Swift: Developing iOS Applications

Downloading the background image

Before moving on to downloading the actual forecast, we'll introduce the topic of networking downloading a geo-localized background image.

Searching in Flickr

To get an image, we'll use the API of Flickr, a famous image-hosting website, using a convenient Pod. First of all, we override the viewWillAppear function in PrettyWeatherApp so that a new image will be downloaded every time View Controller appears:

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)
    
    let lat:Double = 48.8567
    let lon:Double = 2.3508

    FlickrDatastore().retrieveImageAtLat(lat, lon: lon){ image in
        self.render(image)
    }
}

To implement the searching feature, we set a dummy value using the coordinates of Paris. Then, we create ...