AEM Interview Questions Part 4

This is part four of my AEM interview questions. You find the other parts here:

Part 1 - Part 2 - Part 3 - Part 5 - Part 6 - Part 7 - Part 8 - PDF

Here are some more AEM interview questions that could come up during a technical interview:

Q: How does sightly differ from other templating systems?

A: Sightly differs from other templating systems in three ways. Sightly is secure by default, it offers separation of concerns, and sightly is HTML5 because it is a valid HTML5 file. Sightly is secure by default because it automatically filters and escapes all variables being output to the presentation layer to prevent cross-site-scripting vulnerabilities.

Sightly offers seperation of concern because it is purposely limited to ensure that a real programming language is used to express the corresponding logic. This is done through the Use-API pattern.

Q: Can you create a page without a template?

A: Pages are usually created by selecting a template for the page when you create them in the Website console. However, a page can be created manually in the crxde by using the same properties that are created when you make a page in the Website console.

For example, in crxde under the content folder, create a node with the following type “cq:Page” and save it. Then add a child node with the following type “cq:PageContent”. Then you can add the required properties to show any components you want displayed on the page.

It is generally not good practice to create pages manually.

Q: What are xtypes and how are they useful in AEM?

A: In the ExtJS language an xtype is a symbolic name given to a class. In AEM these xtypes are widgets that used in the creation of components. AEM comes with a bunch of widgets that are available out of the box. You can also create and define your own xtype to be used in AEM.

An example of an xytpe is when you are creating your dialog for your component, and you want the author to be able to enter text, you would add a “cq:Widget” that has an xtype property of “textfield”.

Q: How do you add properties to the Page Properties dialog?

A: You can add properties to your page properties dialog by copying the dialog located under “libs/foundation/components/page/dialog” and adding it to your page template. This will allow you to add new tabs and add new properties that you would like the author to chooses from for pages that use that template.

You could modify the original page dialog as well to get the same result, however it is not recommended.

Q: What is the difference between the Author and Publish environment?

A: A production environment usually has two difference instances of AEM running. One is the author instance, and the other is the publish instance. These two instances are usually kept in two different settings.

The author instance is where you will enter and manage content for your website. This is where you will administer your site as well. The author environment is usually kept behind a firewall. The publish instance is where you will make your content available for your targeted audience. The publish environment is usually kept in a Demilitarized Zone (DMZ).

I plan to add more interview questions to this blog, so make sure to check back.

I hope you enjoyed this post. Please feel free to post any comments below.