Why remove references to legacy functions?
To avoid any security implications that may discovered in the future (Legacy functions may not be patched by Oracle).
How do I replace a legacy function?
The legacy.js file includes commented lines that may give hints to newer AEPX namespaced functions that will replace the legacy function.
A common legacy function used in legacy APEX applications is confirmDelete.
Use the seach application textbox in the upper right of the application builder to search for occurances where confirmDelete is used in an application.
A report is displayed showing the occurances of the search text. Click the "View" link to edit the component. In this example, the confirmDelete function is called as part of the URL Target of a button action.
Change the URL Target from:
Common legacy functions & replacement
confirmDelete >> apex.confirm
doSubmit >> apex.submit
popupFieldHelp >> apex.theme.popupFieldHelp
APEX 4.2 / 4.2.4