Clarify if 'clearing the collection' affects only client, or client+server

[michielbdejong]

Sometimes I will want to remove all the items from the collection on the server.
Other times (actually, probably only when debugging, or maybe when offline and offering the user something like git checkout -- . to discard unpushed changes), I only want to flush the cache, to make sync start from zero.
It is not clear to me which one of these two is done by http://kintojs.readthedocs.org/en/latest/api/#clearing-the-collection

[leplatrem]

Currently collection.clear() will only clear the local store (records + last sync etag). Hence, if I'm not wrong, it will behave as git checkout --.

In order to remove all items on the server, so far there is no way to do it from kinto.js. It can be done on the API using a DELETE /buckets/{..}/collections/{...}/records though.

What would you suggest to implement this ? Adding a flush option to sync() ? a flush() method ? Don't hesitate to write some dream code, and we'll iterate on that :)

[Natim]

I my opinion, collection.clear() should mark all records of the collection as deleted and should try to delete them during the next sync.

[leplatrem]

I my opinion, collection.clear() should mark all records of the collection as deleted and should try to delete them during the next sync.

Instead, to be consistent with remote API, I would suggest to have a bulk delete method on the collection (with same params as list()).

collection.delete({filters: {complete: true})

[michielbdejong]

For me, having collection.clear() is enough! I just found the phrase 'This will remove all existing records from the collection' in the documentation a bit scary, I was afraid it would wipe the server.

[michielbdejong]

Oh, another thing that surprised me just now is that if I call .clear() and then call .sync(), the records don't reappear. So it's not just a flushing of the cache.

[michielbdejong]

Work-around to 'flush the cache' on a collection is to call indexedDB.deleteDatabase from the console, using 'bucket/collection' as the databaseName (so for instance 'syncto/history'). That has the effect I was expecting .clear() to have.

[n1k0]

Oh, another thing that surprised me just now is that if I call .clear() and then call .sync(), the records don't reappear.

That's probably a bug.

Also, I don't think it's a good idea to wipe data on the server when .clear is called locally — sounds so much catastrophe-prone… Maybe adding an option to the method, eg. .clear({sync: true}) + proper docs would be enough to avoid embarrassing situations.

[n1k0]

While pairing with @ametaireau, we discovered than after clear()ing a collection, metadata were kept — namely collection's lastModified value; we should probably drop these as well.

[michielbdejong]

Yeah, that was probably what caused the behavior that surprised me.