/ 
Net-FluidDB-0.09
/ Net::FluidDB::Object

NAME

Net::FluidDB::Object - FluidDB objects

SYNOPSIS

use Net::FluidDB::Object;

# create, with optional about
$object = Net::FluidDB::Object->new(
    fdb   => $fdb,
    about => $unique_about
);
$object->create;
$object->id; # returns the object's ID in FluidDB 

# get by ID, optionally fetching about
$object = Net::FluidDB::Object->get($fdb, $object_id, about => 1);

# tag
$object->tag("fxn/likes");
$object->tag("fxn/rating", 10, fdb_type => 'integer');
$object->tag("fxn/avatar", $image, mime_type => 'image/png');

# retrieve a tag value
$value = $object->("fxn/rating");

# search
@ids = Net::FluidDB::Object->search($fdb, "has fxn/rating");

DESCRIPTION

Net::FluidDB::Object models FluidDB objects.

USAGE

Inheritance

Net::FluidDB::Object is a subclass of Net::FluidDB::Base.

Class methods

Net::FluidDB::Object->new(%attrs)

Constructs a new object. The constructor accepts these parameters:

fdb (required)

An instance of Net::FluidDB.

about (optional)

A string, if any.

This constructor is only useful for creating new objects in FluidDB. Already existing objects are fetched with get.

Net::FluidDB::Object->get($fdb, $id, %opts)

Retrieves the object with ID $id from FluidDB. Options are:

about (optional, default false)

Tells get whether you want to get the about attribute of the object.

If about is not fetched has_about will be false even if the object has an about attribute in FluidDB.

Net::FluidDB provides a convenience shortcut for this method.

Net::FluidDB::Object->search($fdb, $query)

Performs the query $query and returns a (possibly empty) array of strings with the IDs of the macthing objects.

Net::FluidDB provides a convenience shortcut for this method.

Instance Methods

$object->create

Creates the object in FluidDB.

$object->id

Returns the UUID of the object, or undef if it is new.

$object->has_id

Predicate to test whether the object has an ID.

$object->about
$object->about($about)

Gets/sets the about attribute. About can't be modified in existing objects, the setter is only useful for new objects.

Note that you need to set the about flag when you fetch an object for this attribute to be initialized.

$object->has_about

Says whether the object has an about attribute.

Note that you need to set the about flag when you fetch an object for this attribute to be initialized.

$object->tag_paths

Returns the paths of the existing tags on the object as a (possibly empty) arrayref of strings.

$object->tag($tag_or_tag_path, $value, %options)

Tags an object.

You can pass either a Net::FluidDB::Tag instance instance or a tag path in the first argument. Tag values may be native or non-native.

Tagging with Net::FluidDB::Values

This method accepts Net::FluidDB::Values, in which case no options are needed, but offers a convenience interface to be able to work with plain scalars, see the next item.

Tagging with ordinary scalars

Tagging with ordinary scalars has two interfaces, one for native values, and one for non-native values.

Native values

For native value you need to pass a fdb_type option to indicate its FluidDB type. One of "null", "boolean", "integer", "float", "string", or "set".

$object->tag("fxn/rating", 10, fdb_type => 'integer');

If $value is undef or an arrayref this is not required:

$object->tag("fxn/tags");                    # type null
$object->tag("fxn/tags", undef);             # type null
$object->tag("fxn/tags", ["perl", "moose"]); # type set
Non-native values

To tag with a non-native value you need to pass a mime_type option with a suitable MIME type for it:

$object->tag("fxn/foaf", $foaf, mime_type => "application/rdf+xml");
$object->value($tag_or_tag_path)

Gets the value of a tag on an object.

You can refer to the tag either with a Net::FluidDB::Tag instance or a tag path.

The returned value is an instance of some child of Net::FluidDB::Value. The value method returns the actual scalar value:

$value = $object->value("fxn/rating");
print $value->value;

This object may be inspected: Any value responds to

$value->is_native;
$value->is_non_native;

Native values have predicates:

$value->is_null;
$value->is_boolean;
$value->is_integer;
$value->is_float;
$value->is_string;
$value->is_set;

The MIME type of a non-native value is also available:

$value->mime_type;

FLUIDDB DOCUMENTATION

FluidDB high-level description

http://doc.fluidinfo.com/fluidDB/objects.html

FluidDB API documentation

http://doc.fluidinfo.com/fluidDB/api/objects.html

FluidDB API specification

http://api.fluidinfo.com/fluidDB/api/*/objects/*

AUTHOR

Xavier Noria (FXN), <fxn@cpan.org>

COPYRIGHT AND LICENSE

Copyright (C) 2009 Xavier Noria

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.

See http://dev.perl.org/licenses/ for more information.