Processing XML documents with Oracle JDeveloper 11g:

The structure of an XML document is represented by an XML schema. An XML schema is also an XML document in the namespace http://www.w3.org/2001/XMLSchema.

Create an application and a project in JDeveloper by selecting File|New, and subsequently selecting Categories|General and Items|Generic Application in the New Gallery window. In the Create Generic Application window specify the Application Name, XMLSchema for example, and click on Next. In the Name your Generic project window specify a Project Name, XMLSchema for example, and click on Finish.

In this section we shall create an XML schema, catalog.xsd (as listed in the introduction), in JDeveloper Schema Visual Editor. First, add a schema file to project XMLSchema. Select the XMLSchema node in Application Navigator and select File|New. In the New Gallery window select General|XML in Categories, and XML schema in Items. Click on the OK button.

In the Create XML schema window specify a File Name, catalog.xsd, and click on OK. An XML schema gets added to project XMLSchema. In the Design view, the different components of the schema are displayed in the schema visual editor. In the Source view, the schema document source is listed. The different schema components available to add to a schema are listed in the Schema Components Component Palette.

Components may be added to an XML schema either from the Component Palette or a component node in the schema. As an example of adding a component from a component node, add root element catalog. Right-click on<schema...

In this section we shall register an XML schema in JDeveloper for XML editing. A registered schema may be used to create an instance of an XML document that conforms to the schema. To register a schema, select Tools|Preferences. In the Preferences window select XML schemas. In the XML schemas frame, click the Add button to register a schema.

In the Add Schema window, click the Browse button to select a schema. In the Open window, select catalog.xsd (which was created in the previous section). The catalog.xsd schema gets added to the Add Schema window. Extension specifies the extension of the file type from which the registered schema may be used to create an XML document instance. We have specified Extension as .xml, which implies that the registered schema may be used to create .xml documents. If you were registering an XML schema to create XSLT files, you would specify Extension as .xslt.

The XML schema catalog.xsd gets added to User Schemas for XML Editing...

In this section we shall create an XML document instance, catalog.xml (which was listed in the introduction), from the registered schema catalog.xsd. We're using a registered schema, but it is not essential as it's also possible to create an XML document instance using an XML schema in the file system.

However, using a registered XML schema does have an advantage. You may associate it with a specific file extension. For example, to register an XML schema for generating only .xslt files you would associate the .xslt extension with the XML schema.

Select project node XMLSchema in Application Navigator, and select File|New. In the New Gallery window select Categories|General|XML. Select XML Document from XML schema in the Items listed. Click on the OK button.

The Create XML Document from XML schema wizard gets started. Click on the Next button.

In the File Location window specify the XML File name as catalog.xml. Select Use Registered Schemas to...

In this chapter we introduced the commonly used XML schema structures. We created an XML schema in Oracle JDeveloper Schema Visual Editor. We discussed the various methods by which XML schema components may be added to an XML schema. Subsequently, we registered the XML schema in JDeveloper. Registering a schema associates the schema with a specific file extension. We created an XML document that conformed to the XML schema. In the next chapter we shall validate an XML document with an XML schema.