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Data-Container-0.07
River stage one • 2 direct dependents • 7 total dependents
1 ++
/ Data::Container

NAME

Data::Container - Base class for objects containing a list of items

SYNOPSIS

    package My::Container;
    use base 'Data::Container';
    # ...

    package main;
    my $container = My::Container->new;
    $container->items_push('some_item');

DESCRIPTION

This class implements a container object. The container can contain any object, scalar or reference you like. Typically you would subclass Data::Container and implement custom methods for your specific container.

When the container is stringified, it returns the concatenated stringifications of its items, each two items joined by two newlines.

METHODS

new
    my $obj = Data::Container->new;
    my $obj = Data::Container->new(%args);

Creates and returns a new object. The constructor will accept as arguments a list of pairs, from component name to initial value. For each pair, the named component is initialized by calling the method of the same name with the given value. If called with a single hash reference, it is dereferenced and its key/value pairs are set as described before.

clear_items
    $obj->clear_items;

Deletes all elements from the array.

count_items
    my $count = $obj->count_items;

Returns the number of elements in the array.

index_items
    my $element   = $obj->index_items(3);
    my @elements  = $obj->index_items(@indices);
    my $array_ref = $obj->index_items(@indices);

Takes a list of indices and returns the elements indicated by those indices. If only one index is given, the corresponding array element is returned. If several indices are given, the result is returned as an array in list context or as an array reference in scalar context.

items
    my @values    = $obj->items;
    my $array_ref = $obj->items;
    $obj->items(@values);
    $obj->items($array_ref);

Get or set the array values. If called without an arguments, it returns the array in list context, or a reference to the array in scalar context. If called with arguments, it expands array references found therein and sets the values.

items_clear
    $obj->items_clear;

Deletes all elements from the array.

items_count
    my $count = $obj->items_count;

Returns the number of elements in the array.

items_index
    my $element   = $obj->items_index(3);
    my @elements  = $obj->items_index(@indices);
    my $array_ref = $obj->items_index(@indices);

Takes a list of indices and returns the elements indicated by those indices. If only one index is given, the corresponding array element is returned. If several indices are given, the result is returned as an array in list context or as an array reference in scalar context.

items_pop
    my $value = $obj->items_pop;

Pops the last element off the array, returning it.

items_push
    $obj->items_push(@values);

Pushes elements onto the end of the array.

items_set
    $obj->items_set(1 => $x, 5 => $y);

Takes a list of index/value pairs and for each pair it sets the array element at the indicated index to the indicated value. Returns the number of elements that have been set.

items_shift
    my $value = $obj->items_shift;

Shifts the first element off the array, returning it.

items_splice
    $obj->items_splice(2, 1, $x, $y);
    $obj->items_splice(-1);
    $obj->items_splice(0, -1);

Takes three arguments: An offset, a length and a list.

Removes the elements designated by the offset and the length from the array, and replaces them with the elements of the list, if any. In list context, returns the elements removed from the array. In scalar context, returns the last element removed, or undef if no elements are removed. The array grows or shrinks as necessary. If the offset is negative then it starts that far from the end of the array. If the length is omitted, removes everything from the offset onward. If the length is negative, removes the elements from the offset onward except for -length elements at the end of the array. If both the offset and the length are omitted, removes everything. If the offset is past the end of the array, it issues a warning, and splices at the end of the array.

items_unshift
    $obj->items_unshift(@values);

Unshifts elements onto the beginning of the array.

pop_items
    my $value = $obj->pop_items;

Pops the last element off the array, returning it.

push_items
    $obj->push_items(@values);

Pushes elements onto the end of the array.

set_items
    $obj->set_items(1 => $x, 5 => $y);

Takes a list of index/value pairs and for each pair it sets the array element at the indicated index to the indicated value. Returns the number of elements that have been set.

shift_items
    my $value = $obj->shift_items;

Shifts the first element off the array, returning it.

splice_items
    $obj->splice_items(2, 1, $x, $y);
    $obj->splice_items(-1);
    $obj->splice_items(0, -1);

Takes three arguments: An offset, a length and a list.

Removes the elements designated by the offset and the length from the array, and replaces them with the elements of the list, if any. In list context, returns the elements removed from the array. In scalar context, returns the last element removed, or undef if no elements are removed. The array grows or shrinks as necessary. If the offset is negative then it starts that far from the end of the array. If the length is omitted, removes everything from the offset onward. If the length is negative, removes the elements from the offset onward except for -length elements at the end of the array. If both the offset and the length are omitted, removes everything. If the offset is past the end of the array, it issues a warning, and splices at the end of the array.

unshift_items
    $obj->unshift_items(@values);

Unshifts elements onto the beginning of the array.

items_set_push

Like items_push(), and it also takes a list of items to push into the container, but it doesn't push any items that are already in the container (items are compared deeply to determine equality).

item_grep

Given a package name, it returns those items from the container whose ref() is equal to that package name.

For example, your container could contain some items of type My::Item::Foo and some of type My::Item::Bar. If you only want a list of the items of type My::Item::Foo, you could use:

    my @foo_items = $container->item_grep('My::Item::Foo');
stringify

Stringifies the data container by concatenating the items together, separated by an empty line.

prepare_comparable

Adds support for Data::Comparable by autovivifying the container items array.

BUGS AND LIMITATIONS

No bugs have been reported.

Please report any bugs or feature requests through the web interface at http://rt.cpan.org.

INSTALLATION

See perlmodinstall for information and options on installing Perl modules.

AVAILABILITY

The latest version of this module is available from the Comprehensive Perl Archive Network (CPAN). Visit <http://www.perl.com/CPAN/> to find a CPAN site near you. Or see http://search.cpan.org/dist/Data-Container/.

AUTHORS

Marcel Grünauer, <marcel@cpan.org>

COPYRIGHT AND LICENSE

Copyright 2004-2009 by the authors.

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