Generalize the Javascript menu rendering into an API for templates that only refresh the menu when there are changes. Closes GitLab issue #511. Thanks to Daniel Carrico @daniel1113 for the report.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

HISTORY.rst

@@ -147,6 +147,10 @@
 - Improve the speed of the document indexing.
 - Move the matchHeight call from lazy loading to image loading.
   Reduces the chance of wrongly sized cards.
+- Generalize the Javascript menu rendering into an API for 
+  templates that only refresh the menu when there are changes.
+  Closes GitLab issue #511. Thanks to Daniel Carrico
+  @daniel1113 for the report.
 
 3.0.3 (2018-08-17)
 ==================

docs/releases/3.1.rst

@@ -363,6 +363,10 @@ classes beyond the provide line chart.
 - Improve the speed of the document indexing.
 - Move the matchHeight call from lazy loading to image loading.
   Reduces the chance of wrongly sized cards.
+- Generalize the Javascript menu rendering into an API for 
+  templates that only refresh the menu when there are changes.
+  Closes GitLab issue #511. Thanks to Daniel Carrico
+  @daniel1113 for the report.
 
 Removals
 --------
@@ -446,5 +450,6 @@ Bugs fixed or issues closed
 * `GitLab issue #7 <https://gitlab.com/mayan-edms/mayan-edms/issues/7>`_ Feature: other compressors than zip for compressed documents
 * `GitLab issue #259 <https://gitlab.com/mayan-edms/mayan-edms/issues/259>`_ Thumbnails: why are they created on the fly (therefore: not cached)
 * `GitLab issue #360 <https://gitlab.com/mayan-edms/mayan-edms/issues/360>`_ Should quick rename (optionally) retain original file type extension?
+* `GitLab issue #511 <https://gitlab.com/mayan-edms/mayan-edms/issues/511>`_ Menu bar flickering in 3.1b1
   
 .. _PyPI: https://pypi.python.org/pypi/mayan-edms/

mayan/apps/appearance/static/appearance/js/mayan_app.js

@@ -8,6 +8,15 @@ class MayanApp {
 
         this.ajaxSpinnerSeletor = '#ajax-spinner';
         this.ajaxExecuting = false;
+        this.ajaxMenusOptions = [
+            {
+                app: this,
+                interval: 5000,
+                menuSelector: '#main-menu',
+                url: apiTemplateMainMenuURL,
+            }
+        ];
+        this.ajaxMenuHashes = {};
         this.window = $(window);
     }
 
@@ -113,25 +122,22 @@ class MayanApp {
         }
     }
 
-    doRefreshMainMenu (options) {
-        var self = this;
-        var $mainMenu = $('#main-menu');
-        var $mainMenuBuffer = $('#main-menu-buffer');
-
+    doRefreshAJAXMenu (options) {
         $.ajax({
             complete: function() {
-                setTimeout(app.doRefreshMainMenu, options.interval, options);
+                setTimeout(app.doRefreshAJAXMenu, options.interval, options);
             },
             success: function(data) {
-                var $elements = $('.dropdown.open');
-                if ($elements.length === 0) {
-                    // Don't refresh the HTML if there are open dropdowns
-                    $mainMenuBuffer.html(data);
-                    $mainMenuBuffer.show();
-                    $mainMenu.hide();
-                    $mainMenu.html($mainMenuBuffer.html());
-                    $mainMenu.show();
-                    $mainMenuBuffer.hide();
+                console.log(data);
+                var menuHash = options.app.ajaxMenuHashes[data.name];
+                console.log('menuHash' + menuHash);
+
+                if ((menuHash === undefined) || (menuHash !== data.hex_hash)) {
+                    $(options.menuSelector).html(data.html);
+                    if (options.callback !== undefined) {
+                        options.callback();
+                    }
+                    options.app.ajaxMenuHashes[data.name] = data.hex_hash;
                 }
             },
             url: options.url,
@@ -217,9 +223,8 @@ class MayanApp {
         this.setupItemsSelector();
         this.setupNavbarCollapse();
         this.setupNewWindowAnchor();
-        this.doRefreshMainMenu({
-            interval: 5000,
-            url: '/main_menu'
+        $.each(this.ajaxMenusOptions, function(index, value) {
+            app.doRefreshAJAXMenu(value);
         });
         partialNavigation.initialize();
     }

mayan/apps/appearance/templates/appearance/root.html

@@ -36,7 +36,6 @@
             <div id="main-menu">
                 {% include 'appearance/main_menu.html' %}
             </div>
-            <div id="main-menu-buffer" style="display: none;"></div>
             <div class="container-fluid">
                 <div class="row">
                     <div class="col-xs-12">
@@ -114,6 +113,7 @@
             {# Transfer variable from Django to javascript #}
             var initialURL = '{% url home_view %}';
             var djangoDEBUG = {% if debug %}true{% else %}false{% endif %};
+            var apiTemplateMainMenuURL = '{% url "rest_api:template-detail" "main_menu" %}';
         </script>
         <script src="{% static 'appearance/js/base.js' %}" type="text/javascript"></script>
         <script>

mayan/apps/common/api_views.py

@@ -4,7 +4,8 @@ from django.contrib.contenttypes.models import ContentType
 
 from rest_framework import generics
 
-from .serializers import ContentTypeSerializer
+from .classes import Template
+from .serializers import ContentTypeSerializer, TemplateSerializer
 
 
 class APIContentTypeList(generics.ListAPIView):
@@ -13,3 +14,14 @@ class APIContentTypeList(generics.ListAPIView):
     """
     serializer_class = ContentTypeSerializer
     queryset = ContentType.objects.order_by('app_label', 'model')
+
+
+class APITemplateView(generics.RetrieveAPIView):
+    """
+    Returns the selected partial template details.
+    get: Retrieve the details of the partial template.
+    """
+    serializer_class = TemplateSerializer
+
+    def get_object(self):
+        return Template.get(self.kwargs['name']).render(request=self.request)

mayan/apps/common/apps.py

@@ -17,6 +17,7 @@ from django.utils.translation import ugettext_lazy as _
 
 from mayan.celery import app
 
+from .classes import Template
 from .handlers import (
     handler_pre_initial_setup, handler_pre_upgrade,
     user_locale_profile_session_config, user_locale_profile_create
@@ -89,6 +90,10 @@ class CommonApp(MayanAppConfig):
         if check_for_sqlite():
             warnings.warn(force_text(MESSAGE_SQLITE_WARNING))
 
+        Template(
+            name='main_menu', template_name='appearance/main_menu.html'
+        )
+
         app.conf.CELERYBEAT_SCHEDULE.update(
             {
                 'task_delete_stale_uploads': {

mayan/apps/common/classes.py

@@ -1,8 +1,12 @@
 from __future__ import unicode_literals
 
+import hashlib
+
 from django.apps import apps
+from django.conf import settings
 from django.db import models
 from django.template import loader
+from django.template.response import TemplateResponse
 from django.urls import reverse
 from django.utils.encoding import force_text, python_2_unicode_compatible
 from django.utils.translation import ugettext
@@ -287,3 +291,33 @@ class PropertyHelper(object):
         by each subclass.
         """
         raise NotImplementedError
+
+
+class Template(object):
+    _registry = {}
+
+    @classmethod
+    def get(cls, name):
+        return cls._registry[name]
+
+    def __init__(self, name, template_name):
+        self.name = name
+        self.template_name = template_name
+        self.__class__._registry[name] = self
+
+    def get_absolute_url(self):
+        return reverse('rest_api:template-detail', args=(self.name,))
+
+    def render(self, request):
+        context = {
+            'home_view': settings.HOME_VIEW,
+        }
+        result = TemplateResponse(
+            request=request,
+            template=self.template_name,
+            context=context,
+        ).render()
+
+        self.html = result.content
+        self.hex_hash = hashlib.sha256(result.content).hexdigest()
+        return self

mayan/apps/common/serializers.py

@@ -9,3 +9,9 @@ class ContentTypeSerializer(serializers.ModelSerializer):
     class Meta:
         fields = ('app_label', 'id', 'model')
         model = ContentType
+
+
+class TemplateSerializer(serializers.Serializer):
+    hex_hash = serializers.CharField(read_only=True)
+    name = serializers.CharField(read_only=True)
+    html = serializers.CharField(read_only=True)

mayan/apps/common/urls.py

@@ -3,11 +3,11 @@ from __future__ import unicode_literals
 from django.conf.urls import url
 from django.views.i18n import javascript_catalog, set_language
 
-from .api_views import APIContentTypeList
+from .api_views import APIContentTypeList, APITemplateView
 from .views import (
     AboutView, CheckVersionView, CurrentUserDetailsView, CurrentUserEditView,
     CurrentUserLocaleProfileDetailsView, CurrentUserLocaleProfileEditView,
-    FaviconRedirectView, HomeView, LicenseView, MainMenuView,
+    FaviconRedirectView, HomeView, LicenseView,
     ObjectErrorLogEntryListClearView, ObjectErrorLogEntryListView,
     PackagesLicensesView, RootView, SetupListView, ToolsListView,
     multi_object_action_view
@@ -22,7 +22,6 @@ urlpatterns = [
         name='check_version_view'
     ),
     url(r'^license/$', LicenseView.as_view(), name='license_view'),
-    url(r'^main_menu/$', MainMenuView.as_view(), name='main_menu_view'),
     url(
         r'^packages/licenses/$', PackagesLicensesView.as_view(),
         name='packages_licenses_view'
@@ -78,4 +77,8 @@ api_urls = [
         r'^content_types/$', APIContentTypeList.as_view(),
         name='content-type-list'
     ),
+    url(
+        r'^templates/(?P<name>[-\w]+)/$', APITemplateView.as_view(),
+        name='template-detail'
+    ),
 ]

mayan/apps/common/views.py

@@ -168,11 +168,6 @@ class LicenseView(SimpleView):
     template_name = 'appearance/generic_form.html'
 
 
-class MainMenuView(SimpleView):
-    extra_context = {'home_view': settings.HOME_VIEW}
-    template_name = 'appearance/main_menu.html'
-
-
 class ObjectErrorLogEntryListClearView(ConfirmView):
     def get_extra_context(self):
         return {