make add/remove starter buttons date sensitive

homepage/participo/lib/participoLib/shiai.php

@@ -57,7 +57,20 @@ class Shiai
 		return ($this->place != null ? $this->place : '-');
 	}
 
-	public static function fromArray($member)
+	public static function loadFromDb(int $id)
+	{
+		$query = 'SELECT * FROM `cwsvjudo`.`wettkampfkalender` WHERE `lfdeNr` = :id;';
+		$params = [':id' => ['value' => $id, 'data_type' => PDO::PARAM_INT]];
+		$response = dbConnector::query($query, $params);
+
+		// ids are considered unique. so every other count then 1 is treated as error to prevent unprivileged access
+		if (count($response) != 1) {
+			return null;
+		}
+		return self::fromDbArray($response[0]);
+	}
+
+	public static function fromDbArray($member)
 	{
 		return new shiai(
 			$member['lfdeNr'] ?? null,