Wapp

1.0 Application Template

package require wapp
proc wapp-page-XXXXX {} {
  wapp-trim {
    # Content to deliver for page XXXXX
  }
}
proc wapp-default {} {
  wapp-trim {
    # Content for all other pages
  }
}
wapp-start $argv

2.0 Interfaces

wapp-start $argv	→	Starts up the Wapp application
wapp-subst {TEXT}	→	Append TEXT to the output with substitution
wapp-trim {TEXT}	→	Like wapp-subst but also removes left-margin whitespace
wapp-param NAME DEFAULT	→	Return value of parameter NAME
wapp-set-param NAME VALUE	→	Set parameter NAME to VALUE
wapp-param-exists NAME	→	True if parameter NAME exists
wapp-param-list GLOB	→	Return parameter names matching GLOB
wapp-allow-xorigin-params	→	Allow GET and POST parameters for cross-origin requests
wapp-mimetype MIMETYPE	→	Set the reply mimetype
wapp-reply-code CODE	→	Set the HTTP reply code
wapp-redirect TARGET	→	Redirect to TARGET
wapp-reset	→	Reset the output back to an empty string
wapp-set-cookie NAME VALUE	→	Set cookie NAME to have VALUE
wapp-clear-cookie NAME	→	Delete cookie NAME
wapp-cache-control CONTROL	→	Set caching behavior of current page
wapp-content-security-policy POLICY	→	Set the CSP for the current page
wapp-debug-env	→	Return a text description of the Wapp environment
wapp {TEXT}	→	Append TEXT without substitution
wapp-unsafe TEXT	→	Append TEXT that contains nothing that needs to be escaped
wapp-crash-handler	→	Invoked by Wapp, if it exists, when a TCL error occurs

3.0 CGI Parameters (More detail)

BASE_URL	→	URL for the Wapp script without a method
CONTENT	→	Raw (unparsed) POST content
CONTENT_LENGTH	→	Number of bytes of raw, unparsed POST content
CONTENT_TYPE	→	Mimetype of the POST content
DOCUMENT_ROOT	→	Directory that is the root of the webserver content tree
HTTP_COOKIE	→	Raw, unparsed cookies
HTTP_HOST	→	Hostname to which this request was sent
HTTP_USER_AGENT	→	Name of client program that sent current request
HTTPS	→	Exists and has value "on" if the request is TLS encrypted
PATH_HEAD	→	First element of PATH_INFO. Determines request handler
PATH_INFO	→	URL path beyond the application script name
PATH_TAIL	→	Part of PATH_INFO beyond PATH_HEAD
REMOTE_ADDR	→	IP address of the client
REMOTE_PORT	→	TCP port of the client
REQUEST_METHOD	→	"GET" or "POST" or "HEAD"
SAME_ORIGIN	→	True if this request is from the same origin
SCRIPT_FILENAME	→	Full pathname of the Wapp application script
SCRIPT_NAME	→	Prefix of PATH_INFO that identifies the application script
SELF_URL	→	URL of this request without PATH_TAIL
SERVER_ADDR	→	IP address of the webserver sending an SCGI request
WAPP_MODE	→	One of "cgi", "scgi", "remote-scgi", "server", or "local"

4.0 URL Parsing

Assuming "env.tcl" is the name of the Wapp application script:

https://wapp.tcl.tk/demo/env.tcl/abc/def/ghi?a=5&b=22.425#point42
        \_________/\___________/\__________/ \__________/
             |           |          |             |
         HTTP_HOST  SCRIPT_NAME  PATH_INFO    QUERY_STRING


https://wapp.tcl.tk/demo/env.tcl/abc/def/ghi?a=5&b=22.425#point42
\______________________________/ \_/ \_____/
               |                  |     |
            BASE_URL         PATH_HEAD  `-- PATH_TAIL


https://wapp.tcl.tk/demo/env.tcl/abc/def/ghi?a=5&b=22.425#point42
\__________________________________/         \__________/
               |                                  |
            SELF_URL                         QUERY_STRING


SCRIPT_FILENAME := DOCUMENT_ROOT + SCRIPT_NAME

5.0 Substitutions In wapp-subst and wapp-trim

%html(EXPR)	→	Escape EXPR for display as HTML
%url(EXPR)	→	Escape EXPR for use as a URL
%qp(EXPR)	→	Escape EXPR for use as a URL query parameter
%string(EXPR)	→	Escape EXPR for use as a JSON string
%unsafe(EXPR)	→	Render EXPR exacatly - no escaping

If EXPR contains a ")" character, then use these forms instead:

%html%(EXPR)%	→	Escape EXPR for display as HTML
%url%(EXPR)%	→	Escape EXPR for use as a URL
%qp%(EXPR)%	→	Escape EXPR for use as a URL query parameter
%string%(EXPR)%	→	Escape EXPR for use as a JSON string
%unsafe%(EXPR)%	→	Render EXPR exacatly - no escaping