• Portlet Guide
  • Quick tutorial: deploying the portlet test suite
  • Deployment
    • What is a portlet preparation? Why do I need it?
    • Deploying through the administration user interface
    • Deploying directly through the file system
  • Using in a Jahia page
    • Portlet instances
    • Portlet roles and Jahia permissions
  • Hello world portlet
    • Requirements
    • Project structure
    • Maven project descriptor
    • Portlet Java code
    • Portlet descriptor
    • Web application descriptor
    • The Tomcat deployment descriptor
    • Building and deploying
    • Redeployment
    • Troubleshooting deployment
    • Learning more
  • Support for Bridges
  • How to share portlet objects?
    • Public Render Parameters
    • Portlet Events
    • Jahia Shared Map
      • How to share a simple object?
      • How to read a simple object?
      • How to share a bean?
  • Performance
  • Using portlets on other application servers
  • Additional resources

Portlet instances

Before you may use a portlet inside a Jahia page, you must first create a portlet instance. An instance may be seen as similar to what objects are to classes, meaning that it will have it’s own copy of preferences and configurations for the instance. An instance may be used on multiple pages on a Jahia site, making it easy to re-use the same portlet in multiple locations. If you want different instances of portlets on different pages, you must create different instances and put them on those pages. A good example of the difference between a portlet definition and a portlet instance is a Google Gadget portlet. The definition allows the technology to render a Google Gadget, while the instance would be a specific Google Gadget itself, such as a calendar or a news gadget.

For an example on how to create an instance, please refer to our “Quick Tutorial” that shows how this is done.