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UserPreferencePreInterceptor overrides FormFieldImpl values with values that are stored in PortletPreferences. When this interceptor runs, it looks for FormFieldImpl values that match the regex. By default, your portlet will use the regex of "\\{prefs\\.[\\w.]+\\}", but this can be changed in configuration.properties of the portlet. An example of a valid FormFieldImpl value would be "{prefs.myzimbra.uid}".
These portlet preferences can be edited by the user. The portlet must be configured to support Edit mode. All FormFieldImpl values that match the preferences regex will be displayed for the user to edit as preferences and will be persisted. Secured fields will be encrypted in the database and will be obscured on the Portlet's Edit page.
UserInfoUrlParameterizingPreInterceptor
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Because this is a bean, your implementation can be as simple or as complicated as needed. PortletPreferences will be available to your bean.