inpage - automatic dapp reload

app/scripts/contentscript.js

@@ -1,5 +1,7 @@
 const LocalMessageDuplexStream = require('./lib/local-message-stream.js')
 const PortStream = require('./lib/port-stream.js')
+const ObjectMultiplex = require('./lib/obj-multiplex')
+
 
 
 // inject in-page script
@@ -15,13 +17,22 @@ var pageStream = new LocalMessageDuplexStream({
   name: 'contentscript',
   target: 'inpage',
 })
+pageStream.on('error', console.error.bind(console))
 var pluginPort = chrome.runtime.connect({name: 'contentscript'})
 var pluginStream = new PortStream(pluginPort)
-
-// forward communication across
-pageStream.pipe(pluginStream)
-pluginStream.pipe(pageStream)
-
-// log errors
-pageStream.on('error', console.error.bind(console))
 pluginStream.on('error', console.error.bind(console))
+
+// forward communication plugin->inpage
+pageStream.pipe(pluginStream).pipe(pageStream)
+
+// connect contentscript->inpage control stream
+var mx = ObjectMultiplex()
+mx.on('error', console.error.bind(console))
+mx.pipe(pageStream)
+var controlStream = mx.createStream('control')
+controlStream.on('error', console.error.bind(console))
+
+// if we lose connection with the plugin, trigger tab refresh 
+pluginStream.on('close', function(){
+  controlStream.write({ method: 'reset' })
+})

app/scripts/inpage.js

@@ -5,6 +5,7 @@ const LocalMessageDuplexStream = require('./lib/local-message-stream.js')
 const setupMultiplex = require('./lib/stream-utils.js').setupMultiplex
 const RemoteStore = require('./lib/remote-store.js').RemoteStore
 const Web3 = require('web3')
+const once = require('once')
 restoreContextAfterImports()
 
 // rename on window
@@ -24,32 +25,61 @@ var pluginStream = new LocalMessageDuplexStream({
   target: 'contentscript',
 })
 var mx = setupMultiplex(pluginStream)
-// connect features
+
+// connect to provider
 var remoteProvider = new StreamProvider()
 remoteProvider.pipe(mx.createStream('provider')).pipe(remoteProvider)
 remoteProvider.on('error', console.error.bind(console))
 
+// subscribe to metamask public config
 var initState = JSON.parse(localStorage['MetaMask-Config'] || '{}')
 var publicConfigStore = new RemoteStore(initState)
 var storeStream = publicConfigStore.createStream()
 storeStream.pipe(mx.createStream('publicConfig')).pipe(storeStream)
-
 publicConfigStore.subscribe(function(state){
   localStorage['MetaMask-Config'] = JSON.stringify(state)
 })
 
-
 //
-// global web3
+// setup web3
 //
 
 var web3 = new Web3(remoteProvider)
-window.web3 = web3
 web3.setProvider = function(){
   console.log('MetaMask - overrode web3.setProvider')
 }
 console.log('MetaMask - injected web3')
 
+//
+// automatic dapp reset
+//
+
+// export web3 as a global, checking for usage
+var pageIsUsingWeb3 = false
+var resetWasRequested = false
+window.web3 = ensnare(web3, once(function(){
+  // if web3 usage happened after a reset request, trigger reset late
+  if (resetWasRequested) return triggerReset()
+  // mark web3 as used
+  pageIsUsingWeb3 = true
+  // reset web3 reference
+  window.web3 = web3
+}))
+
+// listen for reset requests
+mx.createStream('control').once('data', function(){
+  resetWasRequested = true
+  // ignore if web3 was not used
+  if (!pageIsUsingWeb3) return
+  // reload after short timeout
+  triggerReset()
+})
+
+function triggerReset(){
+  setTimeout(function(){
+    window.location.reload()
+  }, 500)
+}
 
 //
 // handle synchronous requests
@@ -104,6 +134,34 @@ remoteProvider.send = function(payload){
   }
 }
 
+
+//
+// util
+//
+
+// creates a proxy object that calls cb everytime the obj's properties/fns are accessed
+function ensnare(obj, cb){
+  var proxy = {}
+  Object.keys(obj).forEach(function(key){
+    var val = obj[key]
+    switch (typeof val) {
+      case 'function':
+        proxy[key] = function(){
+          cb()
+          val.apply(obj, arguments)
+        }
+        return
+      default:
+        Object.defineProperty(proxy, key, {
+          get: function(){ cb(); return obj[key] },
+          set: function(val){ cb(); return obj[key] = val },
+        })
+        return
+    }
+  })
+  return proxy
+}
+
 // need to make sure we aren't affected by overlapping namespaces
 // and that we dont affect the app with our namespace
 // mostly a fix for web3's BigNumber if AMD's "define" is defined...

app/scripts/lib/local-message-stream.js

@@ -23,7 +23,7 @@ function LocalMessageDuplexStream(opts){
 
 LocalMessageDuplexStream.prototype._onMessage = function(event){
   var msg = event.data
-  // console.log('LocalMessageDuplexStream ('+this._name+') - heard message...')
+  // console.log('LocalMessageDuplexStream ('+this._name+') - heard message...', event)
   // validate message
   if (event.origin !== location.origin) return //console.log('LocalMessageDuplexStream ('+this._name+') - rejected - (event.origin !== location.origin) ')
   if (typeof msg !== 'object') return //console.log('LocalMessageDuplexStream ('+this._name+') - rejected - (typeof msg !== "object") ')
@@ -31,7 +31,11 @@ LocalMessageDuplexStream.prototype._onMessage = function(event){
   if (!msg.data) return //console.log('LocalMessageDuplexStream ('+this._name+') - rejected - (!msg.data) ')
   // console.log('LocalMessageDuplexStream ('+this._name+') - accepted', msg.data)
   // forward message
-  this.push(msg.data)
+  try {
+    this.push(msg.data)
+  } catch(err) {
+    this.emit('error', err)
+  }
 }
 
 // stream plumbing

app/scripts/lib/port-stream.js

@@ -31,7 +31,8 @@ PortDuplexStream.prototype._onMessage = function(msg){
 
 PortDuplexStream.prototype._onDisconnect = function(){
   try {
-    this.end()
+    // this.end()
+    this.emit('close')
   } catch(err){
     this.emit('error', err)
   }
@@ -54,6 +55,7 @@ PortDuplexStream.prototype._write = function(msg, encoding, cb){
     }
     cb()
   } catch(err){
+    console.error(err)
     // this.emit('error', err)
     cb(new Error('PortDuplexStream - disconnected'))
   }

app/scripts/lib/stream-utils.js

@@ -27,7 +27,6 @@ function setupMultiplex(connectionStream){
   connectionStream.pipe(mx).pipe(connectionStream)
   mx.on('error', function(err) {
     console.error(err)
-    // connectionStream.destroy()
   })
   connectionStream.on('error', function(err) {
     console.error(err)

package.json

@@ -38,6 +38,7 @@
     "inject-css": "^0.1.1",
     "metamask-logo": "^1.1.5",
     "multiplex": "^6.7.0",
+    "once": "^1.3.3",
     "pojo-migrator": "^2.1.0",
     "polyfill-crypto.getrandomvalues": "^1.0.0",
     "pumpify": "^1.3.4",
@@ -46,7 +47,7 @@
     "react-dom": "^0.14.3",
     "react-hyperscript": "^2.2.2",
     "react-redux": "^4.0.3",
-    "readable-stream": "^2.0.5",
+    "readable-stream": "^2.1.2",
     "redux": "^3.0.5",
     "redux-logger": "^2.3.1",
     "redux-thunk": "^1.0.2",