NAME
    XAO::DO::FS::Collection - Collection class for XAO::FS

SYNOPSIS
     my $orders=$odb->collection(class => 'Data::Order');

     my $sr=$orders->search('placed_by', 'eq', 'user@host.name');

DESCRIPTION
    Collection class is similar to List object in the sense that it contains
    Hash objects joined by some criteria.

    All Collection objects are read-only, you can use them to search for
    data and to get data objects from them but not to store.

    Methods are (alphabetically):

    container_key ()
        Makes no sense for Collection, will throw an error.

    delete ($)
        Makes no sense for Collection, will throw an error.

    detach ()
        Not implemented, but safe to use.

    exists ($)
        Checks if an object with the given name exists in the collection and
        returns boolean value.

    get (@)
        Retrieves a Hash object from the Collection using the given name.

        As a convenience you can pass more then one object name to the get()
        method to retrieve multiple Hash references at once.

        If an object does not exist an error will be thrown, use exists()
        method to check if you really need to.

    keys ()
        Returns unsorted list of all keys for all objects stored in that
        list.

    new (%)
        You cannot use this method directly. Use collection() method on Glue
        to get a collection reference. Example:

         my $orders=$odb->collection(class => 'Data::Order');

        Currently the only supported type of collection is by class name, a
        collection that joins together all Hashes of the same class.

    objtype ()
        For all Collection objects always return a string 'Collection'.

    put ($;$)
        Makes no sense on collections. Will throw an error.

    search (@)
        Supports the same syntax as List's search() method. See the
        XAO::DO::FS::List manpage for reference.

    values ()
        Returns a list of all Hash objects in the list.

        Note: the order of values is the same as the order of keys returned
        by keys() method. At least until you modify the object directly on
        indirectly. It is not recommended to use values() method for the
        reason of pure predictability.

    uri ($)
        Makes no sense on collections, will throw an error.

AUTHORS
    Xao, Inc. (c) 2001. This module was developed by Andrew Maltsev
    <am@xao.com> with the help and valuable comments from other team
    members.

SEE ALSO
    Further reading: the XAO::FS manpage, the XAO::DO::FS::Hash manpage (aka
    FS::Hash), the XAO::DO::FS::List manpage (aka FS::List). the
    XAO::DO::FS::Glue manpage (aka FS::Glue).

