fix: date hierarchy is reset on filter (#873) (#875)

Author: PavelPancocha

src/unfold/admin.py

@@ -7,7 +7,6 @@
 from django.contrib.admin import StackedInline as BaseStackedInline
 from django.contrib.admin import TabularInline as BaseTabularInline
 from django.contrib.admin import display, helpers
-from django.contrib.admin.options import IS_POPUP_VAR, TO_FIELD_VAR
 from django.contrib.admin.widgets import RelatedFieldWidgetWrapper
 from django.db import models
 from django.db.models import BLANK_CHOICE_DASH, Model
@@ -477,8 +476,6 @@ def changelist_view(
             {
                 "actions_list": actions,
                 "actions_row": actions_row,
-                "to_field_var": TO_FIELD_VAR,
-                "is_popup_var": IS_POPUP_VAR,
             }
         )
 

src/unfold/templates/unfold/change_list_filter.html

@@ -1,4 +1,4 @@
-{% load i18n admin_list %}
+{% load i18n admin_list unfold %}
 
 <div id="changelist-filter" class="backdrop-blur-sm bg-opacity-80 bg-gray-900 flex inset-0 z-50 fixed {% if not cl.model_admin.list_filter_sheet %}2xl:bg-transparent 2xl:relative 2xl:!block 2xl:z-10{% endif %}" x-show="filterOpen">
     <label for="show-filters" id="changelist-filter-close" class="flex-grow {% if not cl.model_admin.list_filter_sheet %}2xl:hidden{% endif %}" x-on:click="filterOpen = false"></label>
@@ -38,22 +38,7 @@ <h3 class="border-b flex font-semibold mb-4 px-4 py-4 text-font-important-light
             <div class="px-4{% if cl.model_admin.list_filter_submit %} {% endif %}">
                 {% if cl.model_admin.list_filter_submit %}
                     <form id="filter-form" method="get">
-                        {% if request.GET.q %}
-                            <input type="hidden" name="q" value="{{ request.GET.q }}">
-                        {% endif %}
-
-                        {% if request.GET.o %}
-                            <input type="hidden" name="o" value="{{ request.GET.o }}">
-                        {% endif %}
-
-                        {% if is_popup %}
-                            <input type="hidden" name="{{ is_popup_var }}" value="1">
-                        {% endif %}
-
-                        {% if to_field %}
-                            <input type="hidden" name="{{ to_field_var }}" value="{{ to_field }}">
-                        {% endif %}
-
+                        {% preserve_filters %}
                 {% endif %}
 
                 {% for spec in cl.filter_specs %}

src/unfold/templates/unfold/templatetags/preserve_changelist_filters.html

@@ -0,0 +1,3 @@
+{% for key, value in params.items %}
+  <input type="hidden" name="{{ key }}" value="{{ value }}">
+{% endfor %}

src/unfold/templatetags/unfold.py

@@ -1,9 +1,11 @@
-from typing import Any, Dict, List, Mapping, Optional, Union
+from typing import Any, Dict, List, Mapping, Optional, Set, Union
 
 from django import template
 from django.contrib.admin.helpers import AdminForm, Fieldset
+from django.contrib.admin.views.main import ChangeList
 from django.forms import Field
-from django.template import Library, Node, RequestContext, TemplateSyntaxError
+from django.http import HttpRequest
+from django.template import Context, Library, Node, RequestContext, TemplateSyntaxError
 from django.template.base import NodeList, Parser, Token, token_kwargs
 from django.template.loader import render_to_string
 from django.utils.safestring import SafeText
@@ -224,3 +226,28 @@ def add_css_class(field: Field, classes: Union[list, tuple]) -> Field:
         field.field.widget.attrs["class"] = classes
 
     return field
+
+
+@register.inclusion_tag(
+    "unfold/templatetags/preserve_changelist_filters.html",
+    takes_context=True,
+    name="preserve_filters",
+)
+def preserve_changelist_filters(context: Context) -> Dict[str, Dict[str, str]]:
+    """
+    Generate hidden input fields to preserve filters for POST forms.
+    """
+    request: Optional[HttpRequest] = context.get("request")
+    changelist: Optional[ChangeList] = context.get("cl")
+
+    if not request or not changelist:
+        return {"params": {}}
+
+    used_params: Set[str] = {
+        param for spec in changelist.filter_specs for param in spec.used_parameters
+    }
+    preserved_params: Dict[str, str] = {
+        param: value for param, value in request.GET.items() if param not in used_params
+    }
+
+    return {"params": preserved_params}