/ 
Class-DBI-ViewLoader-0.01
River stage one • 1 direct dependent • 1 total dependent
/ Class::DBI::ViewLoader

NAME

Class::DBI::ViewLoader - Load views from database tables as Class::DBI objects

SYNOPSIS

    use Class::DBI::ViewLoader;

    # set up loader object
    $loader = new Class::DBI::ViewLoader (
	    dsn => 'dbi:Pg:dbname=mydb',
	    username => 'me',
	    password => 'mypasswd',
	    options => {
		RaiseError => 1,
		AutoCommit => 1
	    },
	    namespace => 'MyClass::View',
	    exclude => qr(^te(?:st|mp)_)i,
	    include => qr(_foo$),
	);

    # create classes
    @classes = $loader->load_views;

    MyClass::View::LiveFoo->retrieve_all()

DESCRIPTION

This class loads views from databases as Class::DBI classes. It follows roughly the same interface employed by Class::DBI::Loader.

This class behaves as a base class for the database-dependent driver classes, which are loaded by Module::Pluggable. Objects are reblessed into the relevant subclass as soon as the driver is discovered, see set_dsn(). Driver classes should always be named Class::DBI::ViewLoader::<driver_name>.

CONSTRUCTOR

new

$obj = $class->new(%args)

Instantiates a new object. The values of %args are passed to the relevant set_* accessors, detailed below. The following 2 statements should be equivalent:

new Class::DBI::ViewLoader ( dsn => $dsn, username => $user );

new Class::DBI::ViewLoader->set_dsn($dsn)->set_username($user);

ACCESSORS

set_dsn

$obj = $obj->set_dsn($dsn_string)

Sets the datasource for the object. This should be in the form understood by DBI e.g. "dbi:Pg:dbname=mydb"

Calling this method will rebless the object into a handler class for the given driver. If no handler is installed, "No handler for driver" will be raised via croak().

get_dsn

$dsn = $obj->get_dsn

Returns the dsn string, as passed in by set_dsn.

set_username

$obj = $obj->set_username($username)

Sets the username to use when connecting to the database.

get_username

$username = $obj->get_username

Returns the username.

set_password

$obj = $obj->set_password

Sets the password to use when connecting to the database.

get_password

$password = $obj->get_password

Returns the password

set_options

$obj = $obj->set_dbi_options(%opts)

Accepts a hash or a hash reference.

Sets the additional configuration options to pass to DBI.

The hash will be copied internally, to prevent against any accidental modification after assignment.

get_options

\%opts = $obj->get_dbi_options

Returns the DBI options hash. The return value should always be a hash reference, even if there are no dbi options set.

The reference returned by this function is live, so modification of it directly affects the object.

set_namespace

$obj = $obj->set_namespace($namespace)

Sets the namespace to load views into.

get_namespace

$namespace = $obj->get_namespace

Returns the target namespace. If not set, returns an empty list.

set_include

$obj = $obj->set_include($regexp)

Sets a regexp that matches the views to load.

Accepts strings or Regexps, croaks if any other reference is passed.

The value is stored as a Regexp, even if a string was passed in.

get_include

$regexp = $obj->get_include

Returns the include regular expression.

Note that this may not be identical to what was passed in.

set_exclude

$obj = $obj->set_exclude($regexp)

Sets a regexp to use to rule out views.

Accepts strings or Regexps, croaks if any other reference is passed.

The value is stored as a Regexp, even if a string was passed in.

get_exclude

Returns the exclude regular expression.

Note that this may not be identical to what was passed in.

load_views

@classes = $obj->load_views

The main method for the class, loads all relevant views from the database and generates classes for those views.

The generated classes will and be read-only, and have a multi-column primary key containing every column. This is because it is unlikely that the view will have a real primary key.

Returns class names for all created classes.

DRIVER METHODS

The following methods are provided by the relevant driver classes. If they are called on a native Class::DBI::ViewLoader object (one without a dsn set), they will cause fatal errors. They are mostly documented here for the benefit of driver writers but they may prove useful for users also.

base_class

$class = $driver->base_class

Returns the name of the base class to be used by generated classes.

get_views

@views = $driver->get_views;

Returns the names of all the views in the database.

get_view_cols

@columnss = $driver->get_view_cols($view);

Returns the names of all the columns in the given view.

DIAGNOSTICS

The following fatal errors are raised by this class:

  • No handler for driver %s, from dsn %s";

    set_dsn couldn't find a driver handler for the given dsn. You may need to install a plugin to handle your database.

  • No handler loaded

    load_views() or some other driver-dependent method was called on an object which hadn't loaded a driver.

  • %s not overridden

    A driver did not override the given method.

  • Couldn't connect to database

    Self-explanatory. The DBI error string is appended to the error message.

  • Regexp or string required

    set_include or set_exclude called with a ref other than 'Regexp'.

  • Unrecognised arguments in new

    new() encountered unsupported arguments. The offending arguments are listed after the error message.

SEE ALSO

DBI, Class::DBI, Class::DBI::Loader

AUTHOR

Matt Lawrence <mattlaw@cpan.org>