3 files changed, 45 insertions, 0 deletions
diff --git a/app/scripts/background.js b/app/scripts/background.js
index 7eb7b1255..c0b00730d 100644
--- a/app/scripts/background.js
+++ b/app/scripts/background.js
@@ -253,6 +253,7 @@ function setupController (initState, initLangCode) {
     showUnconfirmedMessage: triggerUi,
     unlockAccountMessage: triggerUi,
     showUnapprovedTx: triggerUi,
+    showAddTokenUi: triggerUi,
     // initial state
     initState,
     // initial locale code
@@ -446,3 +447,4 @@ extension.runtime.onInstalled.addListener(function (details) {
     extension.tabs.create({url: 'https://metamask.io/#how-it-works'})
   }
 })
+
diff --git a/app/scripts/controllers/preferences.js b/app/scripts/controllers/preferences.js
index f6250dc16..8a4a63bb6 100644
--- a/app/scripts/controllers/preferences.js
+++ b/app/scripts/controllers/preferences.js
@@ -25,6 +25,7 @@ class PreferencesController {
       frequentRpcList: [],
       currentAccountTab: 'history',
       tokens: [],
+      suggestedTokens: {},
       useBlockie: false,
       featureFlags: {},
       currentLocale: opts.initLangCode,
@@ -35,6 +36,7 @@ class PreferencesController {
     this.diagnostics = opts.diagnostics
 
     this.store = new ObservableStore(initState)
+    this.showAddTokenUi = opts.showAddTokenUi
   }
 // PUBLIC METHODS
 
@@ -48,6 +50,45 @@ class PreferencesController {
     this.store.updateState({ useBlockie: val })
   }
 
+  getSuggestedTokens () {
+    return this.store.getState().suggestedTokens
+  }
+
+  addSuggestedToken (tokenOpts) {
+    // TODO: Validate params
+    const suggested = this.getSuggestedTokens()
+    suggested[tokenOpts.address] = suggested
+    this.store.updateState({ suggestedTokens: suggested })
+  }
+
+  /**
+   * RPC engine middleware for requesting new token added
+   *
+   * @param req
+   * @param res
+   * @param {Function} - next
+   * @param {Function} - end
+   */
+  requestAddToken(req, res, next, end) {
+    if (req.method === 'eth_watchToken') {
+      // TODO: Validate params!
+      const [ rawAddress, symbol, decimals ] = req.params
+
+      const tokenOpts = {
+        address: rawAddress,
+        decimals,
+        symbol,
+      }
+
+      this.addSuggestedToken(tokenOpts)
+      this.showAddTokenUi()
+
+      return end(rawAddress)
+    } else {
+      return next()
+    }
+  }
+
   /**
    * Getter for the `useBlockie` property
    *
diff --git a/app/scripts/metamask-controller.js b/app/scripts/metamask-controller.js
index bcc7075c2..e843ec660 100644
--- a/app/scripts/metamask-controller.js
+++ b/app/scripts/metamask-controller.js
@@ -87,6 +87,7 @@ module.exports = class MetamaskController extends EventEmitter {
     this.preferencesController = new PreferencesController({
       initState: initState.PreferencesController,
       initLangCode: opts.initLangCode,
+      showAddTokenUi: opts.showAddTokenUi,
     })
 
     // currency controller
@@ -1242,6 +1243,7 @@ module.exports = class MetamaskController extends EventEmitter {
     engine.push(createOriginMiddleware({ origin }))
     engine.push(createLoggerMiddleware({ origin }))
     engine.push(filterMiddleware)
+    engine.push(this.preferencesController.requestAddToken.bind(this.preferencesController))
     engine.push(createProviderMiddleware({ provider: this.provider }))
 
     // setup connection