Add ext.php for enable check and bp icon

ext.php

@@ -0,0 +1,63 @@
+<?php
+/**
+*
+* @package Board3 Portal v2.3
+* @copyright (c) 2023 Board3 Group ( www.board3.de )
+* @license GNU General Public License, version 2 (GPL-2.0-only)
+*
+*/
+
+namespace board3\portal;
+
+class ext extends \phpbb\extension\base
+{
+	/**
+	* Check whether the extension can be enabled.
+	* Provides meaningful(s) error message(s) and the back-link on failure.
+	* CLI and 3.2/3.3 compatible.
+	*
+	* @return bool
+	*/
+	public function is_enableable()
+	{
+		$phpbb_min_ver		= '3.2.6';
+		$phpbb_below_ver	= '3.4.0-dev';
+		$php_min_ver		= '7.1.0';
+		$php_below_ver		= '8.3.0-dev';
+
+		if (phpbb_version_compare(PHPBB_VERSION, '3.2.0-dev', '<'))
+		{
+			$lang = $this->container->get('user');
+			$lang->add_lang_ext('board3/portal', 'b3p_enable_error');
+		}
+		else
+		{
+			$lang = $this->container->get('language');
+			$lang->add_lang('b3p_enable_error', 'board3/portal');
+		}
+		$error_message	= [$lang->lang('ERROR_B3P_EXTENSION_NOT_ENABLEABLE', $lang->lang('BOARD3_PORTAL'))];
+
+		if ((phpbb_version_compare(PHPBB_VERSION, $phpbb_min_ver, '<') || phpbb_version_compare(PHPBB_VERSION, $phpbb_below_ver, '>=')))
+		{
+			$error_message[] = $lang->lang('ERROR_B3P_MSG_PHPBB_WRONG_VERSION', $phpbb_min_ver, $phpbb_below_ver);
+		}
+
+		if ((phpbb_version_compare(PHP_VERSION, $php_min_ver, '<') || phpbb_version_compare(PHP_VERSION, $php_below_ver, '>=')))
+		{
+			$error_message[] = $lang->lang('ERROR_B3P_MSG_PHP_WRONG_VERSION', $php_min_ver, $php_below_ver);
+		}
+
+		if (phpbb_version_compare(PHPBB_VERSION, '3.3.0-dev', '<') && count($error_message) > 1)
+		{
+			$error_message = implode('<br>', $error_message);
+			trigger_error($error_message . $this->get_adm_back_link(), E_USER_WARNING);
+		}
+
+		return (count($error_message) > 1) ? $error_message : true;
+	}
+
+	private function get_adm_back_link()
+	{
+		return adm_back_link(append_sid('index.' . $this->container->getParameter('core.php_ext'), 'i=acp_extensions&amp;mode=main'));
+	}
+}