XForms, Warn on Navigate Away

Sample Program

Add this code to global.js

type="text/javascript">
// adding a gmail style function to stop the user from moving away from the page..
function unloadMessage(){message = "This form has not yet been submitted to the database\nAll data will be lost."
return message;}
function setBunload(on){window.onbeforeunload = (on) ? unloadMessage : null;}
setBunload(true);

Mozilla Page [1]

IE Manual [2]

Discussion

Use the xf:load action in combination with an xforms-value-changed event to call a "dirty" function containing setBunload(true).

Likewise, use the load action within the submission to call a "clean" function containing "setBunload(false)".

function dirty() {
setBunload(true);
}
function clean() {
setBunload(false);
}
This one goes in your "submission" element:
resource="javascript:clean()" ev:event="xforms-submit-done"/>

and this
resource="javascript:dirty()" ev:event="xforms-value-changed"/>
goes somewhere in the form - place it at the body-level to capture all change events, or nest it within a more appropriate container.

References

This example was taken from Alex Bleasdale in 2007.

Microsoft documentation on page unload function

Where this page came from

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