---
name: "Jifty::Param"
section: "3pm"
platform: "linux"
package: "libjifty-perl"
version: "1.10518+dfsg-2"
release: "Debian 7 (Wheezy)"
platforms: ["linux"]
url: "https://new.carta.tech/Jifty::Param"
---

# Jifty::Param(3pm)

Parameters for Jifty actions

## NAME

Jifty::Param - Parameters for Jifty actions

## DESCRIPTION

Describes a parameter to a `"Jifty::Action"` object.  Do not construct this by hand -- use Jifty::Param::Schema in the action package to declare parameters instead.

### accessors

Although this class is not derived from **Jifty::Web::Form::Field**, it does share the accessors from it; see Jifty::Web::Form::Field, for the list of possible keys that each parameter can have.

In addition to the list there, you may use these additional keys:

- constructor

  A boolean which, if set, indicates that the argument **must** be present in the `"arguments"` passed to create the action, rather than being expected to be set later.

  Defaults to false.

- valid\_values

  An array reference.  Each element should be either:

  - •

    A hash reference with a `"display"` field for the string to display for the value, and a `"value"` field for the value to actually send to the server.

  - •

    A hash reference with a `"collection"` field containing a Jifty::Collection, and `"display_from"` and `"value_from"` fields containing the names of methods to call on each record in the collection to get `"display"` and `"value"`.

  - •

    A simple string, which is treated as both `"display"` and `"value"`.

- available\_values

  Just like valid\_values, but represents the list of suggested values, instead of the list of acceptable values.

- sort\_order

  An integer of how the parameter sorts relative to other parameters. This is usually implicitly generated by its declaration order.

### new

Creates a new Jifty::Param object.  Note that unlike Jifty::Web::Form::Field, the object is never magically reblessed into a subclass.  Should only be called implicitly from a Jifty::Param::Schema declaration.