Refactor template engine code

- Convert ITemplateEngine interface to abstract class
- Remove dependency to App in FriendicaSmarty and FriendicaSmartyEngine
- Normalize replaceMacro parameter behavior using Smarty template string prefixes
- Remove obsolete FriendicaSmarty->parsed method
- Update unused Smarty directory paths

src/Render/TemplateEngine.php

@@ -0,0 +1,60 @@
+<?php
+/**
+ * @copyright Copyright (C) 2020, Friendica
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Friendica\Render;
+
+/**
+ * Interface for template engines
+ */
+abstract class TemplateEngine
+{
+	/** @var string */
+	static $name;
+
+	/** @var string */
+	protected $theme;
+	/** @var array */
+	protected $theme_info;
+
+	/**
+	 * @param string $theme      The current theme name
+	 * @param array  $theme_info The current theme info array
+	 */
+	abstract public function __construct(string $theme, array $theme_info);
+
+	/**
+	 * Returns the rendered template output from the template string and variables
+	 *
+	 * @param string $template
+	 * @param array  $vars
+	 * @return string
+	 */
+	abstract public function replaceMacros(string $template, array $vars);
+
+	/**
+	 * Returns the template string from a file path and an optional sub-directory from the project root
+	 *
+	 * @param string $file
+	 * @param string $subDir
+	 * @return mixed
+	 */
+	abstract public function getTemplateFile(string $file, string $subDir = '');
+}