Inject Page via path using Sling Model

A common use-case is configuring a path to a page via a dialog and then fetch the wrapper Page object to retrieve information about that page. And there is a really easy way to do so.

The Cumbersome way

Sling models can have a method annotated with the @PostConstruct annotation. This method is called after the sling model has been created and is used to initialise whatever fields you have defined. It looks typically like this for a page:

// @model annotation
public class PageSummary {
  @Inject
  private string articlePath; // this is a property in the dialog

  @Service
  private PageManager pageManager;
  private Page page;

  @PostConstruct
  public void init(){
    page = pageManager.getPage(articlePath);
  }
}

The short way

Somewhere mentioned at the bottom of the sling model documentation page, you have @ResourcePath. As stated in the docs:

Injects a resource either by path or by reading a property with the given name.

All examples you find online use this annotation on a field of type Resource. But what you don’t see in these examples and is not stated literally in the docs: a Page is a resource as well, so you can use this annotation on Page fields. So the snippet above transforms to:

// @model annotation
public class PageSummary {
  @ResourcePath(name="articlePath")
  private Page page;
}

So no need to inject the dialog property, no PageManager wiring and no @PostConstructannotated method!