2 files changed, 16 insertions, 0 deletions
diff --git a/app/class/table.class.php b/app/class/table.class.php
index 2759176..45be8c5 100644
--- a/app/class/table.class.php
+++ b/app/class/table.class.php
@@ -201,6 +201,21 @@ abstract class table
         while (self::isGUID($guid));
         return $guid;
     }
+
+    /*
+     * Assert that this object is of the expected type in the database.
+     * Throw an exception if a type mismatch exists.  Check will only
+     * be performed if guid and objtype are set on this object.
+     */
+    protected function expectType(string $objtype) : void
+    {
+        if (isset($this->guid) && isset($this->objtype))
+        {
+            if ($this->objtype != $objtype)
+                throw new Exception("Invalid object allocation.  " . $this->guid . " is a " .
+                    $this->objtype . ", not a " . $objtype . ".");
+        }
+    }
 }
 
 ?>
diff --git a/app/class/user.class.php b/app/class/user.class.php
index 45fa5a5..7defa8f 100644
--- a/app/class/user.class.php
+++ b/app/class/user.class.php
@@ -38,6 +38,7 @@ class user extends agent
         );
 
         parent::__construct($guid);
+        $this->expectType("user");
     }
 
     /*