1.1 Background

Forms are an important part of the Web, and they continue to be the primary means for enabling interactive web applications. Web applications and electronic commerce solutions have sparked the demand for better web forms with richer interactions. XForms are the response to this demand and provide a new platform-independent markup language for online interaction between an XForms Processor and a remote user agent. XForms are the successor to HTML forms, and benefit from the lessons learned from HTML forms.

Further background information on XForms can be found at http://www.w3.org/MarkUp/Forms.

1.2 Reading the Specification

This specification has been written with various types of readers in mind—in particular XForms authors and XForms implementors. We hope the specification will provide authors with the tools they need to write efficient, attractive and accessible documents without overexposing them to the XForms implementation details. Implementors, however, should find all they need to build conforming XForms Processors. The specification begins with a general presentation of XForms before specifying the technical details of the various XForms components.

The specification has been written with various modes of presentation in mind. In case of a discrepancy, the online electronic version is considered the authoritative version of the document.

This document uses the terms may, must, and should in accord with RFC 2119.

1.3 How the Specification is Organized

The specification is organized into the following chapters:

Chapters 1 and 2

An introduction to XForms. The introduction outlines the design principles and includes a brief tutorial on XForms.

Chapters 3 and up

XForms reference manual. The bulk of the reference manual consists of the specification of XForms. This reference defines XForms and how XForms Processors must interpret the various components in order to claim conformance.

Appendixes

Appendixes contain a normative description of XForms described in XML Schema, information on references, and other useful information.

1.4 Documentation Conventions

Throughout this document, the following namespace prefixes and corresponding namespace identifiers are used:

xforms: The XForms namespace 3.1 The XForms Namespace
html: The XHTML namespace [XHTML 1.0]
xsd: The XML Schema namespace [XML Schema part 1]
xsi: The XML Schema for instances namespace [XML Schema part 1]
xlink: The XLink namespace [XLink]
ev: The XML Events namespace [XML Events]
my: Any user defined namespace

This is only a convention; any namespace prefix may be used in practice.

The following typographical conventions are used to present technical material in this document.

Official terms are defined in the following manner: [Definition: You can find most terms in chapter 12 Glossary Of Terms]. Links to terms may be specially highlighted where necessary.

The XML representations of various elements within XForms are presented as follows: Listed are the element name, names of all attributes, allowed values of attributes appearing after a "=" character, default values of attributes appearing after a ":" character, and allowed content. One or more headings below the listing provide additional explanatory information.

<example
  count = xsd:integer
  size = (small | medium | large) : medium
>
  <!-- Content: (allowed-content) -->
</example>

Certain common attributes 3.2 Horizontally Applicable Markup are not shown in the syntax representations except when special attention needs to be called to their presence.

Examples are set off typographically:

Example Item

References to external documents appear as follows: [Sample Reference] with links to the references section of this document.

Sample Reference

Reference - linked to from above.

The following typesetting convention is used for non-normative commentary: