# NAME

DateTime::Format::CLDR - Parse and format CLDR time patterns

# SYNOPSIS

    use DateTime::Format::CLDR;
    

    my $cldr = new DateTime::Format::CLDR(
        pattern     => 'HH:mm:ss',
        locale      => 'de_AT',
        time_zone   => 'Europe/Vienna',
    );
    

    my $dt = $cldr->parse_datetime('23:16:42');
    

    $cldr->format_datetime($dt);
    # 23:16:42
    

    # Get pattern from selected locale
    my $cldr = new DateTime::Format::CLDR(
        locale      => 'de_AT',
    );
    

    # pattern is taken from 'date_format_medium' in DateTime::Locale::de_AT
    my $dt = $cldr->parse_datetime('23.11.2007');
    

    # Croak when things go wrong:
    my $cldr = new DateTime::Format::CLDR(
        locale      => 'de_AT',
        on_error    => 'croak',
    );
    

    # This will croak
    $cldr->parse_datetime('23.33.2007');

# DESCRIPTION

This module provides a parser (and also a formater) for datetime strings
using patterns as defined by the Unicode CLDR Project 
(Common Locale Data Repository). <http://unicode.org/cldr/>. 

CLDR format is supported by [DateTime](http://search.cpan.org/search?mode=module&query=DateTime) and [DateTime::Locale](http://search.cpan.org/search?mode=module&query=DateTime::Locale) starting with 
version 0.40.

# METHODS

## Constructor

### new

 DateTime::Format::CLDR->new(%PARAMS);

The following parameters are used by DateTime::Format::CLDR:

- * locale

Locale. 

See [locale](http://search.cpan.org/search?mode=module&query=locale) accessor.

- * pattern (optional)

CLDR pattern. If you don't provide a pattern the `date_format_medium` 
pattern from [DateTime::Local](http://search.cpan.org/search?mode=module&query=DateTime::Local) for the selected locale will be used. 

See [pattern](http://search.cpan.org/search?mode=module&query=pattern) accessor.

- * time_zone (optional)

Timezone that should be used by default. If your pattern contains
timezone information this attribute will be ignored. 

See [time_zone](http://search.cpan.org/search?mode=module&query=time_zone) accessor.

- * on_error (optional)

Set the error behaviour.

See [on_error](http://search.cpan.org/search?mode=module&query=on_error) accessor.

- * incomplete (optional)

Set the behaviour how to handle incomplete date information.

See [incomplete](http://search.cpan.org/search?mode=module&query=incomplete) accessor.

## Accessors

### pattern

Get/set pattern. See L<DateTime/"CLDR Patterns"> for details about patterns.

### time_zone

Get/set time_zone. Returns a `DateTime::TimeZone` object.

Accepts either a timezone name or a `DateTime::TimeZone` object.

### locale

Get/set a locale. Returns a `DateTime::Locale` object.

Accepts either a locale name or a `DateTime::Locale::*` object.

### on_error

Get/set the error behaviour.

Accepts the following values

- * 'undef' (Literal) (default)

Returns undef on error and sets [errmsg](http://search.cpan.org/search?mode=module&query=errmsg)

- * 'croak'

Croak on error

- * CODEREF

Run the given coderef on error.

### incomplete

Set the behaviour how to handle incomplete Date information.

Accepts the following values

- * '1' (default)

Sets the missing values to '1'. Thus if you only parse a time you would
get '0001-01-01' as the date.

- * 'incomplete'

Create a [DateTime::Incomplete](http://search.cpan.org/search?mode=module&query=DateTime::Incomplete) object instead.

- * CODEREF

Run the given coderef on incomplete values. The code reference will be
called with the `DateTime::Format::CLDR` object and a hash of parsed values
as supplied to `DateTime->new`. It should return a modified hash which
will be passed to `DateTine->new`.

## Public Methods

### parse_datetime

 my $datetime = $cldr->parse_datetime($string);

Parses a string and returns a `DateTime` object on success (If you provide
incomplete data and set the [incomplete](http://search.cpan.org/search?mode=module&query=incomplete) attribute accordingly it will 
return a `DateTime::Incomplete` object). If the string cannot be parsed 
an error will be thrown (depending on the `on_error` attribute).

### format_datetime

 my $string = $cldr->format_datetime($datetime);

Formats a `DateTime` object using the set locale and pattern. (not the
time_zone)

### errmsg

 my $string = $cldr->errmsg();

Stores the last error message. Usefull if the on_error behavior of the 
object is 'undef', so you can work out why things went wrong.

## Exportable functions

There are no methods exported by default, however the following are available:

### cldr_format

 &cldr_format($pattern,$datetime);

### cldr_parse

 &cldr_format($pattern,$string);
 OR
 &cldr_format($pattern,$string,$locale);
 

Default locale is 'en'.

# CLDR PATTERNS

## Parsing

Some patterns like day of week, quarter, ect. cannot be used to construct
a date. However these patterns can be parsed, and a warning will be 
issued if they do not match the parsed date. 

Ambigous patterns (eg. narrow day of week formats for many locales) will
be parsed but ignored in datetime calculation.

## Supported CLDR Patterns

See L<DateTime/"CLDR Patterns">.

CLDR provides the following pattenrs:

- * G{1,3}

The abbreviated era (BC, AD).

- * GGGG

The wide era (Before Christ, Anno Domini).

- * GGGGG

The narrow era, if it exists (and it mostly doesn't).

Not used to construct a date.

- * y and y{3,}

The year, zero-prefixed as needed.

- * yy

This is a special case. It always produces a two-digit year, so "1976"
becomes "76".

- * Y{1,}

The week of the year, from `$dt->week_year()`.

- * u{1,}

Same as "y" except that "uu" is not a special case.

- * Q{1,2}

The quarter as a number (1..4).

Not used to construct a date.

- * QQQ

The abbreviated format form for the quarter.

Not used to construct a date.

- * QQQQ

The wide format form for the quarter.

Not used to construct a date.

- * q{1,2}

The quarter as a number (1..4).

Not used to construct a date.

- * qqq

The abbreviated stand-alone form for the quarter.

Not used to construct a date.

- * qqqq

The wide stand-alone form for the quarter.

Not used to construct a date.

- * M{1,2}

The numerical month.

- * MMM

The abbreviated format form for the month.

- * MMMM

The wide format form for the month.

- * MMMMM

The narrow format form for the month.

- * L{1,2}

The numerical month.

- * LLL

The abbreviated stand-alone form for the month.

- * LLLL

The wide stand-alone form for the month.

- * LLLLL

The narrow stand-alone form for the month.

- * w{1,2}

The week of the year, from `$dt->week_number()`.

Not used to construct a date.

- * W

The week of the month, from `$dt->week_of_month()`.

Not used to construct a date.

- * d{1,2}

The numeric day of of the month.

- * D{1,3}

The numeric day of of the year.

Not used to construct a date.

- * F

The day of the week in the month, from `$dt->weekday_of_month()`.

Not used to construct a date.

- * g{1,}

The modified Julian day, from `$dt->mjd()`.

Not supported by DateTime::Format::CLDR

- * E{1,3}

The abbreviated format form for the day of the week.

Not used to construct a date.

- * EEEE

The wide format form for the day of the week.

Not used to construct a date.

- * EEEEE

The narrow format form for the day of the week.

Not used to construct a date.

- * e{1,2}

The _local_ day of the week, from 1 to 7. This number depends on what
day is considered the first day of the week, which varies by
locale. For example, in the US, Sunday is the first day of the week,
so this returns 2 for Monday.

Not used to construct a date.

- * eee

The abbreviated format form for the day of the week.

Not used to construct a date.

- * eeee

The wide format form for the day of the week.

Not used to construct a date.

- * eeeee

The narrow format form for the day of the week.

Not used to construct a date.

- * c

The numeric day of the week (not localized).

Not used to construct a date.

- * ccc

The abbreviated stand-alone form for the day of the week.

Not used to construct a date.

- * cccc

The wide stand-alone form for the day of the week.

Not used to construct a date.

- * ccccc

The narrow format form for the day of the week.

Not used to construct a date.

- * a

The localized form of AM or PM for the time.

- * h{1,2}

The hour from 1-12.

- * H{1,2}

The hour from 0-23.

- * K{1,2}

The hour from 0-11.

- * k{1,2}

The hour from 1-24.

- * j{1,2}

The hour, in 12 or 24 hour form, based on the preferred form for the
locale. In other words, this is equivalent to either "h{1,2}" or
"H{1,2}".

- * m{1,2}

The minute.

- * s{1,2}

The second.

- * S{1,}

The fractional portion of the seconds, rounded based on the length of the 
specifier. This returned without a leading decimal point, but may have 
leading or trailing zeroes.

- * A{1,}

The millisecond of the day, based on the current time. In other words, if it 
is 12:00:00.00, this returns 43200000.

Not supported by DateTime::Format::CLDR

- * z{1,3}

The time zone short name.

- * zzzz

The time zone long name.

- * Z{1,3}

The time zone short name and the offset as one string, so something
like "CDT-0500".

- * ZZZZ

The time zone long name.

- * v{1,3}

The time zone short name.

- * vvvv

The time zone long name.

- * V{1,3}

The time zone short name.

- * VVVV

The time zone long name.

# CAVEATS

Patterns without separators (like 'dMy' or 'yMd') are ambigous for some 
dates and might fail.

Quote from the Author of `DateTime::Format::Strptime` which also applies to
this module:

 "If your module uses this module to parse a known format: stop it. This module 
 is clunky and slow because it can parse almost anything. Parsing a known 
 format is not so difficult, is it? You'll make your module faster if you do. 
 And you're not left at the whim of my potentially broken code."

# SUPPORT

Please report any bugs or feature requests to 
`datetime-format-cldr@rt.cpan.org`, or through the web interface at
<http://rt.cpan.org/Public/Bug/Report.html?Queue=DateTime::Format::CLDR>.
I will be notified and then you'll automatically be notified of the progress 
on your report as I make changes.

# AUTHOR

    Maroš Kollár
    CPAN ID: MAROS
    maros [at] k-1.com
    

    L<http://www.revdev.at>

# ACKNOWLEDGEMENTS 

This module was written for Revdev <http://www.revdev.at>, a nice litte
software company I run with Koki and Domm (<http://search.cpan.org/~domm/>).

# COPYRIGHT

DateTime::Format::CLDR is Copyright (c) 2008 Maroš Kollár 
- <http://www.revdev.at>

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

The full text of the license can be found in the
LICENSE file included with this module.

# SEE ALSO

datetime@perl.org mailing list

<http://datetime.perl.org/>

[DateTime](http://search.cpan.org/search?mode=module&query=DateTime), [DateTime::Locale](http://search.cpan.org/search?mode=module&query=DateTime::Locale), [DateTime::TimeZone](http://search.cpan.org/search?mode=module&query=DateTime::TimeZone) 
and [DateTime::Format::Strptime](http://search.cpan.org/search?mode=module&query=DateTime::Format::Strptime)