Offline document cache
What it is
Section titled “What it is”The offline document cache stores copies of documents on your phone so you can open them with no signal: at a strip with no bars, in a hangar with thick walls, or on a foreign trip with data roaming switched off. It holds two kinds of thing: the syndicate’s ship’s papers, and your own pilot documents (your medical certificate and licence, where you have uploaded them). It is the practical answer to “I need to show the insurance, the radio licence, and my medical to a ramp inspector right now”.
The cache is on iOS and Android only. The web does not have a cache; web is treated as a desk-bound environment where you have a connection.
Who can use it
Section titled “Who can use it”- Every member of a syndicate. The cache is a per-member feature; admins and members alike use it.
- Sharing the device with another member does not share their cache. The cache is keyed to the signed-in account.
Where to find it
Section titled “Where to find it”The toggle and badges live on the document library (Syndicate > Documents). Each section has its own offline state.
Routes are unchanged from the library: /syndicates/:syndicateId/documents.
What gets cached
Section titled “What gets cached”| Section | Behaviour |
|---|---|
| Syndicate-level documents | Always cached. Shown with an Available offline badge. No member choice. |
| Asset documents (single-asset syndicate) | Always cached. Shown with an Available offline badge. No member choice. |
| Asset documents (multi-asset syndicate) | Opt-in per asset. Each asset section has a Cache on this device toggle. Off by default. |
| Your own pilot documents (medical, licence) | Always cached, on your own devices only, when a file exists. An uploaded certificate or licence is kept on every device you sign in on; that is the point of uploading it. A medical recorded as an expiry date only has no file, so there is nothing to cache. No other member’s device ever holds your pilot documents. |
The cache holds the whole of each eligible asset’s documents: all of its ARC, insurance, CofA, CofR, radio licence, etc. There is no per-document filter.
How the toggle behaves
Section titled “How the toggle behaves”- Off → On. The next time the app is in the foreground with a connection, it downloads every eligible document in that section.
- On → Off. The cached files for that section are deleted immediately. You won’t be able to open them offline until you turn the toggle back on.
- Toggle state is per member, per asset. Your preference follows your account across your devices. Two members of the same syndicate can have different caches.
What “cached” means at the viewer
Section titled “What “cached” means at the viewer”When you open a document:
- If the file is in the cache, it opens instantly, from disk.
- If it isn’t (web, or a section you haven’t opted in to), the viewer fetches it over the network and renders it.
There is no visible difference between the two paths: the same viewer, the same PDF or image renderer. The only difference is whether your phone needs signal.
Behaviour rules
Section titled “Behaviour rules”- Cache state follows the library. Adding a new asset document syncs it into every device that has the asset opted in. Replacing a document substitutes the new file in the cache (verified against its updated fingerprint). Deleting a document removes the file from every device’s cache at the next sync.
- Cache size is capped by the documents in the syndicate, not by an arbitrary number. Syndik8 does not impose a cache budget; the cache is whatever the syndicate’s documents add up to. If the cache grows uncomfortable, opt fewer asset sections in.
- Files survive an app restart, a phone restart, and a sign-out. Signing out does not clear the cache. This is deliberate: the copy exists so your papers are available where there is no signal, and a sign-out wipe would defeat that. After sign-out the copies are not viewable in the app, but their bytes remain in the app’s private storage until the document is deleted or the app is uninstalled, so avoid recording personal documents on a shared device (the upload form reminds you of this).
- Leaving a syndicate clears that syndicate’s cache, and only that. The syndicate’s and its assets’ documents are removed from your device at the next sync. Your own pilot documents are unaffected: they belong to you, not to any syndicate.
- Deleting a document removes its cached copy. For your medical, both delete outcomes (delete everything, or delete the file and keep the date) remove the certificate from your device as part of the action.
- The cache only ever holds documents your membership grants you access to, plus your own pilot documents. If you’re removed from a syndicate, the cache for that syndicate is cleared the next time the app syncs.
- No web cache. On a desktop browser, the offline cache is a no-op; there’s no toggle and no badge, and the viewer always fetches over the network. Web is for admin work, mobile is for the airfield.
For a full explanation of what caches and why, see How offline document caching works.