This tutorial takes you through the process of creating a custom trait.
A trait is an attribute or property of a visitor or visit, such as age or gender, that you can use to personalize content.
We create a trait that detects the visitor's operating system. Depending on the detected user agent, we serve the visitor a page with a personalized component. We create two component variants named "WINDOWS" and "OS-X" for a Text and image component.
The trait extracts the operating system from the User-Agent in the HTTP header:
- Windows users are served a component with text that refers to the Windows system and a download link at
- OS-X users are served a component with text that refers to the OS-X system and a download link at
- If neither system is detected, Magnolia serves the "ORIGINAL" version of the component, containing generic text and a download link at
Create a module
A trait is deployed with a Magnolia module. Create a module first. Choose from these options depending on your skill level:
Option 1: Clone the project in Git
This option gives you a ready-made project that you can customize to your needs.
Choose this option if you know how to work with a Magnolia project and Git, and want to examine the code locally in your IDE.
Import the project into your IDE. Here's what the project looks like in IntelliJ IDEA:
- Build the project into a JAR and deploy it to your Magnolia instance. Or run the project in your IDE. To run it in an IDE, add the module as a dependency to your Magnolia bundle POM file (see Option 2).
Option 2: Add the project as a dependency to your bundle
Choose this option if you run Magnolia in your IDE, but don't plan to work on the code.
Add the project as a dependency in the POM files of your Magnolia bundle.
For Enterprise Edition bundles:
dependencyManagementsection of the EE-bundle parent POM file, add a
dependencyelement with a version number:
<dependency> <groupId>info.magnolia.documentation</groupId> <artifactId>documentation-trait-tutorial</artifactId> <version>1.2</version> </dependency>
dependenciessection of the enterprise-webapp POM file, add a
dependencyelement without a version number:
<dependency> <groupId>info.magnolia.documentation</groupId> <artifactId>documentation-trait-tutorial</artifactId> </dependency>
If you use IMB WebSphere or Oracle WebLogic, add the
dependencyelement in the appropriate POM file of your webapp of choice.
If you are using a custom bundle, add the
dependency element with a version number in the POM file of your customized bundle.
Option 3: Download the module JAR
Choose this option if you are new to Magnolia and don't have a development environment (IDE). You can use the trait but won't be able to look at the code.
- Install the Magnolia Tomcat bundle.
- Download documentation-trait-tutorial-1.2.jar from Nexus.
- Copy the JAR into
<CATALINA_HOME>/webapps/<contextPath>/WEB-INF/libfolder. Typically this is
- Restart your Magnolia instance and run the Web update. This will install the
Registering a trait
Any module can register a trait. Magnolia observes the
traits folder in your module configuration and adds new traits to a trait registry. Registered traits are then displayed to editors in the user interface.
Trait name. Choose a name that is easy for editors to understand such as
Field used to define permitted values for the trait. See Rule field below.
Field used to enter a single value to test personalized content delivery. See Value field below.
Converter class which must implement
Trait class. Doesn't have to explicitly implement any interface. Usually it is just a plain Java object which allows you to specify the trait and its characteristics.
Voter class which must extend
optional, default is
Adds the trait to the Preview app. Set this property to
A rule field defines values for the trait when you choose an audience. For example, you need two rule fields to define a date range: one for start date and another for end date. Magnolia uses the input entered into the rule field(s) to construct a voter. The voter then decides whether the visitor or visit matches the rule or not. When the rule is met, personalized content is delivered.
The rule field is displayed to users in the Choose audience dialog:
Choose a field definition class that lets the user specify the permitted values. In some cases, a simple text field is enough (country). In others, for example where you need the user to select a value (new visitor, registered visitor, logged-in visitor), a select field is appropriate. For more complex fields, use a composite field. See List of fields for more.
userAgent rule field:
Rule field node
Transformer class which must implement
Field type. In this case it is a bean property of the superclass (
A value field is for previewing variants. The field is displayed to users in the Preview app when viewing the page as a visitor:
When you enter a value that matches the rule, for example "Macintosh" in the image above, the voter tests the value against the rule and Magnolia displays the content variant associated with the value.
userAgent value field:
Value field node.
Field type. In this case it is a bean property of the superclass (
Registering a trait detector filter
Once you have registered the trait, provide a
TraitDetectorFilter and register it in the filter chain to make sure the appropriate variant is served.
UserAgentDetectorFilter registration in the filter chain.
Filter name. Name the filter after your trait. Ideally name the node to match the trait registration node. In our example the filter name is
Class that implements
Position of the filter in the chain
Make sure the filter is in the right position in the chain. Filters are executed in the order they are registered in the chain, from top to bottom. You want to position the filter right after the
When installing a module, you can define the position with
In the example above the configuration tree is simplified. Other filters may also want to be right after
contentType. In a production environment it may look like this:
Creating component variants
Now you can create component variants and choose an audience using the new trait.
documentation-trait-tutorial module installs an example page named
maps-download that contains two custom variants of the Text and image component:
It is not possible to specify an audience for the original. The original acts as fallback (default) content when no variants match the visitor.
Testing the result
You can test the personalized variants using a browser plugin or on different computers running Windows and OS-X. User agent switcher add-ons that allow you to spoof and mimic various user agents are available for Firefox, Chrome/Chromium, and Opera.
You should now be able to see different renderings of the page containing the personalized variants of the Text and image component depending on the user agent.
Windows user agent
OS-X user agent
Other user agents