How does DBIx::Class::Storage::DBI's connect_info work? - perl

Question

The docs for connect_info:
connect_info
This method is normally called by "connection" in DBIx::Class::Schema,
which encapsulates its argument list in an arrayref before passing
them here.
The argument list may contain:
The same 4-element argument set one would normally pass to "connect"
in DBI, optionally followed by extra attributes recognized by
DBIx::Class:
$connect_info_args = [ $dsn, $user, $password, \%dbi_attributes?, \%extra_attributes? ];
A single code reference which returns a
connected DBI database handle optionally followed by extra attributes
recognized by DBIx::Class:
$connect_info_args = [ sub { DBI->connect (...) }, \%extra_attributes? ];
A single hashref with all the attributes and the dsn/user/password
mixed together:
$connect_info_args = [{
dsn => $dsn,
user => $user,
password => $pass,
%dbi_attributes,
%extra_attributes,
}];
$connect_info_args = [{
dbh_maker => sub { DBI->connect (...) },
%dbi_attributes,
%extra_attributes,
}];
This is particularly useful
for Catalyst based applications, allowing the following config
(Config::General style):
<Model::DB>
schema_class App::DB
<connect_info>
dsn dbi:mysql:database=test
user testuser
password TestPass
AutoCommit 1
</connect_info>
</Model::DB>
The dsn/user/password combination can be substituted by the dbh_maker key
whose value is a coderef that returns a connected DBI database handle
Please note that the DBI docs recommend that you always explicitly set
AutoCommit to either 0 or 1. DBIx::Class further recommends that it be
set to 1, and that you perform transactions via our "txn_do" in
DBIx::Class::Schema method. DBIx::Class will set it to 1 if you do not
do explicitly set it to zero. This is the default for most DBDs. See
"DBIx::Class and AutoCommit" for details.
What is this? Is it a method called internally, or a global? And, if it's a method called internally why is it being sent either a dbh maker, or four arguments? What determines what it is sent? It's listed as being a method. What is $connect_info_args?

Answer 1

Here is how I got it to work
Schema Class
You've got to use the storage that's done like this (and you can find it in the docs)
package MyDBIC::Schema;
__PACKAGE__->storage_type("DBIx::Class::Storage::DBI::mysql::MySubClass")
Storage Class
package DBIx::Class::Storage::DBI::mysql::MySubClass;
use mro 'c3';
use base 'DBIx::Class::Storage::DBI::mysql';
sub connect_info {
my $self = shift;
my $retval = $self->next::method([{
username => _username(),
password => $password,
dsn => "my:dsn:"
})
$retval;
};
I found a rough example of how to do it burred here. Talk about shitty docs..
connect_info appears to be broke. Things tried.
Subclassing a Storage with a custom connect_info. It gets called, but nothing it returns does anything useful. Calling ->connect->storage->ensure_connected; on a schema results in error.
Wrapping connect_info with Moose::around(). Fails to wrap. The method 'connect_info' was not found in the inheritance hierarchy.
Calling $self->connect_info() from BUILD... DBIx::Class::Storage::DBI::connect_info gets called but no matter what I hand to it, the sub only gets $self, the first argument.
Calling __PACKAGE__->connect_info({}) or __PACKAGE__->connect_info([{}]) results in both arguments being sent to the DBIx::Class::Storage::DBI::connect_info but the lack of a $self results in Class::XSAccessor: invalid instance method invocant: no hash ref supplied at when the sub tries to write to the accessor.