Custom fields appear beneath Portal Settings under the Configuration heading of the Control Panel. Custom fields are a way to add attributes to many types of assets and resources in the portal. For example, if you’re using Liferay Portal to create a site for rating books, you might create a custom field called Favorite Books for User resource. If you’re using the Wiki for book reviews, you might add fields called Book Title and Book Author.
It’s possible to add custom fields to following kinds of portal resources:
- Blogs Entry
- Bookmarks Entry
- Bookmarks Folder
- Calendar Booking
- Document
- Documents Folder
- Message Boards Category
- Message Boards Message
- Organization
- Page
- Role
- Site
- User
- User Group
- Web Content Article
- Wiki Page
The ability to add custom fields to any of these resources affords flexibility to portal developers. For example, suppose you’d like to define a limitation on the number of users that can be assigned to certain roles. A portal administrator can create a custom field called max-users for the Role resource. Then a portal developer can create a hook plugin that checks this field upon user assignment to roles to make sure that there aren’t too many users assigned to the role.
To add a custom field, click on the Custom Fields link in the Control Panel. Then choose a resource, click on the Edit link next to it and select Add Custom Field.
Figure 17.6: You can add custom fields to these portal resources.
From here you need to add the custom field key. The key appears as the label for
the field on the form. For some portal resources (like the User), custom fields
are a separate section of the form. For others, as can be seen above, custom
fields are integrated with the default fields on the form. Additionally,
developers can access custom fields programatically through the
<liferay-ui:custom-attribute /> tag.
Figure 17.7: The `book-author` and `book-title` custom fields are integrated with the rest of the form for editing a Wiki page.
You can create fields of many different types: text fields (indexed or secret), integers, selection of multiple values and more. Once you’ve created a field, you cannot change its type. However, you can delete custom fields and create new ones. Next, let’s look at how to apply server configurations.