inpage - refactor for modularity

1 files changed, 123 insertions, 0 deletions

diff --git a/app/scripts/lib/inpage-provider.js b/app/scripts/lib/inpage-provider.js
new file mode 100644
index 000000000..66681c3a9
--- /dev/null
+++ b/app/scripts/lib/inpage-provider.js
@@ -0,0 +1,123 @@
+const HttpProvider = require('web3/lib/web3/httpprovider')
+const Streams = require('mississippi')
+const ObjectMultiplex = require('./obj-multiplex')
+const StreamProvider = require('./stream-provider.js')
+const RemoteStore = require('./remote-store.js').RemoteStore
+const MetamaskConfig = require('../config.js')
+
+module.exports = MetamaskInpageProvider
+
+
+function MetamaskInpageProvider(connectionStream){
+  const self = this
+
+  // setup connectionStream multiplexing 
+  var multiStream = ObjectMultiplex()
+  Streams.pipe(connectionStream, multiStream, connectionStream, function(err){
+    console.warn('MetamaskInpageProvider - lost connection to MetaMask')
+    if (err) throw err
+  })
+  self.multiStream = multiStream
+
+  // subscribe to metamask public config
+  var publicConfigStore = remoteStoreWithLocalStorageCache('MetaMask-Config')
+  var storeStream = publicConfigStore.createStream()
+  Streams.pipe(storeStream, multiStream.createStream('publicConfig'), storeStream, function(err){
+    console.warn('MetamaskInpageProvider - lost connection to MetaMask publicConfig')
+    if (err) throw err
+  })
+  self.publicConfigStore = publicConfigStore
+
+  // connect to sync provider
+  self.syncProvider = createSyncProvider(publicConfigStore.get('provider'))
+  // subscribe to publicConfig to update the syncProvider on change
+  publicConfigStore.subscribe(function(state){
+    self.syncProvider = createSyncProvider(state.provider)
+  })
+
+  // connect to async provider
+  var asyncProvider = new StreamProvider()
+  Streams.pipe(asyncProvider, multiStream.createStream('provider'), asyncProvider, function(err){
+    console.warn('MetamaskInpageProvider - lost connection to MetaMask provider')
+    if (err) throw err
+  })
+  asyncProvider.on('error', console.error.bind(console))
+  self.asyncProvider = asyncProvider
+  // overwrite own sendAsync method
+  self.sendAsync = asyncProvider.sendAsync.bind(asyncProvider)
+}
+
+MetamaskInpageProvider.prototype.send = function(payload){
+  const self = this
+
+  var result = null
+  switch (payload.method) {
+
+    case 'eth_accounts':
+      // read from localStorage
+      var selectedAddress = self.publicConfigStore.get('selectedAddress')
+      result = selectedAddress ? [selectedAddress] : []
+      break
+
+    case 'eth_coinbase':
+      // read from localStorage
+      var selectedAddress = self.publicConfigStore.get('selectedAddress')
+      result = selectedAddress || '0x0000000000000000000000000000000000000000'
+      break
+
+    // fallback to normal rpc
+    default:
+      return self.syncProvider.send(payload)
+
+  }
+
+  // return the result
+  return {
+    id: payload.id,
+    jsonrpc: payload.jsonrpc,
+    result: result,
+  }
+}
+
+MetamaskInpageProvider.prototype.sendAsync = function(){
+  throw new Error('MetamaskInpageProvider - sendAsync not overwritten')
+}
+
+MetamaskInpageProvider.prototype.isConnected = function(){
+  return true
+}
+
+// util
+
+function createSyncProvider(providerConfig){
+  providerConfig = providerConfig || {}
+  var syncProviderUrl = undefined
+
+  if (providerConfig.rpcTarget) {
+    syncProviderUrl = providerConfig.rpcTarget
+  } else {
+    switch(providerConfig.type) {
+      case 'testnet':
+        syncProviderUrl = MetamaskConfig.network.testnet
+        break
+      case 'mainnet':
+        syncProviderUrl = MetamaskConfig.network.mainnet
+        break
+      default:
+        syncProviderUrl = MetamaskConfig.network.default
+    }
+  }
+  return new HttpProvider(syncProviderUrl)
+}
+
+function remoteStoreWithLocalStorageCache(storageKey){
+  // read local cache
+  var initState = JSON.parse(localStorage[storageKey] || '{}')
+  var store = new RemoteStore(initState)
+  // cache the latest state locally
+  store.subscribe(function(state){
+    localStorage[storageKey] = JSON.stringify(state)
+  })
+
+  return store
+}
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