Error on non existing relationship

Question

Error on non existing relationship

Ma-He opened this issue 10 years ago · comments

I've got a 'Person' entity with a relationship to a 'Location' entity. But in some cases a 'Person' entity can exists without a 'Location' entity. That's why my JSON model doesn't provide a 'location' key for certain persons.

When I try to deserialize a JSON 'Person' into a ManagedObject without a given location relationship, I get the following error:

*** Assertion failure in -[FEMCache addExistingObject:usingMapping:], /.../FEMCache.m:185
2014-09-08 15:30:47.906 AppName[7866:3191678] 
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'No value for key (locationId) on object (<Location: 0x1782d8330> (entity: Location; id: 0x178826480 <x-coredata:///Location/t149B2931-DA62-4EFC-8C7D-3CFC8058F57A16> ; data: {
city = nil;
country = nil;
houseNumber = nil;
latitude = nil;
locationId = nil;
longitude = nil;
relatedParkingSlot = nil;
streetName = nil;
zipCode = nil;
})) found'

Any suggestions on this?

Dima Vorona · Answer 1 · Mon Sep 08 2014 22:04:03 GMT+0800 (China Standard Time)

@Ma-He
Hello there.

Can you share you mapping description and version?

I assume next case:
You've specified relationship at key "location" (let's assume")
Then Location entity get's created and passed to the cache. However, since there was no data in it - an empty Location is passed.

However, cache can't store objects without Primary Key.. so it crashes..

Mariusz Henke · Answer 2 · Mon Sep 08 2014 22:10:42 GMT+0800 (China Standard Time)

Hi,

yep, that's true. I've specified the location relationship as follows:

[mapping addRelationshipMapping:[self locationMapping]
                                                                   forProperty:PersonRelationships.location
                                                                       keyPath:PersonRelationships.location];

and my 'Location' mapping

+ (FEMManagedObjectMapping *)locationMapping
{
    return [FEMManagedObjectMapping mappingForEntityName:[Location entityName]
                                           configuration:^(FEMManagedObjectMapping *mapping) {
                                               [mapping addAttributeMappingDictionary:@{LocationAttributes.locationId : @"id",
                                                                                        LocationAttributes.houseNumber : @"streetNumber",
                                                                                        LocationAttributes.streetName : @"streetname"}];
                                               [mapping addAttributeMappingFromArray:@[LocationAttributes.city,
                                                                                       LocationAttributes.country,
                                                                                       LocationAttributes.latitude,
                                                                                       LocationAttributes.longitude,
                                                                                       LocationAttributes.zipCode]];

                                               mapping.primaryKey = LocationAttributes.locationId;
                                           }];
}

I'm using the current version 0.3.8

Dima Vorona · Answer 3 · Mon Sep 08 2014 22:24:29 GMT+0800 (China Standard Time)

Basically, we don't have to create relationship if this key not found or represented as Null
Looks like a bug :)

Mariusz Henke · Answer 4 · Mon Sep 08 2014 22:35:57 GMT+0800 (China Standard Time)

That's just what I was thinking :-) First, I've assumed I've done something wrong with my mapping, but after some tests and different JSON representations it looks like a bug to me.
Thanks @poteryaysya for your help ;-)

Dima Vorona · Answer 5 · Tue Sep 09 2014 00:24:26 GMT+0800 (China Standard Time)

@Ma-He
you can help me with pull request (if you'd like to!) ;)
i'll be ready closer to the end of the week

Es Spectacularrr · Answer 6 · Tue Oct 14 2014 18:05:11 GMT+0800 (China Standard Time)

Having the same issue, had to add a null check.

Dima Vorona · Answer 7 · Tue Oct 14 2014 22:19:35 GMT+0800 (China Standard Time)

@JacquesPienaar, @Ma-He
Just get back from my vacation.
I'll take a look in a few days

Dima Vorona · Answer 8 · Thu Oct 16 2014 01:48:43 GMT+0800 (China Standard Time)

@Ma-He, @JacquesPienaar
Can you, guys, share JSON input for me?
Basically, it happens, when there is a mapping for some relationship, but no object presented in JSON, correct?

Es Spectacularrr · Answer 9 · Fri Oct 17 2014 17:23:17 GMT+0800 (China Standard Time)

Correct

eg:

[mapping addToManyRelationshipMapping:[self promotion] forProperty:@"promotions" keyPath:@"promotions"];

json
"promotions": null

Dima Vorona · Answer 10 · Fri Oct 17 2014 17:50:57 GMT+0800 (China Standard Time)

@JacquesPienaar thanks for help!

Dima Vorona · Answer 11 · Fri Oct 17 2014 22:59:49 GMT+0800 (China Standard Time)

@JacquesPienaar
can reproduce it on to-one relationship, when key in JSON is missing.
it generate empty entity with nil fields. (which is obviously a bug)

Dima Vorona · Answer 12 · Fri Oct 17 2014 23:24:57 GMT+0800 (China Standard Time)

@JacquesPienaar can you try 3e2f506?

Or give me some more info, because with NULL relationship it appears to be working correctly.
However with missing key it generated empty objects..

Dima Vorona · Answer 13 · Sat Oct 18 2014 20:09:10 GMT+0800 (China Standard Time)

Resolved by #21

Dima Vorona · Answer 14 · Tue Oct 21 2014 00:18:43 GMT+0800 (China Standard Time)

@Ma-He, @JacquesPienaar
I have some issues with my pod trunk session.
Meanwhile you can grab latest source by tag 0.4.0
I'll push it to the trunk as soon as permissions will be renewed

Dima Vorona · Answer 15 · Wed Oct 22 2014 19:15:17 GMT+0800 (China Standard Time)

@Ma-He. @JacquesPienaar
0.4.1 should be available in Cocoapods, update repo :)