenX
17    earn: string,
18    // undecimal amount of unclaimed earning token
19    pending: string,
20    poolId: string,
21    // address of pool
22    poolAddress: string,
24    // if sellXEarnY is true, sell tokenX
25    tokenX: TokenInfoFormatted,
26    tokenY: TokenInfoFormatted,
27    createTime: Number,
28    // point of limit order
29    point: number,
30    // price of this order
31    priceXByY: BigNumber,
32    priceXByYDecimal: number,
33    // true for sellX, false for sellY
34    sellXEarnY: boolean,
35    // whether this limit order is active
36    active: boolean

after this step, we have successfully fetched all limit orders of the user.