Wapp

  2.  As a stand-alone web server

  3.  As a CGI script

  4.  As an SCGI program

All four methods use the same application code and present the same
interface to the application user.  An application can be developed on
the desktop using stand-alone mode (1), then deployed as a stand-alone
server (2), or a CGI script (3), or as an SCGI program (4).

2.0 Hello World!
----------------

Wapp is designed to be easy to use.  A hello-world program is as follows:

>
    package require wapp  ;# OR just "source wapp.tcl"
    proc wapp-default {req} {
       wapp-subst {<h1>Hello, World!</h1>\n}
    }
    wapp-start $::argv

The application defines one or more procedures that accept HTTP requests
and generate appropriate replies.

     "%unsafe(...)") so that the result is safe for inclusion within the
     body of an HTML document, a URL, a query parameter, or a javascript
     string literal, respectively.

  +  **wapp-trim** _TEXT_  
     Just like wapp-subst, this routine appends _TEXT_ to the web page
     under construction, using the %html, %url, %qp, %string, and %unsafe
     substitutions.  The difference is that this routine also removes
     surplus whitespace from the left margin, so that if the _TEXT_
     argument is intended in the source script, it will appear at the
     left margin in the generated output.

  +  **wapp-param** _NAME_ _DEFAULT_  
     Return the value of the query parameter or environment variable _NAME_,
     or return _DEFAULT_ if there is no such query parameter or environment
     variable.  If _DEFAULT_ is omitted, then it is an empty string.
     The same information can be obtained directly from the
     $::wapp dict.  This command is merely a convenient shortcut.

  +  **wapp-mimetype** _MIMETYPE_  
     Set the MIME-type for the generated web page.  The default is "text/html".

  +  **wapp-reply-code** _CODE_
     Set the reply-code for the HTTP request.  The default is "200 Ok".