Setting up Hansel Index for dynamic views

Dynamic Views

A UI element is said to be dynamic when it can change its index within its parent ViewGroup.

For example, due to personalization, recommendation1 can be placed at index 2 for a User A whereas the same recommendation1 can be placed at index 5 for another User B. Then the UI element containing recommendation1 data is dynamic in nature.



Support for Dynamic views via the below method is available on smartech-reactnative-nudges version v1.0.16, Android Nudge SDK v8.8.1, and iOS Nudge SDK v8.5.26 onwards

Step 1: Add the tag in the root of every repeated children like below or if exist then just add testID and nativeID.

<View  testID={item.title+'#1'} nativeID = {'hansel_dynamic_view'} >
   {/* All children element */}


  • testID we’re using to get the tag of View in the native side where {item.title} is any unique identifier that you've in repeated view and '#1' is a number of layers in the top of that repeated child element.

For Example: In the below view hierarchy screen have a scroll view with 8 child elements and in that react native bind one extra with every 8 child element. So, for getting actual ReactViewGroup we pass #1 in testID.

  • nativeID is to get the view instance that we need to traverse to find the dynamic view and always set {'hansel_dynamic_view'} identifier string with nativeID.

Step 2: For Android
Please add below code snippet in inside onCreate method to get the dynamic view instance

To ensure that a nudge doesn't lose its context in such a scenario and is always placed on the correct view, provide a custom identifier to the UI elements using the following method:

Set<String> nativeIdSet = new HashSet<>();

  ReactFindViewUtil.addViewsListener(new ReactFindViewUtil.OnMultipleViewsFoundListener() {
      public void onViewFound(final View view, String nativeID) {
          if (nativeID.equals("hansel_dynamic_view")) {
              String[] values1 = view.getTag().toString().split("#");
              String hanselIndex = values1[0];
              int N;
              if (values1.length < 2 || values1[1].isEmpty()) {
                  N = 0;
              } else {
                  N = Integer.parseInt(values1[1]);
              HanselRn.setDynamicHanselIndex(view, hanselIndex, N);
  }, nativeIdSet);

Step 3: For iOS
Set the native tag to the container marked in Step 1 above by adding the following code in the useEffect/componentDidMount or once the screen is loaded on the Javascript code of your React Native screen.