Everyone is familiar with forms, either paper or electronic: a set of fields to be completed. Different types of fields exist, such as fill in the blank text boxes, pick one or pick many items, and so on. Some sort of validation usually ensures that fields are filled out (or filled out correctly). The completed form may need to be transmitted electronically. So, why do we need yet another form syntax? Because this new syntax eliminates some limitations of the previous implementations.
This chapter looks at using defining electronic forms using the W3C XForms standard, and the most commonly used proprietary standard, InfoPath. While neither of these methods is as familiar or offers the ease of development of XHTML forms, both bring benefits to the developer. Both syntaxes enforce best practices in software design, separating the model of the data from the implementation. This makes code and form reuse a much easier process. In addition, by enforcing XML standards, you can use other XML standards, such as XSLT or XPath when working with these XML form implementations. Finally, XForms is intended as the forms model of XHTML 2.0, currently a work in progress. Therefore, its importance will only increase as time goes by.
The most common form syntax in use for electronic forms is that used in HTML/XHTML. Most developers are familiar with this syntax: an outer
<form> tag that contains attributes identifying the target of the form ...