[CONF] Apache Sling Website > Getting Resources and Properties in Sling

[confluence]

Getting Resources and Properties in Sling Page edited by Jean-Christophe KAUTZMANN Changes (1) ... {code} For a list of all the objects available through this tag, please refer to the [JSP Tag Libraries|http://dev.day.com/docs/en/cq/current/howto/taglib.html#%3Csling:defineObjects%3E] page. ... {code} For more details about resources and how to access them in Sling, you can refer to the [http://sling.apache.org/site/resources.html|Sling documentation about Resources|http://sling.apache.org/site/resources.html]. Full Content Getting Resources and Properties in Sling The Resource is one of the central parts of Sling. Extending from JCR's Everything is Content, Sling assumes Everthing is a Resource. Thus Sling is maintaining a virtual tree of resources, which is a merger of the actual contents in the JCR Repository and resources provided by so called resource providers. By doing this Sling fits very well in the paradigm of the REST architecture. In this article we will explore a few ways to programmatically map a resource path (String) to a resource object (Resource) and its properties in Sling, from within an OSGI service, a servlet and a JSP. The whole game consists in first getting a ResourceResolver and then getting the Resource itself. Within an OSGI Service/Compoment You can access a resource through the JcrResourceResolverFactory service: /** @scr.reference */ private SlingRepository repository; /** @scr.reference */ private JcrResourceResolverFactory resolverFactory; public void myMethod() { Session adminSession = null; try { String resourcePath = "path/to/resource"; adminSession = repository.loginAdministrative(null); ResourceResolver resourceResolver = resolverFactory.getResourceResolver(adminSession); Resource res = resourceResolver.getResource(resourcePath); } catch (RepositoryException e) { log.error("RepositoryException: " + e); } finally { if (adminSession != null && adminSession.isLive()) { adminSession.logout(); adminSession = null; } } } Within a Servlet You can access the resource defined by the request URL through the SlingHttpServletRequest: Resource res = req.getResource(); // req is the SlingHttpServletRequest You can access any resource by first accessing the ResourceResolver: String resourcePath = "path/to/resource"; ResourceResolver resourceResolver = req.getResourceResolver(); // req is the SlingHttpServletRequest Resource res = resourceResolver.getResource(resourcePath); Within a JSP file When you use the <sling:defineObjects> tag in a JSP file, you have access to a few handy objects, one of them is 'resource', the resource that is resolved from the URL. Another one is 'resourceResolver', the ResourceResolver defined through the SlingHttpServletRequest. To access a resource: <sling:defineObjects> <% String resourcePath = "path/to/resource"; Resource res = resourceResolver.getResource(resourcePath); %> For a list of all the objects available through this tag, please refer to the JSP Tag Libraries page. If needed you can adapt a Sling Resource to a JCR Node: Node node = resource.adaptTo(Node.class); Note: resource.adaptTo(Node.class) may return null if the resource is not backed by a JCR node. This is particularly the case for NonExistingResource resources or resource provided by a non-JCR resource provider. Accessing a Property The ValueMap is an easy way to access properties of a resource. With most resources you can use Adaptable.adaptTo(Class) to adapt the resource to a value map: ValueMap properties = res.adaptTo(ValueMap.class); // res is the Resource You can also access the properties through the ResourceUtil utility class: ValueMap properties = ResourceUtil.getValueMap(res); // res is the Resource Then, to access a specific String property called 'propName': String rule = properties.get(propName, (String) null); For more details about resources and how to access them in Sling, you can refer to the Sling documentation about Resources. Change Notification Preferences View Online | View Changes | Add Comment