In any application user interface that involves HTML forms, there is a possibility of duplicate requests being unintentionally created by the browser. Problems can occur when requests that result in updating data are unintentionally submitted multiple times. For example, a duplicate request may get generated when the browser is manually refreshed by the user. The user intended to perform the update only once; however, multiple requests for the same update can be generated.
To avoid potential problems created by duplicate requests, the application infrastructure framework uses page tokens to verify that only the original request is processed. When a user logs into the , a unique identifier called a page token is assigned to the screens that are opened. This page token is validated every time an update request is sent by the browser. If the token does not match the one assigned to the screens earlier, then the request is ignored. This safeguard is built into the application infrastructure framework.