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import { Web3Wrapper } from '@0xproject/web3-wrapper';
import * as _ from 'lodash';
import { artifacts } from '../artifacts';
import { Token, TokenMetadata } from '../types';
import { assert } from '../utils/assert';
import { constants } from '../utils/constants';
import { ContractWrapper } from './contract_wrapper';
import { TokenRegistryContract } from './generated/token_registry';
/**
* This class includes all the functionality related to interacting with the 0x Token Registry smart contract.
*/
export class TokenRegistryWrapper extends ContractWrapper {
private _tokenRegistryContractIfExists?: TokenRegistryContract;
private _contractAddressIfExists?: string;
private static _createTokenFromMetadata(metadata: TokenMetadata): Token | undefined {
if (metadata[0] === constants.NULL_ADDRESS) {
return undefined;
}
const token = {
address: metadata[0],
name: metadata[1],
symbol: metadata[2],
decimals: metadata[3].toNumber(),
};
return token;
}
constructor(web3Wrapper: Web3Wrapper, networkId: number, contractAddressIfExists?: string) {
super(web3Wrapper, networkId);
this._contractAddressIfExists = contractAddressIfExists;
}
/**
* Retrieves all the tokens currently listed in the Token Registry smart contract
* @return An array of objects that conform to the Token interface.
*/
public async getTokensAsync(): Promise<Token[]> {
const addresses = await this.getTokenAddressesAsync();
const tokenPromises: Array<Promise<Token | undefined>> = _.map(addresses, async (address: string) =>
this.getTokenIfExistsAsync(address),
);
const tokens = await Promise.all(tokenPromises);
return tokens as Token[];
}
/**
* Retrieves all the addresses of the tokens currently listed in the Token Registry smart contract
* @return An array of token addresses.
*/
public async getTokenAddressesAsync(): Promise<string[]> {
const tokenRegistryContract = await this._getTokenRegistryContractAsync();
const addresses = await tokenRegistryContract.getTokenAddresses.callAsync();
return addresses;
}
/**
* Retrieves a token by address currently listed in the Token Registry smart contract
* @return An object that conforms to the Token interface or undefined if token not found.
*/
public async getTokenIfExistsAsync(address: string): Promise<Token | undefined> {
assert.isETHAddressHex('address', address);
const tokenRegistryContract = await this._getTokenRegistryContractAsync();
const metadata = await tokenRegistryContract.getTokenMetaData.callAsync(address);
const token = TokenRegistryWrapper._createTokenFromMetadata(metadata);
return token;
}
public async getTokenAddressBySymbolIfExistsAsync(symbol: string): Promise<string | undefined> {
assert.isString('symbol', symbol);
const tokenRegistryContract = await this._getTokenRegistryContractAsync();
const addressIfExists = await tokenRegistryContract.getTokenAddressBySymbol.callAsync(symbol);
if (addressIfExists === constants.NULL_ADDRESS) {
return undefined;
}
return addressIfExists;
}
public async getTokenAddressByNameIfExistsAsync(name: string): Promise<string | undefined> {
assert.isString('name', name);
const tokenRegistryContract = await this._getTokenRegistryContractAsync();
const addressIfExists = await tokenRegistryContract.getTokenAddressByName.callAsync(name);
if (addressIfExists === constants.NULL_ADDRESS) {
return undefined;
}
return addressIfExists;
}
public async getTokenBySymbolIfExistsAsync(symbol: string): Promise<Token | undefined> {
assert.isString('symbol', symbol);
const tokenRegistryContract = await this._getTokenRegistryContractAsync();
const metadata = await tokenRegistryContract.getTokenBySymbol.callAsync(symbol);
const token = TokenRegistryWrapper._createTokenFromMetadata(metadata);
return token;
}
public async getTokenByNameIfExistsAsync(name: string): Promise<Token | undefined> {
assert.isString('name', name);
const tokenRegistryContract = await this._getTokenRegistryContractAsync();
const metadata = await tokenRegistryContract.getTokenByName.callAsync(name);
const token = TokenRegistryWrapper._createTokenFromMetadata(metadata);
return token;
}
/**
* Retrieves the Ethereum address of the TokenRegistry contract deployed on the network
* that the user-passed web3 provider is connected to.
* @returns The Ethereum address of the TokenRegistry contract being used.
*/
public getContractAddress(): string {
const contractAddress = this._getContractAddress(
artifacts.TokenRegistryArtifact,
this._contractAddressIfExists,
);
return contractAddress;
}
private _invalidateContractInstance(): void {
delete this._tokenRegistryContractIfExists;
}
private async _getTokenRegistryContractAsync(): Promise<TokenRegistryContract> {
if (!_.isUndefined(this._tokenRegistryContractIfExists)) {
return this._tokenRegistryContractIfExists;
}
const web3ContractInstance = await this._instantiateContractIfExistsAsync(
artifacts.TokenRegistryArtifact,
this._contractAddressIfExists,
);
const contractInstance = new TokenRegistryContract(
web3ContractInstance,
this._web3Wrapper.getContractDefaults(),
);
this._tokenRegistryContractIfExists = contractInstance;
return this._tokenRegistryContractIfExists;
}
}
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