helper.php

<?php

/**
 * Provides a collection of usevel methods for our application
 */
class Helper {

    /*
     * Get the URL Get Query Parameter or null
     */
    public static function getURLGETParameter($name) {
        return (isset($_GET[$name])) ? urldecode($_GET[$name]) : null;
    }

    /**
     * Retrieve the device ID based on the UID
     */
    public static function getDeviceID($deviceUID) {
        $qb = new QueryBuilder();
        $r = $qb
            ->table('devices')
            ->fields(['id'])
            ->where(["uid = $deviceUID"])
            ->select();
        if (count($r->values) == 0) 
            throw new HttpException(404, "Device not found");

        return $r->values[0]->id;
    }
    
    /**
     * Retrieve the sensor ID based on the UID and it's device UID
     */
    public static function getSensorID($deviceUID, $sensorUID) {
        $device_id = self::getDeviceID($deviceUID);
        $qb = new QueryBuilder();
        $r = $qb
            ->table('sensors')
            ->fields(['id'])
            ->where(["devices_id = $device_id AND uid = $sensorUID"])
            ->select();
        if (count($r->values) == 0) 
            throw new HttpException(404, "Sensor not found");
        
        return $r->values[0]->id;
    }

    /**
     * Local LOG function
     */
    public static function log($message) {
        try {        
			$qb = new QueryBuilder();
			$r = $qb
				->table('log')
				->fields(['timestamp', 'calling', 'message'])
				->insert([date('Y-m-d H:i:s'), self::getCallingFunctionName(2), $message]);        
        } catch (Exception $e) {
            $data = $message.PHP_EOL;
            $fp = fopen('exception_log.txt', 'a');
            fwrite($fp, $data);
        }
    }
    
    /**
     * Get the name of the last called function. $level tell us if we want the last
     * parent caller, or the last-last parent caller, so on...
     * $level = 0, is the same function
     * $level = 1, is the function before
     * $level = 2, is the function before before
     * $level = 3, ... etc.
     */
    private static function getCallingFunctionName($level) { 
      
        // Create an exception 
        $ex = new Exception(); 
        
        // Call getTrace() function 
        $trace = $ex->getTrace(); 
        
        // Position 0 would be the line 
        // that called this function 
        $final_call = $trace[$level]; 
        
        // Display associative array  
        return print_r($final_call, true); 
    }
}