Apollo Controller

ApolloController.swift

import Apollo

struct ApolloController {
    //MARK: Properties
    //The Apollo graph QL Root object
    var apollo: ApolloClient?
    
    
    //MARK: Init
    init() {
        self.apollo = self.configureApolloWithWebSockets()
    }
    
    
    //MARK: Functions
    private func configureApolloWithWebSockets() -> ApolloClient? {
        //Struct I have to obfuscate my Auth headers.
        let authHeaders = Hasura_Auth_Headers()
        //I have dev and staging environments in my app. This struct will return the correct one.
        let environment = EnvironmentController().retreiveEnvironment()
        //Just get the default configuraiton per the docs
        let configuration = URLSessionConfiguration.default
        // Add additional headers as needed from my header struct.
        configuration.httpAdditionalHeaders = authHeaders.dictionaryOfHeaders
        //Take my Ec2 Server string and make a URL for the graph QL and subscriptions
        guard let httpURL = environment.graphQLServerURL, let webSocketURL = environment.subscriptionServerURL else {
            return nil
        }
        
        let httpTransport = HTTPNetworkTransport(url: httpURL, configuration: configuration, sendOperationIdentifiers: false)
 
        let request = URLRequest(url: webSocketURL)
        //This is tricky and not well documented on either Hasura or Apollo. I had a hard time following the GraphQL Spec to see if this is compliant or not.
        let map: GraphQLMap = ["headers": authHeaders.accessHeaderDictionary]
        
        let webSocketTransport = WebSocketTransport(request: request, connectingPayload: map)
        
        let splitTransport = SplitNetworkTransport(httpNetworkTransport: httpTransport, webSocketNetworkTransport: webSocketTransport)
        
        //Initalize the APolloClient with that URL.
        return ApolloClient(networkTransport: splitTransport)
    }
}