- To be done
- - Support elements in the HTML header that allow controlling the page,
such as setting the CGI-header, authorization, etc.
- Allow external styling. Pass through reply_html_page/2?
Allow filtering the DOM before/after PWP?
This module provides convenience predicates to include PWP (Prolog
Well-formed Pages) in a Prolog web-server. It provides the following
predicates:
pwp_handler / 2- This is a complete web-server aimed at serving static pages, some of
which include PWP. This API is intended to allow for programming the
web-server from a hierarchy of pwp files, prolog files and static
web-pages.
reply_pwp_page / 3- Return a single PWP page that is executed in the context of the calling
module. This API is intended for individual pages that include so much
text that generating from Prolog is undesirable.
- pwp_handler(+Options,
+Request)
- Handle PWP files. This predicate is defined to create a simple HTTP
server from a hierarchy of PWP, HTML and other files. The interface is
kept compatible with the
library(http/http_dispatch). In the typical usage scenario,
one needs to define an http location and a file-search path that is used
as the root of the server. E.g., the following declarations create a
self-contained web-server for files in /web/pwp/.
user:file_search_path(pwp, '/web/pwp').
:- http_handler(root(.), pwp_handler([path_alias(pwp)]), [prefix]).
Options include:
- path_alias(+Alias)
- Search for PWP files as Alias(Path). See absolute_file_name/3.
- index(+Index)
- Name of the directory index (pwp) file. This option may appear multiple
times. If no such option is provided,
pwp_handler/2 looks for
index.pwp.
- view(+Boolean)
- If
true (default is false), allow for
?view=source to serve PWP file as source.
- index_hook(:Hook)
- If a directory has no index-file, pwp_handler/2
calls
Hook(PhysicalDir, Options, Request). If
this semidet predicate succeeds, the request is considered handled.
- hide_extensions(+List)
- Hide files of the given extensions. The default is to hide .pl files.
- dtd(?DTD)
- DTD to parse the input file with. If unbound, the generated
DTD is returned
- Errors
permission_error(index, http_location, Location) is raised
if the handler resolves to a directory that has no index.- See also
- reply_pwp_page/3
- reply_pwp_page(:File,
+Options, +Request)
- Reply a PWP file. This interface is provided to server individual
locations from PWP files. Using a PWP file rather than generating the
page from Prolog may be desirable because the page contains a lot of
text (which is cumbersome to generate from Prolog) or because the
maintainer is not familiar with Prolog.
Options supported are:
- mime_type(+Type)
- Serve the file using the given mime-type. Default is text/html.
- unsafe(+Boolean)
- Passed to http_safe_file/2
to check for unsafe paths.
- pwp_module(+Boolean)
- If
true, (default false), process the PWP file
in a module constructed from its canonical absolute path. Otherwise, the
PWP file is processed in the calling module.
Initial context:
- SCRIPT_NAME
- Virtual path of the script.
- SCRIPT_DIRECTORY
- Physical directory where the script lives
- QUERY
- Var=Value list representing the query-parameters
- REMOTE_USER
- If access has been authenticated, this is the authenticated user.
- REQUEST_METHOD
- One of
get, post, put or head
- CONTENT_TYPE
- Content-type provided with HTTP POST and PUT requests
- CONTENT_LENGTH
- Content-length provided with HTTP POST and PUT requests
While processing the script, the file-search-path pwp includes the
current location of the script. I.e., the following will find myprolog
in the same directory as where the PWP file resides.
pwp:ask="ensure_loaded(pwp(myprolog))"
- See also
- pwp_handler/2.
- To be done
- complete the initial context, as far as possible from CGI variables. See http://hoohoo.ncsa.illinois.edu/docs/cgi/env.html