Constructor

new($SUBJECT_ID|$ARGS)

This constructs a new object and returns a referent to it. If the parameter passed is a hash reference, it is handled as normal, per Class::Std mechanics. If the value is a scalar, it is assumed to be the subject's ID within the system, and is looked up by that.

If the argument is the hash-reference form, then a new object is always constructed; to perform searches see the search() and find() methods. Thus, the following two lines are in fact different:

    $book = WebService::ISBNDB::API::Subjects->
        new({ id => "internet_programming" });

    $book = WebService::ISBNDB::API::Subjects->new('internet_programming');
    

The first creates a new object that has only the "id" attribute set. The second returns a new object that represents the given subject, with all data present.

The class also defines:

copy($TARGET)

Copies the target object into the calling object. All attributes (including the ID) are copied. This method is marked "CUMULATIVE" (see Class::Std), and any sub-class of this class should provide their own copy() and also mark it "CUMULATIVE", to ensure that all attributes at all levels are copied.

See the copy() method in WebService::ISBNDB::API.

Accessors

id

The unique ID within the isbndb.com system for this subject.

name

The name of the subject.

book_count

The number of books listed under this subject.

marc_field

marc_indicator_1

marc_indicator_2

These three attributes make up the subject's MARC (MAchine-Readable Cataloging) information.

categories

A list of category objects for the categories the subject is listed in.

The following accessors are provided to manage these attributes:

get_id

Return the category ID.

set_id($ID)

Sets the category ID. This method is restricted to this class, and cannot be called outside of it. In general, you shouldn't need to set the ID after the object is created, since isbndb.com is a read-only source.

get_name

Return the author's name. This is the full name, as would appear in the "author_text" field of a WebService::ISBNDB::API::Books object.

set_name($NAME)

Set the name to the value in $NAME.

get_book_count

Returns the number of books under this subject.

set_book_count($COUNT)

Set the number of books under this subject.

get_marc_field

Get the MARC field value.

set_marc_field($MARC)

Set the MARC field value.

get_marc_indicator_1

Get the value for the first MARC indicator.

set_marc_indicator_1($MARC_1)

Set the value for the first MARC indicator.

get_marc_indicator_2

Get the value for the second MARC indicator.

set_marc_indicator_2($MARC_1)

Set the value for the second MARC indicator.

get_categories

Return a list-reference of the categories this aubject is listed in. Each element of the list will be an instance of WebService::ISBNDB::API::Categories.

set_categories($CATEGORIES)

Set the categories to the list-reference given in $CATEGORIES. When the author object is first created from the XML data, this list is populated with the IDs of the categories. They are not converted to objects until requested (via get_categories()) by the user.

Utility Methods

find($ARG|$ARGS)

This is a specialization of find() from the parent class. It allows the argument passed in to be a scalar in place of the usual hash reference. If the value is a scalar, it is searched for as if it were the ID. If the value is a hash reference, it is passed to the super-class method.

normalize_args($ARGS)

This method maps the user-visible arguments as defined for find() and search() into the actual arguments that must be passed to the service itself. In addition, some arguments are added to the request to make the service return extra data used for retrieving categories, location, etc. The method changes $ARGS in place, and also returns $ARGS as the value from the method.

See the next section for an explanation of the available keys for searches.