feat: persist navigation state only for the current session (#110)

Fixes #78

assets/js/components/tree.js

@@ -16,7 +16,7 @@ class Tree {
     constructor(el) {
         this._el = $(el);
         this._id = this._el[0].id;
-        this._state = storage.get(`tree.${this._id}.state`, []);
+        this._state = storage.get(`tree.${this._id}.state`, [], 'session');
         this._collections = $.map(this._el.find('[data-behaviour="collection"]'), (c) => new TreeCollection(c, this));
         this._collapseButton = this._el.find('[data-behaviour="collapse-tree"]');
 
@@ -61,7 +61,7 @@ class Tree {
 
     saveState() {
         this._state = this._collections.filter((c) => c.isOpen).map((c) => c.id);
-        storage.set(`tree.${this._id}.state`, this._state);
+        storage.set(`tree.${this._id}.state`, this._state, 'session');
         this._updateCollapseButtonVisibility();
     }
 

assets/js/storage.js

@@ -1,12 +1,17 @@
 'use strict';
 
+const storages = {
+    local: localStorage,
+    session: sessionStorage,
+};
+
 module.exports = {
-    get(name, fallback) {
-        const result = localStorage.getItem(name);
+    get(name, fallback, storage = 'local') {
+        const result = storages[storage].getItem(name);
         return result ? JSON.parse(result) : fallback;
     },
 
-    set(name, value) {
-        localStorage.setItem(name, JSON.stringify(value));
+    set(name, value, storage = 'local') {
+        storages[storage].setItem(name, JSON.stringify(value));
     },
 };