SnapshotManager.getSnapshots

Returns an array of candidate snapshots that match the search criteria specified in query. These snapshots could then be offered to the user and when a selection is made, method #restoreSnapshot(String) can be called to implement the restore.

Further documentation.

Javascript example 1. Find a snapshot with a specific id:

 var query = new SnapshotQuery();
 query.setSnapshotId("123456789-HHH-BBB");
 var snapshots = system.snapshotManager.getSnapshots(query);
 if(snapshots.length == 1) 
 {
      //found a match, do something...
      var snapshot = snapshots[0];
      .....
 }
 

Javascript example 2. Find snapshots for the current form and for current user which have not expired:

 var query = new SnapshotQuery();
 var snapshot_fields = {};
 snapshot_fields.form_id = form.elementName;
 snapshot_fields.username = system.securityManager.userName;
 query.setFields(snapshot_fields);
 var snapshots = system.snapshotManager.getSnapshots(query);
 if(snapshots.length > 0) 
 {
      //found matches, do something...
      for each(var snapshot in snapshots)
      {
          //do something with snapshot
          .......
      }
 }