DTVR iOS SDK

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Overview

The Nielsen SDK is one of multiple framework SDKs that Nielsen provides to enable measuring linear (live) and on-demand TV viewing using TVs, mobile devices, etc. The App SDK is the framework for mobile application developers to integrate Nielsen Measurement into their media player applications. It supports a variety of Nielsen Measurement Products like Digital in TV Ratings, Digital Content Ratings (DCR & DTVR), Digital Ad Ratings (DAR), and Digital Audio. Nielsen SDKs are also equipped to measure static content and can track key life cycle events of an application like:

  • Application launch events and how long app was running
  • Time of viewing a sub section / page in the application.

If the content being played contains ID3 tags, when played on a mobile device or within a browser, these tags can be sent to Nielsen for collection/processing via the Nielsen SDK.

VOD in TV Ratings (formally knows as Recently Telecast VOD) support is now available; however, you must notify your Nielsen Technical Account Manager to ensure accurate reporting.

Prerequisites

To start using the App SDK, the following details are required:

  • App ID (appid): Unique ID assigned to the player/site and configured by product.
  • sfcode: Unique identifier for the environment that the SDK should point to.
  • Nielsen SDK: The Nielsen SDK package contains a variety of sample players for your reference.

If you do not have any of these prerequisites or if you have any questions, please contact our SDK sales support team. Refer to Digital Measurement Onboarding guide for information on how to get a Nielsen App SDK and appid.

Implementation

This guide covers implementation steps for iOS using Xcode utilizing the Standard Nielsen SDK for DTVR.

Setting up your Development Environment

Configuring Xcode Development Environment

Starting with SDK version 6.0.0.0, the Nielsen App SDK is compatible with Apple iOS versions 8.0 and above. In addition, the SDK uses the WKWebView class instead of the deprecated UIWebView as per Apple guidelines.

Note: All communications between the SDK and the Census (Collection Facility) use HTTPS.

Importing Frameworks

The first step is to ensure that the following frameworks and libraries are imported into the Frameworks folder of the Xcode project before creating an instance of the Nielsen App SDK object.

  • UIKit.framework
  • Foundation.framework
  • AdSupport.framework
  • JavascriptCore.framework
  • WebKit.framework
  • SystemConfiguration.framework
  • Security.framework
    • Nielsen Analytics framework makes use of a number of functions in this library.
  • AVFoundation.framework
  • NielsenAppApi.framework
  • libc++.tbd (as SDK contains Objective C++ source file)
    • Alternatively, include -lstdc++ in Build Settings → Other Linker Flag of the Xcode project
Example
  • Extract “NielsenAppApi.Framework” from the Nielsen App SDK sample app and copy it to Frameworks folder of the Xcode project.
  • Add the code -#import NielsenAppApi/NielsenAppApi.h to the View Controller’s header file.

Ensure that the following are included in the Linked Frameworks and Libraries list (located in the project’s Summary settings).

  • Nielsen App SDK
  • iOS security framework


Using Swift To import a set of Objective-C files in the same app target as your Swift code, you rely on an Objective-C bridging header to expose those files to Swift. Xcode offers to create this header file when you add a Swift file to an existing Objective-C app, or an Objective-C file to an existing Swift app.

  • Select File/New File/Objective-C File
  • Xcode will prompt you to create a bridging header.
bridgingheader 2x.png

Once this file has been created, you need to add the following:

#import <NielsenAppApi/NielsenAppApi.h>

Using Objective-C Add the code

#import <NielsenAppApi/NielsenAppApi.h>

to the View Controller’s header file.

SDK Initialization

The latest version of the Nielsen App SDK allows instantiating multiple instances of the SDK object, which can be used simultaneously without any issue. The sharedInstance API that creates a singleton object was deprecated prior to version 5.1.1. (Version 4.0 for Android)

  • A maximum of four SDK instances per appid are supported.
  • When four SDK instances exist, you must destroy an old instance before creating a new one.

The following table contains the list of arguments that can be passed via the AppInfo JSON schema.

  • The appid is provided by the Nielsen Technical Account Manager (TAM). The appid is a GUID data type and is specific to the application.
Parameter / Argument Description Source Required? Example
appid Unique id for the application assigned by Nielsen. It is GUID data type. Nielsen-specified Yes PXXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
appname Name of the application Client-defined Optional; automatically detected in SDK 6.0.0.4 and above Nielsen Sample App
sfcode Nielsen collection facility to which the SDK should connect. Nielsen-specified Yes us
containerID View ID of the UI element used as player view in application for Viewability Client-defined Optional "1234567"
nol_devDebug Enables Nielsen console logging. Only required for testing Nielsen-specified Optional "DEBUG"

Debug flag for development environment

Player application developers / integrators can use Debug flag to check whether an App SDK API call made is successful. To activate the Debug flag, Pass the argument @"nol_devDebug":@"INFO", in the JSON string . The permitted values are:

  • INFO: Displays the API calls and the input data from the application (validate player name, app ID, etc.). It can be used as certification Aid.
  • WARN: Indicates potential integration / configuration errors or SDK issues.
  • ERROR: Indicates important integration errors or non-recoverable SDK issues.
  • DEBUG: Debug logs, used by the developers to debug more complex issues.

Once the flag is active, it logs each API call made and the data passed. The log created by this flag is minimal.

Note: DO NOT activate the Debug flag in a production environment.

Sample SDK Initialization Code

Swift

Swift 4.0 Example: NielsenInit.swift

import Foundation
import NielsenAppApi

class NielsenInit : NSObject {
    class func createNielsenApi(delegate: NielsenAppApiDelegate) -> NielsenAppApi?{
        
        let appInformation:[String: String] = [
            
            "appid": "PDA7D5EE6-B1B8-4123-9277-2A788XXXXXXX",
            "sfcode": "us",
            "nol_devDebug": "DEBUG"
            "containerId": String(containerId)   //Keep container id unique constant, you can use tag property of player.
        ]
        
        return NielsenAppApi(appInfo:appInformation, delegate:delegate)
    }
}


Sample code using AVPlayer. ViewController.swift

class ViewController: UIViewController, NielsenAppApiDelegate, AVPlayerViewControllerDelegate  {

// your code//    

  override func viewDidLoad() {
        super.viewDidLoad()

        //Getting the instance of NielsenApi
        self.nielsenApi = NielsenInit.createNielsenApi(delegate: self)

            }
  }

Objective C

Initialize the Nielsen App object within the viewDidLoad view controller delegate method using initWithAppInfo:delegate:

If App SDK is initialized using init or new methods, it will ignore the API calls resulting in no measurement. The SDK will not return any errors.
    
#import "NielsenInit.h"
#import <NielsenAppApi/NielsenEventTracker.h>

@implementation NielsenInit

+ (NielsenEventTracker *)createNielsenEventTrackerWithDelegate:(id<NielsenEventTrackerDelegate>)delegate
{
    //Initialising the NielsenEventTracker class by passing app information which returns the instance of NielsenEventTracker.
    
    NSDictionary *appInformation = @{ @"appid": @"PDA7D5EE6-B1B8-4123-9277-2A788XXXXXXX",
                            @"appversion": @"1.0",
                            @"sfcode": @"us",
                            @"nol_devDebug": @"DEBUG",
                            @"containerId": @"1" };
    
    return [[NielsenEventTracker alloc] initWithAppInfo:appInformation delegate:delegate];
}

@end


The following would be the NielsenInit.h file:

#import <Foundation/Foundation.h>

@class NielsenEventTracker;
@protocol NielsenEventTrackerDelegate;

@interface NielsenInit : NSObject

+ (NielsenEventTracker *)createNielsenEventTrackerWithDelegate:(id<NielsenEventTrackerDelegate>)delegate;

@end



APP SDK Error & Event Codes

To view the Error and Event codes for iOS and Android, please review the App SDK Event Code Reference page.

Content Metadata and SDK Events

Content Metadata

Content metadata should remain constant throughout the completion of an episode or live stream.

Key Description Values Required
channelName Any string representing the channel/stream 32-character free-form text
type type of asset "content"
adModel linear vs dynamic ad model 1 = Linear matches TV ad load
    
- (NSDictionary *)loadChannelInfo
{
    //Loading Channel Info.    
    NSString *strUrl = self.url.absoluteString;  
    NSDictionary *channel = @{  @"channelName" : @"TheGreatBigMovie": strUrl };   
    return channel;
}
- (NSDictionary *)loadDtvr{
    
    //Loading DTVR data  
    NSDictionary *dtvr = @{ @"adModel":@"1" ,  
                            @"type":@"content",};  
    return dtvr;
}

SDK Events

icon

Event Parameter Description
'loadMetadata' content/ad metadata object Needs to be called at the beginning of each asset to pass type, channelName, and adModel.
'play' program or feed name Call when starting or resuming a streaming session.
'stop' playhead position Call when content or ads complete playing and pass playhead position
'sendID3' Used to send the ID3 tag payload retrieved from the stream Needs to be called at the beginning of playback
'end' Content end Call when the current video asset completes playback or when a stream is interrupted.

Example: At the end of the content stream, if the user switches to another piece of content, when the browser is refreshed or closed.

Configure API calls - play

Swift

nielsenAppApi?.play(loadChannelInfo);

Objective C

   [nielsenAppApi play:(loadChannelInfo)];


Configure API calls - loadMetadata

Use loadMetadata to pass ‘content’ and ‘ad’ Digital Measurement Metadata. The CMS data must be passed as a JSON object.

Swift

self.nielsenAppApi?.loadMetadata(loadDtvr)

Objective C

[nielsenApi loadMetadata:(loadDtvr)];


Configure API calls - sendID3

sendID3 API is a receiver for timed metadata events (ID3 tags) provided through iOS’s NSNotificationCenter notification system. This API filters out Nielsen-specific ID3 tags from the system and buffers the data for transfer to Nielsen’s collection facility.

Swift

 [nielsenApi sendID3:extraString];

Objective C

[nielsenApi sendID3:extraString];


Sample ID3 tags

  • www.nielsen.com/X100zdCIGeIlgZnkYj6UvQ==/X100zdCIGeIlgZnkYj6UvQ==/AAAB2Jz2_k74GXSzx4npHuI_JwJd3QSUpW30rDkGTcbHEzIMWleCzM-uvNOP9fzJcQMWQLJqzXMCAxParOb5sGijSV9dNM3QiBniJYGZ5GI-lL1fXTTN0IgZ4iWBmeRiPpS9AAAAAAAAAAAAAAAAAAAAAFJWFM5SVhTONNU=/00000/00000/00
  • www.nielsen.com/X100zdCIGeIlgZnkYj6UvQ==/R8WHe7pEBeqBhu8jTeXydg==/AAICoyitYqlxT7n6aZ0oMCGheFi4CXFp46AMUPZz1lMr_M9tr3_cjee1SHqxrOiVerMDLeyn9xzocZSKwi746Re8vNOtpNCAZjYABs_J0R25IHpvOc1HS8QHGgD5TgOJeS6gX100zdCIGeIlgZnkYj6UvVJWFNhSVhTiPE0=/00000/46016/00

Refer to Retrieving ID3 Tags section to know more details.

Configure API calls - stop

Call stop in case of interruptions during playback like flight mode, Wi-Fi toggle, etc. Call play when resuming the stream / starting the new stream.

Swift

nielsenApi.stop()

Objective C

[nielsenApi stop];


Configure API calls - end

Call end only at the end of playback.

Swift

nielsenApi.end()

Objective C

[nielsenApi end];


Retrieving ID3 Tags

ID3 tags have a payload of about 249 characters and start with "www.nielsen.com".

ID3 tags are extracted by observing a property called timedMetadata on the iOS player item. Now this is done via a concept called KVO (Key Value Observing), where you register interest in a property, and the runtime will let you know when it has changed.

Both the iOS native players have the ability to extract ID3 tags, If any other player apart from iOS native players (AVPlayer, MPMoviePlayer) is used, check and ensure that the player has the capability to extract ID3 tags.

Examples of extracting ID3 tags from the iOS Native Player

Swift

 
      //Setting observer to track timedMetadata
            player.addObserver(self, forKeyPath: timedMetadataKey, options: NSKeyValueObservingOptions.new, context: &TimedMetadataObserverContext)

 
   override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
        
        if keyPath == timedMetadataKey {
            if(context == &TimedMetadataObserverContext){
                if change != nil {
                    let timedMetadataArray = change![.newKey]
                    if timedMetadataArray != nil && (timedMetadataArray! as AnyObject) is Array<Any> {
                        for item in timedMetadataArray as! [AVMetadataItem]  {
                            //Handling TimedMetadata
                            self.handleTimedMetadata(metadataItem: item)
                        }
                    }
                }
            }
        }

 
 func handleTimedMetadata(metadataItem: AVMetadataItem) {
        guard let extraAttributeType = metadataItem.extraAttributes else {
            return
        }
        let info : AVMetadataExtraAttributeKey = AVMetadataExtraAttributeKey(rawValue: "info")
        let extraString = extraAttributeType[info] as AnyObject
        let key = metadataItem.key as! String
        
        //If tag starts with "www.nielsen.com", then only sending to SDK
        if key == "PRIV" && extraString.range(of: "www.nielsen.com").length > 0 {
            
            DispatchQueue.global(qos: .default).async { () -> Void in
                self.nielsenApi?.sendID3(extraString as! String)
            }
        }
    }

Objective C

    //Adding observer to player to track play,pause and reverse
    [player addObserver:self
             forKeyPath:@"rate"
                options:(NSKeyValueObservingOptionNew)
                context:nil];

       
        //Setting observer to track timedMetadata
        [player addObserver:self
                 forKeyPath: timedMetadataKey
                    options: (NSKeyValueObservingOptionNew)
                    context: &TimedMetadataObserverContext];

     
- (void)observeValueForKeyPath:(NSString *)keyPath
                      ofObject:(id)object
                        change:(NSDictionary *)change
                       context:(void *)context
{
    if(keyPath == timedMetadataKey){
        if(context == &TimedMetadataObserverContext){
            
            id newMetadataArray = [change objectForKey:NSKeyValueChangeNewKey];
            if (newMetadataArray != [NSNull null])
            {
                array = newMetadataArray;
                for (AVMetadataItem *metadataItem in array)
                {
                    //Handling TimedMetadata
                    [self handleTimedMetadata: metadataItem];
                }
            }
            
        }
    }

     
- (void)handleTimedMetadata:(AVMetadataItem *)timedMetadata
{
    // We expect the content to contain plists encoded as timed metadata
    // AVPlayer turns these into NSDictionaries
    
    id extraAttributeType = [timedMetadata extraAttributes];
    NSString *extraString = nil;
    if ([extraAttributeType isKindOfClass:[NSDictionary class]])
    {
        extraString = [extraAttributeType valueForKey:@"info"];
    }
    else if ([extraAttributeType isKindOfClass:[NSString class]])
    {
        extraString = extraAttributeType;
    }
    
    NSString *key = [NSString stringWithFormat:@"%@", [timedMetadata key]];
    
    //If tag starts with "www.nielsen.com", then only sending to SDK
    if ([key isEqualToString:@"PRIV"] && [extraString rangeOfString:@"www.nielsen.com"].length > 0)
    {
        
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
            [nielsenApi sendID3:extraString];
        });
    }
}


Life cycle of SDK instance

Life cycle of SDK instance includes four general states:

  1. Initial state – The SDK is not initialized and hence, not ready to process playing information. Once the SDK is moved out of this state, it needs instantiation of the new SDK instance in order to get the instance in the Initial state.
  2. Idle state – The SDK is initialized and is ready to process playing information. Once Initialized, the SDK instance is not processing any data, but is listening for the play event to occur.
  3. Processing state – The SDK instance is processing playing information. The play and loadMetadata calls move the SDK instance into this state. In this state, the SDK instance will be able to process the following calls.
    1. stop – Call this API when the playback is paused, switches between content and ad (within the same content playback) or encounters interruptions.
    2. end – SDK instance exits from Processing state when this API is called.
  4. Disabled state – The SDK instance is disabled and is not processing playing information. SDK instance moves into this state in one of the following scenarios.
    1. Initialization fails
    2. appDisableApi is set to true (This is testing purposes only. Not for User Opt-Out.)
Note: For API Version 5.1 and above, App SDK will fire data pings and continue measurement even after the user has opted out from Nielsen measurement on a device. The data ping will be marked as opted-out ping.

Note: In case of any interruptions during playback due to alarm, calendar, call, flight mode, Wi-Fi toggle, channel change, etc., call stop to stop the measurement.

Handling Foreground and Background states

For iOS, background/foreground detection is handled by the app lifecylce APIs which are provided by Apple:

Foreground/Background state measurement is a requirement of Nielsen AppSDK implementation which is especially crucial for static measurement.

Interruptions during playback

As part of integrating Nielsen App SDK with the player application, the Audio / Video app developer needs to handle the following possible interruption scenarios:

  • Pause / Play
  • Network Loss (Wi-Fi / Airplane / Cellular)
  • Call Interrupt (SIM or Third party Skype / Hangout call)
  • Alarm Interrupt
  • Content Buffering
  • Device Lock / Unlock (Video players only, not for Audio players)
  • App going in the Background/Foreground (Video players only, not for Audio players)
  • Channel / Station Change Scenario
  • Unplugging of headphone

In case of encountering one of the above interruptions, the player application needs to

  • Call stop immediately (except when content is buffering) and withhold sending playhead position.
  • Call play once the playback resumes.

Pre-Certification Checklists

After the application is ready to be sent for Nielsen Certification, please go through the Digital Pre-Certification Checklist App SDK and ensure the app behaves as expected, before submitting to Nielsen.

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" ("Limit Ad Tracking" for Android) 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

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)
        }
    }

Retrieve current Opt-Out preference

Whether the user is opted out viaOS-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.

Going Live

Following Nielsen testing, users need to make one update to the initialization call to ensure that the site is being measured properly.

  1. Debug Logging: Disable logging by deleting {nol_sdkDebug: 'DEBUG'} from initialization call.

Note: before going live you have to inform Nielsen team - this is necessary, because Nielsen team has to adjust internal configuration parameter to enable data collection. Without that notification no data will be collected and no data will be reported.

Sample Applications

The below sample applications have been designed to show the API's functionality and are broken into two distinct categories:

  • Advanced - Nielsen Simplified API integrated into a custom video player is contained in the ZIP package.

Testing an Implementation - App

See Digital Measurement Testing.