Workflow::Action::InputField - Metadata about information required by an Action

This documentation describes version 1.09 of this package

 # Declare the fields needed by your action in the configuration...

 <action name="CreateUser">
    <field name="username"
           is_required="yes"
           source_class="App::Field::ValidUsers" />
    <field name="email"
           is_required="yes" />
    <field name="office"
           source_list="Pittsburgh,Hong Kong,Moscow,Portland" />
 ...

A workflow Action can declare one or more input fields required to do its job. Think of it as a way for the external world (your application) to discover what information an action needs from it. The application can request these fields from the workflow by action name and present them to the user in whatever form appropriate for the application. The sample command-line application shipped with this distribution just cycles through them one at a time and presents a query to the user for data entry.

For instance, in the above declaration there are three fields, 'username', 'email' and 'office'. So your application might do:

 my @action_fields = $wf->get_action_fields( 'CreateUser' );
 foreach my $field ( @action_fields ) {
     print "Field ", $field->name, "\n",
           $field->description, "\n",
           "Required? ", $field->is_required, "\n";
     my @enum = $field->get_possible_values;
     if ( scalar @enum ) {
         print "Possible values: \n";
         foreach my $val ( @enum ) {
             print "  $val->{label} ($val->{value})\n";
         }
     }
     print "Input? ";
     my $response = <STDIN>;
     chomp $response;
     $wf->context->param( $field->name => $response );
 }
 $wf->execute_action( 'CreateUser' );

Typical constructor; will throw exception if 'name' is not defined or if the property 'source_class' is defined but the class it specifies is not available.

You will usually not need to use or override this method unless you derive your own input field class (see class in "Properties" below). For example, suppose you need to add extra properties to all your fields like "index", "disabled", etc.

In your actions definition XML file, you can just add them and the parser will pick them up. Pay close attention the custom InputField "class" property.

  <actions>
    <type>foo</type>
    <action name="Bar"
      class="your::action::class">
      <field index="0" name="id" type="integer" disabled="yes"
        is_required="yes" class="your::custom::inputfieldclass"/>
    </action>

But you need to give them life by creating the accessors for these extra properties. Just derive your custom fields class like so:

  package your::custom::inputfieldclass;

  use warnings;
  use strict;

  use base qw( Workflow::Action::InputField );
  use Workflow::Exception qw( workflow_error );

  # extra action class properties
  my @EXTRA_PROPS = qw( index disabled );
  __PACKAGE__->mk_accessors(@EXTRA_PROPS);

  sub new {
    my ( $class, $params ) = @_;
    my $self = $class->SUPER::new($params);
    # set only our extra properties
    foreach my $prop (@EXTRA_PROPS) {
      next if ( $self->$prop );
      $self->$prop( $params->{$prop} );
    }
    warn "INDEX IS NOW WORKING:".$self->index;
    warn "AND SO IS DISABLED:".$self->disabled;
    return $self;
  }

  1;

Returns 'yes' if field is required, 'no' if optional.

Returns 'yes' if field is optional, 'no' if required.

Returns list of possible values for this field. Each possible value is represented by a hashref with the keys 'label' and 'value' which makes it easy to create dropdown lists in templates and the like.

Adds possible values to be used for this field. Each item in @values may be a simple scalar or a hashref with the keys 'label' and 'value'.

Init is a dummy and just returns no special actions are taken

name (required)

Name of the field. This is what the action expects as the key in the workflow context.

label (optional)

Label of the field. If not set the value for name is used.

description (optional)

What does the field mean? This is not required for operation but it is strongly encouraged so your clients can create front ends to feed you the information without much fuss.

type (optional)

Field types are implementation dependant are they should be intrinsically implemented by validators. In other words, you can use any mnemonic value for your convinience like "integer", "text", etc. but it won't affect anything unless you use a validator to validate your action data. By default it is set to 'basic'.

requirement ('required'|'optional')

If field is required, 'required', otherwise 'optional'.

source_class (optional)

If set the field will call 'get_possible_values()' on the class when the field is instantiated. This should return a list of either simple scalars or a list of hashrefs with 'label' and 'value' keys.

source_list (optional)

If set the field will use the specified comma-separated values as the possible values for the field. The resulting list returned from get_possible_values() will have the same value for both the 'label' and 'value' keys.

class (optional)

You may specify a custom InputField class. It should use base qw( Workflow::Action ); and probably override the new() method which should call SUPER::new($params). See "new( \%params )" above for an example.

Workflow::Action

Copyright (c) 2003-2007 Chris Winters. All rights reserved.

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

Jonas B. Nielsen (jonasbn) <jonasbn@cpan.org> is the current maintainer.

Chris Winters <chris@cwinters.com>, original author.