1 files changed, 35 insertions, 0 deletions
diff --git a/packages/gitbook-core/src/reducers/navigation.js b/packages/gitbook-core/src/reducers/navigation.js
new file mode 100644
index 0000000..a895186
--- /dev/null
+++ b/packages/gitbook-core/src/reducers/navigation.js
@@ -0,0 +1,35 @@
+const { Record } = require('immutable');
+const ACTION_TYPES = require('../actions/TYPES');
+
+const NavigationState = Record({
+    loading: false,
+    error:   null
+});
+
+function reduceNavigation(state, action) {
+    state = state || NavigationState();
+    switch (action.type) {
+
+    case ACTION_TYPES.PAGE_FETCH_START:
+        return state.merge({
+            loading: true
+        });
+
+    case ACTION_TYPES.PAGE_FETCH_END:
+        return state.merge({
+            loading: false
+        });
+
+    case ACTION_TYPES.PAGE_FETCH_ERROR:
+        return state.merge({
+            loading: false,
+            error:   action.error
+        });
+
+    default:
+        return state;
+
+    }
+}
+
+module.exports = reduceNavigation;