signal callback delegate or function to connect
void callback(javascriptcore.value.Value form, webkitwebprocessextension.frame.Frame sourceFrame, webkitwebprocessextension.frame.Frame targetFrame, webkitwebprocessextension.web_form_manager.WebFormManager webFormManager)
form the #JSCValue to be submitted, which will always correspond to an HTMLFormElement (optional)
sourceFrame the #WebKitFrame containing the form to be submitted (optional)
targetFrame the #WebKitFrame containing the form's target, which may be the same as source_frame if no target was specified (optional)
webFormManager the instance the signal is connected to (optional)
Yes.After to execute callback after default handler, No.After to execute before (default)
Signal ID
Connect to WillSubmitForm signal.
This signal is emitted when form will imminently be submitted. It can no longer be cancelled. This event always occurs immediately before a form is submitted to its target, so use this event to reliably detect when a form is submitted. This signal is emitted after #WebKitWebFormManager::will-send-submit-event if that signal is emitted.