2. Creating a custom implementation

For creating a custom implementation of our OMH Storage interfaces you'll need to get our OMH Storage API dependency:

implementation 'com.openmobilehub.android:storage-api:$version'

Once you've downloaded the dependencies, it's time to extend each interface. Below you can find a step by step guide on how to do it.

Developing your implementation

Implementing the OMH Storage Client

As explained in the OMH Storage Client page, this will be the main interactor for the library. You will need to provide an implementation for each of the functionalities so that the developers can interact with the Storage provider you'll be implementing. For achieve this, you must implement 3 classes: OmhStorageClient, OmhFileRepository and OmhFileRemoteDataSource

Here you must ensure the function getRepository(): OmhFileRepository from your client implementation returns your implementation of OmhFileRepository and also this repository should have a reference to your implementation of OmhFileRemoteDataSource

Implementing the OMH Storage Factory

This will be the most important part of your implementation as this will be how we reflect your library with the provider. Save the path to this class, as we'll be using it further down the line. This class will be responsible of instantiating your OMH Storage Client implementation and returning it to the user as the abstract OmhStorageClient. The only function to implement here is:

fun getStorageClient(authClient: OmhAuthClient): OmhStorageClient

Note: here are some examples of the path that you should be storing: com.example.app.factories.MyCustomFactoryImplementation

Implementing the OMH Tasks abstract class

This is an abstraction for the async layer of your library. The idea is to avoid forcing the user to use a specific async library and give the more flexibility with your OMH Auth implementation. You can read more about it here. Here the only function you need to implement is:

abstract fun execute(): OmhCancellable?

This should execute your async code and return a way to cancel the operation with the OmhCancellable interface if possible. The cancellable interface can be represented as a lambda for convenience.

Using your implementation with the OMH Core Plugin

To use your newly created implementation with out plugin you just need to pass the reflection path and the dependency string in the Service section like this:

omhConfig {
   bundle("gms") {
      storage {
         gmsService {
            dependency = "com.example.app:custom-implementation:1.0"
            path = "com.example.app.factories.MyOwnFactoryImplementation"
         }
      }
   }
}

STORAGE_GMS_PATH and STORAGE_NON_GMS_PATH

The factory implementation is provided using reflection. When a developer provides it's own factory implementation is necessary to configure which path will be used for this purpose. In this way the purpose of STORAGE_GMS_PATH and STORAGE_NON_GMS_PATH constants on the gradle file is set the path of the custom factory that will be used by the library.

In this way, they're constructed during compile time to avoid hardcoding the factory path. Also have in mind, if you modify the path's value is necessary rebuild the project to apply the change.

Resources

You can always look into our own implementations of the OMH Storage API (GMS and non GMS as a reference to help you develop your own implementation.