Template::Iterator - phpMan

NAME
    Template::Iterator - Data iterator used by the FOREACH directive

SYNOPSIS
        my $iter = Template::Iterator->new(\@data, \%options);

DESCRIPTION
    The "Template::Iterator" module defines a generic data iterator for use
    by the "FOREACH" directive.

    It may be used as the base class for custom iterators.

PUBLIC METHODS
  new($data)
    Constructor method. A reference to a list of values is passed as the
    first parameter. Subsequent calls to get_first() and get_next() calls
    will return each element from the list.

        my $iter = Template::Iterator->new([ 'foo', 'bar', 'baz' ]);

    The constructor will also accept a reference to a hash array and will
    expand it into a list in which each entry is a hash array containing a
    '"key"' and '"value"' item, sorted according to the hash keys.

        my $iter = Template::Iterator->new({
            foo => 'Foo Item',
            bar => 'Bar Item',
        });

    This is equivalent to:

        my $iter = Template::Iterator->new([
            { key => 'bar', value => 'Bar Item' },
            { key => 'foo', value => 'Foo Item' },
        ]);

    When passed a single item which is not an array reference, the
    constructor will automatically create a list containing that single
    item.

        my $iter = Template::Iterator->new('foo');

    This is equivalent to:

        my $iter = Template::Iterator->new([ 'foo' ]);

    Note that a single item which is an object based on a blessed ARRAY
    references will NOT be treated as an array and will be folded into a
    list containing that one object reference.

        my $list = bless [ 'foo', 'bar' ], 'MyListClass';
        my $iter = Template::Iterator->new($list);

    equivalent to:

        my $iter = Template::Iterator->new([ $list ]);

    If the object provides an "as_list()" method then the Template::Iterator
    constructor will call that method to return the list of data. For
    example:

        package MyListObject;

        sub new {
            my $class = shift;
            bless [ @_ ], $class;
        }

        package main;

        my $list = MyListObject->new('foo', 'bar');
        my $iter = Template::Iterator->new($list);

    This is then functionally equivalent to:

        my $iter = Template::Iterator->new([ $list ]);

    The iterator will return only one item, a reference to the
    "MyListObject" object, $list.

    By adding an "as_list()" method to the "MyListObject" class, we can
    force the "Template::Iterator" constructor to treat the object as a list
    and use the data contained within.

        package MyListObject;

        ...

        sub as_list {
            my $self = shift;
            return $self;
        }

        package main;

        my $list = MyListObject->new('foo', 'bar');
        my $iter = Template::Iterator->new($list);

    The iterator will now return the two items, '"foo"' and '"bar"', which
    the "MyObjectList" encapsulates.

  get_first()
    Returns a "($value, $error)" pair for the first item in the iterator
    set. The $error returned may be zero or undefined to indicate a valid
    datum was successfully returned. Returns an error of "STATUS_DONE" if
    the list is empty.

  get_next()
    Returns a "($value, $error)" pair for the next item in the iterator set.
    Returns an error of "STATUS_DONE" if all items in the list have been
    visited.

  get_all()
    Returns a "(\@values, $error)" pair for all remaining items in the
    iterator set. Returns an error of "STATUS_DONE" if all items in the list
    have been visited.

  size()
    Returns the size of the data set or undef if unknown.

  max()
    Returns the maximum index number (i.e. the index of the last element)
    which is equivalent to size() - 1.

  index()
    Returns the current index number which is in the range 0 to max().

  count()
    Returns the current iteration count in the range 1 to size(). This is
    equivalent to index() + 1.

  first()
    Returns a boolean value to indicate if the iterator is currently on the
    first iteration of the set.

  last()
    Returns a boolean value to indicate if the iterator is currently on the
    last iteration of the set.

  prev()
    Returns the previous item in the data set, or "undef" if the iterator is
    on the first item.

  next()
    Returns the next item in the data set or "undef" if the iterator is on
    the last item.

  parity()
    Returns the text string "even" or "odd" to indicate the parity of the
    current iteration count (starting at 1). This is typically used to
    create striped *zebra tables*.

        <table>
        [% FOREACH name IN ['Arthur', 'Ford', 'Trillian'] -%]
          <tr class="[% loop.parity %]">
            <td>[% name %]</td>
          </tr>
        [% END %]
        </table>

    This will produce the following output:

        <table>
          <tr class="odd">
            <td>Arthur</td>
          </tr>
          <tr class="even">
            <td>Ford</td>
          </tr>
          <tr class="odd">
            <td>Trillian</td>
          </tr>
        </table>

    You can then style the "tr.odd" and "tr.even" elements using CSS:

        tr.odd td {
            background-color: black;
            color: white;
        }

        tr.even td {
            background-color: white;
            color: black;
        }

  odd()
    Returns a boolean (0/1) value to indicate if the current iterator count
    (starting at 1) is an odd number. In other words, this will return a
    true value for the first iterator, the third, fifth, and so on.

  even()
    Returns a boolean (0/1) value to indicate if the current iterator count
    (starting at 1) is an even number. In other words, this will return a
    true value for the second iteration, the fourth, sixth, and so on.

AUTHOR
    Andy Wardley <abw AT wardley.org> <http://wardley.org/>

COPYRIGHT
    Copyright (C) 1996-2007 Andy Wardley. All Rights Reserved.

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

SEE ALSO
    Template