Custom Sling Model Exporter in AEM 6.3

Hello Everyone,

You have already seen the magic of Sling Model Exporters in my previous blog.But there is something left with Sling Model Exporters which I would like to continue in this blog.

I have mentioned in the previous blog that we can have custom exporters in

Sling Model Exporters.

So let’s have some examples of creating custom exporters.Here I am going to demonstrate

“GSON” and “JAXB” as two custom exporters in the concept of Sling Model Exporters.

ModelExporter Interface

To create a custom exporter, we need to create a service that implements ModelExporter

with these three methods:

Fig - Model Exporter Interface

Here we will see two implementations of ModelExporter Interface:

• ModelExporter Example: GSON

@Component(service = ModelExporter.class) public class NewExporter implements ModelExporter {   public <T> T export(Object model, Class<T> clazz,                       Map<String, String> options)           throws org.apache.sling.models.factory.ExportException {       return (T) new Gson().toJson(model);   }   public String getName()   {       return "gson";   }   public boolean isSupported(Class Model1)   {       return true;   } }

And then this “gson” exporter can be used in the Sling Model like this.

@Model(adaptables = Resource.class, resourceType = {"weretail/components/structure/page"}, defaultInjectionStrategy = DefaultInjectionStrategy.OPTIONAL) @Exporter(name = "gson", selector = "test",extensions = "json") public class Model3 {   @ValueMapValue(name = "jcr:title")   private String title;   public String getTitle()   {       return title;   } }

Fig - Response in JSON format using GSON Exporter

• ModelExporter Example: JAXB

@Component(service = ModelExporter.class) public class NewExporter implements ModelExporter {   public <T> T export(Object model, Class<T> clazz,                       Map<String, String> options)           throws org.apache.sling.models.factory.ExportException {           StringWriter sw = new StringWriter();       try {           JAXBContext jaxbContext =                   JAXBContext.newInstance(model.getClass());           Marshaller marshaller = jaxbContext.createMarshaller();           marshaller.marshal(model, sw);       } catch (JAXBException e) {           e.printStackTrace();       }       return (T) sw.toString();   }   public String getName() {       return "jaxb";   }   public boolean isSupported(Class Model1) {       return true;   } }

And then this “jaxb” exporter can be used in the Sling Model like this.

@Model(adaptables = Resource.class, resourceType = {"weretail/components/structure/page"}, defaultInjectionStrategy = DefaultInjectionStrategy.OPTIONAL) @Exporter(name = "jaxb", selector = "test",extensions = "xml") @XmlRootElement public class Model3 {   @ValueMapValue(name = "jcr:title")   private String title;   @XmlElement   public String getTitle()   {       return title;   } }

Fig - Response in XML format using JAXB Exporter

Let's have a demonstration video on Custom Sling Model Exporter:

Tips and Trick of Sling Model Exporters

• Sling Model Exporters internally works on sling:resourceSuperType as well.If you have defined a resourceType in sling Model Exporter, it will check the resourceType of a request, if it doesn’t present it will go to its sling:resourceSuperType.

• Sling Model Exporters can be adapt using Modelfactory Interface.

You can see the example here:

public class ResolveServletUsingPath extends SlingSafeMethodsServlet {   @Reference   private ModelFactory modelFactory;   @Override   protected void doGet(SlingHttpServletRequest request, SlingHttpServletResponse response) throws IOException {       Resource resource = request.getResourceResolver().getResource("/content/we-retail/ca/en/experience/jcr:content");       try {          response.getWriter().print( modelFactory.exportModelForResource(resource,"jaxb",Model3.class,new HashMap<>()));       } catch (ExportException e) {           e.printStackTrace();       } catch (MissingExporterException e) {           e.printStackTrace();       }   }

Let's have a demonstration video on Tips and Tricks of Sling Model Exporters:

If you have any query or suggestion then kindly comment or mail us at sgaem.blog02@gmail.com

Hope it will help you guys !!

Thanks and Happy Learning.