Merge

You can merge ApiResponses that contain a List as their generic type into a single ApiResponse based on specific policies. The example below shows how to merge three ApiResponse as a single one if each three ApiResponses are successful.

Merging Multiple ApiResponse

Sandwich allows you to merge multiple ApiResponse instances into a single one based on predefined policies. This is particularly useful when you need to combine the results of multiple API calls. The following example demonstrates how to merge three ApiResponse instances into a single one, provided that all three ApiResponse instances are successful:

disneyService.fetchDisneyPosterList(page = 0).merge(
   disneyService.fetchDisneyPosterList(page = 1),
   disneyService.fetchDisneyPosterList(page = 2),
   mergePolicy = ApiResponseMergePolicy.PREFERRED_FAILURE
).onSuccess { 
  // handles the success case when the merged API requests all receive successful responses.
}.onError { 
  // handles error cases when at least one of the merged API requests gets an error response.
}

ApiResponseMergePolicy

ApiResponseMergePolicy is an enum that defines how merging should be performed based on the success or failure of the responses. There are two policies available:

• IGNORE_FAILURE: This policy ignores failure responses and considers only the successful ones when merging the ApiResponse instances, regardless of the order in which they are merged.
• PREFERRED_FAILURE (default): This policy prefers failure responses over success responses when merging. Even if there is one failure response in the merged list, the final merged ApiResponse will be marked as a failure.

By choosing an appropriate merge policy, you can tailor the merging behavior to your specific requirements, ensuring that the merged ApiResponse accurately represents the combined results of the individual API calls.