How to retrive dynamically created Class in Realm? - ios

Question

I am adding Realm source files in my project. I want to create realm class dynamically. Following is my demo code:
-(void)createDynamicClassObject
{
[self createDynamicSchema];
[self createDynamicSchema2];
}
-(void)createDynamicSchema{
_schema = [[RLMSchema alloc] init];
RLMProperty *prop = [[RLMProperty alloc] initWithName:#"a"
type:RLMPropertyTypeInt
objectClassName:nil
linkOriginPropertyName:nil
indexed:NO
optional:NO];
RLMObjectSchema *objectSchema1 = [[RLMObjectSchema alloc] initWithClassName:#"TrulyDynamicObject"
objectClass:RLMObject.class properties:#[prop]];
_schema.objectSchema = #[objectSchema1];
NSLog(#"dyrealm %#",_dyrealm);
NSLog(#"schema %#",[_schema schemaForClassName:#"TrulyDynamicObject"]);
}
-(void)createDynamicSchema2 {
RLMProperty *prop1 = [[RLMProperty alloc] initWithName:#"apple"
type:RLMPropertyTypeString
objectClassName:nil
linkOriginPropertyName:nil
indexed:NO
optional:NO];
RLMProperty *prop2 = [[RLMProperty alloc] initWithName:#"banana"
type:RLMPropertyTypeFloat
objectClassName:nil
linkOriginPropertyName:nil
indexed:NO
optional:NO];
RLMProperty *prop3 = [[RLMProperty alloc] initWithName:#"Mango"
type:RLMPropertyTypeObject
objectClassName:#"TrulyDynamicObject"
linkOriginPropertyName:nil
indexed:NO
optional:NO];
RLMObjectSchema *objectSchema = [[RLMObjectSchema alloc] initWithClassName:#"DynamicTestObject"
objectClass:RLMObject.class properties:#[prop1,prop2,prop3]];
NSMutableArray *array = [NSMutableArray arrayWithArray:_schema.objectSchema];
[array addObject:objectSchema];
_schema.objectSchema = array;
_dyrealm = [self realmWithTestPathAndSchema:_schema];
NSLog(#"DynamicTestObject dyrealm %#",_dyrealm);
NSLog(#"DynamicTestObject schema %#",[_schema schemaForClassName:#"DynamicTestObject"]);
}
while creating schema2, app is crashing.
2016-06-17 15:10:13.491 realmLibraryDemo[1770:82980] schema TrulyDynamicObject {
a {
type = int;
objectClassName = (null);
linkOriginPropertyName = (null);
indexed = NO;
isPrimary = NO;
optional = NO;
}
}
2016-06-17 15:10:13.499 realmLibraryDemo[1770:82980] *** Terminating app due to uncaught exception 'RLMException', reason: 'Schema validation failed due to the following errors:
- 'Object' property 'Mango' must be nullable.'
*** First throw call stack:
(
0 CoreFoundation 0x000000010217ae65 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x0000000101bf1deb objc_exception_throw + 48
2 Realm 0x0000000101281c49 _Z18RLMSetErrorOrThrowP7NSErrorPU15__autoreleasingS0_ + 985
3 Realm 0x00000001012606e6 _Z26RLMRealmTranslateExceptionPU15__autoreleasingP7NSError + 598
4 Realm 0x0000000101260dfc +[RLMRealm openSharedRealm:error:] + 268
5 Realm 0x0000000101261e66 +[RLMRealm realmWithConfiguration:error:] + 4022
6 realmLibraryDemo 0x0000000100fa4eb9 -[ViewController realmWithTestPathAndSchema:] + 217
7 realmLibraryDemo 0x0000000100fa4cb8 -[ViewController createDynamicSchema2] + 776
8 realmLibraryDemo 0x0000000100fa46f6 -[ViewController createDynamicClassObject] + 70
9 realmLibraryDemo 0x0000000100fa42d0 -[ViewController viewDidLoad] + 288
10 UIKit 0x00000001026bef98 -[UIViewController loadViewIfRequired] + 1198
11 UIKit 0x00000001026bf2e7 -[UIViewController view] + 27
12 UIKit 0x0000000102595ab0 -[UIWindow addRootViewControllerViewIfPossible] + 61
13 UIKit 0x0000000102596199 -[UIWindow _setHidden:forced:] + 282
14 UIKit 0x00000001025a7c2e -[UIWindow makeKeyAndVisible] + 42
15 UIKit 0x0000000102520663 -[UIApplication _callInitializationDelegatesForMainScene:transitionContext:] + 4131
16 UIKit 0x0000000102526cc6 -[UIApplication _runWithMainScene:transitionContext:completion:] + 1760
17 UIKit 0x0000000102523e7b -[UIApplication workspaceDidEndTransaction:] + 188
18 FrontBoardServices 0x0000000104f28754 -[FBSSerialQueue _performNext] + 192
19 FrontBoardServices 0x0000000104f28ac2 -[FBSSerialQueue _performNextFromRunLoopSource] + 45
20 CoreFoundation 0x00000001020a6a31 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
21 CoreFoundation 0x000000010209c95c __CFRunLoopDoSources0 + 556
22 CoreFoundation 0x000000010209be13 __CFRunLoopRun + 867
23 CoreFoundation 0x000000010209b828 CFRunLoopRunSpecific + 488
24 UIKit 0x00000001025237cd -[UIApplication _run] + 402
25 UIKit 0x0000000102528610 UIApplicationMain + 171
26 realmLibraryDemo 0x0000000100fa562f main + 111
27 libdyld.dylib 0x00000001048ce92d start + 1
28 ??? 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
How to check whether TrulyDynamicObject is created or not as when I executed code using only [self createDynamicSchema]; it is working fine.
Anybody knows how to create multiple schemas with realm object as a reference when class is dynamically created?

Answer 1

From the "Optional Properties" section of Realm's docs (link):
RLMObject subclass properties always can be nil and thus cannot be included in requiredProperties, and RLMArray does not support storing nil.
Translated into RLMProperty wording, it means that properties of type RLMPropertyTypeObject must be optional since the underlying data format can't guarantee that there will always be a link there.