Archive for August, 2015

A quick start to Adobe Experience Manager development

With this post, I am concluding the first learning series on Adobe Experience Manager. The idea is to provide you with a head start if you are new to AEM. I hope it will also help you with the basic concepts if you plan to appear for Adobe Certified Exam (ACE) on AEM component development.

There are 20 blog posts, most of them are associated with a video of 5 to 8 minutes duration. You need to have an AEM install to try out the demos. I have provided you with the sample packages in my GitHub account. In each post, I have specified the package that you need to use. Note that you basically need to install the packages one after another.

Here is a quick overview of the posts:

  1. Why do you need Adobe Experience Manager?
  2. Let us start Adobe Experience Manager
  3. Seeing is believing: Explore the AEM installation directory
  4. Adobe Experience Manager authors, and their templates, and components
  5. Introduction to AEM developers, and their templates and components
  6. Create the first AEM template
  7. Summary – Create templates and use packages
  8. Add the Parsys component to template
  9. Enable components in the Components tab
  10. Apply a design to the AEM Sightly template
  11. Summary: Your first Sightly template
  12. Create your first Sightly component (YouTube component !!!)
  13. Create Adobe Experience Manager dialogs (Add a dialog to the YouTube component)
  14. Get data from a dialog using Sightly (Get a custom URL for the YouTube component)
  15. Add a touch-optimized dialog (for the YouTube component)
  16. Create a design dialog (for the YouTube component)
  17. Learn about Edit Config nodes
  18. The AEM – Sling connection simplified
  19. AEM and OSGi
  20. Access Client-Side Libraries

 

AEM and OSGi

I am sure you would had heard about OSGi, the moment you started searching info related to AEM. It is the final topic for this learning series. Open Source Gateway Initiative (OSGi) provides a modular Java development platform. I don’t want to complicate things here. (This is just a general overview of OSGi.)

When you install AEM, you also install a Felix console. Access the console using the following URL: http://localhost:4502/system/console. It’s more like a server where you can deploy your Java programs as bundles.

You can see a lot of bundles here. Bundles are nothing, but Java programs (jar files) running on the server. Each of these bundles is used for accomplishing a specific task. For example, you want to convert your web page to a pdf, things like that. You can create bundles using Eclipse IDE. Adobe provides a plugin for your aid.

I first thought, I will show you how to develop a bundle, deploy it in this console, and access it in one of our pages. I then thought it would be too much for this introductory session.

For the time being, have a basic idea of the OSGi connection. It helps Java developers to create and deploy Java bundles to perform complex tasks.
In the next learning series, we will create, deploy, and access bundles.

This learning series ends here. Hope you enjoyed.

The AEM – Sling connection simplified

Apache Sling is a web framework based on the JCR API. We have seen that the content in AEM is saved as nodes and properties in Oak – a reference implementation of JCR. In most simple term, Sling, in AEM’s context, helps you to issue http requests and render content from Oak repository appropriately.

Use Template Sling Sample.zip from my GitHub account.

Sling uses scripts or servlets to render content. Sling uses the node’s sling:resourceType property to determine the script that renders the content. Let us see what happens when you access a url.

Assume that you access the following url: http://localhost:4502/content/aem-company.html. First the request goes to /content/aem-company. The node has a sling:resourceType property that points to aem-company/components/homepage. Here Sling gets the location of the script or servlet that needs to be used to render the content. It checks for the location in the apps folder and locate the node. And, then render the content based on the default script, body.html. I have explained how body.html becomes the default script in one of the previous posts. Have a look at that.

  1. Now create another script in aem-company/components/homepage. (test.html)
  2. Add a test content: html test page
  3. Let us access the page again with a different url: http://localhost:4502/content/aem-company.test.html

We changed the url by adding test.html which specifies the default script that needs to be used to render the content. (It’s called a selector.) In this way, you can manipulate the url and provide content accordingly. For example, using the same url, but different selector, like  product.html and product.details.html you can provide different and meaningful content.

  1. Create another script at the same location. (details.jsp)
  2. Add a test content: jsp test page
  3. Access the same using the following url: http://localhost:4504/content/aem-company.details.html

See that the page is rendered. In the same location I mentioned above (/apps/aem-company/components/homepage), Sling searches for details.html, obviously couldn’t find it. It then used details.jsp to render the content.

This kind of script resolution mechanism Sling uses is important for you to know. See a cheat sheet Adobe prepared: http://dev.day.com/content/ddc/blog/2008/07/cheatsheet.html
Take a look at this page – there are plenty of information. I hope you got a general idea about Sling now. Consider it as a starting point & happy learning.

See you soon.

Learn about Edit Config nodes

We have learned about dialogs and design dialogs. In this post, I want to familiarize you with another node, called editConfig.

Let us take a look at the image component.

  1. Drag and drop an image component to the page.
  2. Drag and drop an image to the component.
    The action you performed is drag and drop.

To enable this action in the component, you use a different node.
Let us take a look at the Image component using CRXDE Lite.

  1. Navigate to /libs/wcm/foundation/components/image.
  2. See a node named cq:editConfig.

It has another node named cq:dropTargets which provides this functionality. There is a similar node, cq:inplaceEditing, which allows you to update a text in the component without opening the dialog. You should be aware of editConfig nodes to use it appropriately.

In short, node cq:editConfig provides functionalities, such as drag and drop, in place editing, and so on.

Create a design dialog (for the YouTube component)

In this session, I will introduce you to design dialogs.

Use YouTubeComponent-1.0.5.zip from my GitHub account.

We have seen the dialogs associated with components. They can be Touch-Optimized dialogs or Classic dialogs.

Let us quickly take a look at the page we created. You can see three instances of the same YouTube component. We have entered three different URLs in the dialogs and each of them displays a unique video. Means, whatever you enter for a component’s dialog is specific to that instance of the component. This value is not preserved when you use the same component in the web page again.

In certain situations, you may want to use the same value across all the instances of the component. A classic example would be the company icon of your website. You don’t want it to get changed in all the instances. Wherever you use it, the icon is the same. Let us build something similar to it in our YouTube component. Assume that you want to add a copyright information, which is going to be the same in all instance of the component. You would have guessed it, you need to use design dialogs.

Let us start.

  1. Go to the aem-company folder in CRXDE Lite.
  2. Select youtube.
  3. Copy dialog and paste it at the same place.
    It gets pasted as copy of dialog.
  4. Now rename it as design_dialog.
  5. Expand and select the title node, and rename as copyright.
  6. Similarly, change the name value to copyright.
  7. To access this dialog, go to the web page.
  8. Go to the Classic mode.
  9. Select Design and select Edit.
  10. Now, enter the copyright information: Copyrighted by AEM Company
  11. Click OK.

Nothing happens as expected, because we have not written the logic to capture the data entered and display it on the page. Before we do that, let us first see, where this data is written. We have seen that for dialogs, the data is written within the dialog node itself.

  1. Go to /etc/designs/aem-company/jcr:content/homepage/content/youtube.
    Note that the data from design_dialog is written inside the /etc/designs/aem-company. That’s,it can have only one value.
  2. Open the url.js.
  3. Update the code as follows. (I have commented out the update – we had a discussion on the same code earlier. I am not going to do it again.)
use(function () {
 var CONST = {
 PROP_TITLE: "jcr:title",
 PROP_COPYRIGHT: "jcr:copyright"
 }
 var url = {};
 url.text = granite.resource.properties[CONST.PROP_TITLE]
//Capture value from design_dialog
 url.copyright = currentStyle.get(CONST.PROP_COPYRIGHT, "");
 if (url.text ==null)
 {
 url.text = "https://www.youtube.com/embed/dI1yi2mmNuo";
 }
 // Adding the constants to the exposed API
 url.CONST = CONST;
 return url;
});
  1. Open youtube.html and update.
    <div data-sly-use.url="url.js" style="overflow: hidden;">
     <iframe width="600" height="510" src="${url.text}" frameborder="0" allowfullscreen></iframe>
     <h3>${url.copyright}</h3>
    </div>
  2. Refresh the page.
  3. Note that all videos have been updated with the copyright information.

That’s it. Here is the summary: Design_dialog is used to capture information that should be unique across components. It’s stored in /etc/designs/.