About Forms in HTML...
= Index DOT Html by Brian Wilson [bloo@blooberry.com] =

Justification for HTML Forms

Forms are the main method (and also the oldest) for making a web document interactive. Forms allow the input of information by a reader. Various input methods exist to enter this information from the user such as buttons, pull-down menus and text boxes. When a user is finished entering information in an HTML form, they can "submit" this information. Submitting form information can result in the creation of dynamic web pages, the sending of e-mail, or other actions - it is all determined by the the intent of the program that is activated to analyze the form information.

Form Field Types

There are many different types of form input mechanisms. These field types represent many of the common input methods found in paper-based forms. All input mechanisms are bounded by delimiters which mark the range of the form.

Form Delimiter

[<form>]

Forms in an HTML document are created by using the FORM container delimiter tags. These tags serve to encapsulate the fields of the form and contain information on how and where to process the form contents. These delimiters create a form of virtual Block Formatting in a document structure (a line break is added both before and after FORM delimiters.) This formatting does not add any semantic meaning to the structure (like Block Formatting does) but is rather a side-effect of its nature (like with the TABLE structure.) These delimiters also serve to allow multiple forms to exist in a single document.

Form Fields

[<selection list>, <textarea>, <input type=text>, <input type=hidden>, <input type=checkbox>, <input type=radio>, <input type=password>, <input type=file>, <input type=image>, <input type=reset>, <input type=submit>]

It is up to the author to determine which of the various field types best suits their needs in terms of easy usability for a reader and suitability for processing by the destination program.

CGI Binaries

When a form is submitted for evaluation, the information that has been entered is encoded and sent to a program invoked by the submission process. This program evaluates and processes the information entered in the form, and takes actions based on the input. This information transfer method is called the "Common Gateway Interface" (CGI) - a standard for external programs to interface with HTTP servers.

The program used to analyze the form data is called a "Common Gateway Interface Binary" (CGI-Bin for short.) A CGI-bin program can be written in any language that allows it to be executed on a server system, such as C/C++, Fortran, Perl, Python, shell scripts, TCL, AppleScript, etc. Many types of information can be entered via an HTML forms interface, but it is always up to this CGI-Bin program to make sense out of what is received and react accordingly.

While it is within the scope of these documents to discuss the HTML side of forms creation, any explanation of how to write a CGI-Bin program would definitely be a separate matter. Please look to the Related Sites section below for sites that cover this topic.

Official References

ftp://ds.internic.net/rfc/rfc1866.txt

RFC 1866: The HTML 2.0 specification (plain text)

http://www.w3.org/pub/WWW/MarkUp/html-spec

The web version of the HTML 2.0 (RFC 1866) specification

http://www.w3.org/pub/WWW/MarkUp/Wilbur/

The HTML 3.2 (Wilbur) proposal
[Includes all HTML 2 form elements in common use]

http://www.w3.org/pub/WWW/MarkUp/Cougar/HTML.dtd

The experimental HTML (Cougar) draft
[Demonstrates some of the directions HTML is taking - including new options for form fields]

http://home.netscape.com/assist/net_sites/html_extensions_3.html

Netscape Extensions to HTML 3.0
[mentions the use of File Upload (INPUT TYPE=file)]

http://www.microsoft.com/workshop/author/newhtml/htmlr020.htm

Internet Explorer 3.0 Tag reference
[Details form field usage supported in 2.0 and 3.2 as well as a new INPUT TYPE=textarea not covered here.]

Tutorials

http://www.ncsa.uiuc.edu/SDG/Software/Mosaic/Docs/fill-out-forms/overview.html

Mosaic for X version 2.0 Fill-Out Form Support

http://hoohoo.ncsa.uiuc.edu/cgi/forms.html

NCSA's "Decoding FORMs with CGI" tutorial

http://robot0.ge.uiuc.edu/~carlosp/cs317/cft.html

Carlos' Forms Tutorial

http://www.webcom.com/~webcom/html/tutor/forms

WWW Fill-out Forms Tutorial

http://www.utoronto.ca/webdocs/HTMLdocs/NewHTML/forms.html

The Information Commons Introduction to HTML: Forms

Other Related Links

http://www.research.digital.com/nsl/formtest

Digital Corp. HTML Form Testing

http://www.yahoo.com/...../Forms/

Yahoo's HTML Forms section