Merge pull request #444 from 0xProject/dedupWeb3Wrapper

Remove custom web3Wrapper from website

21 files changed, 308 insertions, 278 deletions

diff --git a/packages/web3-wrapper/CHANGELOG.md b/packages/web3-wrapper/CHANGELOG.md
index ac0f5ff0b..6dabc7eb4 100644
--- a/packages/web3-wrapper/CHANGELOG.md
+++ b/packages/web3-wrapper/CHANGELOG.md
@@ -1,5 +1,9 @@
 # CHANGELOG
 
+## v0.2.1 _TBD_
+
+    * Add a `getProvider` method (#444)
+
 ## v0.2.0 _March 4, 2018_
 
     * Ensure all returned user addresses are lowercase (#373)
diff --git a/packages/web3-wrapper/src/index.ts b/packages/web3-wrapper/src/index.ts
index 64a19f531..e14eb2914 100644
--- a/packages/web3-wrapper/src/index.ts
+++ b/packages/web3-wrapper/src/index.ts
@@ -11,7 +11,7 @@ export class Web3Wrapper {
         if (_.isUndefined((provider as any).sendAsync)) {
             // Web3@1.0 provider doesn't support synchronous http requests,
             // so it only has an async `send` method, instead of a `send` and `sendAsync` in web3@0.x.x`
-            // We re-assign the send method so that Web3@1.0 providers work with 0x.js
+            // We re-assign the send method so that Web3@1.0 providers work with @0xproject/web3-wrapper
             (provider as any).sendAsync = (provider as any).send;
         }
         this._web3 = new Web3();
@@ -22,6 +22,9 @@ export class Web3Wrapper {
     public getContractDefaults(): Partial<TxData> {
         return this._defaults;
     }
+    public getProvider(): Web3.Provider {
+        return this._web3.currentProvider;
+    }
     public setProvider(provider: Web3.Provider) {
         this._web3.setProvider(provider);
     }
diff --git a/packages/website/package.json b/packages/website/package.json
index db3035642..a7fc1fe26 100644
--- a/packages/website/package.json
+++ b/packages/website/package.json
@@ -22,6 +22,7 @@
         "@0xproject/react-docs": "^0.0.1",
         "@0xproject/react-shared": "^0.0.1",
         "@0xproject/subproviders": "^0.7.0",
+        "@0xproject/web3-wrapper": "^0.2.1",
         "@0xproject/utils": "^0.4.1",
         "accounting": "^0.4.1",
         "basscss": "^8.0.3",
diff --git a/packages/website/ts/blockchain.ts b/packages/website/ts/blockchain.ts
index fca9504d7..14582eae9 100644
--- a/packages/website/ts/blockchain.ts
+++ b/packages/website/ts/blockchain.ts
@@ -24,9 +24,11 @@ import {
     RedundantRPCSubprovider,
 } from '@0xproject/subproviders';
 import { BigNumber, intervalUtils, promisify } from '@0xproject/utils';
+import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import * as _ from 'lodash';
 import * as React from 'react';
 import contract = require('truffle-contract');
+import { BlockchainWatcher } from 'ts/blockchain_watcher';
 import { TokenSendCompleted } from 'ts/components/flash_messages/token_send_completed';
 import { TransactionSubmitted } from 'ts/components/flash_messages/transaction_submitted';
 import { trackedTokenStorage } from 'ts/local_storage/tracked_token_storage';
@@ -47,7 +49,6 @@ import { configs } from 'ts/utils/configs';
 import { constants } from 'ts/utils/constants';
 import { errorReporter } from 'ts/utils/error_reporter';
 import { utils } from 'ts/utils/utils';
-import { Web3Wrapper } from 'ts/web3_wrapper';
 import Web3 = require('web3');
 import ProviderEngine = require('web3-provider-engine');
 import FilterSubprovider = require('web3-provider-engine/subproviders/filters');
@@ -63,8 +64,8 @@ export class Blockchain {
     private _zeroEx: ZeroEx;
     private _dispatcher: Dispatcher;
     private _web3Wrapper?: Web3Wrapper;
-    private _exchangeAddress: string;
-    private _userAddress: string;
+    private _blockchainWatcher?: BlockchainWatcher;
+    private _userAddressIfExists: string;
     private _cachedProvider: Web3.Provider;
     private _cachedProviderNetworkId: number;
     private _ledgerSubprovider: LedgerWalletSubprovider;
@@ -115,7 +116,6 @@ export class Blockchain {
     }
     constructor(dispatcher: Dispatcher, isSalePage: boolean = false) {
         this._dispatcher = dispatcher;
-        this._userAddress = '';
         const defaultGasPrice = GWEI_IN_WEI * 30;
         this._defaultGasPrice = new BigNumber(defaultGasPrice);
         // tslint:disable-next-line:no-floating-promises
@@ -137,8 +137,8 @@ export class Blockchain {
         }
     }
     public async userAddressUpdatedFireAndForgetAsync(newUserAddress: string) {
-        if (this._userAddress !== newUserAddress) {
-            this._userAddress = newUserAddress;
+        if (this._userAddressIfExists !== newUserAddress) {
+            this._userAddressIfExists = newUserAddress;
             await this.fetchTokenInformationAsync();
             await this._rehydrateStoreWithContractEvents();
         }
@@ -189,14 +189,14 @@ export class Blockchain {
 
         // Cache injected provider so that we can switch the user back to it easily
         if (_.isUndefined(this._cachedProvider)) {
-            this._cachedProvider = this._web3Wrapper.getProviderObj();
+            this._cachedProvider = this._web3Wrapper.getProvider();
             this._cachedProviderNetworkId = this.networkId;
         }
 
-        this._web3Wrapper.destroy();
+        this._blockchainWatcher.destroy();
 
-        this._userAddress = '';
-        this._dispatcher.updateUserAddress(''); // Clear old userAddress
+        delete this._userAddressIfExists;
+        this._dispatcher.updateUserAddress(undefined); // Clear old userAddress
 
         const provider = new ProviderEngine();
         const ledgerWalletConfigs = {
@@ -211,10 +211,15 @@ export class Blockchain {
         this.networkId = networkId;
         this._dispatcher.updateNetworkId(this.networkId);
         const shouldPollUserAddress = false;
-        this._web3Wrapper = new Web3Wrapper(this._dispatcher, provider, this.networkId, shouldPollUserAddress);
+        this._web3Wrapper = new Web3Wrapper(provider);
+        this._blockchainWatcher = new BlockchainWatcher(
+            this._dispatcher,
+            this._web3Wrapper,
+            this.networkId,
+            shouldPollUserAddress,
+        );
         this._zeroEx.setProvider(provider, this.networkId);
-        await this._postInstantiationOrUpdatingProviderZeroExAsync();
-        this._web3Wrapper.startEmittingNetworkConnectionAndUserBalanceState();
+        this._blockchainWatcher.startEmittingNetworkConnectionAndUserBalanceState();
         this._dispatcher.updateProviderType(ProviderType.Ledger);
     }
     public async updateProviderToInjectedAsync() {
@@ -224,21 +229,27 @@ export class Blockchain {
             return; // Going from injected to injected, so we noop
         }
 
-        this._web3Wrapper.destroy();
+        this._blockchainWatcher.destroy();
 
         const provider = this._cachedProvider;
         this.networkId = this._cachedProviderNetworkId;
 
         const shouldPollUserAddress = true;
-        this._web3Wrapper = new Web3Wrapper(this._dispatcher, provider, this.networkId, shouldPollUserAddress);
+        this._web3Wrapper = new Web3Wrapper(provider);
+        this._blockchainWatcher = new BlockchainWatcher(
+            this._dispatcher,
+            this._web3Wrapper,
+            this.networkId,
+            shouldPollUserAddress,
+        );
 
-        this._userAddress = await this._web3Wrapper.getFirstAccountIfExistsAsync();
+        const userAddresses = await this._web3Wrapper.getAvailableAddressesAsync();
+        this._userAddressIfExists = userAddresses[0];
 
         this._zeroEx.setProvider(provider, this.networkId);
-        await this._postInstantiationOrUpdatingProviderZeroExAsync();
 
         await this.fetchTokenInformationAsync();
-        this._web3Wrapper.startEmittingNetworkConnectionAndUserBalanceState();
+        this._blockchainWatcher.startEmittingNetworkConnectionAndUserBalanceState();
         this._dispatcher.updateProviderType(ProviderType.Injected);
         delete this._ledgerSubprovider;
         delete this._cachedProvider;
@@ -251,7 +262,7 @@ export class Blockchain {
         this._showFlashMessageIfLedger();
         const txHash = await this._zeroEx.token.setProxyAllowanceAsync(
             token.address,
-            this._userAddress,
+            this._userAddressIfExists,
             amountInBaseUnits,
             {
                 gasPrice: this._defaultGasPrice,
@@ -260,10 +271,13 @@ export class Blockchain {
         await this._showEtherScanLinkAndAwaitTransactionMinedAsync(txHash);
     }
     public async transferAsync(token: Token, toAddress: string, amountInBaseUnits: BigNumber): Promise<void> {
+        utils.assert(!_.isUndefined(this._zeroEx), 'ZeroEx must be instantiated.');
+        utils.assert(this._doesUserAddressExist(), BlockchainCallErrs.UserHasNoAssociatedAddresses);
+
         this._showFlashMessageIfLedger();
         const txHash = await this._zeroEx.token.transferAsync(
             token.address,
-            this._userAddress,
+            this._userAddressIfExists,
             toAddress,
             amountInBaseUnits,
             {
@@ -305,6 +319,7 @@ export class Blockchain {
         return zeroExSignedOrder;
     }
     public async fillOrderAsync(signedOrder: SignedOrder, fillTakerTokenAmount: BigNumber): Promise<BigNumber> {
+        utils.assert(!_.isUndefined(this._zeroEx), 'ZeroEx must be instantiated.');
         utils.assert(this._doesUserAddressExist(), BlockchainCallErrs.UserHasNoAssociatedAddresses);
 
         const shouldThrowOnInsufficientBalanceOrAllowance = true;
@@ -314,7 +329,7 @@ export class Blockchain {
             signedOrder,
             fillTakerTokenAmount,
             shouldThrowOnInsufficientBalanceOrAllowance,
-            this._userAddress,
+            this._userAddressIfExists,
             {
                 gasPrice: this._defaultGasPrice,
             },
@@ -347,7 +362,7 @@ export class Blockchain {
         return unavailableTakerAmount;
     }
     public getExchangeContractAddressIfExists() {
-        return this._exchangeAddress;
+        return this._zeroEx.exchange.getContractAddress();
     }
     public async validateFillOrderThrowIfInvalidAsync(
         signedOrder: SignedOrder,
@@ -373,12 +388,15 @@ export class Blockchain {
     public async pollTokenBalanceAsync(token: Token) {
         utils.assert(this._doesUserAddressExist(), BlockchainCallErrs.UserHasNoAssociatedAddresses);
 
-        const [currBalance] = await this.getTokenBalanceAndAllowanceAsync(this._userAddress, token.address);
+        const [currBalance] = await this.getTokenBalanceAndAllowanceAsync(this._userAddressIfExists, token.address);
 
         const newTokenBalancePromise = new Promise((resolve: (balance: BigNumber) => void, reject) => {
             const tokenPollInterval = intervalUtils.setAsyncExcludingInterval(
                 async () => {
-                    const [balance] = await this.getTokenBalanceAndAllowanceAsync(this._userAddress, token.address);
+                    const [balance] = await this.getTokenBalanceAndAllowanceAsync(
+                        this._userAddressIfExists,
+                        token.address,
+                    );
                     if (!balance.eq(currBalance)) {
                         intervalUtils.clearAsyncExcludingInterval(tokenPollInterval);
                         resolve(balance);
@@ -397,7 +415,7 @@ export class Blockchain {
     }
     public async signOrderHashAsync(orderHash: string): Promise<ECSignature> {
         utils.assert(!_.isUndefined(this._zeroEx), 'ZeroEx must be instantiated.');
-        const makerAddress = this._userAddress;
+        const makerAddress = this._userAddressIfExists;
         // If makerAddress is undefined, this means they have a web3 instance injected into their browser
         // but no account addresses associated with it.
         if (_.isUndefined(makerAddress)) {
@@ -427,22 +445,27 @@ export class Blockchain {
         const mintableContract = await this._instantiateContractIfExistsAsync(MintableArtifacts, token.address);
         this._showFlashMessageIfLedger();
         await mintableContract.mint(constants.MINT_AMOUNT, {
-            from: this._userAddress,
+            from: this._userAddressIfExists,
             gasPrice: this._defaultGasPrice,
         });
     }
-    public async getBalanceInEthAsync(owner: string): Promise<BigNumber> {
-        const balance = await this._web3Wrapper.getBalanceInEthAsync(owner);
-        return balance;
+    public async getBalanceInWeiAsync(owner: string): Promise<BigNumber> {
+        const balanceInWei = await this._web3Wrapper.getBalanceInWeiAsync(owner);
+        return balanceInWei;
     }
     public async convertEthToWrappedEthTokensAsync(etherTokenAddress: string, amount: BigNumber): Promise<void> {
         utils.assert(!_.isUndefined(this._zeroEx), 'ZeroEx must be instantiated.');
         utils.assert(this._doesUserAddressExist(), BlockchainCallErrs.UserHasNoAssociatedAddresses);
 
         this._showFlashMessageIfLedger();
-        const txHash = await this._zeroEx.etherToken.depositAsync(etherTokenAddress, amount, this._userAddress, {
-            gasPrice: this._defaultGasPrice,
-        });
+        const txHash = await this._zeroEx.etherToken.depositAsync(
+            etherTokenAddress,
+            amount,
+            this._userAddressIfExists,
+            {
+                gasPrice: this._defaultGasPrice,
+            },
+        );
         await this._showEtherScanLinkAndAwaitTransactionMinedAsync(txHash);
     }
     public async convertWrappedEthTokensToEthAsync(etherTokenAddress: string, amount: BigNumber): Promise<void> {
@@ -450,9 +473,14 @@ export class Blockchain {
         utils.assert(this._doesUserAddressExist(), BlockchainCallErrs.UserHasNoAssociatedAddresses);
 
         this._showFlashMessageIfLedger();
-        const txHash = await this._zeroEx.etherToken.withdrawAsync(etherTokenAddress, amount, this._userAddress, {
-            gasPrice: this._defaultGasPrice,
-        });
+        const txHash = await this._zeroEx.etherToken.withdrawAsync(
+            etherTokenAddress,
+            amount,
+            this._userAddressIfExists,
+            {
+                gasPrice: this._defaultGasPrice,
+            },
+        );
         await this._showEtherScanLinkAndAwaitTransactionMinedAsync(txHash);
     }
     public async doesContractExistAtAddressAsync(address: string) {
@@ -460,21 +488,29 @@ export class Blockchain {
         return doesContractExist;
     }
     public async getCurrentUserTokenBalanceAndAllowanceAsync(tokenAddress: string): Promise<BigNumber[]> {
-        const tokenBalanceAndAllowance = await this.getTokenBalanceAndAllowanceAsync(this._userAddress, tokenAddress);
+        utils.assert(this._doesUserAddressExist(), BlockchainCallErrs.UserHasNoAssociatedAddresses);
+
+        const tokenBalanceAndAllowance = await this.getTokenBalanceAndAllowanceAsync(
+            this._userAddressIfExists,
+            tokenAddress,
+        );
         return tokenBalanceAndAllowance;
     }
-    public async getTokenBalanceAndAllowanceAsync(ownerAddress: string, tokenAddress: string): Promise<BigNumber[]> {
+    public async getTokenBalanceAndAllowanceAsync(
+        ownerAddressIfExists: string,
+        tokenAddress: string,
+    ): Promise<BigNumber[]> {
         utils.assert(!_.isUndefined(this._zeroEx), 'ZeroEx must be instantiated.');
 
-        if (_.isEmpty(ownerAddress)) {
+        if (_.isUndefined(ownerAddressIfExists)) {
             const zero = new BigNumber(0);
             return [zero, zero];
         }
         let balance = new BigNumber(0);
         let allowance = new BigNumber(0);
         if (this._doesUserAddressExist()) {
-            balance = await this._zeroEx.token.getBalanceAsync(tokenAddress, ownerAddress);
-            allowance = await this._zeroEx.token.getProxyAllowanceAsync(tokenAddress, ownerAddress);
+            balance = await this._zeroEx.token.getBalanceAsync(tokenAddress, ownerAddressIfExists);
+            allowance = await this._zeroEx.token.getProxyAllowanceAsync(tokenAddress, ownerAddressIfExists);
         }
         return [balance, allowance];
     }
@@ -487,10 +523,10 @@ export class Blockchain {
     // by-passes the web3Wrapper logic for updating the prevUserAddress. We therefore need to
     // manually update it. This should only be called by the LedgerConfigDialog.
     public updateWeb3WrapperPrevUserAddress(newUserAddress: string) {
-        this._web3Wrapper.updatePrevUserAddress(newUserAddress);
+        this._blockchainWatcher.updatePrevUserAddress(newUserAddress);
     }
     public destroy() {
-        this._web3Wrapper.destroy();
+        this._blockchainWatcher.destroy();
         this._stopWatchingExchangeLogFillEvents();
     }
     public async fetchTokenInformationAsync() {
@@ -503,7 +539,9 @@ export class Blockchain {
 
         const tokenRegistryTokensByAddress = await this._getTokenRegistryTokensByAddressAsync();
 
-        const trackedTokensByAddress = trackedTokenStorage.getTrackedTokensByAddress(this._userAddress, this.networkId);
+        const trackedTokensByAddress = _.isUndefined(this._userAddressIfExists)
+            ? {}
+            : trackedTokenStorage.getTrackedTokensByAddress(this._userAddressIfExists, this.networkId);
         const tokenRegistryTokens = _.values(tokenRegistryTokensByAddress);
         if (_.isEmpty(trackedTokensByAddress)) {
             _.each(configs.DEFAULT_TRACKED_TOKEN_SYMBOLS, symbol => {
@@ -511,9 +549,11 @@ export class Blockchain {
                 token.isTracked = true;
                 trackedTokensByAddress[token.address] = token;
             });
-            _.each(trackedTokensByAddress, (token: Token, address: string) => {
-                trackedTokenStorage.addTrackedTokenToUser(this._userAddress, this.networkId, token);
-            });
+            if (!_.isUndefined(this._userAddressIfExists)) {
+                _.each(trackedTokensByAddress, (token: Token, address: string) => {
+                    trackedTokenStorage.addTrackedTokenToUser(this._userAddressIfExists, this.networkId, token);
+                });
+            }
         } else {
             // Properly set all tokenRegistry tokens `isTracked` to true if they are in the existing trackedTokens array
             _.each(trackedTokensByAddress, (trackedToken: Token, address: string) => {
@@ -539,7 +579,7 @@ export class Blockchain {
                 address: mostPopularTradingPairTokens[1].address,
             },
         };
-        this._dispatcher.batchDispatch(allTokensByAddress, this.networkId, this._userAddress, sideToAssetToken);
+        this._dispatcher.batchDispatch(allTokensByAddress, this.networkId, this._userAddressIfExists, sideToAssetToken);
 
         this._dispatcher.updateBlockchainIsLoaded(true);
     }
@@ -560,7 +600,7 @@ export class Blockchain {
         return receipt;
     }
     private _doesUserAddressExist(): boolean {
-        return this._userAddress !== '';
+        return !_.isUndefined(this._userAddressIfExists);
     }
     private async _rehydrateStoreWithContractEvents() {
         // Ensure we are only ever listening to one set of events
@@ -605,16 +645,18 @@ export class Blockchain {
                     this._updateLatestFillsBlockIfNeeded(decodedLog.blockNumber);
                     const fill = await this._convertDecodedLogToFillAsync(decodedLog);
                     if (decodedLogEvent.isRemoved) {
-                        tradeHistoryStorage.removeFillFromUser(this._userAddress, this.networkId, fill);
+                        tradeHistoryStorage.removeFillFromUser(this._userAddressIfExists, this.networkId, fill);
                     } else {
-                        tradeHistoryStorage.addFillToUser(this._userAddress, this.networkId, fill);
+                        tradeHistoryStorage.addFillToUser(this._userAddressIfExists, this.networkId, fill);
                     }
                 }
             },
         );
     }
     private async _fetchHistoricalExchangeLogFillEventsAsync(indexFilterValues: IndexedFilterValues) {
-        const fromBlock = tradeHistoryStorage.getFillsLatestBlock(this._userAddress, this.networkId);
+        utils.assert(this._doesUserAddressExist(), BlockchainCallErrs.UserHasNoAssociatedAddresses);
+
+        const fromBlock = tradeHistoryStorage.getFillsLatestBlock(this._userAddressIfExists, this.networkId);
         const blockRange: BlockRange = {
             fromBlock,
             toBlock: 'latest' as BlockParam,
@@ -630,7 +672,7 @@ export class Blockchain {
             }
             this._updateLatestFillsBlockIfNeeded(decodedLog.blockNumber);
             const fill = await this._convertDecodedLogToFillAsync(decodedLog);
-            tradeHistoryStorage.addFillToUser(this._userAddress, this.networkId, fill);
+            tradeHistoryStorage.addFillToUser(this._userAddressIfExists, this.networkId, fill);
         }
     }
     private async _convertDecodedLogToFillAsync(decodedLog: LogWithDecodedArgs<LogFillContractEventArgs>) {
@@ -654,10 +696,12 @@ export class Blockchain {
     }
     private _doesLogEventInvolveUser(decodedLog: LogWithDecodedArgs<LogFillContractEventArgs>) {
         const args = decodedLog.args;
-        const isUserMakerOrTaker = args.maker === this._userAddress || args.taker === this._userAddress;
+        const isUserMakerOrTaker = args.maker === this._userAddressIfExists || args.taker === this._userAddressIfExists;
         return isUserMakerOrTaker;
     }
     private _updateLatestFillsBlockIfNeeded(blockNumber: number) {
+        utils.assert(this._doesUserAddressExist(), BlockchainCallErrs.UserHasNoAssociatedAddresses);
+
         const isBlockPending = _.isNull(blockNumber);
         if (!isBlockPending) {
             // Hack: I've observed the behavior where a client won't register certain fill events
@@ -668,7 +712,7 @@ export class Blockchain {
             // TODO: Debug if this is a race condition, and apply a more precise fix
             const blockNumberToSet =
                 blockNumber - BLOCK_NUMBER_BACK_TRACK < 0 ? 0 : blockNumber - BLOCK_NUMBER_BACK_TRACK;
-            tradeHistoryStorage.setFillsLatestBlock(this._userAddress, this.networkId, blockNumberToSet);
+            tradeHistoryStorage.setFillsLatestBlock(this._userAddressIfExists, this.networkId, blockNumberToSet);
         }
     }
     private _stopWatchingExchangeLogFillEvents(): void {
@@ -739,20 +783,21 @@ export class Blockchain {
         this._zeroEx = new ZeroEx(provider, zeroExConfigs);
         this._updateProviderName(injectedWeb3);
         const shouldPollUserAddress = true;
-        this._web3Wrapper = new Web3Wrapper(this._dispatcher, provider, this.networkId, shouldPollUserAddress);
-        await this._postInstantiationOrUpdatingProviderZeroExAsync();
-        this._userAddress = await this._web3Wrapper.getFirstAccountIfExistsAsync();
-        this._dispatcher.updateUserAddress(this._userAddress);
+        this._web3Wrapper = new Web3Wrapper(provider);
+        this._blockchainWatcher = new BlockchainWatcher(
+            this._dispatcher,
+            this._web3Wrapper,
+            this.networkId,
+            shouldPollUserAddress,
+        );
+
+        const userAddresses = await this._web3Wrapper.getAvailableAddressesAsync();
+        this._userAddressIfExists = userAddresses[0];
+        this._dispatcher.updateUserAddress(this._userAddressIfExists);
         await this.fetchTokenInformationAsync();
-        this._web3Wrapper.startEmittingNetworkConnectionAndUserBalanceState();
+        this._blockchainWatcher.startEmittingNetworkConnectionAndUserBalanceState();
         await this._rehydrateStoreWithContractEvents();
     }
-    // This method should always be run after instantiating or updating the provider
-    // of the ZeroEx instance.
-    private async _postInstantiationOrUpdatingProviderZeroExAsync() {
-        utils.assert(!_.isUndefined(this._zeroEx), 'ZeroEx must be instantiated.');
-        this._exchangeAddress = this._zeroEx.exchange.getContractAddress();
-    }
     private _updateProviderName(injectedWeb3: Web3) {
         const doesInjectedWeb3Exist = !_.isUndefined(injectedWeb3);
         const providerName = doesInjectedWeb3Exist
@@ -762,7 +807,7 @@ export class Blockchain {
     }
     private async _instantiateContractIfExistsAsync(artifact: any, address?: string): Promise<ContractInstance> {
         const c = await contract(artifact);
-        const providerObj = this._web3Wrapper.getProviderObj();
+        const providerObj = this._web3Wrapper.getProvider();
         c.setProvider(providerObj);
 
         const artifactNetworkConfigs = artifact.networks[this.networkId];
diff --git a/packages/website/ts/blockchain_watcher.ts b/packages/website/ts/blockchain_watcher.ts
new file mode 100644
index 000000000..d3801cef4
--- /dev/null
+++ b/packages/website/ts/blockchain_watcher.ts
@@ -0,0 +1,107 @@
+import { BigNumber, intervalUtils, promisify } from '@0xproject/utils';
+import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import * as _ from 'lodash';
+import { Dispatcher } from 'ts/redux/dispatcher';
+import { utils } from 'ts/utils/utils';
+
+export class BlockchainWatcher {
+    private _dispatcher: Dispatcher;
+    private _web3Wrapper: Web3Wrapper;
+    private _prevNetworkId: number;
+    private _shouldPollUserAddress: boolean;
+    private _watchNetworkAndBalanceIntervalId: NodeJS.Timer;
+    private _prevUserEtherBalanceInWei: BigNumber;
+    private _prevUserAddressIfExists: string;
+    constructor(
+        dispatcher: Dispatcher,
+        web3Wrapper: Web3Wrapper,
+        networkIdIfExists: number,
+        shouldPollUserAddress: boolean,
+    ) {
+        this._dispatcher = dispatcher;
+        this._prevNetworkId = networkIdIfExists;
+        this._shouldPollUserAddress = shouldPollUserAddress;
+        this._web3Wrapper = web3Wrapper;
+    }
+    public destroy() {
+        this._stopEmittingNetworkConnectionAndUserBalanceStateAsync();
+        // HACK: stop() is only available on providerEngine instances
+        const provider = this._web3Wrapper.getProvider();
+        if (!_.isUndefined((provider as any).stop)) {
+            (provider as any).stop();
+        }
+    }
+    // This should only be called from the LedgerConfigDialog
+    public updatePrevUserAddress(userAddress: string) {
+        this._prevUserAddressIfExists = userAddress;
+    }
+    public startEmittingNetworkConnectionAndUserBalanceState() {
+        if (!_.isUndefined(this._watchNetworkAndBalanceIntervalId)) {
+            return; // we are already emitting the state
+        }
+
+        let prevNodeVersion: string;
+        this._prevUserEtherBalanceInWei = new BigNumber(0);
+        this._dispatcher.updateNetworkId(this._prevNetworkId);
+        this._watchNetworkAndBalanceIntervalId = intervalUtils.setAsyncExcludingInterval(
+            async () => {
+                // Check for network state changes
+                let currentNetworkId;
+                try {
+                    currentNetworkId = await this._web3Wrapper.getNetworkIdAsync();
+                } catch (err) {
+                    // Noop
+                }
+                if (currentNetworkId !== this._prevNetworkId) {
+                    this._prevNetworkId = currentNetworkId;
+                    this._dispatcher.updateNetworkId(currentNetworkId);
+                }
+
+                // Check for node version changes
+                const currentNodeVersion = await this._web3Wrapper.getNodeVersionAsync();
+                if (currentNodeVersion !== prevNodeVersion) {
+                    prevNodeVersion = currentNodeVersion;
+                    this._dispatcher.updateNodeVersion(currentNodeVersion);
+                }
+
+                if (this._shouldPollUserAddress) {
+                    const addresses = await this._web3Wrapper.getAvailableAddressesAsync();
+                    const userAddressIfExists = addresses[0];
+                    // Update makerAddress on network change
+                    if (this._prevUserAddressIfExists !== userAddressIfExists) {
+                        this._prevUserAddressIfExists = userAddressIfExists;
+                        this._dispatcher.updateUserAddress(userAddressIfExists);
+                    }
+
+                    // Check for user ether balance changes
+                    if (!_.isUndefined(userAddressIfExists)) {
+                        await this._updateUserWeiBalanceAsync(userAddressIfExists);
+                    }
+                } else {
+                    // This logic is primarily for the Ledger, since we don't regularly poll for the address
+                    // we simply update the balance for the last fetched address.
+                    if (!_.isUndefined(this._prevUserAddressIfExists)) {
+                        await this._updateUserWeiBalanceAsync(this._prevUserAddressIfExists);
+                    }
+                }
+            },
+            5000,
+            (err: Error) => {
+                utils.consoleLog(`Watching network and balances failed: ${err.stack}`);
+                this._stopEmittingNetworkConnectionAndUserBalanceStateAsync();
+            },
+        );
+    }
+    private async _updateUserWeiBalanceAsync(userAddress: string) {
+        const balanceInWei = await this._web3Wrapper.getBalanceInWeiAsync(userAddress);
+        if (!balanceInWei.eq(this._prevUserEtherBalanceInWei)) {
+            this._prevUserEtherBalanceInWei = balanceInWei;
+            this._dispatcher.updateUserWeiBalance(balanceInWei);
+        }
+    }
+    private _stopEmittingNetworkConnectionAndUserBalanceStateAsync() {
+        if (!_.isUndefined(this._watchNetworkAndBalanceIntervalId)) {
+            intervalUtils.clearAsyncExcludingInterval(this._watchNetworkAndBalanceIntervalId);
+        }
+    }
+}
diff --git a/packages/website/ts/components/dialogs/eth_weth_conversion_dialog.tsx b/packages/website/ts/components/dialogs/eth_weth_conversion_dialog.tsx
index 5c61f0d57..d1bdb447f 100644
--- a/packages/website/ts/components/dialogs/eth_weth_conversion_dialog.tsx
+++ b/packages/website/ts/components/dialogs/eth_weth_conversion_dialog.tsx
@@ -1,5 +1,7 @@
+import { ZeroEx } from '0x.js';
 import { colors } from '@0xproject/react-shared';
 import { BigNumber } from '@0xproject/utils';
+import * as _ from 'lodash';
 import Dialog from 'material-ui/Dialog';
 import FlatButton from 'material-ui/FlatButton';
 import * as React from 'react';
@@ -7,6 +9,7 @@ import { Blockchain } from 'ts/blockchain';
 import { EthAmountInput } from 'ts/components/inputs/eth_amount_input';
 import { TokenAmountInput } from 'ts/components/inputs/token_amount_input';
 import { Side, Token } from 'ts/types';
+import { constants } from 'ts/utils/constants';
 
 interface EthWethConversionDialogProps {
     blockchain: Blockchain;
@@ -17,7 +20,7 @@ interface EthWethConversionDialogProps {
     onCancelled: () => void;
     isOpen: boolean;
     token: Token;
-    etherBalance: BigNumber;
+    etherBalanceInWei: BigNumber;
     lastForceTokenStateRefetch: number;
 }
 
@@ -75,6 +78,7 @@ export class EthWethConversionDialog extends React.Component<
                 ? 'Convert your Ether into a tokenized, tradable form.'
                 : "Convert your Wrapped Ether back into it's native form.";
         const isWrappedVersion = this.props.direction === Side.Receive;
+        const etherBalanceInEth = ZeroEx.toUnitAmount(this.props.etherBalanceInWei, constants.DECIMAL_PLACES_ETH);
         return (
             <div>
                 <div className="pb2">{explanation}</div>
@@ -103,7 +107,7 @@ export class EthWethConversionDialog extends React.Component<
                             />
                         ) : (
                             <EthAmountInput
-                                balance={this.props.etherBalance}
+                                balance={etherBalanceInEth}
                                 amount={this.state.value}
                                 onChange={this._onValueChange.bind(this)}
                                 shouldCheckBalance={true}
@@ -182,8 +186,9 @@ export class EthWethConversionDialog extends React.Component<
         this.props.onCancelled();
     }
     private async _fetchEthTokenBalanceAsync() {
+        const userAddressIfExists = _.isEmpty(this.props.userAddress) ? undefined : this.props.userAddress;
         const [balance] = await this.props.blockchain.getTokenBalanceAndAllowanceAsync(
-            this.props.userAddress,
+            userAddressIfExists,
             this.props.token.address,
         );
         if (!this._isUnmounted) {
diff --git a/packages/website/ts/components/dialogs/ledger_config_dialog.tsx b/packages/website/ts/components/dialogs/ledger_config_dialog.tsx
index 8a242cd33..87b75ed95 100644
--- a/packages/website/ts/components/dialogs/ledger_config_dialog.tsx
+++ b/packages/website/ts/components/dialogs/ledger_config_dialog.tsx
@@ -1,3 +1,4 @@
+import { ZeroEx } from '0x.js';
 import { colors, constants as sharedConstants } from '@0xproject/react-shared';
 import { BigNumber } from '@0xproject/utils';
 import * as _ from 'lodash';
@@ -160,14 +161,15 @@ export class LedgerConfigDialog extends React.Component<LedgerConfigDialogProps,
     }
     private _renderAddressTableRows() {
         const rows = _.map(this.state.userAddresses, (userAddress: string, i: number) => {
-            const balance = this.state.addressBalances[i];
+            const balanceInWei = this.state.addressBalances[i];
             const addressTooltipId = `address-${userAddress}`;
             const balanceTooltipId = `balance-${userAddress}`;
             const networkName = sharedConstants.NETWORK_NAME_BY_ID[this.props.networkId];
             // We specifically prefix kovan ETH.
             // TODO: We should probably add prefixes for all networks
             const isKovanNetwork = networkName === 'Kovan';
-            const balanceString = `${balance.toString()} ${isKovanNetwork ? 'Kovan ' : ''}ETH`;
+            const balanceInEth = ZeroEx.toUnitAmount(balanceInWei, constants.DECIMAL_PLACES_ETH);
+            const balanceString = `${balanceInEth.toString()} ${isKovanNetwork ? 'Kovan ' : ''}ETH`;
             return (
                 <TableRow key={userAddress} style={{ height: 40 }}>
                     <TableRowColumn colSpan={2}>
@@ -204,7 +206,7 @@ export class LedgerConfigDialog extends React.Component<LedgerConfigDialogProps,
         this.props.blockchain.updateWeb3WrapperPrevUserAddress(selectedAddress);
         // tslint:disable-next-line:no-floating-promises
         this.props.blockchain.fetchTokenInformationAsync();
-        this.props.dispatcher.updateUserEtherBalance(selectAddressBalance);
+        this.props.dispatcher.updateUserWeiBalance(selectAddressBalance);
         this.setState({
             stepIndex: LedgerSteps.CONNECT,
         });
@@ -233,8 +235,8 @@ export class LedgerConfigDialog extends React.Component<LedgerConfigDialogProps,
         try {
             userAddresses = await this._getUserAddressesAsync();
             for (const address of userAddresses) {
-                const balance = await this.props.blockchain.getBalanceInEthAsync(address);
-                addressBalances.push(balance);
+                const balanceInWei = await this.props.blockchain.getBalanceInWeiAsync(address);
+                addressBalances.push(balanceInWei);
             }
         } catch (err) {
             utils.consoleLog(`Ledger error: ${JSON.stringify(err)}`);
diff --git a/packages/website/ts/components/eth_weth_conversion_button.tsx b/packages/website/ts/components/eth_weth_conversion_button.tsx
index 62bafdba7..8e13d0aae 100644
--- a/packages/website/ts/components/eth_weth_conversion_button.tsx
+++ b/packages/website/ts/components/eth_weth_conversion_button.tsx
@@ -18,7 +18,7 @@ interface EthWethConversionButtonProps {
     ethToken: Token;
     dispatcher: Dispatcher;
     blockchain: Blockchain;
-    userEtherBalance: BigNumber;
+    userEtherBalanceInWei: BigNumber;
     isOutdatedWrappedEther: boolean;
     onConversionSuccessful?: () => void;
     isDisabled?: boolean;
@@ -74,7 +74,7 @@ export class EthWethConversionButton extends React.Component<
                     isOpen={this.state.isEthConversionDialogVisible}
                     onComplete={this._onConversionAmountSelectedAsync.bind(this)}
                     onCancelled={this._toggleConversionDialog.bind(this)}
-                    etherBalance={this.props.userEtherBalance}
+                    etherBalanceInWei={this.props.userEtherBalanceInWei}
                     token={this.props.ethToken}
                     lastForceTokenStateRefetch={this.props.lastForceTokenStateRefetch}
                 />
diff --git a/packages/website/ts/components/eth_wrappers.tsx b/packages/website/ts/components/eth_wrappers.tsx
index 7ac5d5c9c..b12c637e5 100644
--- a/packages/website/ts/components/eth_wrappers.tsx
+++ b/packages/website/ts/components/eth_wrappers.tsx
@@ -15,7 +15,6 @@ import { configs } from 'ts/utils/configs';
 import { constants } from 'ts/utils/constants';
 import { utils } from 'ts/utils/utils';
 
-const PRECISION = 5;
 const DATE_FORMAT = 'D/M/YY';
 const ICON_DIMENSION = 40;
 const ETHER_ICON_PATH = '/images/ether.png';
@@ -34,7 +33,7 @@ interface EthWrappersProps {
     dispatcher: Dispatcher;
     tokenByAddress: TokenByAddress;
     userAddress: string;
-    userEtherBalance: BigNumber;
+    userEtherBalanceInWei: BigNumber;
     lastForceTokenStateRefetch: number;
 }
 
@@ -98,6 +97,10 @@ export class EthWrappers extends React.Component<EthWrappersProps, EthWrappersSt
             EtherscanLinkSuffixes.Address,
         );
         const tokenLabel = this._renderToken('Wrapped Ether', etherToken.address, configs.ICON_URL_BY_SYMBOL.WETH);
+        const userEtherBalanceInEth = ZeroEx.toUnitAmount(
+            this.props.userEtherBalanceInWei,
+            constants.DECIMAL_PLACES_ETH,
+        );
         return (
             <div className="clearfix lg-px4 md-px4 sm-px2" style={{ minHeight: 600 }}>
                 <div className="relative">
@@ -144,7 +147,7 @@ export class EthWrappers extends React.Component<EthWrappersProps, EthWrappersSt
                                         </div>
                                     </TableRowColumn>
                                     <TableRowColumn>
-                                        {this.props.userEtherBalance.toFixed(PRECISION)} ETH
+                                        {userEtherBalanceInEth.toFixed(configs.AMOUNT_DISPLAY_PRECSION)} ETH
                                     </TableRowColumn>
                                     <TableRowColumn>
                                         <EthWethConversionButton
@@ -157,7 +160,7 @@ export class EthWrappers extends React.Component<EthWrappersProps, EthWrappersSt
                                             ethToken={etherToken}
                                             dispatcher={this.props.dispatcher}
                                             blockchain={this.props.blockchain}
-                                            userEtherBalance={this.props.userEtherBalance}
+                                            userEtherBalanceInWei={this.props.userEtherBalanceInWei}
                                         />
                                     </TableRowColumn>
                                 </TableRow>
@@ -167,7 +170,7 @@ export class EthWrappers extends React.Component<EthWrappersProps, EthWrappersSt
                                     </TableRowColumn>
                                     <TableRowColumn>
                                         {this.state.isWethStateLoaded ? (
-                                            `${wethBalance.toFixed(PRECISION)} WETH`
+                                            `${wethBalance.toFixed(configs.AMOUNT_DISPLAY_PRECSION)} WETH`
                                         ) : (
                                             <i className="zmdi zmdi-spinner zmdi-hc-spin" />
                                         )}
@@ -184,7 +187,7 @@ export class EthWrappers extends React.Component<EthWrappersProps, EthWrappersSt
                                             ethToken={etherToken}
                                             dispatcher={this.props.dispatcher}
                                             blockchain={this.props.blockchain}
-                                            userEtherBalance={this.props.userEtherBalance}
+                                            userEtherBalanceInWei={this.props.userEtherBalanceInWei}
                                         />
                                     </TableRowColumn>
                                 </TableRow>
@@ -267,7 +270,7 @@ export class EthWrappers extends React.Component<EthWrappersProps, EthWrappersSt
                 const outdatedEtherTokenState = this.state.outdatedWETHStateByAddress[outdatedWETHIfExists.address];
                 const balanceInEthIfExists = isStateLoaded
                     ? ZeroEx.toUnitAmount(outdatedEtherTokenState.balance, constants.DECIMAL_PLACES_ETH).toFixed(
-                          PRECISION,
+                          configs.AMOUNT_DISPLAY_PRECSION,
                       )
                     : undefined;
                 const onConversionSuccessful = this._onOutdatedConversionSuccessfulAsync.bind(
@@ -304,7 +307,7 @@ export class EthWrappers extends React.Component<EthWrappersProps, EthWrappersSt
                                 ethToken={outdatedEtherToken}
                                 dispatcher={this.props.dispatcher}
                                 blockchain={this.props.blockchain}
-                                userEtherBalance={this.props.userEtherBalance}
+                                userEtherBalanceInWei={this.props.userEtherBalanceInWei}
                                 onConversionSuccessful={onConversionSuccessful}
                             />
                         </TableRowColumn>
@@ -348,8 +351,9 @@ export class EthWrappers extends React.Component<EthWrappersProps, EthWrappersSt
                 [outdatedWETHAddress]: false,
             },
         });
+        const userAddressIfExists = _.isEmpty(this.props.userAddress) ? undefined : this.props.userAddress;
         const [balance, allowance] = await this.props.blockchain.getTokenBalanceAndAllowanceAsync(
-            this.props.userAddress,
+            userAddressIfExists,
             outdatedWETHAddress,
         );
         this.setState({
@@ -369,8 +373,9 @@ export class EthWrappers extends React.Component<EthWrappersProps, EthWrappersSt
     private async _fetchWETHStateAsync() {
         const tokens = _.values(this.props.tokenByAddress);
         const wethToken = _.find(tokens, token => token.symbol === 'WETH');
+        const userAddressIfExists = _.isEmpty(this.props.userAddress) ? undefined : this.props.userAddress;
         const [wethBalance, wethAllowance] = await this.props.blockchain.getTokenBalanceAndAllowanceAsync(
-            this.props.userAddress,
+            userAddressIfExists,
             wethToken.address,
         );
 
@@ -379,7 +384,7 @@ export class EthWrappers extends React.Component<EthWrappersProps, EthWrappersSt
         const outdatedWETHStateByAddress: OutdatedWETHStateByAddress = {};
         for (const address of outdatedWETHAddresses) {
             const [balance, allowance] = await this.props.blockchain.getTokenBalanceAndAllowanceAsync(
-                this.props.userAddress,
+                userAddressIfExists,
                 address,
             );
             outdatedWETHStateByAddress[address] = {
@@ -420,8 +425,9 @@ export class EthWrappers extends React.Component<EthWrappersProps, EthWrappersSt
     }
     private async _refetchEthTokenStateAsync() {
         const etherToken = this._getEthToken();
+        const userAddressIfExists = _.isEmpty(this.props.userAddress) ? undefined : this.props.userAddress;
         const [balance, allowance] = await this.props.blockchain.getTokenBalanceAndAllowanceAsync(
-            this.props.userAddress,
+            userAddressIfExists,
             etherToken.address,
         );
         this.setState({
diff --git a/packages/website/ts/components/generate_order/generate_order_form.tsx b/packages/website/ts/components/generate_order/generate_order_form.tsx
index 26fa904fe..ea1d57a7b 100644
--- a/packages/website/ts/components/generate_order/generate_order_form.tsx
+++ b/packages/website/ts/components/generate_order/generate_order_form.tsx
@@ -237,8 +237,9 @@ export class GenerateOrderForm extends React.Component<GenerateOrderFormProps, G
 
         // Check if all required inputs were supplied
         const debitToken = this.props.sideToAssetToken[Side.Deposit];
+        const userAddressIfExists = _.isEmpty(this.props.userAddress) ? undefined : this.props.userAddress;
         const [debitBalance, debitAllowance] = await this.props.blockchain.getTokenBalanceAndAllowanceAsync(
-            this.props.userAddress,
+            userAddressIfExists,
             debitToken.address,
         );
         const receiveAmount = this.props.sideToAssetToken[Side.Receive].amount;
diff --git a/packages/website/ts/components/inputs/allowance_toggle.tsx b/packages/website/ts/components/inputs/allowance_toggle.tsx
index 7fe303cf4..3d353d87c 100644
--- a/packages/website/ts/components/inputs/allowance_toggle.tsx
+++ b/packages/website/ts/components/inputs/allowance_toggle.tsx
@@ -67,6 +67,7 @@ export class AllowanceToggle extends React.Component<AllowanceToggleProps, Allow
     private async _onToggleAllowanceAsync(): Promise<void> {
         if (this.props.userAddress === '') {
             this.props.dispatcher.updateShouldBlockchainErrDialogBeOpen(true);
+            return;
         }
 
         this.setState({
diff --git a/packages/website/ts/components/inputs/token_amount_input.tsx b/packages/website/ts/components/inputs/token_amount_input.tsx
index 53248c065..b55840fc4 100644
--- a/packages/website/ts/components/inputs/token_amount_input.tsx
+++ b/packages/website/ts/components/inputs/token_amount_input.tsx
@@ -109,8 +109,9 @@ export class TokenAmountInput extends React.Component<TokenAmountInputProps, Tok
         this.setState({
             isBalanceAndAllowanceLoaded: false,
         });
+        const userAddressIfExists = _.isEmpty(userAddress) ? undefined : userAddress;
         const [balance, allowance] = await this.props.blockchain.getTokenBalanceAndAllowanceAsync(
-            userAddress,
+            userAddressIfExists,
             tokenAddress,
         );
         if (!this._isUnmounted) {
diff --git a/packages/website/ts/components/portal.tsx b/packages/website/ts/components/portal.tsx
index d71e821c6..7df340f45 100644
--- a/packages/website/ts/components/portal.tsx
+++ b/packages/website/ts/components/portal.tsx
@@ -46,7 +46,7 @@ export interface PortalAllProps {
     providerType: ProviderType;
     screenWidth: ScreenWidths;
     tokenByAddress: TokenByAddress;
-    userEtherBalance: BigNumber;
+    userEtherBalanceInWei: BigNumber;
     userAddress: string;
     shouldBlockchainErrDialogBeOpen: boolean;
     userSuppliedOrderCache: Order;
@@ -121,8 +121,9 @@ export class Portal extends React.Component<PortalAllProps, PortalAllState> {
             });
         }
         if (nextProps.userAddress !== this.state.prevUserAddress) {
+            const newUserAddress = _.isEmpty(nextProps.userAddress) ? undefined : nextProps.userAddress;
             // tslint:disable-next-line:no-floating-promises
-            this._blockchain.userAddressUpdatedFireAndForgetAsync(nextProps.userAddress);
+            this._blockchain.userAddressUpdatedFireAndForgetAsync(newUserAddress);
             this.setState({
                 prevUserAddress: nextProps.userAddress,
             });
@@ -279,7 +280,7 @@ export class Portal extends React.Component<PortalAllProps, PortalAllState> {
                 dispatcher={this.props.dispatcher}
                 tokenByAddress={this.props.tokenByAddress}
                 userAddress={this.props.userAddress}
-                userEtherBalance={this.props.userEtherBalance}
+                userEtherBalanceInWei={this.props.userEtherBalanceInWei}
                 lastForceTokenStateRefetch={this.props.lastForceTokenStateRefetch}
             />
         );
@@ -306,7 +307,7 @@ export class Portal extends React.Component<PortalAllProps, PortalAllState> {
                 tokenByAddress={this.props.tokenByAddress}
                 trackedTokens={trackedTokens}
                 userAddress={this.props.userAddress}
-                userEtherBalance={this.props.userEtherBalance}
+                userEtherBalanceInWei={this.props.userEtherBalanceInWei}
                 networkId={this.props.networkId}
                 lastForceTokenStateRefetch={this.props.lastForceTokenStateRefetch}
             />
diff --git a/packages/website/ts/components/token_balances.tsx b/packages/website/ts/components/token_balances.tsx
index 7e7596fd7..894e0721f 100644
--- a/packages/website/ts/components/token_balances.tsx
+++ b/packages/website/ts/components/token_balances.tsx
@@ -48,7 +48,6 @@ const ETHER_ICON_PATH = '/images/ether.png';
 const ETHER_TOKEN_SYMBOL = 'WETH';
 const ZRX_TOKEN_SYMBOL = 'ZRX';
 
-const PRECISION = 5;
 const ICON_DIMENSION = 40;
 const ARTIFICIAL_FAUCET_REQUEST_DELAY = 1000;
 const TOKEN_TABLE_ROW_HEIGHT = 60;
@@ -79,7 +78,7 @@ interface TokenBalancesProps {
     tokenByAddress: TokenByAddress;
     trackedTokens: Token[];
     userAddress: string;
-    userEtherBalance: BigNumber;
+    userEtherBalanceInWei: BigNumber;
     networkId: number;
     lastForceTokenStateRefetch: number;
 }
@@ -119,11 +118,14 @@ export class TokenBalances extends React.Component<TokenBalancesProps, TokenBala
         this._isUnmounted = true;
     }
     public componentWillReceiveProps(nextProps: TokenBalancesProps) {
-        if (nextProps.userEtherBalance !== this.props.userEtherBalance) {
+        if (nextProps.userEtherBalanceInWei !== this.props.userEtherBalanceInWei) {
             if (this.state.isBalanceSpinnerVisible) {
-                const receivedAmount = nextProps.userEtherBalance.minus(this.props.userEtherBalance);
+                const receivedAmountInWei = nextProps.userEtherBalanceInWei.minus(this.props.userEtherBalanceInWei);
+                const receivedAmountInEth = ZeroEx.toUnitAmount(receivedAmountInWei, constants.DECIMAL_PLACES_ETH);
                 const networkName = sharedConstants.NETWORK_NAME_BY_ID[this.props.networkId];
-                this.props.dispatcher.showFlashMessage(`Received ${receivedAmount.toString(10)} ${networkName} Ether`);
+                this.props.dispatcher.showFlashMessage(
+                    `Received ${receivedAmountInEth.toString(10)} ${networkName} Ether`,
+                );
             }
             this.setState({
                 isBalanceSpinnerVisible: false,
@@ -205,6 +207,10 @@ export class TokenBalances extends React.Component<TokenBalancesProps, TokenBala
                                   token balances in order to execute trades.<br> \
                                   Toggling sets an allowance for the<br> \
                                   smart contract so you can start trading that token.';
+        const userEtherBalanceInEth = ZeroEx.toUnitAmount(
+            this.props.userEtherBalanceInWei,
+            constants.DECIMAL_PLACES_ETH,
+        );
         return (
             <div className="lg-px4 md-px4 sm-px1 pb2">
                 <h3>{isTestNetwork ? 'Test ether' : 'Ether'}</h3>
@@ -241,7 +247,7 @@ export class TokenBalances extends React.Component<TokenBalancesProps, TokenBala
                                 <img style={{ width: ICON_DIMENSION, height: ICON_DIMENSION }} src={ETHER_ICON_PATH} />
                             </TableRowColumn>
                             <TableRowColumn>
-                                {this.props.userEtherBalance.toFixed(PRECISION)} ETH
+                                {userEtherBalanceInEth.toFixed(configs.AMOUNT_DISPLAY_PRECSION)} ETH
                                 {this.state.isBalanceSpinnerVisible && (
                                     <span className="pl1">
                                         <i className="zmdi zmdi-spinner zmdi-hc-spin" />
@@ -493,7 +499,7 @@ export class TokenBalances extends React.Component<TokenBalancesProps, TokenBala
     }
     private _renderAmount(amount: BigNumber, decimals: number) {
         const unitAmount = ZeroEx.toUnitAmount(amount, decimals);
-        return unitAmount.toNumber().toFixed(PRECISION);
+        return unitAmount.toNumber().toFixed(configs.AMOUNT_DISPLAY_PRECSION);
     }
     private _renderTokenName(token: Token) {
         const tooltipId = `tooltip-${token.address}`;
@@ -681,9 +687,10 @@ export class TokenBalances extends React.Component<TokenBalancesProps, TokenBala
     }
     private async _fetchBalancesAndAllowancesAsync(tokenAddresses: string[]) {
         const trackedTokenStateByAddress = this.state.trackedTokenStateByAddress;
+        const userAddressIfExists = _.isEmpty(this.props.userAddress) ? undefined : this.props.userAddress;
         for (const tokenAddress of tokenAddresses) {
             const [balance, allowance] = await this.props.blockchain.getTokenBalanceAndAllowanceAsync(
-                this.props.userAddress,
+                userAddressIfExists,
                 tokenAddress,
             );
             trackedTokenStateByAddress[tokenAddress] = {
@@ -710,8 +717,9 @@ export class TokenBalances extends React.Component<TokenBalancesProps, TokenBala
         return trackedTokenStateByAddress;
     }
     private async _refetchTokenStateAsync(tokenAddress: string) {
+        const userAddressIfExists = _.isEmpty(this.props.userAddress) ? undefined : this.props.userAddress;
         const [balance, allowance] = await this.props.blockchain.getTokenBalanceAndAllowanceAsync(
-            this.props.userAddress,
+            userAddressIfExists,
             tokenAddress,
         );
         this.setState({
diff --git a/packages/website/ts/components/trade_history/trade_history_item.tsx b/packages/website/ts/components/trade_history/trade_history_item.tsx
index 6b8d7c7b5..dbe72259b 100644
--- a/packages/website/ts/components/trade_history/trade_history_item.tsx
+++ b/packages/website/ts/components/trade_history/trade_history_item.tsx
@@ -9,8 +9,8 @@ import * as ReactTooltip from 'react-tooltip';
 import { EtherScanIcon } from 'ts/components/ui/etherscan_icon';
 import { Party } from 'ts/components/ui/party';
 import { Fill, Token, TokenByAddress } from 'ts/types';
+import { configs } from 'ts/utils/configs';
 
-const PRECISION = 5;
 const IDENTICON_DIAMETER = 40;
 
 interface TradeHistoryItemProps {
@@ -131,7 +131,7 @@ export class TradeHistoryItem extends React.Component<TradeHistoryItemProps, Tra
                     {this._renderAmount(givenAmount, givenToken.symbol, givenToken.decimals)}
                 </div>
                 <div style={{ color: colors.grey400, fontSize: 14 }}>
-                    {exchangeRate.toFixed(PRECISION)} {givenToken.symbol}/{receiveToken.symbol}
+                    {exchangeRate.toFixed(configs.AMOUNT_DISPLAY_PRECSION)} {givenToken.symbol}/{receiveToken.symbol}
                 </div>
             </div>
         );
@@ -163,7 +163,7 @@ export class TradeHistoryItem extends React.Component<TradeHistoryItemProps, Tra
         const unitAmount = ZeroEx.toUnitAmount(amount, decimals);
         return (
             <span>
-                {unitAmount.toFixed(PRECISION)} {symbol}
+                {unitAmount.toFixed(configs.AMOUNT_DISPLAY_PRECSION)} {symbol}
             </span>
         );
     }
diff --git a/packages/website/ts/components/visual_order.tsx b/packages/website/ts/components/visual_order.tsx
index ec2d47f39..3bf464e92 100644
--- a/packages/website/ts/components/visual_order.tsx
+++ b/packages/website/ts/components/visual_order.tsx
@@ -3,10 +3,9 @@ import * as _ from 'lodash';
 import * as React from 'react';
 import { Party } from 'ts/components/ui/party';
 import { AssetToken, Token, TokenByAddress } from 'ts/types';
+import { configs } from 'ts/utils/configs';
 import { utils } from 'ts/utils/utils';
 
-const PRECISION = 5;
-
 interface VisualOrderProps {
     makerAssetToken: AssetToken;
     takerAssetToken: AssetToken;
@@ -67,7 +66,7 @@ export class VisualOrder extends React.Component<VisualOrderProps, VisualOrderSt
         const unitAmount = ZeroEx.toUnitAmount(assetToken.amount, token.decimals);
         return (
             <div style={{ fontSize: 13 }}>
-                {unitAmount.toNumber().toFixed(PRECISION)} {token.symbol}
+                {unitAmount.toNumber().toFixed(configs.AMOUNT_DISPLAY_PRECSION)} {token.symbol}
             </div>
         );
     }
diff --git a/packages/website/ts/containers/portal.ts b/packages/website/ts/containers/portal.ts
index befa16bdb..725564ead 100644
--- a/packages/website/ts/containers/portal.ts
+++ b/packages/website/ts/containers/portal.ts
@@ -21,7 +21,7 @@ interface ConnectedState {
     providerType: ProviderType;
     tokenByAddress: TokenByAddress;
     lastForceTokenStateRefetch: number;
-    userEtherBalance: BigNumber;
+    userEtherBalanceInWei: BigNumber;
     screenWidth: ScreenWidths;
     shouldBlockchainErrDialogBeOpen: boolean;
     userAddress: string;
@@ -72,7 +72,7 @@ const mapStateToProps = (state: State, ownProps: PortalComponentAllProps): Conne
         tokenByAddress: state.tokenByAddress,
         lastForceTokenStateRefetch: state.lastForceTokenStateRefetch,
         userAddress: state.userAddress,
-        userEtherBalance: state.userEtherBalance,
+        userEtherBalanceInWei: state.userEtherBalanceInWei,
         userSuppliedOrderCache: state.userSuppliedOrderCache,
         flashMessage: state.flashMessage,
         translate: state.translate,
diff --git a/packages/website/ts/redux/dispatcher.ts b/packages/website/ts/redux/dispatcher.ts
index 5c40ded2c..13e9a10cc 100644
--- a/packages/website/ts/redux/dispatcher.ts
+++ b/packages/website/ts/redux/dispatcher.ts
@@ -86,7 +86,7 @@ export class Dispatcher {
             type: ActionTypes.UpdateOrderTakerAddress,
         });
     }
-    public updateUserAddress(address: string) {
+    public updateUserAddress(address?: string) {
         this._dispatch({
             data: address,
             type: ActionTypes.UpdateUserAddress,
@@ -125,14 +125,14 @@ export class Dispatcher {
     public batchDispatch(
         tokenByAddress: TokenByAddress,
         networkId: number,
-        userAddress: string,
+        userAddressIfExists: string | undefined,
         sideToAssetToken: SideToAssetToken,
     ) {
         this._dispatch({
             data: {
                 tokenByAddress,
                 networkId,
-                userAddress,
+                userAddressIfExists,
                 sideToAssetToken,
             },
             type: ActionTypes.BatchDispatch,
@@ -155,7 +155,7 @@ export class Dispatcher {
             type: ActionTypes.UpdateOrderECSignature,
         });
     }
-    public updateUserEtherBalance(balance: BigNumber) {
+    public updateUserWeiBalance(balance: BigNumber) {
         this._dispatch({
             data: balance,
             type: ActionTypes.UpdateUserEtherBalance,
diff --git a/packages/website/ts/redux/reducer.ts b/packages/website/ts/redux/reducer.ts
index 1f489db85..a628f65c2 100644
--- a/packages/website/ts/redux/reducer.ts
+++ b/packages/website/ts/redux/reducer.ts
@@ -38,7 +38,7 @@ export interface State {
     tokenByAddress: TokenByAddress;
     lastForceTokenStateRefetch: number;
     userAddress: string;
-    userEtherBalance: BigNumber;
+    userEtherBalanceInWei: BigNumber;
     // Note: cache of supplied orderJSON in fill order step. Do not use for anything else.
     userSuppliedOrderCache: Order;
 
@@ -77,7 +77,7 @@ const INITIAL_STATE: State = {
     tokenByAddress: {},
     lastForceTokenStateRefetch: moment().unix(),
     userAddress: '',
-    userEtherBalance: new BigNumber(0),
+    userEtherBalanceInWei: new BigNumber(0),
     userSuppliedOrderCache: undefined,
 
     // Docs
@@ -138,7 +138,7 @@ export function reducer(state: State = INITIAL_STATE, action: Action) {
         case ActionTypes.UpdateUserEtherBalance: {
             return {
                 ...state,
-                userEtherBalance: action.data,
+                userEtherBalanceInWei: action.data,
             };
         }
 
@@ -184,10 +184,11 @@ export function reducer(state: State = INITIAL_STATE, action: Action) {
         }
 
         case ActionTypes.BatchDispatch: {
+            const userAddress = _.isUndefined(action.data.userAddressIfExists) ? '' : action.data.userAddressIfExists;
             return {
                 ...state,
                 networkId: action.data.networkId,
-                userAddress: action.data.userAddress,
+                userAddress,
                 sideToAssetToken: action.data.sideToAssetToken,
                 tokenByAddress: action.data.tokenByAddress,
             };
@@ -284,9 +285,10 @@ export function reducer(state: State = INITIAL_STATE, action: Action) {
         }
 
         case ActionTypes.UpdateUserAddress: {
+            const userAddress = _.isUndefined(action.data) ? '' : action.data;
             return {
                 ...state,
-                userAddress: action.data,
+                userAddress,
             };
         }
 
diff --git a/packages/website/ts/utils/configs.ts b/packages/website/ts/utils/configs.ts
index f33b06c0a..f966cedbe 100644
--- a/packages/website/ts/utils/configs.ts
+++ b/packages/website/ts/utils/configs.ts
@@ -9,6 +9,7 @@ const isDevelopment = _.includes(
 const INFURA_API_KEY = 'T5WSC8cautR4KXyYgsRs';
 
 export const configs = {
+    AMOUNT_DISPLAY_PRECSION: 5,
     BACKEND_BASE_URL: 'https://website-api.0xproject.com',
     BASE_URL,
     BITLY_ACCESS_TOKEN: 'ffc4c1a31e5143848fb7c523b39f91b9b213d208',
diff --git a/packages/website/ts/web3_wrapper.ts b/packages/website/ts/web3_wrapper.ts
deleted file mode 100644
index 9d8d771af..000000000
--- a/packages/website/ts/web3_wrapper.ts
+++ /dev/null
@@ -1,157 +0,0 @@
-import { BigNumber, intervalUtils, promisify } from '@0xproject/utils';
-import * as _ from 'lodash';
-import { Dispatcher } from 'ts/redux/dispatcher';
-import { utils } from 'ts/utils/utils';
-import * as Web3 from 'web3';
-
-export class Web3Wrapper {
-    private _dispatcher: Dispatcher;
-    private _web3: Web3;
-    private _prevNetworkId: number;
-    private _shouldPollUserAddress: boolean;
-    private _watchNetworkAndBalanceIntervalId: NodeJS.Timer;
-    private _prevUserEtherBalanceInEth: BigNumber;
-    private _prevUserAddress: string;
-    constructor(
-        dispatcher: Dispatcher,
-        provider: Web3.Provider,
-        networkIdIfExists: number,
-        shouldPollUserAddress: boolean,
-    ) {
-        this._dispatcher = dispatcher;
-        this._prevNetworkId = networkIdIfExists;
-        this._shouldPollUserAddress = shouldPollUserAddress;
-
-        this._web3 = new Web3();
-        this._web3.setProvider(provider);
-    }
-    public isAddress(address: string) {
-        return this._web3.isAddress(address);
-    }
-    public async getAccountsAsync(): Promise<string[]> {
-        const addresses = await promisify<string[]>(this._web3.eth.getAccounts)();
-        return addresses;
-    }
-    public async getFirstAccountIfExistsAsync() {
-        const addresses = await this.getAccountsAsync();
-        if (_.isEmpty(addresses)) {
-            return '';
-        }
-        return addresses[0];
-    }
-    public async getNodeVersionAsync(): Promise<string> {
-        const nodeVersion = await promisify<string>(this._web3.version.getNode)();
-        return nodeVersion;
-    }
-    public getProviderObj() {
-        return this._web3.currentProvider;
-    }
-    public async getNetworkIdIfExists() {
-        try {
-            const networkId = await this._getNetworkAsync();
-            return Number(networkId);
-        } catch (err) {
-            return undefined;
-        }
-    }
-    public async getBalanceInEthAsync(owner: string): Promise<BigNumber> {
-        const balanceInWei: BigNumber = await promisify<BigNumber>(this._web3.eth.getBalance)(owner);
-        const balanceEthOldBigNumber = this._web3.fromWei(balanceInWei, 'ether');
-        const balanceEth = new BigNumber(balanceEthOldBigNumber);
-        return balanceEth;
-    }
-    public async doesContractExistAtAddressAsync(address: string): Promise<boolean> {
-        const code = await promisify<string>(this._web3.eth.getCode)(address);
-        // Regex matches 0x0, 0x00, 0x in order to accomodate poorly implemented clients
-        const zeroHexAddressRegex = /^0[xX][0]*$/;
-        const didFindCode = _.isNull(code.match(zeroHexAddressRegex));
-        return didFindCode;
-    }
-    public async signTransactionAsync(address: string, message: string): Promise<string> {
-        const signData = await promisify<string>(this._web3.eth.sign)(address, message);
-        return signData;
-    }
-    public async getBlockTimestampAsync(blockHash: string): Promise<number> {
-        const { timestamp } = await promisify<Web3.BlockWithoutTransactionData>(this._web3.eth.getBlock)(blockHash);
-        return timestamp;
-    }
-    public destroy() {
-        this._stopEmittingNetworkConnectionAndUserBalanceStateAsync();
-        // HACK: stop() is only available on providerEngine instances
-        const provider = this._web3.currentProvider;
-        if (!_.isUndefined((provider as any).stop)) {
-            (provider as any).stop();
-        }
-    }
-    // This should only be called from the LedgerConfigDialog
-    public updatePrevUserAddress(userAddress: string) {
-        this._prevUserAddress = userAddress;
-    }
-    public startEmittingNetworkConnectionAndUserBalanceState() {
-        if (!_.isUndefined(this._watchNetworkAndBalanceIntervalId)) {
-            return; // we are already emitting the state
-        }
-
-        let prevNodeVersion: string;
-        this._prevUserEtherBalanceInEth = new BigNumber(0);
-        this._dispatcher.updateNetworkId(this._prevNetworkId);
-        this._watchNetworkAndBalanceIntervalId = intervalUtils.setAsyncExcludingInterval(
-            async () => {
-                // Check for network state changes
-                const currentNetworkId = await this.getNetworkIdIfExists();
-                if (currentNetworkId !== this._prevNetworkId) {
-                    this._prevNetworkId = currentNetworkId;
-                    this._dispatcher.updateNetworkId(currentNetworkId);
-                }
-
-                // Check for node version changes
-                const currentNodeVersion = await this.getNodeVersionAsync();
-                if (currentNodeVersion !== prevNodeVersion) {
-                    prevNodeVersion = currentNodeVersion;
-                    this._dispatcher.updateNodeVersion(currentNodeVersion);
-                }
-
-                if (this._shouldPollUserAddress) {
-                    const userAddressIfExists = await this.getFirstAccountIfExistsAsync();
-                    // Update makerAddress on network change
-                    if (this._prevUserAddress !== userAddressIfExists) {
-                        this._prevUserAddress = userAddressIfExists;
-                        this._dispatcher.updateUserAddress(userAddressIfExists);
-                    }
-
-                    // Check for user ether balance changes
-                    if (!_.isEmpty(userAddressIfExists)) {
-                        await this._updateUserEtherBalanceAsync(userAddressIfExists);
-                    }
-                } else {
-                    // This logic is primarily for the Ledger, since we don't regularly poll for the address
-                    // we simply update the balance for the last fetched address.
-                    if (!_.isEmpty(this._prevUserAddress)) {
-                        await this._updateUserEtherBalanceAsync(this._prevUserAddress);
-                    }
-                }
-            },
-            5000,
-            (err: Error) => {
-                utils.consoleLog(`Watching network and balances failed: ${err.stack}`);
-                this._stopEmittingNetworkConnectionAndUserBalanceStateAsync();
-            },
-        );
-    }
-    private async _getNetworkAsync() {
-        const networkId = await promisify(this._web3.version.getNetwork)();
-        return networkId;
-    }
-    private async _updateUserEtherBalanceAsync(userAddress: string) {
-        const balance = await this.getBalanceInEthAsync(userAddress);
-        if (!balance.eq(this._prevUserEtherBalanceInEth)) {
-            this._prevUserEtherBalanceInEth = balance;
-            this._dispatcher.updateUserEtherBalance(balance);
-        }
-    }
-    private _stopEmittingNetworkConnectionAndUserBalanceStateAsync() {
-        if (!_.isUndefined(this._watchNetworkAndBalanceIntervalId)) {
-            intervalUtils.clearAsyncExcludingInterval(this._watchNetworkAndBalanceIntervalId);
-        }
-    }
-}