How does tiddlyweb and localstorage plugin handle deletion

[linonetwo]

When fixing tiddly-gittly/tw-mobile-sync#7 , I think I may need to know how other plugins handle async deletion.

If a client is offline, and later online, how will it let tiddlyweb server know there is an deletion? By sending a full tiddlers list to it? (This will be huge, I have 20k tiddlers now).

I think it may just record the recent changes since last sync, and it contains changedTiddlers, which has delete and modify field set to true.

I need to read the code to learn this. Just record here.

[Jermolene]

Hi @linonetwo

The tiddlyweb adaptor handles deletions via the syncer module which keeps track of the tiddlers that are known on the server; if it later finds a tiddler that it marked as present on the server but not present on the client, then it will send a deletion request to the server. The code is here:

https://github.com/Jermolene/TiddlyWiki5/blob/cce23ac6cddbccc88a848dcc5c456e57c01b2c20/core/modules/syncer.js#L566-L575

The browser storage plugin uses similar logic in https://github.com/Jermolene/TiddlyWiki5/blob/master/plugins/tiddlywiki/browser-storage/rawmarkup.js

[linonetwo]

Thank you. I see, this task queue is in-memory, so if network broken, and a user restart wiki before the network is re-connected (before syncadaptor.isReady become true), the delete state will be lost. Next time when network is connected again, that user will find deleted tiddlers "rewind".

So I can consider this problem is not resolved in tiddlyweb too.

(Looks like browser storage plugin won't have this disconnected problem...)

But maybe we can utilize Developer demo of alternate wiki store implementation #7329 to also store tasks in sqlite...Or just use

[Jermolene]

Hi @linonetwo in v5.2.7 we extended the browser-storage plugin to work with the tiddlyweb plugin to provide support for broken network connections.