Using RCTAsyncLocalStorage + getAllKeys - objective-c

Question

I'm trying to get the AsyncStorage on iOS native code. So this is my code
- (void)jsonFromLocalRNStrogeForKey:(NSString *)key completion:(void (^)(NSDictionary * _Nullable, NSError * _Nullable))completion {
RCTResponseSenderBlock rnCompletion = ^(NSArray *response) {
NSString *jsonAsString;
if (response.count > 1) {
NSArray *response1 = response[1];
if (response1.count > 0) {
NSArray *response2 = response1[0];
if (response2.count > 1) {
jsonAsString = response2[1];
}
}
}
#try {
NSData *jsonAsData = [jsonAsString dataUsingEncoding:NSUTF8StringEncoding];
NSError *error;
NSDictionary *json = [
NSJSONSerialization
JSONObjectWithData:jsonAsData
options:NSJSONReadingMutableContainers
error:&error
];
completion(json, error);
}
#catch (NSException *exception) {
NSLog(#"error: %#", exception.reason);
NSMutableDictionary * info = [NSMutableDictionary dictionary];
[info setValue:exception.name forKey:#"ExceptionName"];
[info setValue:exception.reason forKey:#"ExceptionReason"];
[info setValue:exception.callStackReturnAddresses forKey:#"ExceptionCallStackReturnAddresses"];
[info setValue:exception.callStackSymbols forKey:#"ExceptionCallStackSymbols"];
[info setValue:exception.userInfo forKey:#"ExceptionUserInfo"];
NSError *error = [[NSError alloc] initWithDomain:#"" code:1 userInfo:info];
completion(nil, error);
}
};
// RCTAsyncLocalStorage *storage = [RCTAsyncLocalStorage new];
RCTAsyncLocalStorage *storage = [[RCTAsyncLocalStorage alloc] init];
dispatch_async(storage.methodQueue, ^{
#try {
// [storage performSelector:#selector(multiGet:callback:) withObject:#[key] withObject:rnCompletion];
[storage performSelector:#selector(getAllKeys:callback:) withObject:rnCompletion];
}
#catch (NSException *exception) {
NSLog(#"error: %#", exception.reason);
}
});
}
When I try to get one of my keys (multiGet)
[self jsonFromLocalRNStrogeForKey:#"session" completion:^(NSDictionary* data,NSError* error) {
if (data) {
NSString * name = [data valueForKeyPath: #"token"];
if (![name isKindOfClass:[NSNull class]]) {
[self reportIncomingCallFrom:name withUUID:callInvite.uuid];
}
} else {
NSLog(#"error: JSON Parsing Error: %#",error.localizedFailureReason);
}
}];
I'm always getting null
And when I try to get all the keys (...#selector(getAllKeys:...) to see what do I have in my AsyncStorage I got the exception
#"NSInvalidArgumentException" - reason: #"-[RCTAsyncLocalStorage getAllKeys:callback:]: unrecognized selector sent to instance 0x1085512c0"
The RN have RCT_EXPORT_METHOD(getAllKeys:(RCTResponseSenderBlock)callback) in RCTAsyncLocalStorage.m; but at RCTAsyncLocalStorage.h (void)getAllKeys:(RCTResponseSenderBlock)callback it doesn't exists and even adding it doesn't work (https://github.com/facebook/react-native/blob/master/React/Modules/RCTAsyncLocalStorage.h).
"react-native": "^0.48.4",
How can I return NSJsonSerialization

Answer 1

Firstly,
The RN have
RCT_EXPORT_METHOD(getAllKeys:(RCTResponseSenderBlock)callback) in
RCTAsyncLocalStorage.m; but at RCTAsyncLocalStorage.h
(void)getAllKeys:(RCTResponseSenderBlock)callback it doesn't exists
In Objective-C, you can invoke a method even though it is not declared in the header file using performSelector:withObject:.
Invoking this method directly (without first checking if the target respondsToSelector:) is bad practice, as the internal method declaration may change.
Secondly, this line is incorrect:
[storage performSelector:#selector(getAllKeys:callback:) withObject:rnCompletion];
Here, you're saying getAllKeys:: takes two arguments, however the implementation declares only one.
Hence, the correct way to extract all keys is the following:
dispatch_async(storage.methodQueue, ^{
if([storage respondsToSelector:#selector(getAllKeys:)]){
[storage performSelector:#selector(getAllKeys:) withObject:[^(NSArray* response){
NSLog(#"Contents: %#",response);
} copy]];
}else{
NSLog(#"storage does not respond to selector `getAllKeys:`");
}
});