Secrets of Their Forging and Active Conditions?

[Bandobras Took]

After following the discussions here, it seems like discarding/tapping cards can be an active condition of playing others (Sac of Form, for example -- discarding Wizard has been ruled to be an active condition).

Sage only. Playable on a sage during the site phase at a site where Information is playable if a character in his company has a gold ring item. Tap the sage and the site. You may replace the gold ring with a special item ring from your hand (except for The One Ring) for which the gold ring could normally be tested. Discard the gold ring item.

Given the Sacrifice of Form logic, is discarding the gold ring item an active condition of Secrets of Their Forging? If so, how can you replace a gold ring which is no longer in play when the card resolves?

[jaded]

If discarding a wizard is an active condition, this means his items are lost. If putting items off to the side and discarding non items cards are also active conditions, this means you cannot play SoF if you do not have items and non items cards that wizard controls. Do you see here any logic to follow?

[Konrad Klar]

I'd say that gold ring is target of last action of this card. So gold ring is condition, not discarding of gold ring.