Stateful strategy - store incomplete form data in the database and pass off a temporary token for lookup.
This is pretty much exactly what Gravity Forms' "Save & Continue" functionality accomplishes - it's possible that some of it's implementation might be leveraged without completely hijacking the feature. If not, it can be used as a model for the strategy - standalone might be more desirable anyway for not depending on undocumented and unexposed interfaces.
Stateful strategy - store incomplete form data in the database and pass off a temporary token for lookup.
This is pretty much exactly what Gravity Forms' "Save & Continue" functionality accomplishes - it's possible that some of it's implementation might be leveraged without completely hijacking the feature. If not, it can be used as a model for the strategy - standalone might be more desirable anyway for not depending on undocumented and unexposed interfaces.