QR Code generator component for Adobe AEM / CQ5

I like so much Adobe AEM: it is very easy to customize this product and make our customers happier. Moreover, Adobe AEM is based on a wonderful stack: it is easier to work on a state of art technology: Apache Jackrabbit OAK, Apache Sling, Apache Felix and the most important layer, Adobe AEM are so well integrated and very powerful technologies.

A new customer requirement

A customer asked me to create a new Adobe AEM component to generate on the fly QR Code images. The functional requirement is pretty simple: the author wants to add a QR Code that "renders" the current url page url. Occasionally the author wants to create a QR Code to an external Url or different page. QR Code are very useful because with a smartphone or tablet, everyone can scan the QR Code from a monitor and continue the browsing far from the desktop or far from a digital .

In addition, if the end user print the page that contains a QR Code, it will be super fast to scan the QR Code and, again, to continue to surf the same printed information days or months later, without to enter an annoying url. Eventually, QR Code can store more than 4.000 characters on a single image:  it is possible to store on a printed page any kind of information on a QR Code, like Sling selectors and parameters used to access the original page, visitor navigation path or detailed information of a specific product showed in the web site.

Why QR Code?

If you think that this is another strange requirement from your digital marketing team, you should change idea. QR Code are in some way related to digital marketing because these can connect a casual visitor to a specific page or, better, to a new web site that he or she never knewed or visited before. Think about digital signage in a shopping center. If you are, like me, a digital marketer newbie probably still don't get the importance of  the QR Code technology. Ok, this is not what you should appreciate or love, this is just a an image but probably your digital marketing team will ask you something similar soon.

Adobe Experience Manager is used not just to publish sites, to create cool web applications or Html5 based apps for mobile phones or tablets.

With AEM your digital marketing team can engage shoppers in large  in a shopping aisle of a shopping center, in the airport, in a public place, using digital signage or digital kiosks. Evantually, do you know that public administrations are using Adobe AEM? Visitors are not just shoppers: casual visitors could be also citizens that are looking for useful documents from local public administration, in few seconds just watching a digital kiosk in a public place.

By the way, did you notice the new "Screen" link in the AEM 6 projects console? There are and there will be more features in AEM that integrate digital experiences in phisical stores.

The QR Generator component implementation

This is what my customer was asking, it is not more than that: a new component to create a QR Code, that he or she can drag and drop directly into the web page (or to statically include in every page):

Of course, customer wants that the new component works and can be configured via the new Touch UI interface:

With libraries like ZXing it is very easy to create a QR Code image from a string.  So, the first thing to do is to import one of these libraries as an OSGI bundle.

The good news is that Adobe already provides a similar bundle in the standard implementation. Adobe is using this bundle to publish the url of the authored mobile apps via QR Code. In the OSGI system console you can easily find this bundle:

The same bundle is in the "active" state in the publish instance too so we don't have to manually activate it. The bundle implements a simple servlet that renders a QR Code just passing the "url" parameters to the servlet ...url. So, for example, to create a QR Code to the Adobe CRX DE Lite application, one can just enter this url (try it in your AEM development environment): http://localhost:4502/libs/wcm/mobile/qrcode.png?url=http://localhost:4502/crx/de

With this bundle, the implementation required few steps and, litterally, very few lines of Java code. I just created a new component named qrcode-generator. Here, below, the Java code that I wrote for the component logic:

<%@ page import="com.day.cq.commons.Externalizer,
javax.jcr.Node"%>
<%@ include file="/libs/foundation/global.jsp"%>

<%
final String CODE = "qrcode"; // the qr code property name
final String WIDTH = "width";
Node n = currentNode;
if(!n.hasProperty(CODE))
{
String extension = "." + slingRequest.getRequestPathInfo().getExtension();
Externalizer externalizer = resourceResolver.adaptTo(Externalizer.class);
String myExternalizedUrl = externalizer.publishLink(resourceResolver, currentPage.getPath() + extension);
n.setProperty(CODE,myExternalizedUrl);
n.setProperty(WIDTH,100); // default width
n.getSession().save();
}
%>

<img width="<%=properties.get(WIDTH,"")%>" src="<%= request.getContextPath() %>/libs/wcm/mobile/qrcode.png?url=<%=properties.get(CODE,"")%>"/>

Configuration

I created the component dialogs for both the Classic and the Touch UI, just using the CRX DE Lite.

One important point is that the standard Adobe bundle generates QR Code just for urls (not for any kind of text) and only for the urls that are in a whitelist defined as a regex. Url based on the Externalizer service are automatically whitelisted: that's why I used the Externalizer in the component logic implementation. The externalizer.publishLink creates a link to the Adobe AEM publish instance. If you need to create QR Code for generic text, you have just to modify the component configuration via the Apache Felix Console, using the menu OSGI >> Configuration:

 And that's it. Now the author can create a new QR Code in few seconds!

The component package

I like to share my Adobe AEM experience and it is a pleasure to do that when many other colleagues do the same, daily. I created a new package that contains the custom component and everything needed to use the new component. Just click on the image below

to download the package and try it on your environment (as usual, you have to install the package and enable the new coomponent in your pages but I am supposing you know how to do that).

Next steps

It is good to include the Alt text and a Description to the rendered QR Code as per every html <img /> tag. Then it is needed to update the dialogs in order to enable user input for the new attributes. I am going to complete these changes (just few minutes required usingAEM stack!).

Digital marketing team is composed by "volcanic" people. They are never satisfied and they wants more and more, every day, something different, something more innovative.

In the future they will want someghing like newer and fancy QR Code. We are ready to make our digital marketing team happy because with Adobe AEM stack we can concentrate "just" on business logic.

If you need more information or if you need a custom AEM implementations, just ask me or to my company, Next 2U Consulting, a consultancy firm based in Rome, Italy.

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