IBM Version 5 manual Namespace support, Editing an XSL file, Validating the XSL file

Editing an XSL file

The XSL editor provides a text editor to handle the source code of the XSL file. It has several text editing features, such as content assist and syntax highlighting. The content assist feature helps you in writing you XSL code, as it is aware of the proper XSL grammar rules. When editing the XSL document, content assist can be invoked to prompt the you with a list of possible XSL constructs to use.

Concerning the syntax highlighting feature, you will notice that whenever you select any of the XSL file components listed in the Outline view, the corresponding XSL code for that component will be selected, and vice versa.

Validating the XSL file

Another useful feature of the XSL editor, like the rest of the editors, is the incremental validation feature. At any point during your development of an XSL file, you can invoke the Validate process to validate the file. Just right-click on the file name in the Navigator view, and select the Validate XSL File option. In addition to the manual invocation of the validation process, the validation is also automatically run when you save the document. Any validation errors will be reported in the Task view with a little red marker for the corresponding line in the source code of the XSL file.

5.3 Namespace support

Namespaces are useful when there is a need for elements and attributes of the same name to take on different meaning depending on the context in which they are used. So, the XML namespace is the means to distinguish between elements that have the same name but come from different problem domain. An XML Schema supports namespaces.

Let us say for example we are taking about an attribute called Name. It will can have different meanings depending on whether it is applied to a customer, or flight carrier. If both entities (a customer and a flight carrier) need to define the same document such as in a flight entry, which associates a flight with its corresponding information, and the list passengers on that flight. We need some mechanism to distinguish between the two, and apply the correct semantic description for the attribute name, whenever it is used in the document. Namespaces provide the mechanism that allows us to write XML documents that contain information relevant to the problem domain.

To include your namespace information into your XML file when creating your XML document, select the option Create XML file from an XML Schema file, which specifies the namespace information. When you do that, the target namespace and prefix from the XML Schema file is automatically picked up when creating the document.

90 The XML Files: Development of XML/XSL Applications Using WebSphere Studio