Monitor different state layers with OrderWatcher

Allow instantiation of stand-alone OrderWatchers
that can monitor different blockchain state
layers (e.g. pending or latest)

2 files changed, 11 insertions, 5 deletions

diff --git a/packages/0x.js/src/order_watcher/event_watcher.ts b/packages/0x.js/src/order_watcher/event_watcher.ts
index 246ab8292..deb1ffbff 100644
--- a/packages/0x.js/src/order_watcher/event_watcher.ts
+++ b/packages/0x.js/src/order_watcher/event_watcher.ts
@@ -22,8 +22,10 @@ export class EventWatcher {
     private _pollingIntervalMs: number;
     private _intervalIdIfExists?: NodeJS.Timer;
     private _lastEvents: LogEntry[] = [];
-    constructor(web3Wrapper: Web3Wrapper, pollingIntervalIfExistsMs: undefined | number) {
+    private _stateLayer: BlockParamLiteral;
+    constructor(web3Wrapper: Web3Wrapper, pollingIntervalIfExistsMs: undefined | number, stateLayer: BlockParamLiteral = BlockParamLiteral.Pending) {
         this._web3Wrapper = web3Wrapper;
+        this._stateLayer = stateLayer;
         this._pollingIntervalMs = _.isUndefined(pollingIntervalIfExistsMs)
             ? DEFAULT_EVENT_POLLING_INTERVAL_MS
             : pollingIntervalIfExistsMs;
@@ -69,8 +71,8 @@ export class EventWatcher {
     }
     private async _getEventsAsync(): Promise<LogEntry[]> {
         const eventFilter = {
-            fromBlock: BlockParamLiteral.Pending,
-            toBlock: BlockParamLiteral.Pending,
+            fromBlock: this._stateLayer,
+            toBlock: this._stateLayer,
         };
         const events = await this._web3Wrapper.getLogsAsync(eventFilter);
         return events;
diff --git a/packages/0x.js/src/order_watcher/order_state_watcher.ts b/packages/0x.js/src/order_watcher/order_state_watcher.ts
index 9cccadb7f..fcf3c351d 100644
--- a/packages/0x.js/src/order_watcher/order_state_watcher.ts
+++ b/packages/0x.js/src/order_watcher/order_state_watcher.ts
@@ -76,6 +76,7 @@ export class OrderStateWatcher {
     private _balanceAndProxyAllowanceLazyStore: BalanceAndProxyAllowanceLazyStore;
     private _cleanupJobInterval: number;
     private _cleanupJobIntervalIdIfExists?: NodeJS.Timer;
+    private _stateLayer: BlockParamLiteral;
     constructor(
         web3Wrapper: Web3Wrapper,
         abiDecoder: AbiDecoder,
@@ -86,10 +87,13 @@ export class OrderStateWatcher {
         this._abiDecoder = abiDecoder;
         this._web3Wrapper = web3Wrapper;
         const pollingIntervalIfExistsMs = _.isUndefined(config) ? undefined : config.eventPollingIntervalMs;
-        this._eventWatcher = new EventWatcher(web3Wrapper, pollingIntervalIfExistsMs);
+        this._stateLayer = _.isUndefined(config) || _.isUndefined(config.stateLayer)
+            ? BlockParamLiteral.Pending
+            : config.stateLayer;
+        this._eventWatcher = new EventWatcher(web3Wrapper, pollingIntervalIfExistsMs, this._stateLayer);
         this._balanceAndProxyAllowanceLazyStore = new BalanceAndProxyAllowanceLazyStore(
             token,
-            BlockParamLiteral.Pending,
+            this._stateLayer,
         );
         this._orderFilledCancelledLazyStore = new OrderFilledCancelledLazyStore(exchange);
         this._orderStateUtils = new OrderStateUtils(