Add category system to categorize posts (readme)

This commit implements a new category system to categorize posts. Each
category can have an unlimited number of nested children categories. A
single post don't necessarily need to be in a category, but it can.

Each category can have a full content body like posts or pages, so you
have enough space to describe the content of your categories.

Please note that you need to have at least the following MySQL/MariaDB
versions to use the category system, because it uses "WITH RECURSIVE"
database queries, the so-called "Common-Table-Expressions (CTE)".

MariaDB: 10.2.2
MySQL: 8.0

See: https://mariadb.com/kb/en/with/
See: https://dev.mysql.com/doc/refman/8.0/en/with.html

1 files changed, 84 insertions, 0 deletions

diff --git a/admin/category/update.php b/admin/category/update.php
new file mode 100644
index 0000000..7cee587
--- /dev/null
+++ b/admin/category/update.php
@@ -0,0 +1,84 @@
+<?php
+#===============================================================================
+# DEFINE: Administration
+#===============================================================================
+const ADMINISTRATION = TRUE;
+const AUTHENTICATION = TRUE;
+
+#===============================================================================
+# INCLUDE: Initialization
+#===============================================================================
+require '../../core/application.php';
+
+#===============================================================================
+# Get repositories
+#===============================================================================
+$CategoryRepository = Application::getRepository('Category');
+
+#===============================================================================
+# Throw 404 error if category could not be found
+#===============================================================================
+if(!$Category = $CategoryRepository->find(HTTP::GET('id'))) {
+	Application::error404();
+}
+
+#===============================================================================
+# Check for update request
+#===============================================================================
+if(HTTP::issetPOST('parent', 'slug', 'name', 'body', 'argv', 'time_insert', 'time_update', 'update')) {
+	$Category->set('slug', HTTP::POST('slug') ?: generateSlug(HTTP::POST('name')));
+	$Category->set('name', HTTP::POST('name') ?: NULL);
+	$Category->set('body', HTTP::POST('body') ?: NULL);
+	$Category->set('argv', HTTP::POST('argv') ?: NULL);
+	$Category->set('time_insert', HTTP::POST('time_insert') ?: date('Y-m-d H:i:s'));
+	$Category->set('time_update', HTTP::POST('time_update') ?: date('Y-m-d H:i:s'));
+
+	# Modify parent field only if it is not a self-reference
+	if(HTTP::POST('parent') != $Category->getID()) {
+		$Category->set('parent', HTTP::POST('parent') ?: NULL);
+	}
+
+	if(HTTP::issetPOST(['token' => Application::getSecurityToken()])) {
+		try {
+			$CategoryRepository->update($Category);
+		} catch(PDOException $Exception) {
+			$messages[] = $Exception->getMessage();
+		}
+	}
+
+	else {
+		$messages[] = $Language->text('error_security_csrf');
+	}
+}
+
+#===============================================================================
+# Generate category list
+#===============================================================================
+foreach($CategoryRepository->getAll([], 'name ASC') as $_Category) {
+	$categoryList[] = [
+		'ID' => $_Category->getID(),
+		'NAME' => $_Category->get('name'),
+		'PARENT' => $_Category->get('parent'),
+	];
+}
+
+#===============================================================================
+# Build document
+#===============================================================================
+$FormTemplate = Template\Factory::build('category/form');
+$FormTemplate->set('FORM', [
+	'TYPE' => 'UPDATE',
+	'INFO' => $messages ?? [],
+	'DATA' => array_change_key_case($Category->getAll(), CASE_UPPER),
+	'CATEGORY_LIST' => $categoryList ??  [],
+	'CATEGORY_TREE' => generateCategoryDataTree($categoryList ?? []),
+	'TOKEN' => Application::getSecurityToken()
+]);
+
+$InsertTemplate = Template\Factory::build('category/update');
+$InsertTemplate->set('HTML', $FormTemplate);
+
+$MainTemplate = Template\Factory::build('main');
+$MainTemplate->set('NAME', $Language->text('title_category_update'));
+$MainTemplate->set('HTML', $InsertTemplate);
+echo $MainTemplate;