adding sanity checks to bootstrap to detect upgrade/missing config/etc;

src/bootstrap.php

@@ -88,14 +88,36 @@ foreach($includes as $file) {
 // init db connection
 $db = new psm\Service\Database();
 
-if($db->status() && (!defined('PSM_INSTALL') || !PSM_INSTALL)) {
-	psm_load_conf();
+// sanity check!
+if(defined('PSM_INSTALL') && PSM_INSTALL) {
+	// install mode
+	if($db->status()) {
+		// connection established, attempt to load config.
+		// no biggie if it doesnt work because the user is still in the install module.
+		psm_load_conf();
+	}
 } else {
-	// no config yet! lets help them in the right direction
-	if(!defined('PSM_INSTALL')) {
+	if($db->getDbHost() === null) {
+		// no config file has been loaded, redirect the user to the install
 		header('Location: install.php');
 		die();
 	}
+	// config file has been loaded, check if we have a connection
+	if(!$db->status()) {
+		die('Unable to establish database connection...');
+	}
+	// attempt to load configuration from database
+	if(!psm_load_conf()) {
+		// unable to load from config table
+		die('We were unable to find an existing installation. <a href="install.php">Please click here to install PHP Server Monitor</a>.');
+	}
+	// config load OK, make sure database version is up to date
+	$version_db = psm_get_conf('version');
+
+	if(version_compare(PSM_VERSION, $version_db, '>')) {
+		die('Your database is for an older version, <a href="install.php">please click here</a> to update your database to the latest version.');
+	}
 }
+
 $lang = psm_get_conf('language', 'en_US');
-psm_load_lang($lang);
+psm_load_lang($lang);

src/includes/functions.inc.php

@@ -128,6 +128,7 @@ function psm_get_conf($key, $alt = null) {
  * Load config from the database to the $GLOBALS['sm_config'] variable
  *
  * @global object $db
+ * @return boolean
  * @see psm_get_conf()
  */
 function psm_load_conf() {
@@ -135,14 +136,19 @@ function psm_load_conf() {
 
 	// load config from database into global scope
 	$GLOBALS['sm_config'] = array();
-	$config_db = $db->select(PSM_DB_PREFIX . 'config', null, array('key', 'value'));
-	foreach($config_db as $setting) {
-		$GLOBALS['sm_config'][$setting['key']] = $setting['value'];
-	}
 
-	if(empty($GLOBALS['sm_config']) && basename($_SERVER['SCRIPT_NAME']) != 'install.php') {
-		// no config found, go to install page
-		die('Failed to load config table. Please run the install.php file');
+	if(!$db->ifTableExists(PSM_DB_PREFIX.'config')) {
+		return false;
+	}
+	$config_db = $db->select(PSM_DB_PREFIX . 'config', null, array('key', 'value'));
+
+	if(is_array($config_db) && !empty($config_db)) {
+		foreach($config_db as $setting) {
+			$GLOBALS['sm_config'][$setting['key']] = $setting['value'];
+		}
+		return true;
+	} else {
+		return false;
 	}
 }
 

src/psm/Module/Install/Controller/InstallController.class.php

@@ -335,13 +335,7 @@ class InstallController extends AbstractController {
 		if(!$this->db->status()) {
 			return false;
 		}
-		$confExists = $this->db->query("SHOW TABLES LIKE '".PSM_DB_PREFIX."config';", false)->rowCount();
-
-		if($confExists > 0) {
-			return true;
-		} else {
-			return false;
-		}
+		return $this->db->ifTableExists(PSM_DB_PREFIX.'config');
 	}
 
 	/**

src/psm/Service/Database.class.php

@@ -313,6 +313,29 @@ class Database {
 		return $this->last;
 	}
 
+	/**
+	 * Check if a certain table exists.
+	 * @param string $table
+	 * @return boolean
+	 */
+	public function ifTableExists($table) {
+		$table = $this->quote($table);
+		$db = $this->quote($this->getDbName());
+
+		$if_exists = "SELECT COUNT(*) AS `cnt`
+			FROM `information_schema`.`tables`
+			WHERE `table_schema` = {$db}
+			AND `table_name` = {$table};
+		";
+		$if_exists = $this->query($if_exists);
+
+		if(isset($if_exists[0]['cnt']) && $if_exists[0]['cnt'] == 1) {
+			return true;
+		} else {
+			false;
+		}
+	}
+
 	/**
 	 * Quote a string
 	 * @param string $value