Edit stash

Optimistic save (a.k.a. pre-emptive edit parsing or edit stashing) is a MediaWiki feature to speed up the user-perceived performance of saving page edits. At some point when the UI predicts that the user won't be making further changes (for the plain editing interface this happens when the user focuses on the edit summary field, for VisualEditor when the user opens the save dialog), the current content of the edit area is sent over via AJAX, parsed, and stashed. If the user does indeed save, and no conflicting change has happened in the meantime, the stashed edit is turned into a real revision.

More information

 * the  ResourceLoader module
 * the  API module
 * the related ticket: T1096
 * the related ticket: T1096