Show more records, records items per page (#306)

* Add show more button and items per page options

* Add test cases for plugin list

* Use number from per_page_list for show more

qgis-app/plugins/templates/plugins/plugin_list.html

@@ -108,8 +108,54 @@ <h2>{% if title %}{{title}}{% else %}{% trans "All plugins" %}{% endif %}</h2>
             {% endfor %}
         </tbody>
     </table>
-    <div class="pagination">
+    <div class="pagination" style="display:flex;justify-content: space-between;align-items: center;">
     {% include 'sortable_listview/pagination.html' %}
+
+    <div style="margin-top:20px;">
+        {% if show_more_items_number <= page_obj.paginator.count %}
+        <button class="btn" onclick="set_per_page({{show_more_items_number}})">
+            {% trans "Show more" %}
+        </button>
+        {% else %}
+        <button class="btn" disabled>
+            {% trans "Show more" %}
+        </button>
+        {% endif %}
+    </div>
+    <div style="margin-top:20px;">
+        <span>
+            {% trans "Elements per page:" %}&nbsp;
+        </span>
+        <select class="form-select" id="items_per_page" style="margin:0;">
+            {% if paginator.per_page not in per_page_list%}
+                <option>{{paginator.per_page}}</option>
+            {% endif %}
+            {% for p in per_page_list %}
+                <option value="{{ p }}" {% if p ==  paginator.per_page%} selected {% endif %}>{{ p }}</option>
+            {% endfor %}
+        </select>
+
+    </div>
+    <script type="text/javascript">
+        function set_per_page(n){
+            if(window.location.href.search('per_page') >= 0){
+                 new_page = window.location.href.replace(/per_page=\d+/, 'per_page=' + n);
+            } else {
+                new_page = -1 == window.location.href.search('\\?') ? window.location.href + '?' + 'per_page=' + n : window.location.href + '&' + 'per_page=' + n;
+            }
+            // Reset page
+            new_page = new_page.replace(/&page=\d+/, '&page=1');
+            new_page = new_page.replace(/\?page=\d+/, '?page=1');
+            window.location.href = new_page;
+        }
+
+        let itemsPerPageSelect = document.getElementById("items_per_page");
+        itemsPerPageSelect.addEventListener("change", function () {
+            if (itemsPerPageSelect.value) {
+                set_per_page(itemsPerPageSelect.value)
+            }
+        });
+    </script>
     </div>
     <div class="alert">
         <button type="button" class="close" data-dismiss="alert">&times;</button>

qgis-app/plugins/tests/test_plugin_list.py

@@ -0,0 +1,57 @@
+from django.test import TestCase
+from django.urls import reverse
+from ..models import Plugin
+
+class PluginsListViewTestCase(TestCase):
+    fixtures = [
+        "fixtures/styles.json",
+        "fixtures/auth.json",
+        "fixtures/simplemenu.json",
+        "fixtures/plugins.json",
+    ]
+
+    def setUp(self):
+        pass
+
+    def test_plugins_list_view(self):
+        # Test the main plugins list view without any parameters
+        response = self.client.get(reverse('approved_plugins'))
+        self.assertEqual(response.status_code, 200)
+        self.assertTemplateUsed(response, 'plugins/plugin_list.html')
+        self.assertTrue('current_sort_query' in response.context)
+        self.assertTrue('current_querystring' in response.context)
+        self.assertTrue('per_page_list' in response.context)
+        self.assertTrue('show_more_items_number' in response.context)
+
+    def test_plugins_list_pagination(self):
+        # Test the plugins list view with pagination
+        response = self.client.get(reverse('approved_plugins'), {'per_page': 20})
+        self.assertEqual(response.status_code, 200)
+        self.assertTrue('current_sort_query' in response.context)
+        self.assertTrue('current_querystring' in response.context)
+        self.assertTrue('per_page_list' in response.context)
+        self.assertTrue('show_more_items_number' in response.context)
+
+        show_more_items_number = response.context['show_more_items_number']
+        self.assertEqual(show_more_items_number, 50)
+
+        response = self.client.get(reverse('approved_plugins'), {'per_page': 110})
+        self.assertEqual(response.status_code, 200)
+        self.assertTrue('current_sort_query' in response.context)
+        self.assertTrue('current_querystring' in response.context)
+        self.assertTrue('per_page_list' in response.context)
+        self.assertTrue('show_more_items_number' in response.context)
+
+        show_more_items_number = response.context['show_more_items_number']
+        records_count = Plugin.approved_objects.count()
+        self.assertEqual(show_more_items_number, records_count + 1)
+
+    def test_plugins_list_sorting(self):
+        # Test the plugins list view with sorting
+        response = self.client.get(reverse('approved_plugins'), {'sort': 'name'})
+        self.assertEqual(response.status_code, 200)
+        self.assertTrue('current_sort_query' in response.context)
+        self.assertTrue('current_querystring' in response.context)
+        self.assertTrue('per_page_list' in response.context)
+        self.assertTrue('show_more_items_number' in response.context)
+

qgis-app/plugins/views.py

@@ -641,6 +641,20 @@ def get_context_data(self, **kwargs):
         context.update(self.additional_context)
         context["current_sort_query"] = self.get_sortstring()
         context["current_querystring"] = self.get_querystring()
+        context["per_page_list"] = [20, 50, 75, 100]
+
+        try:
+            # Get the next value of per page from per_page_list
+            next_per_page_id = context["per_page_list"].index(context["paginator"].per_page) + 1
+            next_per_page = context["per_page_list"][next_per_page_id]
+        except (ValueError, IndexError):
+            # If the 'per_page' value in the request parameter 
+            # is not found in the 'per_page_list' or if the 
+            # next index is out of range, set the 'next_per_page' 
+            # value to a number greater than the total count 
+            # of records. This action effectively disables the button."
+            next_per_page = context["paginator"].count + 1
+        context["show_more_items_number"] = next_per_page
         return context
 
     def get_sortstring(self):