Workflow::Config(3) User Contributed Perl Documentation Workflow::Config(3)NAMEWorkflow::Config - Parse configuration files for the workflow
components
VERSION
This documentation describes version 1.12 of this package
SYNOPSIS
# 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'
);
DESCRIPTION
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.)
CLASS METHODS
parse_all_files( $workflow_config_type, @files )
Runs through each file in @files and processes it according to the
valid
SUBCLASSING
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:
FACTORY->add_config_from_file(
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',
'workflow'.
get_valid_config_types()
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:
· 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.)
· 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
CONFIGURATION INFORMATION
This gives you an idea of the configuration information in the various
workflow pieces:
workflow
workflow
type $
description $
persister $
observer \@
sub $
class $
state \@
name $
description $
action \@
name $
resulting_state $
condition \@
name $
· the 'type' and 'description' keys are at the top level
· the 'extra_data' key holds an array of zero or more hashrefs with
'table', 'field', 'class' and 'context' keys
· 'state' key holds array of one or more 'state' declarations; one of
them must be 'INITIAL'
· each 'state' declaration holds 'description' and 'name' keys and
multiple 'action' declarations
· each 'action' declaration holds 'name' and 'resulting_state' keys
and may hold a 'condition' key with one or more named conditions
condition
conditions:
condition \@
name $
class $
param \@
name $
value $
· array of one or more hashrefs with 'name' and 'class' keys
validator
validators:
validator \@
name $
class $
param \@
name $
value $
· array of one or more hashrefs with 'name' and 'class' keys, plus
possibly one or more 'param' hashrefs each with 'name' and 'value'
keys
action
actions:
action \@
name $
field \@
name $
is_required yes|no
type $
source_list \@ of $
source_class $
param \@
name $
value $
validator \@
name $
arg \@
value $
· array of one or more action hashrefs with 'name', 'class' and
'description' keys
· each 'action' may have zero or more values used to fill it; each
value has a 'name', 'description' and 'necessity' ('required' or
'optional')
· each 'action' may have any number of 'param' hashrefs, each with
'name' and 'value'
· each 'action' may have any number of 'validator' hashrefs, each
with a 'name' key and array of 'arg' declarations
persister
persister:
extra_table $
extra_field $
extra_class $
extra_context $
COPYRIGHT
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.
AUTHORS
Chris Winters <chris@cwinters.com>
perl v5.14.1 2011-07-21 Workflow::Config(3)
