How to share data between a page and a component in AEM 6.2?

Question

Is there a way how I can call the same instance of a model within HTL using the same data? I want to create an object within the model of a page, let's say a String object, and then use it in the model of a component. To create the bean (or model instance), I call

<sly data-sly-use.model="myModel"/>

in the page and in the component Problem is that I have now 2 instances with 2 sets of local data - what I do NOT want to have.

Answer 1

The SlingHttpServletRequest (in general) provides an instance of SlingBindings, which contains a reference to "currentPage" (I am using the static field WCMBindings.CURRENT_PAGE [dependency: groupId: com.adobe.cq.sightly, artifactId: cq-wcm-sightly-extension, version: 1.2.30] in my example).

The Optional I am using in my example is a Java 8 class which can be used to avoid too many checks for null references.

final Optional<Page> optional = Optional.ofNullable(request)
        .map(req -> (SlingBindings) req.getAttribute(SlingBindings.class.getName()))
        .map(b -> (Page) b.get(WCMBindings.CURRENT_PAGE));

A simplified/explicit example would be

Page getCurrentPageFromRequest(@Nonnull final SlingHttpServletRequest request) {
  final SlingBindings bindings = (SlingBindings) request.getAttribute(SlingBindings.class.getName())
  if (bindings == null) {
    return null;
  }
  return (Page) bindings.get(WCMBindings.CURRENT_PAGE);
}

In your Sling model you would just call

@Model(adaptables={ SlingHttpServletRequest.class, })
public class Model {

  public Model(@Nonnull final SlingHttpServletRequest request) {
    final Page currentPage = getCurrentPageFromRequest(request);
    // read properties.
  }

  Page getCurrentPageFromRequest(@Nonnull final SlingHttpServletRequest request) {
    final SlingBindings bindings = (SlingBindings) request.getAttribute(SlingBindings.class.getName())
    if (bindings == null) {
      return null;
    }
    return (Page) bindings.get(WCMBindings.CURRENT_PAGE);
  }
}