When it happens
- Automatically, once, the first time Tandem scans your games.
- Whenever you ask, with Settings › Library › Import details. Run it again after scraping more games in ES-DE, or after making a new Cocoon backup.
Importing never touches the files it reads, and your old frontend keeps working.
Where Tandem looks
For each system, Tandem checks these places and uses every file it finds:
| Source | Location |
|---|---|
| A gamelist next to the games | ROMs/<system folder>/gamelist.xml |
| ES-DE | ES-DE/gamelists/<system>/gamelist.xml in internal storage |
| Cocoon | The newest ROMs/backups/cocoon_backup_* folder, in categories/metadata/<system>/gamelist.xml |
<system> is the system's id or one of its art names from platforms.json, so for the 3DS both n3ds and 3ds work.
To import from Cocoon, make a backup in Cocoon first and make sure it is saved under ROMs/backups/.
What comes across
Each <game> entry is matched to a game in your library by file name, so the files need to be the same ones the other frontend saw.
| Tandem field | Read from |
|---|---|
| Title | Cocoon's own title, or name |
| Description | desc |
| Genres | genre, split on ;, , and / |
| Developer, publisher | developer, publisher |
| Year | the first four digits of releasedate |
| Players, rating | players, rating |
| Favorite, hidden | favorite, hidden |
| Play count, last played | playcount, lastplayed |
| Play time | Cocoon's play time |
| Cover | Cocoon's local box art, or image, or thumbnail |
| Hero | Cocoon's local hero, or fanart |
| Logo | Cocoon's local logo, or marquee |
| Screenshot | Cocoon's gameplay or title screenshot, or screenshot |
Artwork paths can be relative to the gamelist (./media/…), start with ~/, be absolute, or be content links into internal storage. Tandem only keeps a path if the file is actually there.
What wins when both have a value
Tandem never overwrites what it already has:
- Text and artwork (titles, descriptions, genres and so on): Tandem's value stays if it has one; the import only fills gaps.
- Favorite and hidden: a game is a favorite if either side says so. The same goes for hidden.
- Play count, play time and last played: the larger value wins, so history from both places isn't double counted, and isn't lost.
Themes from Cocoon
Theme packs you downloaded in Cocoon (in ROMs/themes) show up in Settings › Look & feel › Theme packs by themselves, with their wallpapers, system icons, heroes and logos. You can also import a pack from a folder or a .zip. See Themes for what Tandem reads from a pack, and the example of the format.
Import my Cocoon setup (Settings › Library › Bring your details) goes further: from your newest Cocoon backup it brings over the home grid arrangement, folders, the theme pack and appearance values. Undo Cocoon import puts everything back as it was.
Going the other way
Tandem's own data is plain JSON. Settings › Data & about › Back up writes it to a dated folder in ROMs/tandem/backup/, and any tool can read it. See Back up and restore.