How to populate my tableview with a mutablearray from json

Question

So I\'m fetching data from a url which is in a json format. I\'m trying to display the data in my tableview but, even though it feels simple, I can\'t figure out how to do it.<

Answer 1

You can't use return within the closure of an asynchronous network request, you have to use a callback instead.

You need a NSMutableArray from the request, so first, let's make a callback for this:

completion: (array: NSMutableArray)->()

We add this callback to the method signature:

func getJSON(completion: (array: NSMutableArray)->())

And then at the location where the array will be available, we place this completion handler:

class CompanyModel {
    func getJSON(completion: (array: NSMutableArray)->()) {
        let companyArray: NSMutableArray = NSMutableArray()
        let requestURL: NSURL = NSURL(string: "http://localhost/Companies/JSON.php")!
        let urlRequest: NSMutableURLRequest = NSMutableURLRequest(URL: requestURL)
        let session = NSURLSession.sharedSession()
        let task = session.dataTaskWithRequest(urlRequest) {
            (data, response, error) -> Void in
            let httpResponse = response as! NSHTTPURLResponse
            let statusCode = httpResponse.statusCode
            if (statusCode == 200) {
                do{
                    let json = try NSJSONSerialization.JSONObjectWithData(data!, options:.AllowFragments)
                    if let companies = json["companies"] as? [[String: AnyObject]] {
                        for company in companies {
                            if let name = company["name"] as? String,
                                let phoneNumber = company["phone_number"] as? String,
                                let website = company["website"] as? String,
                                let email = company["email"] as? String,
                                let address = company["address"] as? String {
                                let company = CompanyModel()
                                company.name = name
                                company.phoneNumber = phoneNumber
                                company.website = website
                                company.email = email
                                company.address = address
                                companyArray.addObject(company)
                            }
                        }

                        // CALLBACK HERE
                        completion(array: companyArray)

                    }
                } catch {
                    print("Error with Json: \(error)")
                }
            }
        }
        task.resume()
    }
}

Now to get the array from the network we use a trailing closure like this:

getJSON { (array) in
    print(array)
}