Discover Sling in 15 minutesPage edited by Felix MeschbergerChanges (24)
Full ContentDiscover Sling in 15 minutes - the Sling LaunchpadThe Sling Launchpad is a ready-to-run Sling configuration, providing an embedded JCR content repository and web server, a selection of Sling components, documentation and examples. The Launchpad makes it easy to get started with Sling and to develop script-based applications. This page will help you get started with the Launchpad. Fifteen minutes should be enough to get an overview of what Sling does. While simple to run and understand, the Launchpad is a fully-featured instance of Sling, an example configuration that we have created with the most common modules and configurations. The full functionality of Sling is available by loading additional Sling (or custom) OSGi modules as needed, using the Launchpad's web-based OSGi management console. See AlsoExample applications and mini-applications for Sling can be found under http://svn.apache.org/repos/asf/sling/trunk/samples/ (each application has a README.txt file, see these for more details). Once you grok the basic examples of this page, we recommend studying the espblog and webloader samples for more complete examples. The javashell sample is useful to play with JCR java code (or any java code, for that matter) interactively. PrerequisitesIf using the self-runnable jar from the Sling distribution, you only need a Java 5 JDK. If using the war file from the Sling distribution, you need a suitable servlet container (all recent versions of Jetty or Tomcat should work), running under a Java 5 JDK. If building Sling yourself (which is the best way to get the latest and greatest), you'll need:
And in all cases you'll need cURL to run the examples below. Any HTTP client would do, but cURL is the easiest to document in a reproducible way. A WebDAV client makes editing server-side scripts much more convenient, but to make our examples easy to reproduce, we're using cURL below to create and update files in the JCR repository, via the Sling WebDAV server. Get the LaunchpadSee Getting and Building Sling - you can either use a released version (if it is current enough), or build it yourself. Start the LaunchpadIf using the self-runnable jar from the Sling distribution, start it by double-clicking or with java -jar .... If using the war file from the Sling distribution, install it in your servlet container and start that. If you built Sling yourself, change to the launchpad/builder directory under the top-level sling directory, and run mvn jetty:run To start the launchpad. The examples below assume that Sling is running on port 8888, which is the default for the launchpad/builder module. If your setup is different you'll need to adjust the port number accordingly.
Store this script under apps/foo/bar/html.esp, either using a WebDAV client (connected to http://admin:ad...@localhost:8888/), or using cURL as shown here, after creating the html.esp script in the current directory on your system: curl -X MKCOL http://admin:ad...@localhost:8888/apps/foo curl -X MKCOL http://admin:ad...@localhost:8888/apps/foo/bar create a local file html.esp and copy above content. curl -T html.esp http://admin:ad...@localhost:8888/apps/foo/bar/html.esp The HTML rendering of your node, at http://localhost:8888/content/mynode.html, is now created by this ESP script. You should see the node's title alone as an <h1> element in that page. A script named POST.esp instead of html.esp would be called for a POST request, DELETE.esp for DELETE, xml.esp for a GET request with a .xml extension, etc. See URL to Script Resolution on the Sling wiki for more info. Servlets can also be easily "wired" to handle specific resource types, extensions, etc., in the simplest case by using SCR annotations in the servlet source code. Servlets and scripts are interchangeable when it comes to processing Sling requests. What next?These simple examples show how Sling uses scripts to work with JCR data, based on sling:resourceType or node types. There's much more to Sling of course - you'll find some additional simple examples below, and above in the see also section. We are working on debugging features to help trace the way Sling processes requests. Have a look at SLING-3 to see what's possible already. Additional examplesLet Sling generate the path of a newly created node.To create a node with a unique path at a given location, end the URL of the POST request with /*. In this case, the Sling response redirects to the URL of the created node. Start by creating a new /blog folder: curl -X POST "http://admin:ad...@localhost:8888/content/blog" And create a node with a Sling-generated name under it: curl -D - -F"title=Adventures with Sling" "http://admin:ad...@localhost:8888/content/blog/*" Using cURL's -D option shows the full HTTP response, which includes a Location header to indicate where the new node was created: Location: http://localhost:8888/content/blog/adventures_with_slin_0 The actual node name might not be adventures_with_slin_0 - depending on existing content in your repository, Sling will find a unique name for this new node, based on several well-know property values like title, description, etc. which are used for this if provided. So, in our case, our new node can be displayed in HTML via the http://localhost:8888/content/blog/adventures_with_slin_0.html URL. Note that we didn't set a sling:resourceType property on our node, so if you want to render that node with a script, you'll have to store the script under /apps/nt/unstructured/html.esp. Add a page header with sling.includeThe sling.include function can be called from scripts to include the rendered result of another node. In this example, we create a node at /content/header, rendered with a logo using an html.esp script, then use that header at the top of the html.esp script that we created previously for the foo/bar resource type. Start by checking that http://localhost:8888/content/mynode.html is rendered using the html.esp script created above. Create this script and name it header.esp: header.esp <div> <p style="color:blue;"> <img src="" class="code-quote">"/images/sling.jpg" align="right"/> <%= currentNode.headline %> </p> </div> Upload it so that it is used to render resources having sling:resourceType=foo/header: curl -X MKCOL http://admin:ad...@localhost:8888/apps/foo/header/ curl -T header.esp http://admin:ad...@localhost:8888/apps/foo/header/html.esp Create the header node: curl -F"sling:resourceType=foo/header" -F"headline=Hello, Sling world" http://admin:ad...@localhost:8888/content/header Upload the logo that the script uses (using sling.jpg or another logo in the current directory): curl -X MKCOL http://admin:ad...@localhost:8888/images/ curl -T sling.jpg http://admin:ad...@localhost:8888/images/sling.jpg And check that the header is rendered with the logo at http://localhost:8888/content/header.html. Now, update the html.esp script that we created for our first example above, to include the header: html.esp <html> <body> <div id="header"> <% sling.include("/content/header"); %> </div> <h1><%= currentNode.title %></h1> </body> </html> And upload it again to replace the previous version: curl -T html.esp http://admin:ad...@localhost:8888/apps/foo/bar/html.esp The http://localhost:8888/content/mynode.html, once refreshed, now shows the blue headline and logo, and this layout also applies to any node created with sling:resourceType=foo/bar.
Change Notification Preferences
View Online
|
View Changes
|
Add Comment
|
- [CONF] Apache Sling Website > Discover Sling in 15 minutes confluence
