Jifty::Param::Schema(3) Declare parameters of a Jifty action with ease.


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;


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".


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.


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.


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'

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