Document list views

Closes #510

Author: BurntimeX

docs/php/api/list_views.md

@@ -0,0 +1,279 @@
+# List Views
+
+List views are a generic solution for the creation of listings that are ubiquitous in the software.
+In contrast to [grid views](grid_views.md), list views do not specify a particular layout.
+The developer must specify a custom template that takes care of the rendering of the entries.
+A list view takes care of sorting, filtering and pagination, and ensure that a lot of boilerplating becomes obsolete.
+
+The implementation essentially offers the following advantages:
+1. A uniform appearance and usability for the user.
+2. An easy way for developers to create their own list views.
+3. An easy way for developers to extend existing list views using plugins.
+
+## Usage
+
+### AbstractListView
+
+List views obtain their data from a database object list and display it using custom template.
+
+Example:
+
+```php
+<?php
+
+namespace wcf\system\listView\user;
+
+use wcf\data\DatabaseObjectList;
+use wcf\system\listView\AbstractListView;
+use wcf\system\WCF;
+
+class ExampleListView extends AbstractListView
+{
+    #[\Override]
+    protected function createObjectList(): DatabaseObjectList
+    {
+        return new ExampleList();
+    }
+
+    #[\Override]
+    public function isAccessible(): bool
+    {
+        return true;
+    }
+
+    #[\Override]
+    public function renderItems(): string
+    {
+        return WCF::getTPL()->render('wcf', 'exampleListItems', ['view' => $this]);
+    }
+}
+```
+
+Example `exampleListItems.tpl`:
+
+```smarty
+{foreach from=$view->getItems() item='item'}
+	<div class="listView__item" data-object-id="{$item->getObjectID()}">
+		<h2>{$item->getTitle()}</h2>
+	</div>
+{/foreach}
+```
+
+### AbstractListViewPage
+
+A list view can be displayed on a page by inheriting from `AbstractListViewPage`.
+
+Example:
+
+```php
+<?php
+
+namespace wcf\page;
+
+use wcf\system\listView\user\ArticleListView;
+
+class ExampleListPage extends AbstractListViewPage
+{
+    #[\Override]
+    protected function createListView(): ExampleListView
+    {
+        return new ExampleListView();
+    }
+}
+```
+
+```smarty
+{include file='header'}
+
+<div class="section">
+	{unsafe:$listView->render()}
+</div>
+
+{include file='footer'}
+```
+
+## Sorting
+
+The `addAvailableSortFields` method allows you to define columns that the user can use to sort the list.
+The columns must exist in the linked database object list.
+
+```php
+class ExampleListView extends AbstractListView
+{
+    public function __construct() {
+        $this->addAvailableSortFields([
+            new ListViewSortField('time', 'wcf.global.date'),
+            new ListViewSortField('title', 'wcf.global.title'),
+        ]);
+    }
+}
+```
+
+By default, sorting is based on the `id` (first parameter) of the specified sort field.
+Optionally, you can specify the name of an alternative database column to be used for sorting instead:
+
+```php
+new ListViewSortField('title', 'wcf.global.title', 'table_alias.columnName'),
+```
+
+The default sorting can be defined after the configuration of the sort fields has been defined:
+
+```php
+class ExampleListView extends AbstractListView
+{
+    public function __construct()
+    {
+        $this->addAvailableSortFields([
+            new ListViewSortField('time', 'wcf.global.date'),
+            new ListViewSortField('title', 'wcf.global.title'),
+        ]);
+        
+        $this->setSortField('title');
+        $this->setSortOrder('ASC');
+    }
+}
+```
+
+## Filtering
+
+Filters can be defined for columns so that the user has the option to filter by the content of a column.
+
+```php
+class ExampleListView extends AbstractListView
+{
+    public function __construct()
+    {
+        $this->addAvailableFilters([
+            new TextFilter('title', 'wcf.global.title'),
+        ]);
+    }
+}
+```
+
+## Customization
+
+### Number of Items
+
+By default, list views use a pagination that shows 20 items per page. You can set a custom number of items per page:
+
+```php
+class ExampleListView extends AbstractListView
+{
+    public function __construct()
+    {
+        $this->setItemsPerPage(50);
+    }
+}
+```
+
+There are some cases where only a list with a fixed number of items is required, for example, showcasing the 10 latests items.
+
+```php
+class ExampleListView extends AbstractListView
+{
+    public function __construct()
+    {
+        $this->fixedNumberOfItems(10);
+    }
+}
+```
+
+### CSS Class Names
+
+Optionally, a CSS class can be set on the surrounding HTML element:
+
+```php
+class ExampleListView extends AbstractListView
+{
+    public function __construct()
+    {
+        $this->setCssClassName('exampleList');
+    }
+}
+```
+
+### Additional Parameters
+
+A list view can be provided with additional parameters, e.g. to filter them by a specific category:
+
+```php
+class ExampleListView extends AbstractListView
+{
+    public function __construct(public readonly int $categoryID)
+    {
+        parent::__construct();
+    }
+
+    #[\Override]
+    protected function createObjectList(): DatabaseObjectList
+    {
+        $list = new ExampleList();
+        $list->getConditionBuilder()->add('categoryID = ?', [$this->categoryID]);
+
+        return $list;
+    }
+
+    #[\Override]
+    public function getParameters(): array
+    {
+        return ['categoryID' => $this->categoryID];
+    }
+}
+```
+
+```php
+<?php
+
+namespace wcf\page;
+
+use wcf\system\listView\AbstractListView;
+use wcf\system\request\LinkHandler;
+
+class ExampleListPage extends AbstractListViewPage
+{
+    public int $categoryID = 0;
+
+    #[\Override]
+    public function readParameters()
+    {
+        if (isset($_REQUEST['categoryID'])) {
+            $this->categoryID = \intval($_REQUEST['categoryID']);
+        }
+
+        parent::readParameters();
+    }
+
+    #[\Override]
+    protected function createListView(): AbstractListView
+    {
+        return new ExampleListView($this->categoryID);
+    }
+
+    #[\Override]
+    protected function initListView(): void
+    {
+        parent::initListView();
+
+        $this->listView->setBaseUrl(LinkHandler::getInstance()->getControllerLink(static::class, [
+            'categoryID' => $this->categoryID,
+        ]));
+    }
+}
+```
+
+## Events
+
+Existing list views can be modified using events.
+
+Example of adding an additional sort field:
+
+```php
+$eventHandler->register(
+    \wcf\event\listView\user\ArticleListViewInitialized::class,
+    static function (\wcf\event\listView\user\ArticleListViewInitialized $event) {
+         $event->listView->addAvailableSortField(
+            new ListViewSortField('example', 'wcf.global.example'),
+        );
+    }
+);
+```

mkdocs.yml

@@ -40,6 +40,7 @@ nav:
               - 'Validation and Data': 'php/api/form_builder/validation_data.md'
               - 'Dependencies': 'php/api/form_builder/dependencies.md'
           - 'Grid Views': 'php/api/grid_views.md'
+          - 'List Views': 'php/api/list_views.md'
           - 'Package Installation Plugins': 'php/api/package_installation_plugins.md'
           - 'RPC API': 'php/api/rpc_api.md'
           - 'User Activity Events': 'php/api/user_activity_events.md'