reload() and fetchById don't restore changed belongsTo

[artych]

It is known that if you change record's belongsTo property without saving, record doesn't become dirty and can't be restored by rollback() emberjs/rfcs#21.

But it was unexpected for me that it also can't be restored by reload(), and can't be reloaded by store.fetchById(). The only way works for me is record.unloadRecord() and then store.find(..). See http://jsbin.com/qoyacagigi/edit?html,js,output.

Feel free to close if this is expected behavior.

[pangratz]

The related test is unit/model/merge-test which checks that locally modified attributes are not reset after a merge. The test (currently) doesn't have assertions for relationships, so I guess the correct behavior is yet to be decided. I definitely think it should be the same as for attributes, so locally changed relationships should not be reset after a reload.

[artych]

@pangratz, thanks. And what about fetchById? http://emberjs.com/api/data/classes/DS.Store.html#method_fetchById. I expected it to be "hard reset version" of find method (that fetch model from backend and then create/override model in store).

[pangratz]

According to the doc fetchById only calls reload so the same semantics apply.

Restoring local relationship changes via rollback should eventually work; it is on the meta list for 1.0 (first entry).

[artych]

I mean is my expectation about fetchById wrong or not?
Looks like I am not alone, for example see last 2 comments in http://discuss.emberjs.com/t/force-store-to-reload-data-from-api/4441/12.

[pangratz]

I mean is my expectation about fetchById wrong or not?

Your confusion is justified as the naming of the methods is not consistent at the moment. There is an open RFC which discusses the semantics of the various methods to get a consistent naming.

[artych]

@pangratz, thanks for link.
After reading emberjs/rfcs#27 it is clear that fetchById is expected to load data from the server, even if it's already in the local store.
Therefore I think this is valid issue in case findById fetchById method.

[artych]

about reload(): "locally modified attributes are not reset after a merge..."

as for me reload() is very confusing name for such a behavior
and no description about it here: http://emberjs.com/api/data/classes/DS.Model.html#method_reload

[pangratz]

That method documentation is highly outdated and has been last updated at 22. April 2013 😮 Want to submit a PR?

[artych]

I'd like to, but it is not clearly for me what such a behavior for, so I do not know what description should be written. May be somebody can explain me...

[artych]

I would like to propose PR with changes:

• for reload() method add optional parameter to specify merge strategy.

For example: force: boolean, defaultValue: false, so model.reload() and model.reload(false) behaves as is now, but model.reload(true) loads record from server with "hard reset" merging strategy (ignoring locally modified attributes and associations).

• in store.fetchById(...) source code changereload() for reload(true)
• documentation fixing.

Does it look reasonable?

[artych]

As an alternative just to implement new fetching method with "hard reset" merging strategy. Something like this:

    fetchOriginById: function(modelName, id, preload) {
        if (this.hasRecordForId(modelName, id)) {
            this.getById(modelName, id).unloadRecord();
        }
        return this.find(modelName, id, preload);
    }

UPD: this code fails with #3084 issue.

[artych]

closed since no confirmation