When dragging an item to another library, we have to check if there's a
linked item in the target library, but items might not yet be laoded in
the other library, so item.getLinkedItem() can fail with "Item [n] not
yet loaded].
Fixing required asyncifying the follow functions:
- Zotero.Item::getLinkedItem()
- Zotero.Collection::getLinkedCollection()
- Zotero.URI.getURIItem()
- Zotero.URI.getURICollection()
- Various integration functions
This allows Zotero.Relations.getByPredicateAndObject()/getByObject() and
Zotero.Item::getLinkedItem()/Zotero.Collection::getLinkedCollection() to
be synchronous, which is necessary for word processor integration.
While trying to get translation and citing working with asynchronously
generated data, we realized that drag-and-drop support was going to
be...problematic. Firefox only supports synchronous methods for
providing drag data (unlike, it seems, the DataTransferItem interface
supported by Chrome), which means that we'd need to preload all relevant
data on item selection (bounded by export.quickCopy.dragLimit) and keep
the translate/cite methods synchronous (or maintain two separate
versions).
What we're trying instead is doing what I said in #518 we weren't going
to do: loading most object data on startup and leaving many more
functions synchronous. Essentially, this takes the various load*()
methods described in #518, moves them to startup, and makes them operate
on entire libraries rather than individual objects.
The obvious downside here (other than undoing much of the work of the
last many months) is that it increases startup time, potentially quite a
lot for larger libraries. On my laptop, with a 3,000-item library, this
adds about 3 seconds to startup time. I haven't yet tested with larger
libraries. But I'm hoping that we can optimize this further to reduce
that delay. Among other things, this is loading data for all libraries,
when it should be able to load data only for the library being viewed.
But this is also fundamentally just doing some SELECT queries and
storing the results, so it really shouldn't need to be that slow (though
performance may be bounded a bit here by XPCOM overhead).
If we can make this fast enough, it means that third-party plugins
should be able to remain much closer to their current designs. (Some
things, including saving, will still need to be made asynchronous.)
Previously, if .synced was already true, setting it to true and saving
would result in .synced == false unless skipSyncedUpdate was passed. Now
the value assigned to .synced is always used on the next save. If the
value hasn't changed and no other values have changed, a save will be a
no-op.
Relations are now properties of collections and items rather than
first-class objects, stored in separate collectionRelations and
itemRelations tables with ids for subjects, with foreign keys to the
associated data objects.
Related items now use dc:relation relations rather than a separate table
(among other reasons, because API syncing won't necessarily sync both
items at the same time, so they can't be stored by id).
The UI assigns related-item relations bidirectionally, and checks for
related-item and linked-object relations are done unidirectionally by
default.
dc:isReplacedBy is now dc:replaces, so that the subject is an existing
object, and the predicate is now named
Zotero.Attachments.replacedItemPredicate.
Some additional work is still needed, notably around following
replaced-item relations, and migration needs to be tested more fully,
but this seems to mostly work.
- Moved ::_get() and _set() from Collection/Search into DataObject, and
disabled in Item
- Don't disable new items after save. We now put new objects into the
DataObjects cache from save() so that changes made post-save are
picked up by other code using .get().
- Added 'skipCache' save() option to avoid reloading data on new objects
and adding them to the cache. (This will be used in syncing, where
objects might be in another library where they're not needed right
away.) Objects created with this option are instead disabled to
prevent reuse.
- Modified some tests to try to make sure we're reloading everything properly
after a save.
- Documented save() options
- Fixes some saving and erasing issues with collections and searches
- Adds Zotero.DataObject::eraseTx() to automatically start transaction,
and have .erase() log a warning like .save()
- Adds createUnsavedDataObject() and createDataObject() helper functions
for tests
