NAME

       Jifty::Param::Schema - Declare parameters of a Jifty action with ease.

SYNOPSIS

           package MyApp::Action::Login;
           use Jifty::Param::Schema;
           use Jifty::Action schema {

           param email =>
               label is 'Email address',
               is mandatory,
               ajax validates;

           param password =>
               type is 'password',
               label is 'Password',
               is mandatory;

           param remember =>
               type is 'checkbox',
               label is 'Remember me?',
               hints is 'If you want, your browser can remember your login for you',
               default is 0;

           };

DESCRIPTION

       This module provides a simple syntax to declare action parameters.

       It re-exports "defer" and "lazy" from Scalar::Defer, for setting parameter fields that
       must be recomputed at request-time:

           param name =>
               default is defer { Jifty->web->current_user->name };

       See Scalar::Defer for more information about "defer".

   schema
       The "schema" block from a Jifty::Action subclass describes an action for a Jifty
       application.

       Within the "schema" block, the localization function "_" is redefined with "defer", so
       that it resolves into a dynamic value that will be recalculated upon each request,
       according to the user's current language preference.

   param
       Each "param" statement inside the "schema" block sets out the name and attributes used to
       describe one named parameter, which is then used to build a Jifty::Param object.  That
       class defines possible field names to use in the declarative syntax here.

       The "param" function is not available outside the "schema" block.

ALIASES

       In addition to the labels provided by Jifty::Web::Form::Field and Jifty::Param, this
       module offers the following aliases:

           ajax validates,             # ajax_validates is 1
           ajax canonicalizes,         # ajax_canonicalizes is 1
           order is -1,                # sort_order is -1
           default is 0,               # default_value is 0
           valid are qw( 1 2 3 ),      # valid_values are qw( 1 2 3 )
           available are qw( 1 2 3 ),  # available_values are qw( 1 2 3 )
           render as 'select',         # render_as is 'select'

SEE ALSO

       Object::Declare, Scalar::Defer

   merge_params HASHREF HASHREF
       Takes two hashrefs. Merges them together and returns the merged hashref.

           - Empty fields in subclasses don't override nonempty fields in superclass anymore.
           - Arrays don't merge; e.g. if parent class's valid_values is [1,2,3,4], and
             subclass's valid_values() is [1,2], they don't somehow become [1,2,3,4,1,2].

       BUG: This should either be a private routine or factored out into Jifty::Util