Migrating old extension environments

Because Ext plugins are an evolution of the extension environment provided in Liferay 5.2 and earlier, you might need to migrate your extension environment into Ext plugins when upgrading Liferay. If you need to do this, we have good news; migrating is automated and relatively easy.

Tip: When migrating an extension environment, first consider whether any of the extension environment’s features can be moved into other types of plugins. Portlets and hooks are designed to meet specific needs and they’re easier to learn. Additionally, they’re easier to maintain since they often require fewer changes when upgrading to a new version of Liferay.

To successfully migrate, execute an Ant target within the ext directory of the Plugins SDK, pointing to the old extension environment and naming the new plugin. Be sure to remove the line escape character \ from the following example:

ant upgrade-ext -Dext.dir=/projects/liferay/ext -Dext.name=my-ext\
-Dext.display.name="My Ext"

Let’s look at the three parameters we used above:

• ext.dir: The location of the old extension environment.
• ext.name: The name of the Ext plugin that you want to create.
• ext.display.name: The display name.

After executing the target, you should see the logs of several copy operations that will take files from the extension environment and copy them into the equivalent directory within the Ext plugin (see the section Creating an Ext plugin for an explanation of the main directories within the plugin).

With the migration process finished, you can upgrade your code to the new version of Liferay by completing a few additional tasks. Most commonly, you should do the following:

• Review the uses of Liferay’s APIs and adapt them accordingly.
• Review any changes to the new version of Liferay’s JSPs. Merge your changes into the JSPs of the new Liferay version.
• Run ant build-service again, to use Service Builder. It’s also recommended to consider moving this code to a portlet plugin, because Service Builder is deprecated in Ext, and plugins allow for greater modularity and maintainability.
• If you implemented any portlets in the old extension environment, migrate them to portlet plugins; extension environment portlets have been deprecated since Liferay Portal 6.0, and support isn’t guaranteed in future Liferay Portal releases.

Licensing and Contributing

Liferay Portal is Open Source software licensed under the LGPL 2.1 license (http://www.gnu.org/licenses/lgpl-2.1.html). If you reuse any code snippet and redistribute it, whether publicly or to a specific customer, make sure your modifications are compliant with the license. One common way is to make the source code of your modifications available to the community under the same license. Make sure you read the license text yourself to find the option that best fits your needs.

If your goal in making changes is fixing a bug or improving Liferay, it could be of interest to a broader audience. Consider contributing it back to the project. That benefits all users of the product, including you since you won’t have to maintain the changes with each newly released version of Liferay. You can notify Liferay of bugs or improvements in issues.liferay.com. There is also a wiki page with instructions on how to contribute to Liferay:

http://www.liferay.com/community/wiki/-/wiki/Main/Contributing