refresh certifications automatically (#3878)

* certifications: eth.getLogs -> filters

* linting 👕, indentation

* certifications: fetch filter changes

* certifications: prevent overlapping

* certifications: watch blockNumber to refresh

* fix email certification contract

See ethcore/contracts@d86490e302

* update email certification contract

js/package.json

@@ -135,6 +135,7 @@
     "blockies": "0.0.2",
     "brace": "0.9.0",
     "bytes": "2.4.0",
+    "debounce": "1.0.0",
     "es6-error": "4.0.0",
     "es6-promise": "4.0.5",
     "ethereumjs-tx": "1.1.4",

js/src/modals/Verification/email-store.js

@@ -23,7 +23,7 @@ import VerificationStore, {
 } from './store';
 import { postToServer } from '../../3rdparty/email-verification';
 
-const EMAIL_VERIFICATION = 4; // id in the `BadgeReg.sol` contract
+const EMAIL_VERIFICATION = 7; // id in the `BadgeReg.sol` contract
 
 export default class EmailVerificationStore extends VerificationStore {
   @observable email = '';

js/src/redux/providers/certifications/middleware.js

@@ -15,12 +15,41 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
 import { uniq } from 'lodash';
+import debounce from 'debounce';
 
 import ABI from '~/contracts/abi/certifier.json';
 import Contract from '~/api/contract';
 import Contracts from '~/contracts';
 import { addCertification, removeCertification } from './actions';
 
+// TODO: move this to a more general place
+const updatableFilter = (api, onFilter) => {
+  let filter = null;
+
+  const update = (address, topics) => {
+    if (filter) {
+      filter = filter.then((filterId) => {
+        api.eth.uninstallFilter(filterId);
+      });
+    }
+    filter = (filter || Promise.resolve())
+      .then(() => api.eth.newFilter({
+        fromBlock: 0,
+        toBlock: 'latest',
+        address,
+        topics
+      }))
+      .then((filterId) => {
+        onFilter(filterId);
+        return filterId;
+      })
+      .catch((err) => {
+        console.error('Failed to create certifications filter:', err);
+      });
+  };
+  return update;
+};
+
 export default class CertificationsMiddleware {
   toMiddleware () {
     const api = Contracts.get()._api;
@@ -29,75 +58,96 @@ export default class CertificationsMiddleware {
     const Confirmed = contract.events.find((e) => e.name === 'Confirmed');
     const Revoked = contract.events.find((e) => e.name === 'Revoked');
 
-    let certifiers = [];
-    let accounts = []; // these are addresses
-
-    const fetchConfirmedEvents = (dispatch) => {
-      if (certifiers.length === 0 || accounts.length === 0) return;
-      api.eth.getLogs({
-        fromBlock: 0,
-        toBlock: 'latest',
-        address: certifiers.map((c) => c.address),
-        topics: [ [ Confirmed.signature, Revoked.signature ], accounts ]
-      })
-        .then((logs) => contract.parseEventLogs(logs))
-        .then((logs) => {
-          logs.forEach((log) => {
-            const certifier = certifiers.find((c) => c.address === log.address);
-            if (!certifier) {
-              throw new Error(`Could not find certifier at ${log.address}.`);
-            }
-            const { id, name, title, icon } = certifier;
-
-            if (log.event === 'Revoked') {
-              dispatch(removeCertification(log.params.who.value, id));
-            } else {
-              dispatch(addCertification(log.params.who.value, id, name, title, icon));
-            }
-          });
-        })
-        .catch((err) => {
-          console.error('Failed to fetch Confirmed events:', err);
-        });
-    };
-
-    return (store) => (next) => (action) => {
-      switch (action.type) {
-        case 'fetchCertifiers':
-          badgeReg.certifierCount().then((count) => {
-            new Array(+count).fill(null).forEach((_, id) => {
-              badgeReg.fetchCertifier(id)
-                .then((cert) => {
-                  if (!certifiers.some((c) => c.id === cert.id)) {
-                    certifiers = certifiers.concat(cert);
-                    fetchConfirmedEvents(store.dispatch);
-                  }
-                })
-                .catch((err) => {
-                  console.warn(`Could not fetch certifier ${id}:`, err);
-                });
-            });
-          });
-
-          break;
-        case 'fetchCertifications':
-          const { address } = action;
-
-          if (!accounts.includes(address)) {
-            accounts = accounts.concat(address);
-            fetchConfirmedEvents(store.dispatch);
+    return (store) => {
+      const onLogs = (logs) => {
+        logs = contract.parseEventLogs(logs);
+        logs.forEach((log) => {
+          const certifier = certifiers.find((c) => c.address === log.address);
+          if (!certifier) {
+            throw new Error(`Could not find certifier at ${log.address}.`);
           }
+          const { id, name, title, icon } = certifier;
 
-          break;
-        case 'setVisibleAccounts':
-          const { addresses } = action;
-          accounts = uniq(accounts.concat(addresses));
-          fetchConfirmedEvents(store.dispatch);
+          if (log.event === 'Revoked') {
+            store.dispatch(removeCertification(log.params.who.value, id));
+          } else {
+            store.dispatch(addCertification(log.params.who.value, id, name, title, icon));
+          }
+        });
+      };
 
-          break;
-        default:
-          next(action);
-      }
+      let filter = null;
+
+      const onFilter = (filterId) => {
+        filter = filterId;
+        api.eth.getFilterLogs(filterId)
+          .then(onLogs)
+          .catch((err) => {
+            console.error('Failed to fetch certifier events:', err);
+          });
+      };
+
+      const fetchChanges = debounce(() => {
+        api.eth.getFilterChanges(filter)
+          .then(onLogs)
+          .catch((err) => {
+            console.error('Failed to fetch new certifier events:', err);
+          });
+      }, 10 * 1000, true);
+      api.subscribe('eth_blockNumber', (err) => {
+        if (err) return;
+        fetchChanges();
+      });
+
+      const updateFilter = updatableFilter(api, onFilter);
+      let certifiers = [];
+      let accounts = []; // these are addresses
+
+      const fetchConfirmedEvents = () => {
+        updateFilter(certifiers.map((c) => c.address), [
+          [ Confirmed.signature, Revoked.signature ],
+          accounts
+        ]);
+      };
+
+      return (next) => (action) => {
+        switch (action.type) {
+          case 'fetchCertifiers':
+            badgeReg.certifierCount().then((count) => {
+              new Array(+count).fill(null).forEach((_, id) => {
+                badgeReg.fetchCertifier(id)
+                  .then((cert) => {
+                    if (!certifiers.some((c) => c.id === cert.id)) {
+                      certifiers = certifiers.concat(cert);
+                      fetchConfirmedEvents();
+                    }
+                  })
+                  .catch((err) => {
+                    console.warn(`Could not fetch certifier ${id}:`, err);
+                  });
+              });
+            });
+
+            break;
+          case 'fetchCertifications':
+            const { address } = action;
+
+            if (!accounts.includes(address)) {
+              accounts = accounts.concat(address);
+              fetchConfirmedEvents();
+            }
+
+            break;
+          case 'setVisibleAccounts':
+            const { addresses } = action;
+            accounts = uniq(accounts.concat(addresses));
+            fetchConfirmedEvents();
+
+            break;
+          default:
+            next(action);
+        }
+      };
     };
   }
 }

js/src/ui/Certifications/certifications.css

@@ -22,6 +22,7 @@
 .certification {
   display: inline-block;
   position: relative;
+  margin-top: 1em;
   margin-right: .5em;
   padding: .3em .6em .2em 2.6em;
   border-radius: 1em;