Refs #2129 - integrates new installer code from http://github.com/cash/Elgg - does not work yet with non-Apache web servers

git-svn-id: http://code.elgg.org/elgg/trunk@6991 36083f99-b078-4883-b0ff-0f9b5a30f544

1 files changed, 1274 insertions, 0 deletions

diff --git a/install/ElggInstaller.php b/install/ElggInstaller.php
new file mode 100644
index 000000000..6d1553572
--- /dev/null
+++ b/install/ElggInstaller.php
@@ -0,0 +1,1274 @@
+<?php
+/**
+ * Elgg Installer.
+ * Controller for installing Elgg.
+ *
+ * @package Elgg
+ * @subpackage Installer
+ * @author Curverider Ltd
+ * @link http://elgg.org/
+ */
+
+class ElggInstaller {
+
+	protected $steps = array(
+		'welcome',
+		'requirements',
+		'database',
+		'settings',
+		'admin',
+		'complete',
+		);
+
+	protected $status = array(
+		'database' => FALSE,
+		'settings' => FALSE,
+		'admin' => FALSE,
+	);
+
+	protected $isAction;
+
+	/**
+	 * Constructor bootstraps the Elgg engine
+	 */
+	public function __construct() {
+		$this->isAction = $_SERVER['REQUEST_METHOD'] === 'POST';
+
+		$this->bootstrapConfig();
+		
+		$this->bootstrapEngine();
+
+		elgg_set_viewtype('failsafe');
+
+		set_error_handler('__elgg_php_error_handler');
+		set_exception_handler('__elgg_php_exception_handler');
+	}
+
+	/**
+	 * Dispatches a request to one of the step controllers
+	 *
+	 * @param string $step
+	 */
+	public function run($step) {
+
+		// check if this a mod rewrite test coming in
+		$this->runModRewriteTest();
+
+		if (!in_array($step, $this->getSteps())) {
+			throw new InstallationException("$step is an unknown installation step.");
+		}
+
+		$this->setInstallStatus();
+
+		$this->checkInstallCompletion($step);
+
+		// check if this is an install being resumed
+		$this->resumeInstall($step);
+
+		$this->finishBootstraping($step);
+
+		$params = $this->getPostVariables();
+		$this->$step($params);
+	}
+
+	/**
+	 * Renders the data passed by a controller
+	 *
+	 * @param string $step
+	 * @param array $vars
+	 */
+	protected function render($step, $vars = array()) {
+
+		$vars['next_step'] = $this->getNextStep($step);
+
+		$title = elgg_echo("install:$step");
+		$body = elgg_view("install/pages/$step", $vars);
+		page_draw(
+				$title,
+				$body,
+				'page_shells/install',
+				array(
+					'step' => $step,
+					'steps' => $this->getSteps(),
+					)
+				);
+		exit;
+	}
+
+	/**
+	 * Step controllers
+	 */
+
+	/**
+	 * Welcome controller
+	 *
+	 * @param array $vars Not used
+	 */
+	protected function welcome($vars) {
+		$this->render('welcome');
+	}
+
+	/**
+	 * Requirements controller
+	 *
+	 * Checks version of php, libraries, permissions, and rewrite rules
+	 *
+	 * @param array $vars
+	 */
+	protected function requirements($vars) {
+
+		$report = array();
+		
+		// check PHP parameters and libraries
+		$this->checkPHP($report);
+
+		// @todo - rewrite this to handle different web servers
+		// attempt to create .htaccess file
+		$htaccessExists = $this->createHtaccess($report);
+
+		// check rewrite module
+		if ($htaccessExists) {
+			$this->checkRewriteModule($report);
+		}
+		
+		// check for existence of settings file
+		if ($this->checkSettingsFile() != TRUE) {
+			// no file, so check permissions on engine directory
+			$this->checkEngineDir($report);
+		}
+
+		// check the database later
+		$report['database'] = array(array(
+			'severity' => 'info',
+			'message' => elgg_echo('install:check:database')
+		));
+
+		// any failures?
+		$numFailures = $this->countNumConditions($report, 'failure');
+
+		// any warnings
+		$numWarnings = $this->countNumConditions($report, 'warning');
+
+
+		$params = array(
+			'report' => $report,
+			'num_failures' => $numFailures,
+			'num_warnings' => $numWarnings,
+		);
+
+		$this->render('requirements', $params);
+	}
+
+	/**
+	 * Database set up controller
+	 * 
+	 * Creates the settings.php file and creates the database tables
+	 *
+	 * @param array $submissionVars Submitted form variables
+	 */
+	protected function database($submissionVars) {
+
+		$formVars = array(
+			'dbuser' => array(
+				'type' => 'text',
+				'value' => '',
+				'required' => TRUE,
+				),
+			'dbpassword' => array(
+				'type' => 'password',
+				'value' => '',
+				'required' => TRUE,
+				),
+			'dbname' => array(
+				'type' => 'text',
+				'value' => '',
+				'required' => TRUE,
+				),
+			'dbhost' => array(
+				'type' => 'text',
+				'value' => 'localhost',
+				'required' => TRUE,
+				),
+			'dbprefix' => array(
+				'type' => 'text',
+				'value' => 'elgg_',
+				'required' => TRUE,
+				),
+		);
+
+		if ($this->checkSettingsFile()) {
+			// user manually created settings file so we fake out action test
+			$this->isAction = TRUE;
+		}
+
+		if ($this->isAction) {
+			do {
+				// only create settings file if it doesn't exist
+				if (!$this->checkSettingsFile()) {
+					if (!$this->validateDatabaseVars($submissionVars, $formVars)) {
+						// error so we break out of action and serve same page
+						break;
+					}
+
+					if (!$this->createSettingsFile($submissionVars)) {
+						break;
+					}
+				}
+
+				// check db version and connect 
+				if (!$this->connectToDatabase()) {
+					break;
+				}
+
+				if (!$this->installDatabase()) {
+					break;
+				}
+
+				system_message('Database has been installed.');
+
+				$this->continueToNextStep('database');
+			} while (FALSE);  // PHP doesn't support breaking out of if statements
+		}
+
+		$formVars = $this->makeFormSticky($formVars, $submissionVars);
+
+		$params = array('variables' => $formVars,);
+
+		if ($this->checkSettingsFile()) {
+			// settings file exists and we're here so failed to create database
+			$params['failure'] = TRUE;
+		}
+
+		$this->render('database', $params);
+	}
+
+	/**
+	 * Site settings controller
+	 *
+	 * Sets the site name, URL, data directory, etc.
+	 *
+	 * @param array $submissionVars
+	 */
+	protected function settings($submissionVars) {
+		global $CONFIG;
+		
+		$languages = get_installed_translations();
+		$formVars = array(
+			'sitename' => array(
+				'type' => 'text',
+				'value' => 'New Elgg site',
+				'required' => TRUE,
+				),
+			'siteemail' => array(
+				'type' => 'text',
+				'value' => '',
+				'required' => FALSE,
+				),
+			'wwwroot' => array(
+				'type' => 'text',
+				'value' => $CONFIG->wwwroot,
+				'required' => TRUE,
+				),
+			'path' => array(
+				'type' => 'text',
+				'value' => $CONFIG->path,
+				'required' => TRUE,
+				),
+			'dataroot' => array(
+				'type' => 'text',
+				'value' => '',
+				'required' => TRUE,
+				),
+			'language' => array(
+				'type' => 'pulldown',
+				'value' => 'en',
+				'options_values' => $languages,
+				'required' => TRUE,
+				),
+			'siteaccess' => array(
+				'type' => 'access',
+				'value' =>  ACCESS_PUBLIC,
+				'required' => TRUE,
+				),
+		);
+		
+		if ($this->isAction) {
+			do {
+				if (!$this->validateSettingsVars($submissionVars, $formVars)) {
+					break;
+				}
+
+				if (!$this->saveSiteSettings($submissionVars)) {
+					break;
+				}
+				
+				system_message('Site settings have been saved.');
+
+				$this->continueToNextStep('settings');
+
+			} while (FALSE);  // PHP doesn't support breaking out of if statements
+		}
+		
+		$formVars = $this->makeFormSticky($formVars, $submissionVars);
+
+		$this->render('settings', array('variables' => $formVars));
+	}
+
+	/**
+	 * Admin account controller
+	 *
+	 * Creates an admin user account
+	 *
+	 * @param array $submissionVars
+	 */
+	protected function admin($submissionVars) {
+		$formVars = array(
+			'displayname' => array(
+				'type' => 'text',
+				'value' => '',
+				'required' => TRUE,
+				),
+			'email' => array(
+				'type' => 'text',
+				'value' => '',
+				'required' => TRUE,
+				),
+			'username' => array(
+				'type' => 'text',
+				'value' => '',
+				'required' => TRUE,
+				),
+			'password1' => array(
+				'type' => 'password',
+				'value' => '',
+				'required' => TRUE,
+				),
+			'password2' => array(
+				'type' => 'password',
+				'value' => '',
+				'required' => TRUE,
+				),
+		);
+
+		if ($this->isAction) {
+			do {
+				if (!$this->validateAdminVars($submissionVars, $formVars)) {
+					break;
+				}
+
+				if (!$this->createAdminAccount($submissionVars)) {
+					break;
+				}
+				
+				system_message('Admin account has been created.');
+
+				$this->continueToNextStep('admin');
+
+			} while (FALSE);  // PHP doesn't support breaking out of if statements
+		}
+		
+		$formVars = $this->makeFormSticky($formVars, $submissionVars);
+
+		$this->render('admin', array('variables' => $formVars));
+	}
+
+	/**
+	 * Controller for last step
+	 *
+	 * @param array $vars
+	 */
+	protected function complete($vars) {
+
+		$this->render('complete');
+	}
+
+	/**
+	 * Step management
+	 */
+
+	/**
+	 * Get an array of steps
+	 *
+	 * @return array
+	 */
+	protected function getSteps() {
+		return $this->steps;
+	}
+
+	/**
+	 * Forwards the browser to the next step
+	 * 
+	 * @param string $currentStep
+	 */
+	protected function continueToNextStep($currentStep) {
+		$this->isAction = FALSE;
+		forward($this->getNextStepUrl($currentStep));
+	}
+
+	/**
+	 * Get the next step as a string
+	 *
+	 * @param string $currentStep
+	 * @return string
+	 */
+	protected function getNextStep($currentStep) {
+		return $this->steps[1 + array_search($currentStep, $this->steps)];
+	}
+
+	/**
+	 * Get the URL of the next step
+	 * 
+	 * @param string $currentStep
+	 * @return string
+	 */
+	protected function getNextStepUrl($currentStep) {
+		global $CONFIG;
+		$nextStep = $this->getNextStep($currentStep);
+		return "{$CONFIG->wwwroot}install.php?step=$nextStep";
+	}
+
+	/**
+	 * Check the different nstall steps for completion
+	 */
+	protected function setInstallStatus() {
+		global $CONFIG;
+		
+		$settingsCreated = $this->checkSettingsFile();
+		if ($settingsCreated == FALSE) {
+			return;
+		}
+
+		$this->loadSettingsFile();
+		
+		// must be able to connect to database to jump install steps
+		$dbSettingsPass = $this->checkDatabaseSettings(
+				$CONFIG->dbuser,
+				$CONFIG->dbpass,
+				$CONFIG->dbname,
+				$CONFIG->dbhost
+				);
+		if ($dbSettingsPass == FALSE) {
+			return;
+		}
+
+		if (!include_once("{$CONFIG->path}engine/lib/database.php")) {
+			throw new InstallationException("Could not load database.php");
+		}
+
+		// check that the config table has been created
+		$query = "show tables";
+		$result = get_data($query);
+		if ($result) {
+			foreach ($result as $table) {
+				$table = (array) $table;
+				if (in_array("{$CONFIG->dbprefix}config", $table)) {
+					$this->status['database'] = TRUE;
+				}
+			}
+			if ($this->status['database'] == FALSE) {
+				return;
+			}
+		}
+
+		// check that the config table has entries
+		$query = "SELECT COUNT(*) AS total FROM {$CONFIG->dbprefix}config";
+		$result = get_data($query);
+		if ($result && $result[0]->total > 0) {
+			$this->status['settings'] = TRUE;
+		} else {
+			return;
+		}
+
+		// check that the users entity table has an entry
+		$query = "SELECT COUNT(*) AS total FROM {$CONFIG->dbprefix}users_entity";
+		$result = get_data($query);
+		if ($result && $result[0]->total > 0) {
+			$this->status['admin'] = TRUE;
+		} else {
+			return;
+		}
+	}
+
+	/**
+	 * Security check to ensure the installer cannot be run after installation
+	 * has finished. If this is detected, the viewer is sent to the front page.
+	 *
+	 * @param string $step
+	 */
+	protected function checkInstallCompletion($step) {
+		if ($step != 'complete') {
+			if (!in_array(FALSE, $this->status)) {
+				// install complete but someone is trying to view an install page
+				forward();
+			}
+		}
+	}
+
+	/**
+	 * Check if this is a case of a install being resumed and figure
+	 * out where to continue from. Returns the best guess on the step.
+	 *
+	 * @param string $step
+	 * @return string
+	 */
+	protected function resumeInstall($step) {
+		global $CONFIG;
+
+		// only do a resume from the first step
+		if ($step !== 'welcome') {
+			return;
+		}
+
+		if ($this->status['database'] == FALSE) {
+			return;
+		}
+
+		if ($this->status['settings'] == FALSE) {
+			forward("{$CONFIG->wwwroot}install.php?step=settings");
+		}
+
+		if ($this->status['admin'] == FALSE) {
+			forward("{$CONFIG->wwwroot}install.php?step=admin");
+		}
+
+		// everything appears to be set up
+		forward("{$CONFIG->wwwroot}install.php?step=complete");
+	}
+
+	/**
+	 * Bootstraping
+	 */
+
+	/**
+	 * Load the essential libraries of the engine
+	 */
+	protected function bootstrapEngine() {
+		global $CONFIG;
+
+		$lib_dir = $CONFIG->path . 'engine/lib/';
+
+		// bootstrapping with required files in a required order
+		$required_files = array(
+			'exceptions.php', 'elgglib.php', 'views.php', 'access.php', 'system_log.php', 'export.php',
+			'sessions.php', 'languages.php', 'input.php', 'install.php', 'cache.php', 'output.php'
+		);
+
+		foreach ($required_files as $file) {
+			$path = $lib_dir . $file;
+			if (!include($path)) {
+				echo "Could not load file '$path'. "
+					. 'Please check your Elgg installation for all required files.';
+				exit;
+			}
+		}
+	}
+
+	/**
+	 * Load remaining engine libraries and complete bootstraping (see start.php)
+	 * 
+	 * @param string $step
+	 */
+	protected function finishBootstraping($step) {
+
+		// install has its own session handling
+		session_name('Elgg');
+		session_start();
+		unregister_elgg_event_handler('boot', 'system', 'session_init');
+
+		// once the database has been created, load rest of engine
+		$dbIndex = array_search('database', $this->getSteps());
+		$stepIndex = array_search($step, $this->getSteps());
+
+		if ($stepIndex > $dbIndex) {
+			global $CONFIG;
+			$lib_dir = $CONFIG->path . 'engine/lib/';
+
+			$this->loadSettingsFile();
+			
+			$lib_files = array(
+				// these want to be loaded first apparently?
+				'database.php', 'actions.php',
+
+				'admin.php', 'annotations.php', 'api.php',
+				'calendar.php', 'configuration.php', 'cron.php', 'entities.php',
+				'extender.php', 'filestore.php', 'group.php',
+				'location.php', 'mb_wrapper.php',
+				'memcache.php', 'metadata.php', 'metastrings.php', 'notification.php',
+				'objects.php', 'opendd.php', 'pagehandler.php',
+				'pageowner.php', 'pam.php', 'plugins.php', 'query.php',
+				'relationships.php', 'river.php', 'sites.php', 'social.php',
+				'statistics.php', 'tags.php', 'usersettings.php',
+				'users.php', 'version.php', 'widgets.php', 'xml.php', 'xml-rpc.php'
+ 			);
+			
+			foreach ($lib_files as $file) {
+				$path = $lib_dir . $file;
+				if (!include_once($path)) {
+					throw new InstallationException("Could not load {$file}");
+				}
+			}
+
+			set_default_config();
+
+			trigger_elgg_event('boot', 'system');
+			trigger_elgg_event('init', 'system');
+		}
+	}
+
+	/**
+	 * Set up configuration variables
+	 */
+	protected function bootstrapConfig() {
+		global $CONFIG;
+		if (!isset($CONFIG)) {
+			$CONFIG = new stdClass;
+		}
+
+		$CONFIG->wwwroot = $this->getBaseUrl();
+		$CONFIG->url = $CONFIG->wwwroot;
+		$CONFIG->path = dirname(dirname(__FILE__)) . '/';
+	}
+
+	/**
+	 * Get the best guess at the base URL
+	 * @todo Should this be a core function?
+	 * @return string
+	 */
+	protected function getBaseUrl() {
+		$protocol = 'http';
+		if (!empty($_SERVER["HTTPS"]) && $_SERVER["HTTPS"] == "on") {
+			$protocol = 'https';
+		}
+		$port = ':' . $_SERVER["SERVER_PORT"];
+		if ($port == ':80' || $port == ':443') {
+			$port = '';
+		}
+		$uri = $_SERVER['REQUEST_URI'];
+		$cutoff = strpos($uri, 'install.php');
+		$uri = substr($uri, 0, $cutoff);
+
+		$url = "$protocol://{$_SERVER['SERVER_NAME']}$port{$uri}";
+		return $url;
+	}
+
+	function loadSettingsFile() {
+		global $CONFIG;
+		
+		if (!include_once("{$CONFIG->path}engine/settings.php")) {
+			throw new InstallationException("Elgg could not load the settings file. It does not exist or there is a permissions issue.");
+		}
+	}
+
+	/**
+	 * Action handling methods
+	 */
+
+	/**
+	 * Return an associative array of post variables
+	 * (could be selective based on expected variables)
+	 * 
+	 * @return array
+	 */
+	protected function getPostVariables() {
+		$vars = array();
+		foreach ($_POST as $k => $v) {
+			$vars[$k] = $v;
+		}
+		return $vars;
+	}
+
+	/**
+	 * If form is reshown, remember previously submitted variables
+	 *
+	 * @param array $formVars
+	 * @param array $submissionVars
+	 * @return array
+	 */
+	protected function makeFormSticky($formVars, $submissionVars) {
+		foreach ($submissionVars as $field => $value) {
+			$formVars[$field]['value'] = $value;
+		}
+		return $formVars;
+	}
+
+	/**
+	 * Requirement checks support methods
+	 */
+
+	/**
+	 * Create Elgg's .htaccess file or confirm that it exists
+	 *
+	 * @param array $report Reference to the report array
+	 * @return bool
+	 */
+	protected function createHtaccess(&$report) {
+		global $CONFIG;
+
+		$filename = "{$CONFIG->path}.htaccess";
+		if (file_exists($filename)) {
+			// check that this is the Elgg .htaccess
+			$data = file_get_contents($filename);
+			if ($data === FALSE) {
+				// don't have permission to read the file
+			}
+			if (strpos($data, 'Elgg') === FALSE) {
+				$report['htaccess'] = array(
+					array(
+						'severity' => 'failure',
+						'message' => elgg_echo('install:check:htaccess_exists'),
+					)
+				);
+				return FALSE;
+			} else {
+				// Elgg .htaccess is already there
+				return TRUE;
+			}
+		}
+		
+		if (!is_writable($CONFIG->path)) {
+			$report['htaccess'] = array(
+				array(
+					'severity' => 'failure',
+					'message' => elgg_echo('install:check:root'),
+				)
+			);
+			return FALSE;
+		}
+
+		// create the .htaccess file
+		$result = copy("{$CONFIG->path}htaccess_dist", $filename);
+		if (!$result) {
+			$report['htaccess'] = array(
+				array(
+					'severity' => 'failure',
+					'message' => elgg_echo('install:check:htaccess_fail'),
+				)
+			);
+		}
+
+		return $result;
+	}
+
+	/**
+	 * Check that the engine dir is writable
+	 * @param array $report
+	 * @return bool
+	 */
+	protected function checkEngineDir(&$report) {
+		global $CONFIG;
+		
+		$writable = is_writable("{$CONFIG->path}engine");
+		if (!$writable) {
+			$report['engine'] = array(
+				array(
+					'severity' => 'failure',
+					'message' => elgg_echo('install:check:enginedir'),
+				)
+			);
+			return FALSE;
+		}
+
+		return TRUE;
+	}
+
+	/**
+	 * Check that the settings file exists
+	 * @return bool
+	 */
+	protected function checkSettingsFile() {
+		global $CONFIG;
+
+		if (is_readable("{$CONFIG->path}engine/settings.php")) {
+			return TRUE;
+		}
+
+		return FALSE;
+	}
+
+	/**
+	 * Check version of PHP, extensions, and variables
+	 * @param array $report
+	 */
+	protected function checkPHP(&$report) {
+		$phpReport = array();
+
+		$elgg_php_version = '5.2.0';
+		if (version_compare(PHP_VERSION, $elgg_php_version, '<')) {
+			$phpReport[] = array(
+				'severity' => 'failure',
+				'message' => sprintf(elgg_echo('install:check:php:version'), $elgg_php_version, PHP_VERSION)
+			);
+		}
+
+		$this->checkPhpExtensions($phpReport);
+
+		$this->checkPhpDirectives($phpReport);
+
+		if (count($phpReport) == 0) {
+			$phpReport[] = array(
+				'severity' => 'pass',
+				'message' => elgg_echo('install:check:php:success')
+			);
+		}
+
+		$report['php'] = $phpReport;
+	}
+
+	/**
+	 * Check the server's PHP extensions
+	 *
+	 * @param array $phpReport
+	 */
+	protected function checkPhpExtensions(&$phpReport) {
+		$extensions = get_loaded_extensions();
+		$requiredExtensions = array(
+			'mysql',
+			'json',
+			'xml',
+			'gd',
+		);
+		foreach ($requiredExtensions as $extension) {
+			if (!in_array($extension, $extensions)) {
+				$phpReport[] = array(
+					'severity' => 'failure',
+					'message' => sprintf(elgg_echo('install:check:php:extension'), $extension)
+				);
+			}
+		}
+
+		$recommendedExtensions = array(
+			'mbstring',
+		);
+		foreach ($recommendedExtensions as $extension) {
+			if (!in_array($extension, $extensions)) {
+				$phpReport[] = array(
+					'severity' => 'warning',
+					'message' => sprintf(elgg_echo('install:check:php:extension:recommend'), $extension)
+				);
+			}
+		}
+	}
+
+	/**
+	 * Check PHP parameters
+	 * 
+	 * @param array $phpReport
+	 */
+	protected function checkPhpDirectives(&$phpReport) {
+		if (ini_get('open_basedir')) {
+			$phpReport[] = array(
+				'severity' => 'warning',
+				'message' => elgg_echo("install:check:php:open_basedir")
+			);
+		}
+
+		if (ini_get('safe_mode')) {
+			$phpReport[] = array(
+				'severity' => 'warning',
+				'message' => elgg_echo("install:check:php:safe_mode")
+			);
+		}
+	}
+
+	/**
+	 * Confirm that Apache's rewrite module and AllowOverride are set up
+	 * @param array $report
+	 * @return bool
+	 */
+	protected function checkRewriteModule(&$report) {
+		global $CONFIG;
+
+		$url = "{$CONFIG->wwwroot}modrewrite.php";
+
+		if (function_exists('curl_init')) {
+			// try curl if installed
+			$ch = curl_init();
+			curl_setopt($ch, CURLOPT_URL, $url);
+			curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
+			$response = curl_exec($ch);
+			curl_close($ch);
+			$result = $response === 'success';
+		} else if (ini_get('allow_url_fopen')) {
+			// use file_get_contents as fallback
+			$data = file_get_contents($url);
+			$result = $data === 'success';
+		} else {
+			$report['htaccess'] = array(
+				array(
+					'severity' => 'warning',
+					'message' => elgg_echo('install:check:rewrite:unknown'),
+				)
+			);
+			return FALSE;
+		}
+
+		if ($result) {
+			$report['htaccess'] = array(
+				array(
+					'severity' => 'pass',
+					'message' => elgg_echo('install:check:rewrite:success'),
+				)
+			);
+		} else {
+			$report['htaccess'] = array(
+				array(
+					'severity' => 'failure',
+					'message' => elgg_echo('install:check:rewrite:fail'),
+				)
+			);
+		}
+
+		return $result;
+	}
+
+	/**
+	 * Check if the request is coming from the mod rewrite test on the
+	 * requirements page.
+	 */
+	protected function runModRewriteTest() {
+		if (strpos($_SERVER['REQUEST_URI'], 'modrewrite.php') !== FALSE) {
+			echo 'success';
+			exit;
+		}
+	}
+
+	/**
+	 * Count the number of failures in the requirements report
+	 *
+	 * @param array $report
+	 * @param string $condition 'failure' or 'warning'
+	 * @return int
+	 */
+	protected function countNumConditions($report, $condition) {
+		$count = 0;
+		foreach ($report as $category => $checks) {
+			foreach ($checks as $check) {
+				if ($check['severity'] === $condition) {
+					$count++;
+				}
+			}
+		}
+
+		return $count;
+	}
+
+	
+	/**
+	 * Database support methods
+	 */
+
+	/**
+	 * Validate the variables for the database step
+	 *
+	 * @param array $submissionVars
+	 * @param array $formVars
+	 * @return bool
+	 */
+	protected function validateDatabaseVars($submissionVars, $formVars) {
+
+		foreach ($formVars as $field => $info) {
+			if ($info['required'] == TRUE && !$submissionVars[$field]) {
+				$name = elgg_echo("installation:database:label:$field");
+				register_error("$name is required");
+				return FALSE;
+			}
+		}
+		
+		return $this->checkDatabaseSettings(
+					$submissionVars['dbuser'],
+					$submissionVars['dbpassword'],
+					$submissionVars['dbname'],
+					$submissionVars['dbhost']
+				);
+	}
+
+	/**
+	 * Confirm the settings for the database
+	 *
+	 * @param string $user
+	 * @param string $password
+	 * @param string $dbname
+	 * @param string $host
+	 * @return bool
+	 */
+	function checkDatabaseSettings($user, $password, $dbname, $host) {
+		$mysql_dblink = mysql_connect($host, $user, $password, true);
+		if ($mysql_dblink == FALSE) {
+			register_error('Unable to connect to the database with these settings.');
+			return $FALSE;
+		}
+
+		$result = mysql_select_db($dbname, $mysql_dblink);
+
+		// check MySQL version - must be 5.0 or >
+		$version = mysql_get_server_info();
+		$points = explode('.', $version);
+		if ($points[0] < 5) {
+			register_error("MySQL must be 5.0 or above. Your server is using $version.");
+			return FALSE;
+		}
+
+		mysql_close($mysql_dblink);
+
+		if (!$result) {
+			register_error("Unable to use database $dbname");
+		}
+
+		return $result;
+	}
+
+	/**
+	 * Writes the settings file to the engine directory
+	 *
+	 * @param array $params
+	 * @return bool
+	 */
+	protected function createSettingsFile($params) {
+		global $CONFIG;
+
+		$templateFile = "{$CONFIG->path}engine/settings.example.php";
+		$template = file_get_contents($templateFile);
+		if (!$template) {
+			register_error('Unable to read engine/settings.example.php');
+			return FALSE;
+		}
+
+		foreach ($params as $k => $v) {
+			$template = str_replace("{{".$k."}}", $v, $template);
+		}
+
+		$settingsFilename = "{$CONFIG->path}engine/settings.php";
+		$result = file_put_contents($settingsFilename, $template);
+		if (!$result) {
+			register_error('Unable to write engine/settings.php');
+			return FALSE;
+		}
+
+		return TRUE;
+	}
+
+	/**
+	 * Bootstrap database connection before entire engine is available
+	 *
+	 * @return bool
+	 */
+	protected function connectToDatabase() {
+		global $CONFIG;
+
+		if (!include_once("{$CONFIG->path}engine/settings.php")) {
+			register_error("Elgg could not load the settings file.");
+			return FALSE;
+		}
+
+		if (!include_once("{$CONFIG->path}engine/lib/database.php")) {
+			register_error("Elgg could not load the database library.");
+			return FALSE;
+		}
+
+		try  {
+			setup_db_connections();
+		} catch (Exception $e) {
+			register_error($e->getMessage());
+			return FALSE;
+		}
+
+		return TRUE;
+	}
+
+	/**
+	 * Create the database tables
+	 * 
+	 * @return bool
+	 */
+	protected function installDatabase() {
+		global $CONFIG;
+
+		try {
+			run_sql_script("{$CONFIG->path}engine/schema/mysql.sql");
+		} catch (Exception $e) {
+			register_error($e->getMessage());
+			return FALSE;
+		}
+		
+		return TRUE;
+	}
+
+	/**
+	 * Site settings support methods
+	 */
+
+	/**
+	 * Validate the site settings form variables
+	 *
+	 * @param array $submissionVars
+	 * @param array $formVars
+	 * @return bool
+	 */
+	protected function validateSettingsVars($submissionVars, $formVars) {
+
+		foreach ($formVars as $field => $info) {
+			if ($info['required'] == TRUE && !$submissionVars[$field]) {
+				$name = elgg_echo("installation:settings:label:$field");
+				register_error("$name is required");
+				return FALSE;
+			}
+		}
+
+		// check that data root is writable
+		if (!is_writable($submissionVars['dataroot'])) {
+			register_error("Your data directory {$submissionVars['dataroot']} is not writable by the web server.");
+			return FALSE;
+		}
+
+		// check that data root is not subdirectory of Elgg root
+		if (stripos($submissionVars['dataroot'], $submissionVars['path']) !== FALSE) {
+			register_error("Your data directory {$submissionVars['dataroot']} must be outside of your install path for security.");
+			return FALSE;
+		}
+
+		// @todo move is_email_address to a better library than users.php
+		// check that email address is email address
+		//if ($submissionVars['siteemail'] && !is_email_address($submissionVars['siteemail'])) {
+		//	register_error("{$submissionVars['']} is not a valid email address.");
+		//	return FALSE;
+		//}
+
+		// @todo check that url is a url
+
+
+		return TRUE;
+	}
+
+	/**
+	 * Initialize the site including site entity, plugins, and configuration
+	 *
+	 * @param array $submissionVars
+	 * @return bool
+	 */
+	protected function saveSiteSettings($submissionVars) {
+		global $CONFIG;
+
+		// ensure that file path, data path, and www root end in /
+		$submissionVars['path'] = sanitise_filepath($submissionVars['path']);
+		$submissionVars['dataroot'] = sanitise_filepath($submissionVars['dataroot']);
+		$submissionVars['wwwroot'] = sanitise_filepath($submissionVars['wwwroot']);
+
+		$site = new ElggSite();
+		$site->name      = $submissionVars['sitename'];
+		$site->url       = $submissionVars['wwwroot'];
+		$site->access_id = ACCESS_PUBLIC;
+		$site->email     = $submissionVars['siteemail'];
+		$guid            = $site->save();
+
+		if (!$guid) {
+			register_error("Unable to create the site.");
+			return FALSE;
+		}
+
+		// bootstrap site info
+		$CONFIG->site_guid = $guid;
+		$CONFIG->site = $site;
+
+		datalist_set('installed', time());
+		datalist_set('path', $submissionVars['path']);
+		datalist_set('dataroot', $submissionVars['dataroot']);
+		datalist_set('default_site', $site->getGUID());
+		datalist_set('version', get_version());
+
+		set_config('view', 'default', $site->getGUID());
+		set_config('language', $submissionVars['language'], $site->getGUID());
+		set_config('default_access', $submissionVars['siteaccess'], $site->getGUID());
+		set_config('allow_registration', TRUE, $site->getGUID());
+		set_config('walled_garden', FALSE, $site->getGUID());
+
+		$this->enablePlugins();
+
+		// reset the views path in case of installing over an old data dir.
+		$dataroot = datalist_get('dataroot');
+		$cache = new ElggFileCache($dataroot);
+		$cache->delete('view_paths');
+
+		return TRUE;
+	}
+
+	/**
+	 * Enable a set of default plugins
+	 */
+	protected function enablePlugins() {
+		// activate plugins with manifest.xml: elgg_install_state = enabled
+		$plugins = get_plugin_list();
+		foreach ($plugins as $plugin) {
+			if ($manifest = load_plugin_manifest($plugin)) {
+				if (isset($manifest['elgg_install_state']) && $manifest['elgg_install_state'] == 'enabled') {
+					enable_plugin($plugin);
+				}
+			}
+		}
+	}
+
+	/**
+	 * Admin account support methods
+	 */
+
+	/**
+	 * Validate account form variables
+	 *
+	 * @param array $submissionVars
+	 * @param array $formVars
+	 * @return bool
+	 */
+	protected function validateAdminVars($submissionVars, $formVars) {
+		
+		foreach ($formVars as $field => $info) {
+			if ($info['required'] == TRUE && !$submissionVars[$field]) {
+				$name = elgg_echo("installation:admin:label:$field");
+				register_error("$name is required");
+				return FALSE;
+			}
+		}
+
+		if ($submissionVars['password1'] !== $submissionVars['password2']) {
+			register_error("Your passwords must match.");
+			return FALSE;
+		}
+
+		if (trim($submissionVars['password1']) == "") {
+			register_error("Password cannot be empty.");
+			return FALSE;
+		}
+
+		return TRUE;
+	}
+
+	/**
+	 * Create a user account for the admin
+	 *
+	 * @param array $submissionVars
+	 * @return bool
+	 */
+	protected function createAdminAccount($submissionVars) {
+		global $CONFIG;
+		
+		$guid = register_user(
+				$submissionVars['username'],
+				$submissionVars['password1'],
+				$submissionVars['displayname'],
+				$submissionVars['email']
+				);
+
+		if (!$guid) {
+			register_error("Unable to create an admin account.");
+			return FALSE;
+		}
+
+		// @todo - register plugin hook instead for can edit
+		// need a logged in user to set admin flag so we go directly to database
+		$result = update_data("UPDATE {$CONFIG->dbprefix}users_entity set admin='yes' where guid=$guid");
+		if (!$result) {
+			register_error("Unable to give new user account admin privileges.");
+			return FALSE;
+		}
+
+		return TRUE;
+	}
+}