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Created page with "=== NAME === esmith::DB::db - interface to esmith::db databases in a root terminal you can do perldoc -U esmith::DB::db === SYNOPSIS === Works just like an esmith::DB class ..."
=== NAME ===
esmith::DB::db - interface to esmith::db databases
in a root terminal you can do
perldoc -U esmith::DB::db
=== SYNOPSIS ===
Works just like an esmith::DB class except where noted

=== DESCRIPTION ===
This module provides an abstracted interface to esmith::db flat-file databases. It will read from and write to esmith::db files and can be safely used right along side esmith::db. This follows the esmith::DB interface and will work as documented there unless otherwise stated.

You should use this instead of esmith::db, and replace any existing esmith::db code with this.

Note for esmith::db users the old concept of a ’type’ is now simply another property.

my $type = $record->prop(’type’);

replaces db_get_type().

The $record returned by esmith::DB::db subclass is an esmith::DB::db::Record subclass object. See the esmith::DB::db manpage for details on how it is used.

==== Methods ====


===== create =====
Puts its error on esmith::DB::db->error

open
open_local
as_hash
reload
file
new_record
get
get_all
get_all_by_prop

=== EXAMPLE ===
The full docs can be found in esmith::DB and esmith::DB::Record, but here’s a cheat sheet for esmith::config and esmith::db users.

==== opening the default config ====
use esmith::config
my %config;
tie %config, ’esmith::config;

Now:

use esmith::ConfigDB;
my $config = esmith::ConfigDB->open;

==== opening a specific config database ====
my %config;
tie %config, ’esmith::config’, $config_file;

Now:

my $config = esmith::ConfigDB->open($config_file);

==== creating a new config database ====
This one’s important. Before you could just tie esmith::config to any file and it would create it for you. Now you have to explicitly create it.

my %config;
tie %config, ’esmith::config’, $new_config_file;

Now:

my $config = esmith::ConfigDB->create($new_config_file);

==== checking if a record exists ====
print "Yep" if exists $config{foo};

now:

print "Yep" if $config->get(’foo’); # unless of course, ’foo’ is zero

==== creating a new record ====
Previously you could just create records on the fly:

# single value
$config{foo} = ’whatever’;

# with properties
db_set(\%config, ’whatever’, ’sometype’, { with => ’properties’ });

Now you have to explicitly create them:

# single value
my $foo = $config->new_record(’foo’);
$foo->set_value(’foo’);

# with properties
my %defaults = ( ’type’ => ’sometype’,
’linux’ => ’stable’,
’windows’ => ’stable?’ );
my $foo = $config->new_record(’foo’, \%defaults);

Note that ’type’ is now just another property.

Here’s a handy "create this if it doesn’t already exist" idiom.

my $rec = $config->get($key) ││
$config->new_record($key);

==== getting a value ====
Entries in a database should no longer be thought of as values, but as records.

my $val = $config{foo};

Now this only works with entries with single value. Things with multiple properties are dealt with differently.

my $record = $config->get(’foo’);
my $val = $record->value;

==== setting a value ====
$config{foo} = ’something’;

now

my $record = $config->get(’foo’);
$record->set_value(’something’);

==== getting a property ====
my $this = db_get_prop(\%config, ’foo’, ’this’);

now:

my $foo = $config->get(’foo’);
my $this = $foo->prop(’this’);

==== getting & setting properties ====
my $val = db_get_prop(\%config, ’foo’, ’some prop’);
db_set_prop(\%config, ’foo’, ’some prop’ => $new_val);

now:

my $val = $record->prop(’some prop’);
$record->set_prop(’some prop’ => $new_val);

==== get/setting the type ====
my $type = db_get_type(\%config, ’foo’);
db_set_type(\%config, ’foo’, $new_type);

type is now just a property

my $record = $db->get(’foo’);
my $type = $record->prop(’type’);
$record->set_prop(’type’, $new_type);

==== getting all the properties ====
my %props = db_get_prop(\%config, ’foo’);

now

my %props = $record->props;

=== AUTHOR ===
SME Server Developers <bugs@e-smith.com>
[[Category:Developer]]
[[Category:SME Server Development Framework]]
[[Category:Development Tools]]

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