Liferay DXP 7.2 introduces the Info Framework to provide a greater degree of extensibility for the most common needs of retrieving, processing and displaying any type of information. A key aspect of the Info Framework is that it makes no assumptions about the source of the data or how it is represented in memory (like which Java class the information is from). It can work with information stored in the database, created through some process in memory or retrieved from an external source.
In Liferay DXP 7.2, the Info Framework still has limited functionality, but it sets the foundation for obtaining and displaying information from external systems or custom data models in Liferay. It also provides flexibility in customizing how any piece of information is displayed.
The Info Framework is lightweight. By design, it does not require all the information to implement any specific interface. This means that you can use it with any existing Java class, even if you don’t have access to modify it. It comprises a collection of loosely coupled micro-frameworks, so that developers can choose which features to use and ignore the others. This lowers the learning curve and minimizes work for developers.
The Info Framework helps generalize information handling. Custom applications can use it to make them more generic and extensible.
Some of the out-of-the-box Liferay features use it to achieve that same goal. In particular, Liferay DXP 7.2 uses it in two ways:
The Asset Publisher can display Assets from Information Lists defined by the Info Framework.
Display Pages, which previously only worked for an
AssetEntry, can now leverage the
InfoFrameworkto create display pages for any type of information that can be represented by a Java class. Developers can add support for display pages for various entities like Orders, Categories, and Events that are not Assets.
There are currently two tools provided by the Info Framework: Information Item Renderers and Information List Providers. You can create an Information List Provider to obtain a list of information items from a source, or create an Information Item Renderer to provide a custom renderer for any type of information. These two features can be used together or separately.
Information List Providers obtain a list of information items from a source. To
do this, a developer must implement the
InfoListProvider interface and
provide the necessary logic for retrieving the information from its source. By
providing an implementation of the
InfoListProvider interface, developers can
provide programmatic retrieval of information of any type, as long as it can be
represented through a Java class.
InfoListProvider has four methods to implement:
getLabel() provides the label that is displayed for this provider in the UI of
applications like the Asset Publisher.
getInfoList() provides the information list. This method has two variants:
a plain list or a list with pagination and sorting.
getInfoListCount() provides total number of items. This is needed for the
paginated variant of
For an example of how to create Information List providers, see Creating Information List Providers.
Developers can create custom renderers for any type of information. To do this,
a developer must provide an implementation of the
to provide programmatic rendering of information. It can be any kind of
information as long as it can be represented through a Java class. You can
create multiple renderers for a single type of information.
Internally, Liferay’s Display Pages use this from the Content component. When
it is added to a display page template, this component renders whatever
piece of information is shown through that template (whether it is Content in
the strict sense or some other entity type). It is rendered by the first
InfoItemRenderer class registered that entity. Information Item Renderers will
be leveraged further in future Liferay versions.
To create an Information Item Renderer you must create a class that implements
InfoItemRenderer and registers it as a component. Inside that class, you
render() method that contains your logic. To learn about Information
Item Renderers, see
Creating Information Item Renderers.