Making Repeated Requests to API

Question

I know how to make a regular API call using swift. What I am not able to understand is how to make the API call to be repeated until required.

I want to call the API every one second

API Call Code Snippet:

let url = URL(string: "https://api.darksky.net/forecast/34eaef38915078ea03c22bb9063bd7ea/37.8267,-122.4233")
    let request = URLRequest(url: url!, cachePolicy: URLRequest.CachePolicy.reloadIgnoringCacheData, timeoutInterval: 10)

    let session = URLSession(configuration: URLSessionConfiguration.default, delegate: nil, delegateQueue: OperationQueue.main)



    let task: URLSessionDataTask = session.dataTask(with: request, completionHandler: { (data: Data?, response: URLResponse?, error: Error?) in

        if let error = error {

            print(error)

        } else if let data = data,
            let dataDictionary = try! JSONSerialization.jsonObject(with: data, options: []) as? NSDictionary {
            print("API Data:")
            print(dataDictionary)

        }
    })
    task.resume()

Note: This is not the actual API I will be calling

Device battery will drain while calling API at every 1 second. — Hasya, Jan 23 '17 at 14:01
I guess you need to use Time Machine Request - https://darksky.net/dev/docs/time-machine — Hasya, Jan 23 '17 at 14:13
@Hasya I just gave an example here. I need to call the API to get constantly updated financial data — Supratik Majumdar, Jan 24 '17 at 04:47

score 4 · Accepted Answer · edited May 23 '17 at 12:32

Ideally, for software solutions like financials you mentioned, the server must have support for some sort of Long Polling / websockets mechanism where once connection is established server feeds the client with new values whenever there are updates (refer : https://stackoverflow.com/a/12855533/1436617)

If server does not support : (Not the ideal solution) : You can actually use recursion in this. On response (both success & failure) of the request again call the same function. That way you can continuously keep polling.

Remember to keep request timer short (5 or 10 seconds instead of 60 seconds) so that if there happens to be an network issue you can quickly make the next call.

Making Repeated Requests to API

1 Answers1