Triggered when a remote tab is about to be loaded, after the
beforeActivate event. Can be canceled to prevent the tab panel from
loading content; though the panel will still be activated. This event
is triggered just before the Ajax request is made, so modifications
can be made to ui.jqXHR and ui.ajaxSettings.
Note: Although ui.ajaxSettings is provided and can be modified, some
of these properties have already been processed by jQuery. For
example, prefilters have been applied, data has been processed, and
type has been determined. The beforeLoad event occurs at the same
time, and therefore has the same restrictions, as the beforeSend
callback from jQuery.ajax().
* event Type: Event
* ui Type: Object
* tab Type: jQuery The tab that is being loaded. * panel Type: jQuery The panel which will be populated by the Ajax
response. * jqXHR Type: jqXHR The jqXHR object that is requesting the content. * ajaxSettings Type: Object The properties that will be used by
jQuery.ajax to request the content.