Validate Documents Using SAX

 

[This sample application uses a feature that was first implemented in MSXML 4.0.]

With MSXML 4.0 and later, validation support for SAX applications was added. This example demonstrates that functionality by showing you how to create a simple SAX validator application in Microsoft® Visual Basic® 6.0. The application allows the user to select an XML file and have it validated against an XSD schema file.

In this example, the SAX reader parses the sample XML file (books.xml), and writes validation results as output to a textbox control on the main form for the application.

The application is kept simple to demonstrate the fundamental principles involved. These principles include the following:

• Validating from within SAX applications, which differs from validating XML in DOM-based applications.

• Validating XML file input to a user-selectable XSD schema file.

• Using SAX error handler and SAX locator information to improve error reporting for your SAX application.

This topic is divided into the following sections.

• Overview of the SAX Validator Application

• Application Form (SAX Validator)

• Sample XML and XSD Files (SAX Validator)

• MyValidator Class (SAX Validator)

• Run the Application (SAX Validator)

• How the SAX Validator Application Works

Note

SAX-based validation only supports external XSD schemas. SAX-based validation using Document Type Definition (DTD) files is not supported.

See Also

Sample XML File (books.xml)