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iOS Privacy and Opt-Out

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Revision as of 23:20, 22 May 2019 by ColinBrown (talk | contribs)

Privacy and Opt-Out

There are three primary methods for implementing user Opt-out preferences:

  1. OS-level Opt-out - managed by Limit Ad Tracking setting on device (preferred approach).
  2. Legacy Opt-out - Direct call to SDK; used only for older versions of Nielsen iOS SDK (< 5.1.1.18)
  3. App Level Opt-Out - Where Ad Framework cannot be leveraged

OS-level Opt-out

OS-level Opt-out method available on Nielsen iOS SDK Versions 5.1.1.18 and above.

The Nielsen SDK automatically leverages the iOS's Limit Ad Tracking setting. The user is opted out of demographic measurement if the OS-level "Limit Ad Tracking" setting is enabled. As a publisher, you cannot override this setting.

Legacy Opt-out

The Legacy opt-out method is only necessary for Nielsen iOS SDK versions less than 5.1.1.18.

Nielsen iOS SDK 5.1.1.17 and above will check for OS-level opt-out first, if available. The user will be opted out if indicated at the OS-level OR the App-level.

The legacy opt-out method works as follows:

  • Get the legacy Nielsen opt-out URL via optOutURL
  • Display a WebView element whose loadUrl is set to the value obtained from optOutURL
  • Detect if the WebView URL changes to a special URL that indicates Opt-in, or Opt-out and close the WebView
    • Opt-out if the WebView URL = nielsenappsdk://1
    • Opt-in if the WebView URL = nielsenappsdk://0
  • Pass the detected URL to the userOptOut function
    • Example:
      NielsenAppApi?.userOptOut("nielsenappsdk://1"); // User opt-out
      

Legacy Opt-out example code

Swift

var webView: WKWebView!
var NIELSEN_URL_OPT_OUT : String = "nielsenappsdk://1"
var NIELSEN_URL_OPT_IN : String = "nielsenappsdk://0"

func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {

       let urlStr = navigationAction.request.url?.absoluteString

        if(urlStr == NIELSEN_URL_OPT_OUT || urlStr == NIELSEN_URL_OPT_IN){
            let appApi = self.nielsenApi
            appApi?.userOptOut(urlStr)
            decisionHandler(.allow)

        }else{
           decisionHandler(.cancel)
        }
    }

Objective C

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {

    NSURLRequest *request = [navigationAction request];
    NSString *url = [[request URL]absoluteString];
    
    if([url isEqualToString:self.NIELSEN_URL_OPT_OUT] || [url isEqualToString:self.NIELSEN_URL_OPT_IN]){
        [self.nielsenApi userOptOut:url];
        decisionHandler(WKNavigationActionPolicyAllow);
    }else{
        decisionHandler(WKNavigationActionPolicyCancel);
    }        
}


Retrieve current Opt-Out preference

Whether the user is opted out via OS-level Opt-out or via App-level Opt-out, the current Opt-Out status as detected by the SDK is available via the optOutStatus property in the Nielsen SDK API

Required Privacy Links

Users must either have access to the "About Nielsen Measurement" page, or have similar text available within the native app. Include "About Nielsen Measurement" and "Your Choices" link in the Privacy Policy / EULA or as a button near the link to the app's Privacy Policy.

In addition, the following text must be included in your app store description.

"Please note: This app features Nielsen’s proprietary measurement software which contributes to market research, like Nielsen’s TV Ratings. Please see http://priv-policy.imrworldwide.com/priv/mobile/us/en/optout.html for more information"

Webview Example

The below code is an example of displaying the Nielsen Privacy page to the user.

import UIKit
import WebKit
import NielsenAppApi

class OptOutVC: UIViewController, NielsenAppApiDelegate, WKNavigationDelegate {
    
    var webView: WKWebView!
    var nielsenApi: NielsenAppApi!
    
    override func loadView() {
        webView = WKWebView()
        webView.navigationDelegate = self
        view = webView
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.backgroundColor = UIColor(patternImage: UIImage(named: "new_ios_bg.png")!) 
        self.nielsenApi = NielsenInit.createNielsenApi(delegate: self)
        
        if let appApi = self.nielsenApi {
            //Getting the optPut URL from SDK
            if let url = URL(string: appApi.optOutURL) {
                webView.load(URLRequest(url: url))
                webView.allowsBackForwardNavigationGestures = true
            }
        }
    }
    
}


App Level Opt Out

This is only used if the Ad Framework is not available. The Opt-Out occurs by opening a Nielsen-defined web page and passing the user choice from the 'WebView'. In order to do this, the application needs to:

  • Implement the UIWebView delegate method to open the Nielsen Privacy web page
  • Capture user's selection
  • Pass the selection back to the SDK via the userOptOut.

Capture and forward user selection

-(BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
    NSString *command = [NSString stringWithFormat:@"%@",request.URL];
    if ([command isEqualToString:kNielsenWebClose]) {
        // Close the WebView
        [self performSelector:@selector(closeOptOutView) withObject:nil afterDelay:0];
        return NO;
    }
    // Retrieve next URL if it’s not opt-in/out selection
    return (![nAppApiObject userOptOut:command]);
}
  • The app gets the user selection string via webviews shouldStartLoadWithRequest and invokes userOptOut with user selection. The delegate method handles the 'WebView' URL requests, interprets the commands, and calls the SDK accordingly.
    • [nAppApiObject userOptOut:command] passes the user's selection on Nielsen Privacy page to the SDK to allow the SDK to perform the required functions.

Note: When 'WebView' is closed, pass the status returned from 'WebView' to the SDK within the app. The App SDK manages the user's choice (Opt-Out / Opt-In), the app does not need to manage this status.