等待在rails控制器中完成HTTP请求

Question

I have a scenario where my rails controller action has to make a API request to a backend business logic server which does a lot of computations and returns me the result.

I'm thinking to show a loading page to the user and make the call asynchronous using Faye or any other option and redirect the user when the call is complete..

But even if I make the call asynchronous, the HTTP request needs to wait for the server to return the data after process, which would take around 20 seconds.

I would like to know what is the best way to make such calls in rails.?

Answer 1

I had faced a similar situation, below is the route that I took:

1. When the controller action is triggered a. I fired off a 'async' request to the API using a worker(I used sidekiq) b. Loaded a 'AJAX' spinner gif on top of a modal

2. The worker handling the API request runs on another thread which is synchronous and waits for the result from the API

3. When the processing is done, the worker fires off notification via 'Faye' which removes the modal and populates the data.

Answer 2

Return an HTTP response with status 202 Accepted (for the request that need to take long to process) and start making AJAX requests(to a URL, eg /jobs/1) to check the status of the background job. Once your job has finished, update it's status so that your Javascript(AJAX) can handle the result of that background job.