Teach Yourself e.net - Syspro

6
More Advanced Options
Objectives - In this chapter we deal with two concepts that will advance your use of
ASP.NET with e.net solutions. We will first tackle XSLT, examining the process of
transforming XML output for use in custom applications and by other proprietary
applications. By the end of this section you will be familiar with XSLT and the
transformation of an XmlOut string to an HTML table. In the second section of this
chapter we will deal with the concept of ASP.NET codebehind, separating the
programming logic from the presentation logic.
If you are already familiar with XSLT and ASP.NET codebehind usage then please move
on to the next chapter.
6.1. Transforming XML
XML is useful for transferring data between applications and between objects within an
application. It is, however, not very useful to present an XML file to an accountant or an
auditor or a data capture clerk. The benefit of using XML as a data transfer standard is that
one can also transform that data into other formats that can then be used to display the
information more effectively.
The transformation standards or capabilities for XML were being developed at the same
time that the XML standard was being developed. Using these standards, it is possible to
transform XML into HTML, SQL scripts, emails, and virtually any other document type.
This happens through the use of XSLT (Extensible Style Language Transformation)
definition files and an XSLT processor.
6.1.1. What is XSLT
XSLT (Extensible Style Language Transformation) is a standard that was created to
transform XML files into other formats or other XML Schemas. An XSL processor reads
the XML document and follows the instructions in the XSL stylesheet, then it outputs the
data as an HTML page, a SQL script, an email, an XML file governed by a different
schema, or any other standardized document type.
XSLT transformations are also useful in situations where the XML document's structure
does not match up well with an application that needs access to the data. An XML
document may contain the appropriate data to be imported into a database, for example,
but may not be structured in the format that the application performing the import expects.
The following two examples show how an XML document can be transformed from one