Dialogflow V2 (beta1) SDK for Obj-C

I don't think there's a library written specifically for Dialogflow v2; however, the library google-api-objectivec-client-for-rest is a generic library provided by Google, that simplifies the code to consume their Rest APIs.

This library is updated to be used with Dialogflow V2. In order to use it, you'll need to match the Rest API, with the "Queries" (API methods) and "Objects" (API types) in the library, which is not that difficult because the names are basically the same.

For example, the detectIntent method full name is:

projects.agent.sessions.detectIntent

In the library, it is the equivalent to the Query:

GTLRDialogflowQuery_ProjectsAgentSessionsDetectIntent

Here's an example of a detectIntent request:

// Create the service
GTLRDialogflowService *service = [[GTLRDialogflowService alloc] init];

// Create the request object (The JSON payload)
GTLRDialogflow_GoogleCloudDialogflowV2DetectIntentRequest *request =
                     [GTLRDialogflow_GoogleCloudDialogflowV2DetectIntentRequest object];

// Set the information in the request object
request.inputAudio = myInputAudio;
request.outputAudioConfig = myOutputAudioConfig;
request.queryInput = myQueryInput;
request.queryParams = myQueryParams;

// Create a query with session (Path parameter) and the request object
GTLRDialogflowQuery_ProjectsAgentSessionsDetectIntent *query =
    [GTLRDialogflowQuery_ProjectsAgentSessionsDetectIntent queryWithObject:request
                                                            session:@"session"];

// Create a ticket with a callback to fetch the result
GTLRServiceTicket *ticket =
    [service executeQuery:query
        completionHandler:^(GTLRServiceTicket *callbackTicket,
                            GTLRDialogflow_GoogleCloudDialogflowV2DetectIntentResponse *detectIntentResponse,
                            NSError *callbackError) {
    // This callback block is run when the fetch completes.
    if (callbackError != nil) {
      NSLog(@"Fetch failed: %@", callbackError);
    } else {
      // The response from the agent
      NSLog(@"%@", detectIntentResponse.queryResult.fulfillmentText);
    }
}];

You can find more information and samples, in the library wiki. Finally, the library also has a sample code using Google Cloud Storage which ilustrates its use with GCP services.

I think that without a specific library for Dialogflow V2, this might be the next thing to try before implementing it from scratch.

EDIT

Oops, I was missing the fact that the generated service for Dialogflow does not contain v2beta1.

In this case, it is needed an additional first step, which is to use the Dialogflow v2beta1 DiscoveryDocument and the ServiceGenerator, to create the service interface for v2beta1. Then you can continue working the same as I mentioned before.