=head1 NAME

DBIx::TransactionManager::Developers - docs for developers

=head1 DESCRIPTION

This document describes a document for O/R mapper writer and/or DBIx::* writer.

=head1 MORE DOCUMETNS for DBIx::TransactionManager class

=over 4

=item my $txn = $tm->txn_scope(%args)

Create a new DBIx::TransactionManager::ScopeGuard's instance object.

You can pass an optional argument to C<%args>, to tell the scope guard
where the scope was generated, like so:

    package Foo;
    use Moose;
    sub mymethod {
        my $self = shift;
        my $txn = $tm->txn_scope( caller => [ caller() ] );
        return $txn;
    }

    package main;
    my $obj = Foo->new();
    my $txn = $obj->mymethod();

This will allow the guard object to report the caller's location
from the perspective of C<mymethod()>, not where C<txn_scope()> was
called.

see L</DBIx::TransactionManager::ScopeGuard's METHODS>

=item $tm->txn_begin(%args)

Start the transaction.

C<txn_begin> may optionally take a 'caller' argument. This will allow you to
provide caller information which will be used in C<in_transaction>. For example
if you have a wrapper function that calls C<txn_begin>, you may want to 
let the user think that the caller was one stack above your wrapper.

    # use __my__ caller!
    $tm->txn_begin( caller => [ caller(0) ] ); 

=item $tm->txn_commit()

Commit the current transaction.

If the C<$dbh> is in a nested transaction, TransactionManager doesn't do COMMIT at here. TM just poped transaction stack and do nothing.

=item $tm->txn_rollback()

Rollback the current transaction.

If the C<$dbh> is in a nested transaction, TransactionManager doesn't do ROLLBACK at here. TM just poped transaction stack and do nothing.

=item $tm->in_transaction() : Bool

Returns true if $txn is currently in a middle of a transaction. While normally
you only need to use this value as a boolean, it actually returns a hashref
consisting of 'caller' and 'pid' element. This will tell you exactly where
the currently valid transaction started.

=back