From aa5f0af6dc340fecda0bf32509ddd3ecb8f00008 Mon Sep 17 00:00:00 2001
From: Eric Lipe <elipe@teamraft.com>
Date: Tue, 20 Aug 2024 17:24:33 -0400
Subject: [PATCH] - Working mutliselect with "apply filters" button - parsing
 query out of query string for list filters

---
 .../admin_interface/508/dropdown-filter.js    | 53 ++++++++++---------
 .../admin_interface/dropdown_filter.html      |  2 +-
 django508/tests/admin/dummies.py              |  8 +--
 3 files changed, 30 insertions(+), 33 deletions(-)

diff --git a/admin_interface/static/admin_interface/508/dropdown-filter.js b/admin_interface/static/admin_interface/508/dropdown-filter.js
index 82e964f..0115ef2 100644
--- a/admin_interface/static/admin_interface/508/dropdown-filter.js
+++ b/admin_interface/static/admin_interface/508/dropdown-filter.js
@@ -5,47 +5,48 @@ if (typeof (django) !== 'undefined' && typeof (django.jQuery) !== 'undefined') {
     'use strict';
     $(document).ready(function () {
       const filters = document.querySelectorAll('#changelist-filter .list-filter-dropdown select')
-      let query = ''
-      let multiQuery = ''
-      // Override the default onchange handler of each filter
-      for (const filter of filters) {
-        // This needs to be a function expression so `this` references the filter elements themselves
-        if (!filter.ariaMultiSelectable) {
-          filter.onchange = function() {
-            let value = this.options[this.selectedIndex].value
-            if (query !== '') {
-              value = value.replace('?', '&')
-            }
-            query = query.replace(multiQuery, '')
-            query = query.concat(value)
-          };
-        }
-      }
+      let query = '?'
 
       const applyFiltersButton = document.querySelector('#submit-filters');
       if (applyFiltersButton) {
         applyFiltersButton.onclick = function () {
           for (const filter of filters) {
-            if (filter.ariaMultiSelectable) {
+            let conjunction = query === '?' ? '' : '&'
+            if (!filter.ariaMultiSelectable) {
+              if (filter.selectedIndex !== 0) {
+                // Built in Django filters append the query string to the `value` field on the element. However, when we
+                // have a mult-selectable filter, the select element can't have the `value` field as a query string
+                // because multiple options can be selected and there is no way to track that. Therefore, we strip the
+                // single select filters query param from the existing query string and build and entirely new query
+                // string from that.
+                let opt = filter.options[filter.selectedIndex]
+                let query_str = opt.value
+                let filter_query = ''
+                for (let i = 1; i < query_str.length; i++) {
+                  if (query_str[i] === '&') {
+                    break
+                  }
+                  filter_query += query_str[i]
+                }
+                query = query.concat(conjunction, filter_query)
+              }
+            }
+            else {
+              // All multi select filters are required to set the `key` and `value` fields on the option element to the
+              // individual options to be able to build the correct query string.
               let selected = ''
               for (const option of filter.options) {
                 if (option.selected) {
-                  selected = selected.concat(option.value, '%2C') // Using the hex code for comma is what makes it work!
+                  selected = selected.concat(option.value, '%2C')
                 }
               }
               selected = selected.replace(/,+$/, "")
-              if (query === '' && multiQuery === '') {
-                multiQuery = multiQuery.concat('?')
-              }
               if (selected !== '') {
-                let param = multiQuery === '?' ? '' : '&'
-                multiQuery = multiQuery.concat(param, filter.options[0].getAttribute('key'), '=', selected)
+                query = query.concat(conjunction, filter.options[0].getAttribute('key'), '=', selected)
               }
             }
           }
-          console.log(query)
-          console.log(multiQuery)
-          window.location = query + multiQuery
+          window.location = query
         };
       }
     });
diff --git a/admin_interface/templates/admin_interface/dropdown_filter.html b/admin_interface/templates/admin_interface/dropdown_filter.html
index 162d59f..1998a04 100644
--- a/admin_interface/templates/admin_interface/dropdown_filter.html
+++ b/admin_interface/templates/admin_interface/dropdown_filter.html
@@ -5,7 +5,7 @@ <h3>{% blocktrans with title as filter_title %} By {{ filter_title }} {% endbloc
     <div align="right">
         <select title="{{ title }}">
         {% for choice in choices %}
-            <option {% if choice.selected %}selected{% endif %} value="{{ choice.value }}" key="{{ choice.key }}">{{ choice.display }}</option>
+            <option {% if choice.selected %}selected{% endif %} value="{{ choice.query_string|iriencode }}">{{ choice.display }}</option>
         {% endfor %}
         </select>
     </div>
diff --git a/django508/tests/admin/dummies.py b/django508/tests/admin/dummies.py
index a717c19..afb23ac 100644
--- a/django508/tests/admin/dummies.py
+++ b/django508/tests/admin/dummies.py
@@ -1,5 +1,4 @@
 from django.contrib import admin
-from .filters import DummyModelNameFilter
 from .multi_select_dropdown import MultiSelectDropdownFilter
 
 
@@ -37,10 +36,8 @@ class Dummy_Admin(ReadOnlyDummyMixin):
     ]
 
     list_filter = [
-        # DummyModelNameFilter,
         ('name', MultiSelectDropdownFilter),
-        ('created', MultiSelectDropdownFilter),
-        "name"
+        "created"
     ]
 
 class Dummy2_Admin(ReadOnlyDummyMixin):
@@ -55,8 +52,7 @@ class Dummy2_Admin(ReadOnlyDummyMixin):
     ]
 
     list_filter = [
-        DummyModelNameFilter,
         ('name', MultiSelectDropdownFilter),
-        "name"
+        "created"
     ]