subscribeToEvent -> subscribeToEvents

js/src/contracts/verification.js

@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-import subscribeToEvent from '../util/subscribe-to-event';
+import subscribeToEvents from '../util/subscribe-to-events';
 
 export const checkIfVerified = (contract, account) => {
   return contract.instance.certified.call({}, [account]);
@@ -72,7 +72,7 @@ export const awaitPuzzle = (api, contract, account) => {
   return blockNumber(api)
     .then((block) => {
       return new Promise((resolve, reject) => {
-        const subscription = subscribeToEvent(contract, 'Puzzled', {
+        const subscription = subscribeToEvents(contract, 'Puzzled', {
           from: block.toNumber(),
           filter: (log) => log.params.who.value === account
         });

js/src/util/subscribe-to-event.js

@@ -1,77 +0,0 @@
-// Copyright 2015, 2016 Parity Technologies (UK) Ltd.
-// This file is part of Parity.
-
-// Parity is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-
-// Parity is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License
-// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
-
-import EventEmitter from 'eventemitter3';
-
-const defaults = {
-  from: 0, // TODO
-  to: 'latest',
-  timeout: null,
-  filter: () => true
-};
-
-const subscribeToEvent = (contract, name, opt = {}) => {
-  opt = Object.assign({}, defaults, opt);
-
-  let subscription = null;
-  let timeout = null;
-
-  const unsubscribe = () => {
-    if (subscription) {
-      contract.unsubscribe(subscription);
-      subscription = null;
-    }
-    if (timeout) {
-      clearTimeout(timeout);
-      timeout = null;
-    }
-  };
-
-  const emitter = new EventEmitter();
-  emitter.unsubscribe = unsubscribe;
-
-  if (typeof opt.timeout === 'number') {
-    timeout = setTimeout(() => {
-      unsubscribe();
-      emitter.emit('timeout');
-    }, opt.timeout);
-  }
-
-  const callback = (err, logs) => {
-    if (err) {
-      return emitter.emit('error', err);
-    }
-    for (let log of logs) {
-      if (opt.filter(log)) {
-        emitter.emit('log', log);
-      }
-    }
-  };
-
-  contract.subscribe(name, {
-    fromBlock: opt.from, toBlock: opt.to
-  }, callback)
-  .then((_subscription) => {
-    subscription = _subscription;
-  })
-  .catch((err) => {
-    emitter.emit('error', err);
-  });
-
-  return emitter;
-};
-
-export default subscribeToEvent;

js/src/util/subscribe-to-events.js

@@ -0,0 +1,97 @@
+// Copyright 2015, 2016 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+import EventEmitter from 'eventemitter3';
+
+const defaults = {
+  from: 0,
+  to: 'latest',
+  interval: 5000,
+  filter: () => true
+};
+
+const subscribeToEvents = (contract, events, opt = {}) => {
+  const { api } = contract;
+  opt = Object.assign({}, defaults, opt);
+
+  let filter = null;
+  let interval = null;
+
+  const unsubscribe = () => {
+    if (filter) {
+      filter
+        .then((filterId) => {
+          return api.eth.uninstallFilter(filterId);
+        })
+        .catch((err) => {
+          emitter.emit('error', err);
+        });
+      filter = null;
+    }
+    if (interval) {
+      clearInterval(interval);
+      interval = null;
+    }
+  };
+
+  const emitter = new EventEmitter();
+  emitter.unsubscribe = unsubscribe;
+
+  const fetcher = (method, filterId) => () => {
+    api
+      .eth[method](filterId)
+      .then((logs) => {
+        logs = contract.parseEventLogs(logs);
+
+        for (let log of logs) {
+          if (opt.filter(log)) {
+            emitter.emit('log', log);
+            emitter.emit(log.event, log);
+          }
+        }
+      })
+      .catch((err) => {
+        emitter.emit('error', err);
+      });
+  };
+
+  const signatures = events
+    .filter((event) => contract.instance[event])
+    .map((event) => contract.instance[event].signature);
+
+  filter = api.eth
+    .newFilter({
+      fromBlock: opt.from, toBlock: opt.to,
+      address: contract.address,
+      topics: [signatures]
+    })
+    .then((filterId) => {
+      fetcher('getFilterLogs', filterId)(); // fetch immediately
+
+      const fetchChanges = fetcher('getFilterChanges', filterId);
+      interval = setInterval(fetchChanges, opt.interval);
+
+      return filterId;
+    })
+    .catch((err) => {
+      emitter.emit('error', err);
+      throw err; // reject Promise
+    });
+
+  return emitter;
+};
+
+export default subscribeToEvents;