1 files changed, 29 insertions, 1 deletions
diff --git a/packages/gitbook-core/src/reducers/navigation.js b/packages/gitbook-core/src/reducers/navigation.js
index 439ba21..a6d71f8 100644
--- a/packages/gitbook-core/src/reducers/navigation.js
+++ b/packages/gitbook-core/src/reducers/navigation.js
@@ -1,13 +1,20 @@
 const { Record, List } = require('immutable');
+const { createBrowserHistory, createMemoryHistory } = require('history');
 const ACTION_TYPES = require('../actions/TYPES');
 
+const isServerSide = (typeof window === 'undefined');
+
 const NavigationState = Record({
     // Are we loading a new page
     loading: Boolean(false),
     // Did we fail loading a page?
     error:   null,
     // Listener for history changes
-    listeners: List()
+    listeners: List(),
+    // Function to call to stop listening
+    unlisten: null,
+    // History instance
+    history: null
 });
 
 function reduceNavigation(state, action) {
@@ -30,6 +37,27 @@ function reduceNavigation(state, action) {
             error:   action.error
         });
 
+    case ACTION_TYPES.NAVIGATION_ACTIVATE:
+        const history = isServerSide ? createMemoryHistory() : createBrowserHistory();
+        const unlisten = history.listen(action.listener);
+
+        // We can't use .merge since it convert history to an immutable
+        const newState = state
+            .set('history', history)
+            .set('unlisten', unlisten);
+
+        return newState;
+
+    case ACTION_TYPES.NAVIGATION_DEACTIVATE:
+        if (state.unlisten) {
+            state.unlisten();
+        }
+
+        return state.merge({
+            history:  null,
+            unlisten: null
+        });
+
     case ACTION_TYPES.NAVIGATION_LISTEN:
         return state.merge({
             listeners: state.listeners.push(action.listener)