/ 
Padre-0.80
River stage two • 56 direct dependents • 56 total dependents
/ Padre::DB::Session

NAME

Padre::DB::Session - Padre::DB class for the session table

SYNOPSIS

my @sessions = Padre::DB::Session->select;

DESCRIPTION

This class allows storing in Padre's database the session that Padre knows. This is useful in order to quickly restore a given set of files.

This is the primary table, you also need to check Padre::DB::SessionFiles.

METHODS

last_padre_session

my $session = last_padre_session()

Return a Padre::DB::Session object pointing to last Padre session. If none exists, a new one will be created and returned.

files

my @files = $session->files

Return a list of files (Padre::DB::SessionFile objects) referenced by current $session.

base

# Returns 'Padre::DB'
my $namespace = Padre::DB::Session->base;

Normally you will only need to work directly with a table class, and only with one ORLite package.

However, if for some reason you need to work with multiple ORLite packages at the same time without hardcoding the root namespace all the time, you can determine the root namespace from an object or table class with the base method.

table

# Returns 'session'
print Padre::DB::Session->table;

While you should not need the name of table for any simple operations, from time to time you may need it programatically. If you do need it, you can use the table method to get the table name.

load

my $object = Padre::DB::Session->load( $id );

If your table has single column primary key, a load method will be generated in the class. If there is no primary key, the method is not created.

The load method provides a shortcut mechanism for fetching a single object based on the value of the primary key. However it should only be used for cases where your code trusts the record to already exists.

It returns a Padre::DB::Session object, or throws an exception if the object does not exist.

select

# Get all objects in list context
my @list = Padre::DB::Session->select;

# Get a subset of objects in scalar context
my $array_ref = Padre::DB::Session->select(
    'where id > ? order by id',
    1000,
);

The select method executes a typical SQL SELECT query on the session table.

It takes an optional argument of a SQL phrase to be added after the FROM session section of the query, followed by variables to be bound to the placeholders in the SQL phrase. Any SQL that is compatible with SQLite can be used in the parameter.

Returns a list of Padre::DB::Session objects when called in list context, or a reference to an ARRAY of Padre::DB::Session objects when called in scalar context.

Throws an exception on error, typically directly from the DBI layer.

iterate

Padre::DB::Session->iterate( sub {
    print $_->id . "\n";
} );

The iterate method enables the processing of large tables one record at a time without loading having to them all into memory in advance.

This plays well to the strength of SQLite, allowing it to do the work of loading arbitrarily large stream of records from disk while retaining the full power of Perl when processing the records.

The last argument to iterate must be a subroutine reference that will be called for each element in the list, with the object provided in the topic variable $_.

This makes the iterate code fragment above functionally equivalent to the following, except with an O(1) memory cost instead of O(n).

foreach ( Padre::DB::Session->select ) {
    print $_->id . "\n";
}

You can filter the list via SQL in the same way you can with select.

Padre::DB::Session->iterate(
    'order by ?', 'id',
    sub {
        print $_->id . "\n";
    }
);

You can also use it in raw form from the root namespace for better control. Using this form also allows for the use of arbitrarily complex queries, including joins. Instead of being objects, rows are provided as ARRAY references when used in this form.

Padre::DB->iterate(
    'select name from session order by id',
    sub {
        print $_->[0] . "\n";
    }
);

count

# How many objects are in the table
my $rows = Padre::DB::Session->count;

# How many objects 
my $small = Padre::DB::Session->count(
    'where id > ?',
    1000,
);

The count method executes a SELECT COUNT(*) query on the session table.

It takes an optional argument of a SQL phrase to be added after the FROM session section of the query, followed by variables to be bound to the placeholders in the SQL phrase. Any SQL that is compatible with SQLite can be used in the parameter.

Returns the number of objects that match the condition.

Throws an exception on error, typically directly from the DBI layer.

new

TO BE COMPLETED

The new constructor is used to create a new abstract object that is not (yet) written to the database.

Returns a new Padre::DB::Session object.

create

my $object = Padre::DB::Session->create(

    id => 'value',

    name => 'value',

    description => 'value',

    last_update => 'value',

);

The create constructor is a one-step combination of new and insert that takes the column parameters, creates a new Padre::DB::Session object, inserts the appropriate row into the session table, and then returns the object.

If the primary key column id is not provided to the constructor (or it is false) the object returned will have id set to the new unique identifier.

Returns a new session object, or throws an exception on error, typically from the DBI layer.

insert

$object->insert;

The insert method commits a new object (created with the new method) into the database.

If a the primary key column id is not provided to the constructor (or it is false) the object returned will have id set to the new unique identifier.

Returns the object itself as a convenience, or throws an exception on error, typically from the DBI layer.

delete

# Delete a single instantiated object
$object->delete;

# Delete multiple rows from the session table
Padre::DB::Session->delete('where id > ?', 1000);

The delete method can be used in a class form and an instance form.

When used on an existing Padre::DB::Session instance, the delete method removes that specific instance from the session, leaving the object intact for you to deal with post-delete actions as you wish.

When used as a class method, it takes a compulsory argument of a SQL phrase to be added after the DELETE FROM session section of the query, followed by variables to be bound to the placeholders in the SQL phrase. Any SQL that is compatible with SQLite can be used in the parameter.

Returns true on success or throws an exception on error, or if you attempt to call delete without a SQL condition phrase.

truncate

# Delete all records in the session table
Padre::DB::Session->truncate;

To prevent the common and extremely dangerous error case where deletion is called accidentally without providing a condition, the use of the delete method without a specific condition is forbidden.

Instead, the distinct method truncate is provided to delete all records in a table with specific intent.

Returns true, or throws an exception on error.

ACCESSORS

id

if ( $object->id ) {
    print "Object has been inserted\n";
} else {
    print "Object has not been inserted\n";
}

Returns true, or throws an exception on error.

REMAINING ACCESSORS TO BE COMPLETED

SQL

The session table was originally created with the following SQL command.

CREATE TABLE session (
    id INTEGER NOT NULL PRIMARY KEY,
    name VARCHAR(255) UNIQUE NOT NULL,
    description VARCHAR(255),
    last_update DATE
)

SUPPORT

Padre::DB::Session is part of the Padre::DB API.

See the documentation for Padre::DB for more information.

AUTHOR

Adam Kennedy <adamk@cpan.org>

COPYRIGHT

Copyright 2008-2011 The Padre development team as listed in Padre.pm.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

The full text of the license can be found in the LICENSE file included with this module.