clean up eventSyncer code

src/eventSyncer.js

@@ -1,20 +1,18 @@
 const { fromEvent, interval, ReplaySubject } = require('rxjs');
-const { throttle, filter, distinctUntilChanged } = require('rxjs/operators');
-const loki = require('lokijs')
-const Events = require('events')
-
-function randomString() {
-  return Math.random().toString(36).substring(2, 15) + Math.random().toString(36).substring(2, 15);
-}
+const { throttle, distinctUntilChanged } = require('rxjs/operators');
+const { randomString } = require('./utils.js');
+const loki = require('lokijs');
+const Events = require('events');
 
 class EventSyncer {
 
+  // TODO: pass provider instead of web3 object
   constructor(web3) {
-    // this.events = events;
     this.events = new Events;
     this.web3 = web3;
   }
 
+  // TODO: pass config on where to save database
   init(cb) {
     this.db = new loki('phoenix.db', {
       autoload: true,
@@ -22,7 +20,7 @@ class EventSyncer {
         this.databaseInitialize(cb)
       },
       autosave: true,
-      autosaveInterval: 2000 // save every four seconds for our example
+      autosaveInterval: 2000
     })
   }
 
@@ -39,22 +37,18 @@ class EventSyncer {
     }
 
     let dbChanges = fromEvent(this.events, "updateDB")
-
     dbChanges.pipe(throttle(val => interval(400))).subscribe(() => {
-      console.dir("saving database...")
       this.db.saveDatabase()
     })
 
     cb();
   }
 
-  // trackEvent(eventName, filterConditions) {
   trackEvent(contractInstance, eventName, filterConditionsOrCb) {
     // let eventKey = eventName + "-from0x123";
     let eventKey = eventName;
     let namespace = randomString()
 
-
     let filterConditions, filterConditionsCb;
     if (typeof filterConditionsOrCb === 'function') {
       filterConditionsCb = filterConditionsOrCb
@@ -69,13 +63,10 @@ class EventSyncer {
       lastEvent = tracked.find({ "eventName": eventName })[0]
     }
 
-    console.dir("last id was " + lastEvent.id)
-
     let sub = new ReplaySubject();
 
     let children = this.db.getCollection('children')
     for (let previous of children.find({ 'eventKey': eventKey })) {
-      console.dir("checking previous event: " + previous.id)
       sub.next(previous)
     }
 
@@ -97,9 +88,7 @@ class EventSyncer {
         }
 
         for (let prop of propsToFilter) {
-          if (filterConditions.filter[prop] !== event.returnValues[prop]) {
-            return;
-          }
+          if (filterConditions.filter[prop] !== event.returnValues[prop]) return;
         }
       } else if (filterConditionsCb) {
         if (!filterConditionsCb(event.returnValues)) {
@@ -110,56 +99,34 @@ class EventSyncer {
       this.events.emit("event-" + eventName + "-" + namespace, event);
     }])
 
-    // contractObserver.pipe(filter((x) => x.id > lastEvent.id)).pipe(filter(filterConditions)).subscribe((e) => {
-    contractObserver.pipe().subscribe((e) => {
-      console.dir("------- syncing event");
-      e.eventKey = eventKey
-      // console.dir(e);
-      if (children.find({ 'id': e.id }).length > 0) {
-        console.dir("event already synced: " + e.id)
-      } else {
     // TODO: would be nice if trackEvent was smart enough to understand the type of returnValues and do the needed conversions
-        if (e.returnValues['$loki']) { // was already saved / synced
-          console.dir("already synced")
-          return sub.next(e.returnValues)
-        }
+    contractObserver.pipe().subscribe((e) => {
+      e.eventKey = eventKey
+      if (children.find({ 'id': e.id }).length > 0) return;
+      if (e.returnValues['$loki']) return sub.next(e.returnValues)
+
       children.insert(e.returnValues)
       tracked.updateWhere(((x) => x.eventName === eventName), ((x) => x.id = e.id))
       this.events.emit("updateDB")
       sub.next(e.returnValues)
-      }
     })
 
     return sub;
   }
 
-  trackProperty(contractInstance, propName, filterConditionsOrCb) {
-    // let eventKey = propName + "-from0x123";
-    let eventKey = propName;
-    let namespace = randomString()
-
-    let filterConditions, filterConditionsCb;
-    if (typeof filterConditionsOrCb === 'function') {
-      filterConditionsCb = filterConditionsOrCb
-    } else {
-      filterConditions = filterConditionsOrCb
-    }
-
-    let tracked = this.db.getCollection('tracked')
-
+  // TODO: should save value in database
+  trackProperty(contractInstance, propName, methodArgs, callArgs) {
     let sub = new ReplaySubject();
 
-    let children = this.db.getCollection('children')
-
     // TODO: use call args from user
     let method = contractInstance.methods[propName].apply(contractInstance.methods[propName], [])
 
-    method.call.apply(method.call, [(filterConditions || {}), (err, result) => {
+    method.call.apply(method.call, [{}, (err, result) => {
       sub.next(result)
     }])
 
-    var subscription = this.web3.eth.subscribe('newBlockHeaders', function (error, result) {
-      method.call.apply(method.call, [(filterConditions || {}), (err, result) => {
+    this.web3.eth.subscribe('newBlockHeaders', function (error, result) {
+      method.call.apply(method.call, [({}), (err, result) => {
         sub.next(result)
       }])
     })
@@ -169,8 +136,4 @@ class EventSyncer {
 
 }
 
-// process.on('exit', function () {
-//   db.close()
-// });
-
 module.exports = EventSyncer;

src/utils.js

@@ -0,0 +1,8 @@
+
+function randomString() {
+  return Math.random().toString(36).substring(2, 15) + Math.random().toString(36).substring(2, 15);
+}
+
+module.exports = {
+  randomString
+};