View source for iOS SDK API Reference

{{Breadcrumb|}} {{Breadcrumb|Digital}} {{CurrentBreadcrumb}}
[[Category:Digital]]
The iOS 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. These SDKs leverage the following:
*Nielsen audio watermark technologies for TV audience measurement
*The industry supported ID3 metadata tag specification
*Nielsen Combined Beacon technology
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), [[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
*Application crash events
*Time of viewing a sub section / page in the application.

== Importing Frameworks ==
'''Setting up your Xcode Development Environment'''

Nielsen App SDK is compatible with Apple iOS versions 7.0 and above.

SDK uses the NSURLSession available from iOS 7 instead of the deprecated NSURLConnection.

<blockquote>'''Note''': App SDK supports devices running on iOS 9 and above, as all communications between the SDK and the Census (Collection Facility) use HTTPS.</blockquote>

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
* SystemConfiguration.framework
* Security.framework
** Nielsen Analytics framework makes use of a number of functions in this library.
* AVFoundation.framework
** This framework is mandatory for the iOS SDK version 5.1.1 to work.
* CoreLocation.framework (Not applicable for International (Germany))
* CoreMedia.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

<blockquote>'''Example'''
* Extract “NielsenAppApi.Framework” from the Nielsen App SDK sample app and copy it to Frameworks folder of the Xcode project.
* Add the code <code>-#import NielsenAppApi/NielsenAppApi.h</code> to the View Controller’s header file.</blockquote>
 
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

== Initialization ==
The latest version of App SDK allows instantiating multiple instances of App SDK object and can be used simultaneously without any issues (The sharedInstance API that creates a singleton object in previous versions of App SDK is removed).
*Maximum of four SDK instances per appid are supported in this release. When a fifth SDK instance is launched,
**SDK will return “nil” from [[initWithAppInfo:delegate:]]
**Destroy one or more old SDK instances before creating new ones.

=== Stages of SDK Initialization ===
==== Step 1: App SDK Initialization ====
Initialize the Nielsen App object within the viewDidLoad view controller delegate method using initWithAppInfo:delegate:
<blockquote>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.</blockquote>

==== Step 2: Setting up event and error notifications ====
Once the <code>NielsenAppApi</code> object has been initialized, the next step is to enable notifications regarding ID3 tags extracted from the playing stream. In case of standard AVFoundation player, the SDK NSNotificationCenter API is used to
* Collect HLS timed metadata events (ID3 tags) during viewing sessions.
** Set up a timed metadata event listener method for receiving ID3 tags and calling Nielsen [[sendID3]].
* SDK uses the following NielsenAppApiDelegate protocol methods to notify its delegate (set during initialization) about event / error information.
** nielsenAppApi:eventOccurred
** nielsenAppApi:errorOccurred
<blockquote>'''Note''': Ensure to add to your view controller’s <code>@interface</code>.</blockquote>

<syntaxhighlight lang="objective-c">(void)nielsenAppApi:(NielsenAppApi *)appApi eventOccurred:(NSDictionary *)event {NSLog(@"Sample player is Notified by a Event : %@", event);
}
(void)nielsenAppApi:(NielsenAppApi *)appApi errorOccurred:(NSDictionary *)error {NSLog(@"Sample player is Notified by an Error : %@", error);
}</syntaxhighlight>

===== Sample event confirmation to player application upon successful initialization of SDK =====
<syntaxhighlight lang="console">NielsenSDKSampleDebug[9028:237989] [Nls:0] -I- Analytics framework Status:
{
"Event Description" = "Nielsen App SDK Version, ai.4.0.0.4 is initialized by the Player…";
EventStatus = 2001;
TimeStamp = "2015-07-23 14:51:06 +0000";
}</syntaxhighlight>

==== Step 3: Nielsen App SDK Streaming Sessions ====
After setting up observers for SDK events/errors and a listener method to process incoming Nielsen ID3 tags, the next steps are to
* Call [[play]] while starting or resuming a streaming session.
* Load CMS metadata using [[loadMetadata]].
* During session play, call [[playheadPosition]] every one second until the stream is stopped or interrupted (due to ad breaks or buffering).
* Call [[stop]] when pausing, ending a viewing session, or buffering is detected.

'''Serialized JSON string from NSDictionary'''
<syntaxhighlight lang="objective-c">NSDictionary* appInformation = @
{
  @"appid": @"TXXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX",
  @"appname": @"Sample App Name",
  @"appversion": @"2.0",
  @"sfcode": @"uat-cert",
  @"nol_devDebug": @"INFO"
}
NSData* jsonDataAppInfo = [NSJSONSerialization dataWithJSONObject:appInformation options:0 error:nil];
NSString *jsonAppInfoString = [[NSString alloc] initWithData:jsonDataAppInfo encoding:NSUTF8StringEncoding];
nlsAppApiMeter = [[NielsenAppApi alloc] initWithAppInfo:jsonAppInfoString delegate:self];</syntaxhighlight>

Nielsen App SDK object handles filtering of ID3 tags and CMS tags, queuing/buffering of data, and all communications with Nielsen collection facility.

===== Nielsen iOS App SDK Application Life Cycle =====

[[File:initialization_appcycle.png|center|link=]]

Life cycle of SDK instance includes four general states:
# '''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'''.
# '''Idle state''' – The SDK is initialized and is ready to process playing information. Call <code>[[initWithAppInfo:delegate:]]</code> to move into this state. The SDK instance is not processing any data, but is listening for the play event to occur.
# '''Processing state''' – The SDK instance is processing playing information. [[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.
## [[playheadPosition]] – Call this API every one second when playhead position timer is fired.
## [[sendID3]] – Call this API when ID3 tags are identified in the stream.
## [[stop]] – Call this API when the playback is paused, switches between content and ad (within the same content playback) or encounters interruptions.
## [[end]] – SDK instance exits from Processing state when this API is called.
# '''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.
## Initialization fails
## [[appDisableApi]] is called
<blockquote>'''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.
* As soon as the playback resumes, call [[play]], [[loadMetadata]] and [[sendID3]] / [[playheadPosition]].</blockquote>

=== Finite-state machine table ===
This table provides the possible changes of state for the SDK instance, when it is in a specific state and receives an API call.
{| class="wikitable"
|-
! API call received !! Initial State !! Idle State !! Processing State !! Disabled State
|-
| <code>[[initWithAppInfo:delegate:]]</code> || IDLE STATE (OR)

DISABLED STATE
|| IDLE STATE || - || -
|-
| <code>[[play]]</code> & <code>[[loadMetadata]]</code>|| - || PROCESSING

STATE
|| - || -
|-
| <code>[[playheadPosition]]</code> || - || - || PROCESSING

STATE
|| -
|-
| <code>[[sendID3]]</code> || - || - || PROCESSING

STATE
|| -
|-
| <code>[[stop]]</code> || - || - || IDLE STATE || -
|-
| <code>[[end]]</code> || - || - || IDLE STATE || -
|-
| <code>[[appDisableApi]]</code>: YES || - || DISABLED

STATE
|| - || -
|-
| <code>[[appDisableApi]]</code>: NO || - || - || - || IDLE STATE (OR)

DISABLED STATE
|-
| <code>[[userOptOut]]</code>: YES || - || - || IDLE STATE || -
|-
| <code>[[userOptOut]]</code>: NO || - || PROCESSING

STATE
| - 
| -
|-
| colspan = 5 | '-' indicates that no API call is expected.
|}

=== Handling JSON Metadata ===
All the SDK methods handles only two types of objects: NSString, NSDictionary. The parameters passed must be either a JSON formatted string or a NSDictionary object. The JSON passed in the SDK must be well-formed.
* NSDictionary object
** If an object of unexpected type is passed to the method, the error message will be logged.
** If string has invalid JSON format, the error message will be logged.
* JSON value must be string value.
** This includes boolean and numeric values. For example, a value of true should be represented with "true", number value 123 should be "123".
** All the Variable Names like appid, appname, sfcode, dataSrc, title, type etc. are case-sensitive. Use the correct variable name as specified in the documentation.
* JSON string can be prepared using either raw NSString or serialized NSDictionary.

==== JSON for NSDictionary object ====
<syntaxhighlight lang="objective-c">
NSDictionary* appInformation = @{
                                  @"appid": @"TXXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX",
                                  @"appname": @"Sample App Name",
                                  @"appversion": @"2.0",
                                  @"sfcode": @"uat-cert",
                                  @"nol_devDebug": @"INFO"
                                };
nlsAppApiMeter = [[NielsenAppApi alloc] initWithAppInfo:appInformation delegate:delegate];</syntaxhighlight>

<code>appid</code>, <code>appname</code>, and <code>appversion</code> are mandatory parameters while <code>sfcode</code> is optional. <code>nol_devDebug</code> is meant for creating logs in test environments only.

==== JSON string from raw NSString ====
<syntaxhighlight lang="swift">NSString *appInfoString = @"{\"appid\" : \"TXXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX\", \"appname\" : \"Sample App Name\",\"appversion\" : \"2.0\",\"sfcode\" : \"uat-cert\"}";
NielsenAppAPi *appAPI = [[NielsenAppApi alloc] initWithAppInfo:appInfoString delegate:self];</syntaxhighlight>

==== JSON string from serialized NSDictionary ====
<syntaxhighlight lang="objective-c">NSDictionary* appInformation = @
{
@"appid": @"appid",
@"appname": @"appname",
@"appversion": @"2.0",
@"sfcode": @"sfcode",
@"nol_devDebug": @"INFO"
};
nlsAppApiMeter = [[NielsenAppApi alloc] initWithAppInfo:appInformation delegate:self];</syntaxhighlight>

While using JSON format for sending metadat, ensure enough care in including [[special characters]] in the values for arguments.

==== Example ====
<syntaxhighlight lang="objective-c">{
@"type": @"radio", // To send "radio" in metadata string
@"assetid": @"WXYZ-FM'101",
@"stationType": @"3",
@"provider": @"SampleProvider" // To send "SampleProvider" in metadata string
}</syntaxhighlight>
<blockquote>'''Note''': For mandatory parameters like appid, appname, and appversion, please refer to the parameters table in <code>[[initWithAppInfo:delegate:]]</code></blockquote>

== 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.

=== Sample ID3 tags ===
* <code>www.nielsen.com/X100zdCIGeIlgZnkYj6UvQ==/X100zdCIGeIlgZnkYj6UvQ==/AAAB2Jz2_k74GXSzx4npHuI_<wbr />JwJd3QSUpW30rDkGTcbHEzIMWleCzM-uvNOP9fzJcQMWQLJqzXMCAxParOb5sGijSV9dNM3QiBniJYGZ5GI-lL1fXTTN0IgZ4iWBmeRiPpS9AAAAAAAAAAAAAAAAAAAAAFJWFM5SVhTONNU=/00000/00000/00</code>
* <code>www.nielsen.com/X100zdCIGeIlgZnkYj6UvQ==/R8WHe7pEBeqBhu8jTeXydg==/AAICoyitYqlxT7n6aZ0oMCGhe<wbr />Fi4CXFp46AMUPZz1lMr_M9tr3_cjee1SHqxrOiVerMDLeyn9xzocZSKwi746Re8vNOtpNCAZjYABs_J0R25IHpvOc1HS8<wbr />QHGgD5TgOJeS6gX100zdCIGeIlgZnkYj6UvVJWFNhSVhTiPE0=/00000/46016/00</code>

=== Examples of extracting ID3 tags from the iOS Native Player ===
==== AVPlayer ====
ID3 tags will be received in the Player on AVMetadataItem Callback method.
'''Create & get the AVMetadataItem callback method'''
<syntaxhighlight lang="swift">[self.player addObserver:self
        forKeyPath: kTimedMetadataKey
        options: NSKeyValueObservingOptionNew
        Context: MyStreamingMovieViewControllerTimedMetadataObserverContext];</syntaxhighlight>


<syntaxhighlight lang="objective-c">
– (void)observeValueForKeyPath:(NSString*) path
                      ofObject: (id)object
                        change: (NSDictionary*)change
                       context: (void*)context
{
/* Set the AVPlayerLayer on the view to allow the AVPlayer object to display
     its content. */
    //[playerLayerView.playerLayer setPlayer:player];
/* AVPlayerItem "status" property value observer. */
if (context == MyStreamingMovieViewControllerTimedMetadataObserverContext)
        {
            id newMetadataArray = [change objectForKey:NSKeyValueChangeNewKey];
            if (newMetadataArray != [NSNull null])
            {
                array = newMetadataArray;
                for (AVMetadataItem *metadataItem in array)
                  {
                    [self handleTimedMetadata: metadataItem];
                  }
            }
}
</syntaxhighlight>


<syntaxhighlight lang="objective-c">
– (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;
    }
  if ([(NSString *)[timedMetadata key] isEqualToString:@"PRIV"]&&[extraString rangeOfString:@"www.nielsen.com"].length> 0)
  {
   if ([[timedMetadata value] isKindOfClass:[NSData class]])
   {
            // Sending ID3 Tag
/* The  sendID3: sends the extracted Nielsen ID3 payload to the App SDK for analysis. */
            [[NielsenAppApi sharedInstance]sendID3: extraString];
            NSString *value=[timedMetadata stringValue];
            if (value != nil)
            {
               // NSString *strMessage=[[@"ID3 Tag Received " stringByAppendingFormat:@"%d\n",countForMetadata] stringByAppendingString:value];
                [self appendLogConsoleText:extraString];
            }
   }
  }
    else
    {
        NSLog(@"Could not send ID3 tags");
    }
    countForMetadata++;
    
}
</syntaxhighlight>

==== Movie Player ====
ID3 tags will be received in the Player on MPTimedMetadata Callback method.
'''Sample Implementation of MPTimedMetadata callback'''
<syntaxhighlight lang="objective-c">
– (void)handleTimedMetadata:(MPTimedMetadata*)timedMetadata
{
    id extraAttributeType = [timedMetadata  allMetadata];
    NSString * extraString= nil;
    if ([extraAttributeType isKindOfClass:[NSDictionary class]])
    {
        extraString = [extraAttributeType valueForKey:@"info"];
    }
    else if([extraAttributeType isKindOfClass:[NSString class]])
    {
        extraString = extraAttributeType;
    }
    
  if ([(NSString *)[timedMetadata key] isEqualToString:@"PRIV"]&&[extraString rangeOfString:@"www.nielsen.com"].length> 0)
    {
     if ([[timedMetadata value] isKindOfClass:[NSData class]])
      {
            // Sending ID3 Tag
            [[NielsenAppApi sharedInstance]sendID3: extraString];
            NSString *value=[timedMetadata value];
            if (value != nil)
            {
                
                [self appendLogConsoleText:extraString];
            }
      }
    }
    else
    {
        NSLog(@"Could not send ID3 tags");
    }
    countForMetadata++;
}
</syntaxhighlight>
<blockquote>'''Note:''' ID3 tags are not applicable for International (Germany)</blockquote>


== IOS SDK API Methods & Properties ==
{| class="wikitable sortable"
|-
! Scenario !! Method / Property !! DTVR !! DAR !! Digital Audio !! DCR !! International (Germany) !! Description
|-
| Initialize || [[initWithAppInfo:delegate:]] || ✔ || ✔ || ✔ || ✔ || ✔ || Used to create a new instance of the SDK object
|-
| Measurement || [[play]] || ✔ || ✔ || ✔ || ✔ || ✔ || Used when there is an ID3 fed product such as DTVR and the client does not want to send in all the CMS metadata that is sent in loadMetadata. This allows the client to send in at least the required “channel name” value associated to the ID3 feed. If this is not called then the “channel name” value populated will be the default value of “defaultChannelName”.
|-
| Measurement || [[loadMetadata]] || ✔ || ✔ || ✔ || ✔ || ✔ || Used to send ad or content metadata to the SDK in the form of JSON string. Application constructs a JSON hashmap and calls this API.
|-
| Measurement || [[sendID3]] || ✔ || ✘ || ✘ || ✘ || ✘ || Used to send the ID3 metadata.
|-
| Measurement || [[playheadPosition]] || ✘ || ✘ || ✔ || ✔ || ✔ || Used to send the playhead position.
|-
| Measurement || [[stop]] || ✔ || ✘ || ✔ || ✔ || ✔ || Used when playback is paused and when switching between ad and content or content and ad.
|-
| Measurement || [[end]] || ✔ || ✔ || ✔ || ✔ || ✔ || Used when content playback is complete. This is triggered 1) at the end of the content stream, 2) if the user switches to another piece of content
|-
| Measurement || [[updateOTT]] || ✘ || ✘ || ✘ || ✘ || ✔ || Used to notify App SDK that the remote OTT device (like Google ChromeCast, Roku, Amazon FireTV, etc.) is connected / disconnected (change of OTT status).
|-
| Opt-out || [[optOutURL]] || ✔ || ✔ || ✔ || ✔ || ✔ || Used to fetch the Nielsen opt-out web page URL.
|-
| Opt-out || [[userOptOut]] || ✔ || ✔ || ✔ || ✔ || ✔ || Used to supply the response message from opt-out webpage to the SDK.
|-
| Opt-out || [[optOutStatus]] || ✔ || ✔ || ✔ || ✔ || ✔ || Call this API to retrieve the Opt-Out or Opt-In state.
|-
| Opt-out
| [[appDisableApi]]
(kill switch) 
|| ✔ || ✔ || ✔ || ✔ || ✔ || Used to disable the SDK.
|-
| Log || [[lastErrorDict]] || ✔ || ✔ || ✔ || ✔ || ✔ || Returns SDK error in the form of dictionary if any error has occurred.
|-
| Log || [[lastEventDict]] || ✔ || ✔ || ✔ || ✔ || ✔ || Returns SDK event in the form of dictionary if any event has occurred.
|-
| Log || [[meterVersion]] || ✔ || ✔ || ✔ || ✔ || ✔ || Returns the current SDK version.
|-
| Log || [[nielsenId]] || ✔ || ✔ || ✔ || ✔ || ✔ || Used to get a string defining the Nielsen ID (NUID) number for the device.
|-
| Log || [[demographicId]] || ✔ || ✔ || ✔ || ✔ || ✔ || Used to retrieve Demographic ID (Device ID) of the current device.
|-
| Log || [[debug]] || ✔ || ✔ || ✔ || ✔ || ✔ || Used to enable/disable debug flags. Newly introduced in SDK version 5.0.0 for International (Germany)
|}

== iOS Opt-Out Implementation ==
To opt out, users must have access to "About Nielsen Measurement" page. User can click this page from app settings screen.

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.
*URL to this web page should be called from SDK by invoking [[optOutURL]] and opened in 'WebView' / External browser.
*If the App SDK returns NULL as Opt-Out URL, handle the exception gracefully and retry later.
*To retrieve the current Opt-Out status of a device, use the [[optOutStatus]] method.

=== Displaying Opt-Out in a WebView ===
<syntaxhighlight lang="objective-c">
NielsenAppApi nAppApiObject;
@property(strong) UIWebView *optOutView;
// create WebView and set self as delegate
self.optOutView=[[UIWebView alloc]initWithFrame:self.view.bounds];
self.optOutView.scalesPageToFit = yes;
// get Nielsen defined web address and load the page
NSString *webAddress = [nAppApiObject optOutURLString];
If(webAddress == nil)
{ // Handle it gracefully and retry later} else
{[optOutView loadRequest:[NSURLRequest requestWithURL:webAddress]];
// show the view to the user
[self.view addSubview:optOutView]; }
</syntaxhighlight>

The app must provide access to "About Nielsen Measurement" page for the users. 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.

[[File:Privacy policy iOS.jpg|link=]]

*URL to this web page should be called from SDK and opened in 'WebView' / External browser.
*If the App SDK returns NULL as Opt-Out URL, handle this case and retry later.
*To retrieve the current Opt-Out status, use the [[optOutStatus]] property from Nielsen's SDK API.
<syntaxhighlight lang="objective-c">
@property (readonly) BOOL optOutStatus;
</syntaxhighlight>
*App should provide a UI control like 'close' or 'back' button to close the 'WebView' / External browser.

=== Sequence Diagram ===
[[File:optoutsequence-ios.jpg|link=]]

== Opt-out SDK Version '''5.1.1.17 or above''' ==
<blockquote>'''Note:''' If using SDK Versions 1.2.3, 4.0.0.8, 5.1.0, 5.1.1.12, skip ahead to: [[#Opt-out SDK Version 1.2.3, 4.0.0.8, 5.1.0, 5.1.1.12|Opt-out SDK Version 1.2.3, 4.0.0.8, 5.1.0, 5.1.1.12]]</blockquote>

Users can opt out or opt back into Nielsen Measurement. Opt-Out feature relies on iOS' system setting – "Limit Ad Tracking". The setting can be accessed in the Settings application on any iOS device: '''Settings → Privacy → Advertising → Limit Ad Tracking'''.

User is opted out of Nielsen online measurement research when the "Limit Ad Tracking" setting is enabled.

[[File:Opt-Out iOS.jpg|link=]]

<blockquote>'''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.</blockquote>

== Opt-out SDK Version '''1.2.3, 4.0.0.8, 5.1.0, 5.1.1.12''' ==
<blockquote>'''Note:''' If using SDK Version 5.1.1.17 or above, refer to documentation above ([[#Opt-out SDK Version 5.1.1.17 or above|Opt-out SDK Version 5.1.1.17 or above]])</blockquote>

When a user clicks the Opt-Out / Opt-In link, the application should invoke [[optOutURL]] to get the link to the Nielsen Privacy page from SDK.
=== Privacy Page ===
[[File:privacy-policy.jpg|link=]]
*There are two click here links – one for Opt-Out and one for Opt-In. Click the required link:
**
[[File:Opt-Out Combined.jpg|link=]]
*Click OK in the dialog that appears, to confirm the action.
*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 ===
<syntaxhighlight lang="objective-c">
-(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]);
}
</syntaxhighlight>

*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.
**<code>[nAppApiObject userOptOut:command]</code> passes the user's selection on Nielsen Privacy page to the SDK to allow the SDK to perform the required functions.
<blockquote>'''Note:''' When 'WebView' is closed, pass the status returned from 'WebView' to the SDK within the app.</blockquote>
<blockquote>'''Note:''' App SDK manages the user's choice (Opt-Out / Opt-In), the app does not need to manage this status.</blockquote>

== TVOS Opt-out ==
To Opt-Out, users must have access to “About Nielsen Measurement” page.

TVOS does not support creating instances of UIWebView and display web pages. Instead it makes use of a TVML page (built on TVML template) which displays information in a specific order.

Opt-Out page is built on descriptiveAlertTemplate and appears as follows:

[[File:TVOs OptOut LimitAdTracking1.png|link=]]

[[File:TVOs OptOut LimitAdTracking2.png|link=]]

Users need to toggle the “Limit Ad Tracking” option in order to Opt-In / Opt-Out of Nielsen Measurement.

To retrieve the current Opt-Out status of a device, use the [[optOutStatus]] method.

<blockquote>'''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.</blockquote>

== NielsenAppApi Class Description ==
The NielsenAppApi class is the primary application interface to the Nielsen App SDK. For example, after an instance object of the NielsenAppApi class is created and initialized, it can be used by the calling application to collect HLS timed metadata using the SDK’s [[sendID3]]: method. These are the public methods and properties exposed by the NielsenAppApi class:
<syntaxhighlight lang="objective-c">
@interface NielsenAppApi: NSObject

  @property (readonly) BOOL optOutStatus;
  @property (assign) BOOL appDisableApi;
  @property (assign) BOOL debug;
  @property (readonly) NSString *nielsenId;
  @property (readonly) NSString *demographicId;
  @property (readonly) NSString *optOutURL;
  @property (readonly) NSString *meterVersion;
  @property (readonly) NSDictionary *lastEventDict;
  @property (readonly) NSDictionary *lastErrorDict;

  – (instancetype)initWithAppInfo:(id)appInfo delegate:(id)delegate;

  – (void)play:(id)channelInfo;
  – (void)loadMetadata:(id)metadata;
  – (void)stop;
  – (void)end;
  – (void)playheadPosition:(long long)playheadPos;
  – (void)sendID3:(NSString *)data;
  – (void)updateOTT:(id)ottInfo;
  – (BOOL)userOptOut:(NSString *)optOut;

  – (NSString *)getNielsenId _attribute((deprecated((“Please use nielsenId property instead.”))));
  – (NSString *)optOutURLString _attribute((deprecated((“Please use optOutURL property instead.”))));
  – (NSString *)getMeterVersion _attribute((deprecated((“Please use meterVersion property instead.”))));
  – (NSDictionary *)getLastEventDict _attribute((deprecated((“Please use lastEventDict property instead.”))));
  – (NSDictionary *)getLastErrorDict _attribute((deprecated((“Please use lastErrorDict property instead.”))));

  @protocol NielsenAppApiDelegate<NSObject>

  @optional
  – (void)nielsenAppApi:(NielsenAppApi *)appApi eventOccurred:(NSDictionary *)event;
  – (void)nielsenAppApi:(NielsenAppApi *)appApi errorOccurred:(NSDictionary *)error;

@end
</syntaxhighlight>

== Nielsen Sample Applications ==
Nielsen iOS sample player application consists of two sample application based on native Players integrated with SDK framework. The player demonstrates all the supported functions of the SDK.
*NielsenVideoPlayer
*NielsenRadioPlayer
Implementation of Video and Audio sample apps is based on native iOS AVPlayer.

The UI components of the iOS App SDK sample applications are common to both as shown below.
*From the Channel Selection buttons ⬇️ & ⬆️ , the user will be able select the channels to stream.
*The Info button ℹ️ displays information of the SDK version, current Nielsen ID used for the device, and the option for opt-out/opt-in.
*The Play ▶️ and Pause ⏸️ buttons will control the streaming of the selected channel.
*The area at the bottom of the window displays the current stream status.
*The Clear button 🔃 clears out the status window.
*The Email button 📧 can be used to email the tags and status in a text file to Nielsen.
If target device supports Picture-in-Picture playing, it could be activated by PIP button in the Video player window.
*Channel URLs and metadata are obtained from two locations:
**Channels 1 and 2 are configured from the Settings application. Channel URLs and metadata parameters can be modified.
**Channels starting from 3 are configured in specific JSON file. URLs to this JSON config file can be changed from the Settings application.

== Nielsen Privacy Requirements ==
Privacy protections that Nielsen ensures to have with each App SDK integration are as follows.
*Disclosure of viewership data collection in app store description
*Disclosure of viewership data collection in EULA / Privacy Policy
*A link in the EULA/Privacy policy, or in another conspicuous location within the App, to a Nielsen-hosted web page outlining what Nielsen is collecting and how it is being used
*Method for users to opt-out of Nielsen measurement, any time while using the application

=== Ratings Data Flow ===
Every view of creditable and watermarked content is measured by Nielsen.
[[File:RatingsDataFlow.png]]

'''Information NOT Shared'''
* '''With Nielsen'''
** User's Identity
* '''With Data Provider'''
** Content information
** Whether user is viewing an ad or video content
** Player used to play the streaming (audio / video, etc.)
** Values being de-duped / aggregating for

Nielsen collects only what it needs for audience measurement. Every view of creditable, watermarked content will be measured by Nielsen.

=== Data Collected ===
{| class="wikitable"
|-
! Type of Information !! Parameter !! Transmitted to Nielsen? !! Sent to Provider?
|-
| rowspan="8" | Nielsen ID3 Watermark
|-
| FinalDistributor Timestamp || Yes || No
|-
| Program Content Timestamp || Yes || No
|-
| Mobile Breakout Code || Yes || No
|-
| Commercial Credit Code – Linear or Dynamic || Yes || No
|-
| Time ShiftedViewing Code || Yes || No
|-
| Segment Number || Yes || No
|-
| Segment View Pattern || Yes || No
|-
| rowspan="10" | Device/App Info
|-
| Device OSVersion || Yes || Yes 
|-
| Device Model || Yes || No
|-
| Device Advertiser ID (Apple IDFA or Google AdID/Android ID) || Yes || Yes 
|-
| Cache Buster || Yes || Yes 
|-
| App Version || Yes || No
|-
| App Name || Yes || No
|-
| SDKDisabled Flag || Yes || No
|-
| ServerCode || Yes || No
|-
| Channel or URL || Yes || No
|-
| rowspan="9" | Nielsen Identifiers
|-
| Client ID || Yes || No
|-
| Campaign ID || Yes || Yes 
|-
| Nielsen Unique Device ID || Yes || No
|-
| Application ID || Yes || No
|-
| DeviceGroup (ex. Tablet, Smartphone, Desktop) || Yes || Yes 
|-
| OS Group (ex. Android, iOS, Windows) || Yes || Yes 
|-
| SDKVersion || Yes || No
|-
| IP Address for DMA, Country Code || Yes || Yes 
|}
<blockquote>'''Note''': Data is hashed, and encrypted using AES 128 before transmission to data provider.</blockquote>

==== Example ping sent to provider ====
* <code><nowiki>https://provider.com/cgi-bin/brandlift.php</nowiki>?campaign_id=ff12725d724fac7934cf6003f096b4cd<wbr />&placement_id=a4164b8fba9ee7c873a9c72c7091bb58<wbr />&creative_id=25280139b61a947e127a52f56c8a2fdd<wbr />&segment1=9000<wbr />&segment2=41<wbr />&segment3=iOS<wbr />&OSVer=iOS6.1<wbr />&c9=<wbr />&devgrp=tablet<wbr />&h=f5f243fe6d<wbr />&rnd=1376971827360</code>


This ping passes the following parameters to the provider:
* Campaign ID – (campaign, placement, creative)
* Country Code
* DMA
* OS Group (ex. iOS, Android)
* DeviceOS Version
* Device Advertiser ID
* DeviceGroup (ex. Tablet, Smartphone, Desktop)
* Cache Buster

=== Nielsen Measurement Opt-Out ===
In accordance with Nielsen’s SDK licensing agreement, developers are required to provide basic informational data to users about Nielsen’s Privacy Policy with a navigation to additional information on Nielsen measurement.

Nielsen currently uses Limit Ad Tracking for the latest versions of the SDK (5.1.1.17 and above). However, for older SDK versions, the app must provide a means for the user to opt out, or opt back in to Nielsen Measurement. Users can opt out of Nielsen online measurement research through this feature.
* If the user has this app running on more than one mobile device, the user will need to opt out of this measurement on each device.
<blockquote>'''Note''': Opt Out feature does NOT rely on "Limit Ad Tracking" setting since Nielsen’s systems provide measurement metrics and do not serve ads to users.</blockquote>

In the Description of the app in App Store, include a short description about Nielsen measurement, as below.

<blockquote>'''Sample App Store Disclosure'''
This app features Nielsen proprietary measurement software which will allow you to contribute to market research, like Nielsen’s TV Ratings.

To learn more about our digital measurement products and your choices in regard to them, please visit http://www.nielsen.com/digitalprivacy for more information.

[[File:measurement-samplescreen.jpg]]</blockquote>

Both iOS-based and TVOS-based player applications need to confirm to Nielsen Privacy Requirements. Refer to the Opt-Out implementation guidelines for iOS and TVOS platforms respectively for more details.

=== Opt-Out Implementation ===
==== Limit Ad Tracking ====
'''This implementation is valid for SDK Versions 5.1.1.17 and above.'''

<blockquote>'''Note''': If using SDK Version 1.2.3, 4.0.0.8, 5.1.0 or 5.1.1.12, refer to Opt-Out Implementation for iOS.</blockquote>

As a global information and measurement leader, Nielsen is committed to protect the privacy and security of the data they collect, process and use. Nielsen strongly believes that the consumer should have a way to opt out of Nielsen measurement.

The Nielsen digital measurement products help Nielsen and its clients to measure and analyze how consumers engage with media across online, mobile and emerging technologies while offering insights into consumer behavior.

To learn more about our digital measurement products and your choices in regard to them, please visit http://www.nielsen.com/digitalprivacy.

To opt out, users must have access to “About Nielsen Measurement” page. User can click this page from app settings screen.

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.
* URL to this web page should be called from SDK by invoking optOutURL and opened in ‘WebView’ / External browser.
* If the App SDK returns NULL as Opt-Out URL, handle the exception gracefully and retry later.
* To retrieve the current Opt-Out status of a device, use the optOutStatus method.
'''Displaying Opt-Out in a WebView'''
<syntaxhighlight lang="objective-c">NielsenAppApi nAppApiObject;
@property(strong) UIWebView *optOutView;
// create WebView and set self as delegate
self.optOutView=[[UIWebView alloc]initWithFrame:self.view.bounds];
self.optOutView.scalesPageToFit = yes;
// get Nielsen defined web address and load the page
NSString *webAddress = [nAppApiObject optOutURLString];
If(webAddress == nil)
{ 
  // Handle it gracefully and retry later
} 
 
else
{
  [optOutView loadRequest:[NSURLRequest requestWithURL:webAddress]];
  // show the view to the user
  [self.view addSubview:optOutView]; 
}</syntaxhighlight>

Users can opt out or opt back into Nielsen Measurement. Opt-Out feature relies on iOS’ system setting – “Limit Ad Tracking”. The setting can be accessed in the Settings application on any iOS device: '''Settings → Privacy → Advertising → Limit Ad Tracking'''.

User is opted out of Nielsen online measurement research when the “Limit Ad Tracking” setting is enabled.

[[File:Opt-Out_iOS.jpg]]
<blockquote>'''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.</blockquote>

The app must provide access to “About Nielsen Measurement” page for the users. 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.

[[File:Privacy_policy_iOS.jpg]]

* URL to this web page should be called from SDK and opened in ‘WebView’ / External browser.
* If the App SDK returns NULL as Opt-Out URL, handle this case and retry later.
* To retrieve the current Opt-Out status, use the [[optOutStatus]] property from Nielsen’s SDK API.
<syntaxhighlight lang="objective-c">@property (readonly) BOOL optOutStatus;</blockquote>
* App should provide a UI control like ‘close’ or ‘back’ button to close the ‘WebView’ / External browser.

'''Sequence Diagram'''
[[File:optoutsequence-ios.jpg]]

== Event and Error Handling ==
=== Constants / Enumerations ===
The following are the details of Delegate Implementation:

<syntaxhighlight lang="objective-c">
-(void)nielsenAppApi:(NielsenAppApi *)appApi eventOccurred:(NSDictionary *)event
{
   NSLog(@"Sample player is Notified by a Event: %@", event);
}
   – (void)nielsenAppApi:(NielsenAppApi *)appApi errorOccurred:(NSDictionary *)error
{
   NSLog(@"Sample player is Notified by an Error: %@", error);
}
</syntaxhighlight>


==== TVOS Implementation ====
As a global information and measurement leader, Nielsen is committed to protect the privacy and security of the data they collect, process and use. Nielsen strongly believes that the client should have a way to Opt-Out of Nielsen measurement.

The Nielsen digital measurement products are not used to identify consumer in any way. They help Nielsen and its clients to measure and analyze how consumers engage with media across online, mobile and emerging technologies while offering insights into consumer behavior.

To learn more about our digital measurement products and your choices in regard to them, please visit http://www.nielsen.com/digitalprivacy.

To Opt-Out, users must have access to “About Nielsen Measurement” page.

TVOS does not support creating instances of UIWebView and display web pages. Instead it makes use of a TVML page (built on TVML template) which displays information in a specific order.

Opt-Out page is built on descriptiveAlertTemplate and appears as follows.

[[File:TVOs_OptOut_LimitAdTracking1.png]]

[[File:TVOs_OptOut_LimitAdTracking2.png]]

Users need to toggle the “Limit Ad Tracking” option in order to Opt-In / Opt-Out of Nielsen Measurement.

To retrieve the current Opt-Out status of a device, use the [[optOutStatus]] method.

<blockquote>'''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.</blockquote>


==== Legacy Opt-Out ====
'''Supported SDK Versions''': 1.2.3, 4.0.0.8, 5.1.0, 5.1.1.12.

<blockquote>'''Note''': If using SDK Version 5.1.1.17 or above, refer to Opt-Out Implementation (Limit Ad Tracking).</blockquote>

As a global information and measurement leader, Nielsen is committed to protect the privacy and security of the data they collect, process and use. Nielsen strongly believes that the consumer should have a way to Opt-Out of Nielsen measurement.

The Nielsen digital measurement products help Nielsen and its clients to measure and analyze how consumers engage with media across online, mobile and emerging technologies while offering insights into consumer behavior.

To learn more about our digital measurement products and your choices in regard to them, please visit http://www.nielsen.com/digitalprivacy.

To opt out, users must have access to “About Nielsen Measurement” page. User can click this page from app settings screen.

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.
* URL to this web page should be called from SDK by invoking [[optOutURL]] and opened in ‘WebView’ within the app and NOT in any external browser.
** Opening the Opt-Out page in any external browser takes the application control out of the Nielsen App SDK context.
** As the App SDK does not expose any direct http/https interface to interact with the world to get the user selection on Privacy page, there will be no way to interact/send notification to the App SDK regarding the user selection.
* If the App SDK returns NULL as Opt-Out URL, handle the exception gracefully and retry later.
* To retrieve the current Opt-Out status of a device, use the [[optOutStatus]] method.
<blockquote>'''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.</blockquote>

'''Sequence Diagram'''
[[File:optoutsequence-ios.jpg]]

Below are the steps to implement user Opt-Out using UIWebView.

When a user clicks the Opt-Out / Opt-In link, the application should invoke [[optOutURL]] to get the link to the Nielsen Privacy page from SDK.

'''Implement WebView with Nielsen Opt-Out URL'''
<syntaxhighlight lang="objective-c">NielsenAppApi nAppApiObject;
@property(strong) UIWebView *optOutView;

// create WebView and set self as delegate
self.optOutView=[[UIWebViewalloc]initWithFrame:self.view.bounds];

self.optOutView.scalesPageToFit = yes;
// get Nielsen defined web address and load the page
NSString *webAddress = [nAppApiObject optOutURLString];

if(webAddress == nil)
    { // Handle it gracefully and retry later}
else
{
    [optOutView loadRequest:[NSURLRequest requestWithURL:webAddress]];
    // show the view to the user
    [self.view addSubview:optOutView];
}</syntaxhighlight>

* The Nielsen Privacy Page appears using UIWebView


'''Privacy Page'''

[[File:privacy-policy.jpg]]

* There are two links – one for Opt-Out and one for Opt-In. Click the required link.
* Click OK in the dialog that appears, to confirm the action.
* 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'''
<syntaxhighlight lang="objective-c">-(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]);
}</syntaxhighlight>
* 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.
* <code>[nAppApiObject userOptOut:command]</code> passes the user’s selection on Nielsen Privacy page to the SDK to allow the SDK to perform the required functions.
<blockquote>'''Note''': When ‘WebView’ is closed, pass the status returned from ‘WebView’ to the SDK within the app.</blockquote>

<blockquote>'''Note''': App SDK manages the user’s choice (Opt-Out / Opt-In), the app does not need to manage this status.</blockquote>

== AppApiEventCode ==
An enumeration with predefined App SDK event state transition codes.
<syntaxhighlight lang="objective-c">
typedef NS_ENUM(unsigned int, AppApiEventCode)
{
     AppApiStartup = 2001,
     AppApiShutdown = 2002,
}AppApiEventCode;
</syntaxhighlight>

== App SDK Event Codes ==
{| class="wikitable"
|-
! Event Code !! Event Name !! Event Description
|-
| 2001 || AppApiStartup || App SDK has initialized successfully. It will happen only after App SDK has received a valid config file
|-
| 2002 || AppApiShutdown || App SDK is shutting down. It will happen just before App SDK is destroyed
|}

== AppApiErrorCode ==
An enumeration with predefined error codes which the App SDK object can generate.
<syntaxhighlight lang="objective-c">
typedef NS_ENUM(unsigned int, AppApiErrorCode)
{
   AppApiNetworkConnectionFailure = 1001,
   AppApiFileWriteFailure = 1002,
   AppApiFileReadFailure = 1003,
   AppApiEmptyValue = 1004,
   AppApiEmptyAppName = 1005,
   AppApiEmptyAppVersion = 1006,
   AppApiEmptyAppId = 1007,
   AppApiAnExceptionOccured = 1008,
   AppApiUnknownExceptionOccured = 1009
};
</syntaxhighlight>

== App SDK Error Codes ==
{| class="wikitable"
|-
! Event Code !! Event Name !! Event Description
|-
| 1001 || AppApiNetworkConnectionFailure || App SDK Could not connect to server
|-
| 1002 || AppApiFileWriteFailure || App SDK Could not write to file
|-
| 1003 || AppApiFileReadFailure || App SDK Could not read data from file
|-
| 1004 || AppApiEmptyValue || Empty value Found.
|-
| 1005 || AppApiEmptyAppName || Cannot initialize SDK Object without an AppName(Player Name)
|-
| 1006 || AppApiEmptyAppVersion || Cannot initialize API Object without an AppVersion
|-
| 1007 || AppApiEmptyAppId || Cannot initialize API Object without an AppId
|-
| 1008 || AppApiAnExceptionOccured || Exception occurred
|-
| 1009 || AppApiUnknownExceptionOccured || Unknown exception occurred
|}