Add navigation buttons for `django-unfold`

mixins.py

"""
backend/apps/core/mixins.py
"""

from urllib.parse import parse_qsl

from django.contrib.admin.widgets import RelatedFieldWidgetWrapper
from django.db import models
from django.utils.safestring import mark_safe
from guardian.admin import GuardedModelAdmin
from import_export.admin import ImportExportModelAdmin
from simple_history.admin import SimpleHistoryAdmin
from unfold.admin import ModelAdmin, StackedInline, TabularInline
from unfold.contrib.import_export.forms import ImportForm, SelectableFieldsExportForm
from unfold.decorators import display
from unfold.widgets import UnfoldAdminSingleDateWidget

from .widgets import WysiwygWidget


class SoeAdminMixin(ModelAdmin, SimpleHistoryAdmin, GuardedModelAdmin, ImportExportModelAdmin):
    """
    This class represents a base admin interface mixin.
    """

    list_per_page = 200
    import_form_class = ImportForm
    export_form_class = SelectableFieldsExportForm
    list_fullwidth = True
    warn_unsaved_form = True
    formfield_overrides = {
        models.TextField: {
            "widget": WysiwygWidget,
        },
        models.DateField: {
            "widget": UnfoldAdminSingleDateWidget(
                # format="%m-%d-%Y",
                attrs={"placeholder": "MM-DD-YYYY"},
            ),
            # "input_formats": ["%m-%d-%Y"],
        },
    }

    @display(description="Notes", ordering="notes")
    def display_notes(self, obj):
        """Display notes as HTML in list view."""
        if obj.notes:
            return mark_safe(obj.notes)
        return "-"

    @display(description="Address", ordering="address")
    def display_address(self, obj):
        """Display address as HTML in list view."""
        if obj.address:
            return mark_safe(obj.address)
        return "-"

    def get_form(self, request, obj=None, **kwargs):
        form = super().get_form(request, obj, **kwargs)
        for _field_name, form_field in form.base_fields.items():
            widget = form_field.widget
            # Check if the widget is a RelatedFieldWidgetWrapper instance
            if isinstance(widget, RelatedFieldWidgetWrapper):
                widget.can_add_related = False
                widget.can_change_related = False
                widget.can_delete_related = False
                widget.can_view_related = False
        return form

    def change_view(self, request, object_id, form_url="", extra_context=None):
        extra_context = extra_context or {}
        obj = self.get_object(request, object_id)

        # Get the base queryset
        qs = self.get_queryset(request)

        # Get and parse filters from the request
        changelist_filters = request.GET.get("_changelist_filters", "")
        if changelist_filters:
            try:
                # Parse the URL-encoded filter string
                filter_dict = dict(parse_qsl(changelist_filters))
                # Apply each filter to the queryset
                qs = qs.filter(**filter_dict)
            except Exception as e:
                # Log error but continue with unfiltered queryset
                print(f"Error applying filters: {e}")

        # Get the ordering from the request
        ordering = request.GET.get("o")  # Django's default ordering parameter
        if ordering:
            try:
                # Convert ordering parameter to field names
                order_fields = []
                for field_index in ordering.split("."):
                    try:
                        index = int(field_index)
                        # Get the actual field from list_display
                        field = self.get_list_display(request)[abs(index)]
                        # If index is negative, it's descending order
                        if index < 0:
                            field = "-" + field
                        order_fields.append(field)
                    except (ValueError, IndexError):
                        continue
                if order_fields:
                    qs = qs.order_by(*order_fields)
            except Exception as e:
                print(f"Error applying ordering: {e}")
        else:
            # Use default ordering from model or admin
            ordering = self.get_ordering(request) or ()
            qs = qs.order_by(*ordering) if ordering else qs.order_by("name")

        # Get the list of IDs in the correct order
        ordered_ids = list(qs.values_list("id", flat=True))

        try:
            # Find current position
            current_position = ordered_ids.index(obj.pk)

            # Get prev/next objects
            prev_obj = None if current_position == 0 else self.model.objects.get(pk=ordered_ids[current_position - 1])
            next_obj = None if current_position == len(ordered_ids) - 1 else self.model.objects.get(pk=ordered_ids[current_position + 1])
        except (ValueError, IndexError):
            prev_obj = next_obj = None

        # Add navigation context
        extra_context.update({
            "prev_obj": prev_obj,
            "next_obj": next_obj,
            "has_prev": bool(prev_obj),
            "has_next": bool(next_obj),
            "opts": self.model._meta,
            "changelist_filters": changelist_filters,
        })
        return super().change_view(request, object_id, form_url, extra_context=extra_context)

submit_line.html

{% load i18n admin_urls %}

<div {% if not is_popup %}id="submit-row"{% endif %} class="relative {% if not is_popup %}lg:mt-16{% endif %} z-20">
    <div class="{% if not is_popup %}max-w-full lg:bottom-0 lg:fixed lg:left-0 lg:right-0{% endif %}" {% if not is_popup %}x-bind:class="{'xl:left-0': !sidebarDesktopOpen, 'xl:left-72': sidebarDesktopOpen}" x-bind:style="'width: ' + mainWidth + 'px'"{% endif %}>
        <div class="backdrop-blur-sm bg-white/80 pb-4 dark:bg-base-900/80 {% if not is_popup %}lg:border-t lg:border-base-200 lg:py-4 relative lg:scrollable-top lg:px-8 dark:border-base-800{% endif %}">
            <div class="flex flex-col-reverse gap-3 items-center mx-auto lg:flex-row-reverse">
                {% block submit-row %}
                    {% if show_save %}
                        <button type="submit" name="_save" class="bg-primary-600 block border border-transparent font-medium px-3 py-2 rounded text-white w-full lg:w-auto">
                            {% translate 'Save' %}
                        </button>
                    {% endif %}

                    {% for action in actions_submit_line %}
                        <button type="submit" {% if not action.attrs.name %}name="{{ action.action_name }}"{% endif %} class="border border-base-200 font-medium px-3 py-2 rounded transition-all w-full hover:bg-base-50 lg:w-auto dark:border-base-700 dark:hover:text-base-200 dark:hover:bg-base-900" {% include "unfold/helpers/attrs.html" with attrs=action.attrs %}>
                            {{ action.description }}
                        </button>
                    {% endfor %}

                    {% if show_save_and_continue %}
                        <button type="submit" name="_continue" class="border border-base-200 font-medium px-3 py-2 rounded transition-all w-full hover:bg-base-50 lg:block lg:w-auto dark:border-base-700  dark:hover:text-base-200 dark:hover:bg-base-900">
                            {% if can_change %}
                                {% translate 'Save and continue editing' %}
                            {% else %}
                                {% translate 'Save and view' %}
                            {% endif %}
                        </button>
                    {% endif %}

                    {% if show_save_and_add_another %}
                        <button type="submit" name="_addanother" class="border border-base-200 font-medium px-3 py-2 rounded transition-all w-full hover:bg-base-50 lg:block lg:w-auto dark:border-base-700  dark:hover:text-base-200 dark:hover:bg-base-900">
                            {% translate 'Save and add another' %}
                        </button>
                    {% endif %}

                    {% if show_save_as_new %}
                        <button type="submit" name="_saveasnew" class="border border-base-200 font-medium px-3 py-2 rounded transition-all w-full hover:bg-base-50 lg:block lg:w-auto dark:border-base-700  dark:hover:text-base-200 dark:hover:bg-base-900">
                            {% translate 'Save as new' %}
                        </button>
                    {% endif %}

                    <!-- Navigation Buttons -->
                    <div class="flex items-center gap-2 mx-auto lg:mx-4">
                        {% url opts|admin_urlname:'change' prev_obj.pk as prev_url %}
                        {% url opts|admin_urlname:'change' next_obj.pk as next_url %}
                        <a href="{% if has_prev %}{{ prev_url }}{% if changelist_filters %}?_changelist_filters={{ changelist_filters }}{% endif %}{% else %}#{% endif %}" 
                           class="border border-base-200 font-medium px-3 py-2 rounded transition-all hover:bg-base-50 lg:w-auto dark:border-base-700 dark:hover:text-base-200 dark:hover:bg-base-900 {% if not has_prev %}opacity-50 cursor-not-allowed pointer-events-none{% endif %}">
                            Previous
                        </a>
                        <a href="{% if has_next %}{{ next_url }}{% if changelist_filters %}?_changelist_filters={{ changelist_filters }}{% endif %}{% else %}#{% endif %}"
                           class="border border-base-200 font-medium px-3 py-2 rounded transition-all hover:bg-base-50 lg:w-auto dark:border-base-700 dark:hover:text-base-200 dark:hover:bg-base-900 {% if not has_next %}opacity-50 cursor-not-allowed pointer-events-none{% endif %}">
                            Next
                        </a>
                    </div>

                    <div class="flex flex-col gap-3 mr-auto w-full lg:flex-row lg:w-auto">
                        {% if show_close or adminform.model_admin.change_form_show_cancel_button %}
                            {% url opts|admin_urlname:'changelist' as changelist_url %}
                            <a href="{{ changelist_url }}{% if changelist_filters %}?_changelist_filters={{ changelist_filters }}{% endif %}" class="border border-base-200 font-medium px-3 py-2 rounded text-center transition-all w-full hover:bg-base-50 lg:block lg:w-auto dark:border-base-700  dark:hover:text-base-200 dark:hover:bg-base-900">
                                {% translate 'Close' %}
                            </a>
                        {% endif %}

                        {% if show_delete_link and original %}
                            {% url opts|admin_urlname:'delete' original.pk|admin_urlquote as delete_url %}
                            <a href="{{ delete_url }}{% if changelist_filters %}?_changelist_filters={{ changelist_filters }}{% endif %}" class="bg-red-600 flex items-center justify-center font-medium h-9.5 ml-auto px-3 py-2 rounded text-center text-white w-full lg:w-auto dark:bg-red-500/20 dark:text-red-500">
                                {% translate "Delete" %} {{ opts.verbose_name }}
                            </a>
                        {% endif %}
                    </div>
                {% endblock %}
            </div>
        </div>
    </div>
</div>