Unable to change global variable from within function

Question

I am trying to change a global variable from within an alamofire variable but am having issues doing it. Here is my code:

var projects = [[String]]()
var xmlToParse = String()
var postTitle = String()
var postLink = String()

override func viewDidLoad() {
    super.viewDidLoad()

    httpRequest("https://www.hello.com/feed") { response in
        self.xmlToParse = response as String
        let xml = SWXMLHash.parse(self.xmlToParse)

        for elem in xml["rss"]["channel"]["item"].all {
            self.postTitle = elem["title"].element!.text
            self.postLink = elem["link"].element!.text                
            self.projects.append([self.postTitle, self.postLink])
        }
    }
    print(self.projects)
}

When I print self.projects here, i get an empty array, however when I print it inside the httpRequest function I get the proper data. Am I not setting the global variable projects within the for loop? How can I get the value outside of that function? I have tried everything I found on SO with no success. Any help is greatly appreciated.

Just for more info, here is my httpRequest function:

func httpRequest(_ section: String, completion: @escaping (String) -> Void) {
    Alamofire.request(section, method: .get).responseString { response in
        completion(response.result.value!)
    }
}

Answer 1

Assuming that xml["rss"]["channel"]["item"] is not nil...

override func viewDidLoad() {
    super.viewDidLoad()

    httpRequest("https://www.hello.com/feed") { response in
        self.xmlToParse = response as String
        let xml = SWXMLHash.parse(self.xmlToParse)

        for elem in xml["rss"]["channel"]["item"].all {
            self.postTitle = elem["title"].element!.text
            self.postLink = elem["link"].element!.text                
            self.projects.append([self.postTitle, self.postLink])
        }

        self.setup()
    }
}

func setup() {
    // Your logic here
}