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Workflow::Config(3)   User Contributed Perl Documentation  Workflow::Config(3)

       Workflow::Config	- Parse	configuration files for	the workflow

       This documentation describes version 1.12 of this package

	# Reference multiple files

	my $parser = Workflow::Config->new( 'xml' );
	my @config = $parser->parse(
	    'action', 'workflow_action.xml', 'other_actions.xml'

	# Read in one of the file contents from	somewhere else
	my $xml_contents = read_contents_from_db( 'other_actions.xml' );
	my @config = $parser->parse(
	    'action', 'workflow_action.xml', \$xml_contents
	# Reference multiple files of mixed types

	my @action_config = Workflow::Config->parse_all_files(
	    'action', 'my_actions.xml',	'your_actions.perl'

       Read in configurations for the various workflow components. Currently
       the class understands XML (preferred) and serialized Perl data
       structures as valid configuration file formats. (I tried	to use INI
       files but there was too much deeply nested information. Sorry.)

       parse_all_files(	$workflow_config_type, @files )

       Runs through each file in @files	and processes it according to the

   Creating Your Own Parser
       If you want to store your configuration in a different format you can
       create your own parser. All you need to do is:

       1.  subclass Workflow::Config

       2.  implement the required methods (listed below)

       3.  register your parser	with Workflow::Config.

       For instance, if	you wanted to use YAML for configuration files you
       would do	something like:

	# just a convention, you can use any namespace you want
	package	Workflow::Config::YAML;

	use strict;

	# Requirement 1: Subclass Workflow::Config
	use base qw( Workflow::Config );

	# Requirement 2: Implement required methods
	sub parse { ...	}

       The third requirement is	registration, which just tells
       Workflow::Config	which parser to	use for	a particular type. To do this
       you have	two options.

       Registration option one

       Register	yourself in your own class, adding the following call anywhere
       the end:

	# Option 1: Register ourselves by name
	Workflow::Config->register_factory_type( yaml => 'Workflow::Config::YAML' );

       Now you just need to include the	configuration class in your workflow
       invocation script:

	use strict;
	use Workflow::Factory qw( FACTORY );
	use Workflow::Config::YAML; # <-- brings in the	registration

       Registration option two

       You can also just explicitly add	the registration from your workflow
       invocation script:

	use strict;
	use Workflow::Factory qw( FACTORY );
	use Workflow::Config;

	# Option 2: explicitly register	your configuration parser
	Workflow::Config->register_factory_type( yaml => 'Workflow::Config::YAML' );

       Whichever one you choose	you can	now parse (in this example) YAML files
       alongside the built-in parsers for XML and Perl files:

	    workflow  => 'workflow.yaml',
	    action    => [ 'my_actions.yaml', 'other_actions.xml' ],
	    validator => 'validators.yaml',
	    condition => [ 'my_conditions.yaml', 'other_conditions.xml'	]
	    persister => 'persister.perl',

   Inherited Methods
       new( $parser_type )

       Instantiates an object of the correct type -- see Class::Factory	for
       how this	is implemented:

	# Parser of type 'Workflow::Config::XML'
	my $xml_parser	= Workflow::Config->new( 'xml' );

	# Parser of type 'Workflow::Config::Perl
	my $perl_parser	= Workflow::Config->new( 'perl'	);

       is_valid_config_type( $config_type )

       Returns true if $config_type is a valid configuration type, false if
       not. Valid configuration	types are: 'action', 'condition', 'validator',


       Returns list of strings representing the	valid configuration types.

       get_config_type_tag( $class, $type )

       Returns string representing a valid configuration type, looking up the
       type parameter in a lookuptable defined in Workflow::Config class.

   Required Object Methods
       parse( $workflow_config_type, @items )

       Parse each item in @items to a hash reference based on the
       configuration type $config_type which must pass the
       "is_valid_config_type()"	test. An 'item'	is either a filename or	a
       scalar reference	with the contents of a file. (You can mix and match as
       seen in the SYNOPSIS.)

       Should throw an exception if:

       o   You pass an invalid workflow	configuration type. Valid workflow
	   configuration types are registered in Workflow::Config and are
	   available from "get_valid_config_types()"; you can check whether a
	   particular type is valid with "is_valid_config_type()". (See	above
	   for descriptions.)

       o   You pass in a file that cannot be read or parsed because of
	   permissions,	malformed XML, incorrect Perl data structure, etc. It
	   does	not do a validation check (e.g., to ensure that	every 'action'
	   within a workflow state has a 'resulting_state' key).

       Returns:	one hash reference for each member of @items

       This gives you an idea of the configuration information in the various
       workflow	pieces:

	     type	   $
	     description   $
	     persister	   $
	     initial_state $
	     observer	 \@
		 sub	       $
		 class	       $
	     state	 \@
		 name	       $
		 description   $
		 action	       \@
		     name	     $
		     resulting_state $
		     condition	     \@
			 name		   $

       o   the 'type' and 'description'	keys are at the	top level

       o   the 'extra_data' key	holds an array of zero or more hashrefs	with
	   'table', 'field', 'class' and 'context' keys

       o   'initial_state' key holds a string declaring	the name of the
	   initial state.  by default, this value is 'INIITAL'.

       o   'state' key holds array of one or more 'state' declarations;	one of
	   them	must be	'INITIAL' (or the value	of initial_state, if it's

       o   each	'state'	declaration holds 'description'	and 'name' keys	and
	   multiple 'action' declarations

       o   each	'action' declaration holds 'name' and 'resulting_state'	keys
	   and may hold	a 'condition' key with one or more named conditions


	    condition \@
	       name  $
	       class $
	       param \@
		   name	 $
		   value $

       o   array of one	or more	hashrefs with 'name' and 'class' keys


	    validator \@
	       name  $
	       class $
	       param \@
		   name	 $
		   value $

       o   array of one	or more	hashrefs with 'name' and 'class' keys, plus
	   possibly one	or more	'param'	hashrefs each with 'name' and 'value'


	   action \@
	      name  $
	      field \@
		 name	      $
		 is_required  yes|no
		 type	      $
		 source_list  \@ of $
		 source_class $
		 param	      \@
		     name  $
		     value $
	      validator	\@
		  name $
		  arg  \@
		      value $

       o   array of one	or more	action hashrefs	with 'name', 'class' and
	   'description' keys

       o   each	'action' may have zero or more values used to fill it; each
	   value has a 'name', 'description' and 'necessity' ('required' or

       o   each	'action' may have any number of	'param'	hashrefs, each with
	   'name' and 'value'

       o   each	'action' may have any number of	'validator' hashrefs, each
	   with	a 'name' key and array of 'arg'	declarations


	  extra_table	$
	  extra_field	$
	  extra_class	$
	  extra_context	$

       Copyright (c) 2003-2004 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.

       Chris Winters <>

perl v5.32.0			  2020-08-09		   Workflow::Config(3)


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