Side menu does not load in custom template

[SpaceShaman]

Hello.
When I create a custom template and load it using the view in the application, the side menu does not appear.

My template looks like:

{% extends "admin/base_site.html" %}
{% load i18n admin_urls static admin_modify jazzmin %}
{% get_jazzmin_settings request as jazzmin_settings %}

{% block content %}

<form method="post" action="{% url 'parts:parts_save' category part_type %}">{% csrf_token %}
  {{ form.as_p }}
  {% if part_id %}
    <input type="hidden" name="part_id" id="id_part_id" value={{ part_id }}>
  {% endif %}
  <input type="submit" value="Save">
</form>

{% endblock %}

And this is what the view calling this template looks like:

    def change_view(self, request, category, part_type, part_id):
        part = get_object_or_404(Part, id=part_id)
        form = self.get_form(category, part_type)
        for field_name, field in form.fields.items():
            field.initial = getattr(part, field_name)

        context = {
            'form': form,
            'category': category,
            'part_type': part_type,
            'part_id': part_id,
        }
        return render(request, 'parts/part_form.html', context=context)

Do you have an idea how I can solve this problem?

[SpaceShaman]

Ok, I already know that I need to send 'available_apps' in context dictionary which will contain the list of applications. But how do I get this list? I try to do this using the get_app_list method from classy AdminSite found in django/contrib/admin/sites.py but I get an empty list.

from django.contrib.admin.sites import AdminSite

    def change_view(self, request, category, part_type, part_id):
        ...

        context = {
            ...
            'available_apps': AdminSite().get_app_list(request)
        }
        return render(request, 'parts/part_form.html', context=context)

[SpaceShaman]

Okay, I solved this problem a bit around the corner.
I defined a function that returns a dictionary with menu items, and I creat an additional context processor for it.

def get_menu_list() -> Dict:
    """ Get menu list to use in side_menu admin template and index admin template. """
    menu_list = {}  # type: Dict[str, List]

    settings_head_icon = 'fas fa-cogs'
    menu_list['Settings'] = [
        {
            'name': 'Users',
            'changelist_url': reverse('admin:auth_user_changelist'),
            'icon': 'fas fa-user-cog',
            'head_icon': settings_head_icon,
            'view_permissions': ['auth.view_user']
        },
        {
            'name': 'Grups',
            'changelist_url': reverse('admin:auth_group_changelist'),
            'icon': 'fas fa-users',
            'head_icon': settings_head_icon,
            'view_permissions': ['auth.view_group']
        }]

    return menu_list


def extra_context_procesor(request):
    """ Context processor which adds to each rendered page a menu_list to context.
    It needs to be added in the settings.py file as in the example below.
    TEMPLATES = [{
        ...
        'OPTIONS': {
            'context_processors': [
                ...
                'parts.menu_list.extra_context_procesor'
            ],},},]
    """
    return {'menu_list': get_menu_list()}

And I override base.html templates like this:

<li class="nav-item">
    <a href="{% url 'admin:index' %}" class="nav-link">
        <i class="nav-icon fas fa-home"></i>
        <p>Dashboard</p>
    </a>
</li>
{% if jazzmin_settings.navigation_expanded %}
{% for header, app in menu_list.items %}
    <li class="nav-header">{{ header }}</li>
    {% for model in app %}
        <li class="nav-item">
            {% if model.changelist_url %}
                <a href="{{ model.changelist_url }}" class="nav-link">
                    <i class="nav-icon {{ model.icon }}"></i> <p>{{ model.name }}</p>
                </a>
            {% else %}
                <span class="nav-link disabled">
                    <i class="nav-icon {{ model.icon }}"></i> <p>{{ model.name }}</p>
                </span>
            {% endif %}
        </li>
    {% endfor %}
{% endfor %}
{% else %}
{% for header, app in menu_list.items %}
    <li class="nav-item has-treeview">
        <a href="#" class="nav-link">
            <i class="nav-icon {{ app.0.head_icon }}"></i>
            <p>{{ header }} <i class="fas fa-angle-left right"></i></p>
        </a>
        <ul class="nav nav-treeview" style="display: none;">
            {% for model in app %}
                <li class="nav-item">
                    <a href="{% if model.changelist_url %}{{ model.changelist_url }}{% else %}javascript:void(0){% endif %}" class="nav-link">
                        <i class="nav-icon {{ model.icon }}"></i>
                        <p>{{ model.name }}</p>
                    </a>
                </li>
            {% endfor %}
        </ul>
    </li>
{% endfor %}
{% endif %}