As schemas become larger, it is often desirable to divide their
content among several schema documents for purposes such as ease of maintenance,
reuse, and readability. You can use an import element to
bring in definitions and declarations from an imported schema into the current
schema.
The imported schema can come from a different namespace than the
current schema does. You can add multiple import elements to an XML schema,
however, prefixes and namespaces have to unique amongst the imported schemas.
The
following instructions were written for the Resource perspective, but they
will also work in many other perspectives.
To add an import element,
complete the following steps:
- Open your XML schema in the XML schema editor. In the Outline view,
select your schema. The entire schema and its contents should be
displayed in the Design view.
- In the Design view, right click in the Directives section
and click Add Import.
- In the Properties view, click the General tab and click
the Browse
button to the right of the Schema
location field.
- If you want to import an XML schema located in the workbench:
- Select Workbench projects and click Next.
- Select the schema you want to import and click Finish.
- If you want to import an XML schema located on the Web:
- Select HTTP and click Next.
- Type the URL of the XML schema and click Finish.
Note: A local copy of the schema will not be stored in the workbench.
Every time you validate your schema, the schema's contents will be checked
from the URL you specify.
- The XML schema editor will retrieve the namespace for the imported
XML schema file and display it as read-only in the Namespace field.
- If necessary, type a unique prefix for this namespace in the Prefix field.
- Click the Documentation tab if you want
to provide any information about this import element. The Documentation page
is used for human readable material, such as a description.
- Click the Extensions tab if you want to
add application information elements to your annotations of schema components.
The Extensions page allows you to specify the
schema and add XML content to your annotations.
Once you have added an import element to your XML schema, when
you define new elements, attributes, complex types, or simple types where
you can specify type information, any declarations from the included schema
will be available in the Type list for the element,
attribute, complex or simple type.