Accessing stored data from native code?

You want to:

From my iOS extension be able to access the data stored by my JavaScript code within the react native app.

Is it possible to call read/write functions from native code?

Exmaple: From javascript

import AsyncStorage from '@react-native-community/async-storage';
await AsyncStorage.setItem('count', 999);

and then, from my native code I want to call what would be equivalent to getItem('count') to access the stored data. In my case, from the iOS share extension which needs to access this data. Are there any working example of how to do this? Is it even possible?

Details:

Sorry for asking questions that are a bit outside the scope of this module. I know it is supposed to be react native context, but some documentation about how this work behind the scene would be fantastic.

[tido64]

This is possible but requires some knowledge of how native modules work in general. I’m not sure how future-proof this is with regards to the upcoming refactoring work in React Native but this is how you could access it today:

// First, get the RNCAsyncStorage instance from the bridge
RNCAsyncStorage *asyncStorage = [bridge moduleForClass:[RNCAsyncStorage class]];

// Then call the getter:
[asyncStorage multiGet:@[@"count"]] callback:^(NSArray *response){
    NSObject *count = response[0];
    if ([count isKindOfClass:[NSError class]]) {
        // Failed to get count
        return;
    }

    // Use count here
}];

Another (arguably better) way to do this is to implement RNCAsyncStorageDelegate as described in this guide. You would have to handle storage yourself but this will allow your extensions to access data directly without knowledge of the bridge or even React Native. We will also strive to have this API stable in the future.

[tido64]

@kodeusz: Unfortunately, I’m not as well-versed on the Android side as I’d like to be. From looking at the code, it seems the Android equivalent is ReactContext.getNativeModule(). There’s an example of it being used in UIManagerHelper. Hope that helps 😄