| Workflow documentation | Contained in the Workflow distribution. |
Workflow::Persister::DBI::ExtraData - Fetch extra data with each workflow and put it into the context
This documentation describes version 1.05 of this package
<persister name="MyPersister"
class="Workflow::Persister::DBI::ExtraData"
dsn="DBI:mysql:database=workflows"
user="wf"
password="mypass"
extra_table="workflow_ticket"
extra_data_field="ticket_id"
extra_context_key="ticket_id"/>
Simple subclass of Workflow::Persister::DBI to allow you to declare an extra table and data field(s) from which to fetch data whenever you fetch a workflow. There is a simple restriction: the table must have a field 'workflow_id' of the same datatype as the 'workflow_id' field in the 'workflow' table.
# Specify a single field 'ticket_id' from the table 'workflow_ticket'
# and store it in the context using the same key:
<persister
...
extra_table="workflow_ticket"
extra_data_field="ticket_id"
...
# How you would use this:
my $wf = FACTORY->fetch_workflow( 'Ticket', 55 );
print "Workflow is associated with ticket: ",
$wf->context->param( 'ticket_id' );
# Specify a single field 'ticket_id' from the table 'workflow_ticket'
# and store it in the context using a different key
<persister
...
extra_table="workflow_ticket"
extra_data_field="ticket_id"
extra_context_key="THE_TICKET_ID"
...
# How you would use this:
my $wf = FACTORY->fetch_workflow( 'Ticket', 55 );
print "Workflow is associated with ticket: ",
$wf->context->param( 'THE_TICKET_ID' );
# Specify multiple fields ('ticket_id', 'last_viewer',
# 'last_view_date') to pull from the 'workflow_ticket' table:
<persister
...
extra_table="workflow_ticket"
extra_data_field="ticket_id,last_viewer,last_view_date"
...
# How you would use this:
my $wf = FACTORY->fetch_workflow( 'Ticket', 55 );
print "Workflow is associated with ticket: ",
$wf->context->param( 'ticket_id' ), " ",
"which was last viewed by ",
$wf->context->param( 'last_viewer' ), " on ",
$wf->context->param( 'last_view_date' );
extra_table (required)
Table where the extra data are kept.
extra_data_field (required)
Can be a single field or a comma-separated list of fields, all in the
same table. If a single field specified you have the option of
declaring a different extra_context_key under which the value
should be stored in the workflow context. Otherwise the values are
stored by the field names in the workflow context.
extra_context_key (optional)
Key under which to save the data from extra_data_field in the
workflow context.
Note: this is ignored when you specify multiple fields in
extra_data_field; we just use the fieldnames for the context keys
in that case. And if you specify a single data field and do not
specify a context key we also use the data field name.
Initializes persister for extra workflow data.
Throws Workflow::Exception if initialization is not successful.
Fetches extra data from database and feeds this to context of given workflow.
Takes a single parameter, a workflow object to which extra data are feed if retrieved successfully.
Throws Workflow::Exception if retrieval is not successful.
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.
| Workflow documentation | Contained in the Workflow distribution. |
package Workflow::Persister::DBI::ExtraData; # $Id: ExtraData.pm 516 2010-01-30 13:41:38Z jonasbn $ use warnings; use strict; use base qw( Workflow::Persister::DBI ); use Log::Log4perl qw( get_logger ); use Workflow::Exception qw( configuration_error persist_error ); use English qw( -no_match_vars ); $Workflow::Persister::DBI::ExtraData::VERSION = '1.05'; my @FIELDS = qw( table data_field context_key ); __PACKAGE__->mk_accessors(@FIELDS); sub init { my ( $self, $params ) = @_; $self->SUPER::init($params); my $log = get_logger(); my @not_found = (); foreach (qw( table data_field )) { push @not_found, $_ unless ( $params->{"extra_$_"} ); } if ( scalar @not_found ) { $log->error( "Required configuration fields not found: ", join ', ', @not_found ); configuration_error "To fetch extra data with each workflow with this implementation ", "you must specify: ", join ', ', @not_found; } $self->table( $params->{extra_table} ); my $data_field = $params->{extra_data_field}; # If multiple data fields specified we don't allow the user to # specify a context key if ( $data_field =~ /,/ ) { $self->data_field( [ split /\s*,\s*/, $data_field ] ); } else { $self->data_field($data_field); my $context_key = $params->{extra_context_key} || $data_field; $self->context_key($context_key); } $log->is_info && $log->info( "Configured extra data fetch with: ", join '; ', $self->table, $data_field, $self->context_key ); } sub fetch_extra_workflow_data { my ( $self, $wf ) = @_; my $log = get_logger(); $log->is_debug && $log->debug( "Fetching extra workflow data for '", $wf->id, "'" ); my $sql = q{ SELECT %s FROM %s WHERE workflow_id = ? }; my $data_field = $self->data_field; my $select_data_fields = ( ref $data_field ) ? join( ', ', @{$data_field} ) : $data_field; $sql = sprintf $sql, $select_data_fields, $self->table; $log->is_debug && $log->debug("Using SQL\n$sql"); $log->is_debug && $log->debug( "Bind parameters: ", $wf->id ); my ($sth); eval { $sth = $self->handle->prepare($sql); $sth->execute( $wf->id ); }; if ($EVAL_ERROR) { persist_error "Failed to retrieve extra data from table ", $self->table, ": $EVAL_ERROR"; } else { $log->is_debug && $log->debug("Prepared/executed extra data fetch ok"); my $row = $sth->fetchrow_arrayref; if ( ref $data_field ) { ## no critic (ProhibitCStyleForLoops) for ( my $i = 0; $i < scalar @{$data_field}; $i++ ) { $wf->context->param( $data_field->[$i], $row->[$i] ); $log->is_info && $log->info( sprintf "Set data from %s.%s into context key %s ok", $self->table, $data_field->[$i], $data_field->[$i] ); } } else { my $value = $row->[0]; $wf->context->param( $self->context_key, $value ); $log->is_info && $log->info( sprintf "Set data from %s.%s into context key %s ok", $self->table, $self->data_field, $self->context_key ); } } } 1; __END__