Overriding Global Language Keys

Language files contain translations of your application’s user interface messages. But you can also override the default language keys globally and in other applications (including your own). Here are the steps for overriding language keys:

1. Determine the language keys to override
2. Override the keys in a new language properties file
3. Create a Resource Bundle service component

Note: Many applications that were once part of Liferay Portal 6.2 are now modularized. Their language keys might have been moved out of Liferay’s language properties files and into one of the application’s modules. The process for overriding a module’s language keys is different from the process for overriding Liferay’s language keys.

Determine the language keys to override

So how do you find global language keys? They’re in the Language[xx_XX].properties files in the source code or your bundle.

• From the source:

  /portal-impl/src/content/Language[xx_XX].properties

• From a bundle:

  portal-impl.jar

All language properties files contain properties you can override, like the language settings properties:

##
## Language settings
##

...
lang.user.name.field.names=prefix,first-name,middle-name,last-name,suffix
lang.user.name.prefix.values=Dr,Mr,Ms,Mrs
lang.user.name.required.field.names=last-name
lang.user.name.suffix.values=II,III,IV,Jr,Phd,Sr
...

There are also many simple keys you can override to update default messages and labels.

##
## Category titles
##

category.admin=Admin
category.alfresco=Alfresco
category.christianity=Christianity
category.cms=Content Management
...

For example, Figure 1 shows a button that uses Liferay’s publish default language key.

`publish=Publish`

Figure 1: Messages displayed in Liferay's user interface can be customized.

Next, you’ll learn how to override this key.

Override the keys in a new language properties file

Once you know the keys to override, create a language properties file for the locale you want (or the default Language.properties file) in your module’s src/main/resources/content folder. In your file, define the keys your way. For example, you could override the publish key.

publish=Publish Override

To enable your change, you must create a resource bundle service component to reference your language file.

Create a Resource Bundle service component

In your module, create a class that extends java.util.ResourceBundle for the locale you’re overriding. Here’s an example resource bundle class for the en_US locale:

@Component(
    property = { "language.id=en_US" }, 
    service = ResourceBundle.class
)
public class MyEnUsResourceBundle extends ResourceBundle {

    @Override
    protected Object handleGetObject(String key) {
        return _resourceBundle.getObject(key);
    }

    @Override
    public Enumeration<String> getKeys() {
        return _resourceBundle.getKeys();
    }

    private final ResourceBundle _resourceBundle = ResourceBundle.getBundle(
        "content.Language_en_US", UTF8Control.INSTANCE);

}

The class’s _resourceBundle field is assigned a ResourceBundle. The call to ResourceBundle.getBundle needs two parameters. The content.Language_en_US parameter is the language file’s qualified name with respect to the module’s src/main/resources folder. The second parameter is a control that sets the language syntax of the resource bundle. To use language syntax identical to Liferay’s syntax, import Liferay’s com.liferay.portal.kernel.language.UTF8Control class and set the second parameter to UTF8Control.INSTANCE.

The class’s @Component annotation declares it an OSGi ResourceBundle service component. It’s language.id property designates it for the en_US locale.

@Component(
    property = { "language.id=en_US" }, 
    service = ResourceBundle.class
)

The class overrides these methods:

• handleGetObject: Looks up the key in the module’s resource bundle (which is based on the module’s language properties file) and returns the key’s value as an Object.

• getKeys: Returns an Enumeration of the resource bundle’s keys.

Your resource bundle service component redirects the default language keys to your module’s language key overrides.

Note: Global language key overrides for multiple locales require a separate module for each locale. Each module’s ResourceBundle extension class (like the MyEnUsResourceBundle class above) must specify its locale in the language.id component property definition and in the language file qualified name parameter. For example, here is what they look like for the Spanish locale.

Component definition:

@Component(
    property = { "language.id=es_ES" },
    service = ResourceBundle.class
)

Resource bundle assignment:

private final ResourceBundle _resourceBundle = ResourceBundle.getBundle(
    "content.Language_es_ES", UTF8Control.INSTANCE);

Important: If your module uses language keys from another module and overrides any of that other module’s keys, make sure to use OSGi headers to specify the capabilities your module requires and provides. This lets you prioritize resource bundles from the modules.

To see your Liferay language key overrides in action, deploy your module and visit the portlets and pages that use the keys.

Figure 2: This button uses the overridden `publish` key.

That’s all there is to overriding Liferay’s language keys.

Related Topics

• Upgrading Core Language Key Hooks
• Overriding a Module’s Language Keys