1.1 Background

Forms are an important part of the Web, and they continue to be the primary means of interactivity used by many Web sites. Web applications and eCommerce solutions have sparked the demand for better web forms with richer interactions. XForms are the response to this demand—extended analysis, followed by the creation of a new platform-independent markup language for online interaction between an XForms Processor and a remote entity. XForms are the successor to HTML forms, and benefit from the lessons learned in the years of HTML forms implementation experience.

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 and becomes more and more technical and specific towards the end. For quick access to information, a general table of contents, specific tables of contents at the beginning of each section provide easy navigation.

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 includes a brief tutorial on XForms, and a discussion of design principles.

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.

Appendices

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

1.4 Documentation Conventions

The following highlighting and typography is used to present technical material in this document:

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

xforms: The XForms namespace 4.1 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 by convention only; any namespace prefix may be used in practice.

Official terms are defined in the following manner: [Definition: You can find most terms in the chapter 3 Terminology]. Links to terms may be specially highlighted in the text, though typically only on introductory usage or when special attention needs to be directed toward the term.

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 table provide additional explanatory information.

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

Certain common attributes 4.2 Horizontally Applicable Markup are not shown in the syntax representations except when special attention needs to be called to their presence.

Non-normative short examples are set off typographically:

Example Item

or

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 highlighting is used for non-normative commentary:

For diff-marked formatted text, note that newly added text appears like this, changed text appears like this, and deleted text appears like