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packages/0x.js/src/contract_wrappers/token_registry_wrapper.ts

@@ -0,0 +1,122 @@
+import * as _ from 'lodash';
+import {Web3Wrapper} from '../web3_wrapper';
+import {assert} from '../utils/assert';
+import {Token, TokenRegistryContract, TokenMetadata} from '../types';
+import {constants} from '../utils/constants';
+import {ContractWrapper} from './contract_wrapper';
+import {artifacts} from '../artifacts';
+
+/**
+ * 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;
+    constructor(web3Wrapper: Web3Wrapper, contractAddressIfExists?: string) {
+        super(web3Wrapper);
+        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 tokenRegistryContract = await this._getTokenRegistryContractAsync();
+
+        const addresses = await this.getTokenAddressesAsync();
+        const tokenPromises: Array<Promise<Token|undefined>> = _.map(
+            addresses,
+            (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 = this._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 = this._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 = this._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 async getContractAddressAsync(): Promise<string> {
+        const tokenRegistryInstance = await this._getTokenRegistryContractAsync();
+        const tokenRegistryAddress = tokenRegistryInstance.address;
+        return tokenRegistryAddress;
+    }
+    private _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;
+    }
+    private _invalidateContractInstance(): void {
+        delete this._tokenRegistryContractIfExists;
+    }
+    private async _getTokenRegistryContractAsync(): Promise<TokenRegistryContract> {
+        if (!_.isUndefined(this._tokenRegistryContractIfExists)) {
+            return this._tokenRegistryContractIfExists;
+        }
+        const contractInstance = await this._instantiateContractIfExistsAsync<TokenRegistryContract>(
+            artifacts.TokenRegistryArtifact, this._contractAddressIfExists,
+        );
+        this._tokenRegistryContractIfExists = contractInstance as TokenRegistryContract;
+        return this._tokenRegistryContractIfExists;
+    }
+}