add memorization of user's position in planning navigation

Gemfile

@@ -39,10 +39,11 @@ gem 'bootstrap4-datetime-picker-rails'
 gem 'cocoon', '~> 1.2', '>= 1.2.12' # Dynamic nested forms
 gem 'devise', '~> 4.7' # Users login/registration management
 gem 'devise_invitable', '~> 2.0.0'
-gem 'draper'
+gem 'draper' # decorators manager
 gem 'dry-transaction'
 gem 'httparty' # Http requests
 gem 'ice_cube' # Calendar events recurrence (for Missions)
+gem 'js_cookie_rails' # Cookie manager for js
 gem 'leaflet-rails' # GeoMap generator
 gem 'mailjet' # Production mailer API
 gem 'pundit' # Authorization management

Gemfile.lock

@@ -256,6 +256,8 @@ GEM
       rails-dom-testing (>= 1, < 3)
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
+    js_cookie_rails (2.2.0)
+      railties (>= 3.1)
     json (2.3.1)
     kaminari (1.2.1)
       activesupport (>= 4.1.0)
@@ -597,6 +599,7 @@ DEPENDENCIES
   image_processing (~> 1.9, >= 1.9.3)
   jbuilder (~> 2.5)
   jquery-rails
+  js_cookie_rails
   leaflet-rails
   letter_opener
   listen (>= 3.0.5, < 3.2)

app/assets/javascripts/application.js

@@ -54,3 +54,4 @@
 //= require thredded
 //= require thredded-custom
 //= require flash_messages_on_xhr
+//= require js.cookie

app/assets/javascripts/fullCalendar.js

@@ -1,4 +1,5 @@
 //= require full_calendar
+//= require js.cookie
 
 document.addEventListener('turbolinks:load', () => {
   const calendarEl = document.getElementById('calendar');
@@ -8,6 +9,7 @@ document.addEventListener('turbolinks:load', () => {
       themeSystem: 'bootstrap',
       height: 'auto',
       defaultView: 'timeGridWeek',
+      defaultDate: Cookies.get('positionInPlanning'), // The displayed date when the calendar is loaded
       allDaySlot: false,
       firstDay: 1,
       locale: 'fr',
@@ -41,6 +43,8 @@ document.addEventListener('turbolinks:load', () => {
           return weekTypes[weekCountBetweenReferenceAndCurrentHour % 4];
         };
 
+        Cookies.set('positionInPlanning', info.view.currentStart);
+
         if (info.view.type === 'timeGridWeek') {
           const currentStart = new Date(info.view.currentStart);
           document.getElementsByClassName('fc-center')[0].firstChild.textContent += ` ${weekType(currentStart)}`;