Add function expectType() to table class

protected function exceptType added for use by subclasses to assert that
the database object loaded is the correct type and to protect against
cases like EG: passing the GUID for a group to new user(...);  If a
problem is detected, throw an exception.

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");
     }
 
     /*