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.

AUTHOR

Jonathan Swartz <swartz@pobox.com>

COPYRIGHT AND LICENSE

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.