NAME
Mason::Manual::RequestDispatch - How request paths get mapped to page components
DESCRIPTION
Given the request path
/news/sports/hockey
Mason searches for the following components in order, setting $m->path_info as noted.
/news/sports/hockey.{mp,mc}
/news/sports/hockey/index.{mp,mc}
/news/sports/hockey/dhandler.{mp,mc}
/news/sports/dhandler.{mp,mc} # $m->path_info = hockey
/news/sports.{mp,mc} # $m->path_info = hockey (but see next section)
/news/dhandler.{mp,mc} # $m->path_info = sports/hockey
/news.{mp,mc} # $m->path_info = sports/hockey (but see next section)
/dhandler.{mp,mc} # $m->path_info = news/sports/hockey
where .{mp,mc}
means either .mp
(indicating a pure-perl component). or .mc
(indicating a top-level component).
The following sections describe these elements in more detail.
Autoextended path
The request path is suffixed with ".mp" and ".mc" to translate it to a component path.
/news/sports/hockey.{mp,mc}
Index
An index matches its exact directory, nothing underneath.
/news/sports/hockey/index.{mp,mc}
Dhandlers
A dhandler matches its directory as well as anything underneath, setting $m->path_info
to the remainder.
/news/sports/hockey/dhandler.{mp,mc}
/news/sports/dhandler.{mp,mc} # $m->path_info = hockey
/news/dhandler.{mp,mc} # $m->path_info = sports/hockey
/dhandler.{mp,mc} # $m->path_info = news/sports/hockey
Partial paths
A component can match an initial part of the URL, setting $m->path_info
to the remainder:
/news/sports.{mp,mc} # $m->path_info = hockey
/news.{mp,mc} # $m->path_info = sports/hockey
Since this isn't always desirable behavior, it must be explicitly enabled for the component. Mason will call method allow_path_info
on the component class, and will only allow the match if it returns true:
<%class>
method allow_path_info { 1 }
</%class>
The default allow_path_info
returns false.
allow_path_info
is not checked on dhandlers, since the whole point of dhandlers is to match partial paths.
Trailing slash
If the request URL has a trailing slash (ends with /
), we remove it before the match process begins and add it to the $m->path_info
. Components that should match must have allow_path_info
return true.
For example:
## request URL /news/
/news/index.{mp,mc} # $m->path_info = / if index.{mp,mc} has
# allow_path_info => true
/news/dhandler.{mp,mc} # $m->path_info = /
/news.{mp,mc} # $m->path_info = / if news.{mp,mc} has
# allow_path_info => true
## request URL /news/sports/
/news/sports/index.{mp,mc} # $m->path_info = / if index.{mp,mc} has
# allow_path_info => true
/news/sports/dhandler.{mp,mc} # $m->path_info = /
/news/sports.{mp,mc} # $m->path_info = / if sports.{mp,mc}
# has allow_path_info => true
/news/dhandler.{mp,mc} # $m->path_info = sports/
/news.{mp,mc} # $m->path_info = /sports/ if news.{mp,mc}
# has allow_path_info => true
Routes
It is possible to use route syntax to more elegantly parse $m->path_info
for dhandlers and partial paths, e.g.
<%class>
route "{year:[0-9]+}/{month:[0-9]{2}}";
</%class>
See Mason::Plugin::RouterSimple.
SEE ALSO
AUTHOR
Jonathan Swartz <swartz@pobox.com>
COPYRIGHT AND LICENSE
This software is copyright (c) 2012 by Jonathan Swartz.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.