PHP date_parse_from_format( ) alternative in PHP 5.2

Since date_parse_from_format( ) is available only in PHP 5.3, I need to write a function that mimics its behaviour in PHP 5.2.

Is it possible to write this function for PHP 5.2 and make it work exactly the same way that it does in PHP 5.3?

Example:

For this input:

<?php
$date = "6.1.2009 13:00+01:00";
print_r(date_parse_from_format("j.n.Y H:iP", $date));
?>

I need this output:

Array
(
    [year] => 2009
    [month] => 1
    [day] => 6
    [hour] => 13
    [minute] => 0
    [second] => 0
    [fraction] => 
    [warning_count] => 0
    [warn开发者_Go百科ings] => Array
        (
        )

    [error_count] => 0
    [errors] => Array
        (
        )

    [is_localtime] => 1
    [zone_type] => 1
    [zone] => -60
    [is_dst] => 
)

<?php
function date_parse_from_format($format, $date) {
  $dMask = array(
    'H'=>'hour',
    'i'=>'minute',
    's'=>'second',
    'y'=>'year',
    'm'=>'month',
    'd'=>'day'
  );
  $format = preg_split('//', $format, -1, PREG_SPLIT_NO_EMPTY); 
  $date = preg_split('//', $date, -1, PREG_SPLIT_NO_EMPTY); 
  foreach ($date as $k => $v) {
    if ($dMask[$format[$k]]) $dt[$dMask[$format[$k]]] .= $v;
  }
  return $dt;
}
?>

Example 1:

<?php
    print_r(date_parse_from_format('mmddyyyy','03232011');
?>

Output 1:

Array ( [month] => 03 [day] => 23 [year] => 2011 )

Example 2:

 <?php
    print_r(date_parse_from_format('yyyy.mm.dd HH:ii:ss','2011.03.23 12:03:00'));
 ?>

Output 2:

Array ( [year] => 2011 [month] => 03 [day] => 23 [hour] => 12 [minute] => 03 [second] => 00 )

Here is my improved version and I think complete. Only errors and warnings are not taken into account.

if( !function_exists('date_parse_from_format') ){
    function date_parse_from_format($format, $date) {
        // reverse engineer date formats
        $keys = array(
            'Y' => array('year', '\d{4}'),              //Année sur 4 chiffres
            'y' => array('year', '\d{2}'),              //Année sur 2 chiffres
            'm' => array('month', '\d{2}'),             //Mois au format numérique, avec zéros initiaux
            'n' => array('month', '\d{1,2}'),           //Mois sans les zéros initiaux
            'M' => array('month', '[A-Z][a-z]{3}'),     //Mois, en trois lettres, en anglais
            'F' => array('month', '[A-Z][a-z]{2,8}'),   //Mois, textuel, version longue; en anglais, comme January ou December
            'd' => array('day', '\d{2}'),               //Jour du mois, sur deux chiffres (avec un zéro initial)
            'j' => array('day', '\d{1,2}'),             //Jour du mois sans les zéros initiaux
            'D' => array('day', '[A-Z][a-z]{2}'),       //Jour de la semaine, en trois lettres (et en anglais)
            'l' => array('day', '[A-Z][a-z]{6,9}'),     //Jour de la semaine, textuel, version longue, en anglais
            'u' => array('hour', '\d{1,6}'),            //Microsecondes
            'h' => array('hour', '\d{2}'),              //Heure, au format 12h, avec les zéros initiaux
            'H' => array('hour', '\d{2}'),              //Heure, au format 24h, avec les zéros initiaux
            'g' => array('hour', '\d{1,2}'),            //Heure, au format 12h, sans les zéros initiaux
            'G' => array('hour', '\d{1,2}'),            //Heure, au format 24h, sans les zéros initiaux
            'i' => array('minute', '\d{2}'),            //Minutes avec les zéros initiaux
            's' => array('second', '\d{2}')             //Secondes, avec zéros initiaux
        );

        // convert format string to regex
        $regex = '';
        $chars = str_split($format);
        foreach ( $chars AS $n => $char ) {
            $lastChar = isset($chars[$n-1]) ? $chars[$n-1] : '';
            $skipCurrent = '\\' == $lastChar;
            if ( !$skipCurrent && isset($keys[$char]) ) {
                $regex .= '(?P<'.$keys[$char][0].'>'.$keys[$char][1].')';
            }
            else if ( '\\' == $char ) {
                $regex .= $char;
            }
            else {
                $regex .= preg_quote($char);
            }
        }

        $dt = array();
        // now try to match it
        if( preg_match('#^'.$regex.'$#', $date, $dt) ){
            foreach ( $dt AS $k => $v ){
                if ( is_int($k) ){
                    unset($dt[$k]);
                }
            }
            if( !checkdate($dt['month'], $dt['day'], $dt['year']) ){
                $dt['error_count'] = 1;
            } else {
                $dt['error_count'] = 0;
            }
        }
        else {
            $dt['error_count'] = 1;
        }

        $dt['errors'] = array();
        $dt['fraction'] = '';
        $dt['warning_count'] = 0;
        $dt['warnings'] = array();
        $dt['is_localtime'] = 0;
        $dt['zone_type'] = 0;
        $dt['zone'] = 0;
        $dt['is_dst'] = '';
        return $dt;
    }
}

If you want it to be exactly like PHP 5.3 function, you're gonna need a lot of code. I'd start with something like this:

$format = '\Y: Y-m-d';
var_dump($format);

$date = date($format);
var_dump($date);

// reverse engineer date formats
$keys = array(
    'Y' => array('year', '\d{4}'),
    'm' => array('month', '\d{2}'),
    'd' => array('day', '\d{2}'),
    'j' => array('day', '\d{1,2}'),
    'n' => array('month', '\d{1,2}'),
    'M' => array('month', '[A-Z][a-z]{2}'),
    'F' => array('month', '[A-Z][a-z]{2,8}'),
    'D' => array('day', '[A-Z][a-z]{2}'),
    // etc etc etc
);

// convert format string to regex
$regex = '';
$chars = str_split($format);
foreach ( $chars AS $n => $char ) {
    $lastChar = isset($chars[$n-1]) ? $chars[$n-1] : '';
    $skipCurrent = '\\' == $lastChar;
    if ( !$skipCurrent && isset($keys[$char]) ) {
        $regex .= '(?P<'.$keys[$char][0].'>'.$keys[$char][1].')';
    }
    else if ( '\\' == $char ) {
        $regex .= $char;
    }
    else {
        $regex .= preg_quote($char);
    }
}

var_dump($regex);

// now try to match it
if ( preg_match('#^'.$regex.'$#', $date, $matches) ) {
    foreach ( $matches AS $k => $v ) if ( is_int($k) ) unset($matches[$k]);
    print_r($matches);
}
else {
    echo 'invalid date "'.$date.'" for format "'.$format.'"'."\n";
}

Result:

string(9) "\Y: Y-m-d"
string(13) "Y: 2011-07-12"
string(51) "\Y\: (?P<year>\d{4})-(?P<month>\d{2})-(?P<day>\d{2})"
Array
(
    [year] => 2011
    [month] => 07
    [day] => 12
)

Incomplete and imperfect.

First I'd like to thank @rudie for his answer and @jeremy refinement of his answer.

I needed a bit more flexible version would could deal with jQueryUI Datepicker with the TimePicker plugin. I also needed it to work with the \ backslash escape character to deal with the odd time formats users enter such as H\h i\m\i\n.

Here's my solution based on those previous answers that I implemented in my Connections Business Directory WordPress plugin.

It more closely matches the functionality of date_parse_from_format() and DateTime::createFromFormat().

Hope this helps someone!

<?php

/**
 * Class cnDate
 */
class cnDate {

    /**
     * Date format characters and their name and regex structure.
     *
     * @access public
     * @since  8.6.4
     *
     * @var array
     */
    protected static $keys = array(
        'Y' => array( 'year', '\d{4}' ),            // Year with 4 Digits
        'y' => array( 'year', '\d{2}' ),            // Year with 2 Digits
        'm' => array( 'month', '\d{2}' ),           // Month with leading 0
        'n' => array( 'month', '\d{1,2}' ),         // Month without the leading 0
        'M' => array( 'month', '[A-Z][a-z]{2}' ),   // Month ABBR 3 letters
        'F' => array( 'month', '[A-Z][a-z]{2,8}' ), // Month Name
        'd' => array( 'day', '\d{2}' ),             // Day with leading 0
        'j' => array( 'day', '\d{1,2}' ),           // Day without leading 0
        'D' => array( 'day', '[A-Z][a-z]{2}' ),     // Day ABBR 3 Letters
        'l' => array( 'day', '[A-Z][a-z]{5,8}' ),   // Day Name
        'h' => array( 'hour', '\d{2}' ),            // Hour 12h formatted, with leading 0
        'H' => array( 'hour', '\d{2}' ),            // Hour 24h formatted, with leading 0
        'g' => array( 'hour', '\d{1,2}' ),          // Hour 12h formatted, without leading 0
        'G' => array( 'hour', '\d{1,2}' ),          // Hour 24h formatted, without leading 0
        'i' => array( 'minute', '\d{2}' ),          // Minutes with leading 0
        's' => array( 'second', '\d{2}' ),          // Seconds with leading 0
        'u' => array( 'hour', '\d{1,6}' ),          // Microseconds
        'a' => array( 'meridiem', '[ap]m' ),        // Lowercase ante meridiem and Post meridiem
        'A' => array( 'meridiem', '[AP]M' ),        // Uppercase ante meridiem and Post meridiem
    );

    /**
     * Create a regex used to parse the supplied datetime format.
     *
     * @access public
     * @since  8.6.4
     *
     * @param string $format The datetime format.
     *
     * @return string
     */
    private static function getFormatRegex( $format ) {

        $keys = self::$keys;

        // Convert format string to regex.
        $regex = '';
        $chars = str_split( $format );

        foreach ( $chars as $n => $char ) {

            $lastChar    = isset( $chars[ $n - 1 ] ) ? $chars[ $n - 1 ] : '';
            $skipCurrent = '\\' == $lastChar;

            if ( ! $skipCurrent && isset( $keys[ $char ] ) ) {

                $regex .= '(?P<' . $keys[ $char ][0] . '>' . $keys[ $char ][1] . ')';

            } elseif ( '\\' == $char || '!' == $char ) {

                /*
                 * No need to add the date format escaping character to the regex since it should not exist in the
                 * supplied datetime string. Including it would cause the preg_match to fail.
                 */
                //$regex .= $char;

            } else {

                $regex .= preg_quote( $char );
            }
        }

        return '#^' . $regex . '$#';
    }

    /**
     * PHP 5.2 does not have a version of @see date_parse_from_format(), this is a mostly PHP 5.2 compatible version.
     *
     * @link http://stackoverflow.com/a/14196482/5351316
     *
     * @access public
     * @since  8.6.4
     *
     * @param string $format The datetime format.
     * @param string $date   The datetime string to parse.
     *
     * @return array
     */
    public static function parseFromFormat( $format, $date ) {

        /** Setup the default values to be returned, matching @see date_parse_from_format() */
        $dt = array(
            'year'          => FALSE,
            'month'         => FALSE,
            'day'           => FALSE,
            'hour'          => FALSE,
            'minute'        => FALSE,
            'second'        => FALSE,
            'fraction'      => FALSE,
            'warning_count' => 0,
            'warnings'      => array(),
            'error_count'   => 0,
            'errors'        => array(),
            'is_localtime'  => FALSE,
            'zone_type'     => 0,
            'zone'          => 0,
            'is_dst'        => '',
        );

        // Now try to match it.
        if ( preg_match( self::getFormatRegex( $format ), $date, $matches ) ) {

            foreach ( $matches as $k => $v ) {

                // Remove unwanted indexes from resulting preg_match.
                if ( is_int( $k ) ) {

                    unset( $matches[ $k ] );
                }

                // Year, month, day, hour, minute, second and fraction should be coerced from string to int.
                if ( in_array( $k, array( 'year', 'month', 'day', 'hour', 'minute', 'second', 'fraction' ) )
                     && is_numeric( $v ) ) {

                    $matches[ $k ] = (int) $v;

                } elseif ( 'month' === $k ) {

                    $parsed = date_parse( $v );
                    $matches[ $k ] = (int) $parsed['month'];

                } elseif ( 'day' === $k ) {

                    $parsed = date_parse( $v );
                    $matches[ $k ] = (int) $parsed['day'];
                }
            }

        } else {

            $dt['error_count'] = 1;
            $dt['errors'][]    = 'Invalid date supplied.'; // @todo match error string from date_parse_from_format()
        }

        return wp_parse_args( $matches, $dt );
    }

    /**
     * PHP 5.2 does not have a version of @see DateTime::createFromFormat(), this is a mostly PHP 5.2 compatible version.
     *
     * @link http://bordoni.me/date_parse_from_format-php-5-2/
     *
     * @access public
     * @since  8.6.4
     *
     * @param  string $format  The datetime format.
     * @param  string $date    The datetime string to parse.
     *
     * @return false|DateTime  Instance of DateTime, false on failure.
     */
    public static function createFromFormat( $format, $date ) {

        $keys  = self::$keys;
        $pos   = strpos( $format, '!' );
        $chars = str_split( $format );

        // Setup default datetime values based on time now or Unix epoch based on if `!` if present in $format.
        if ( FALSE !== $pos ) {

            $datetime = array(
                'year'          => '1970',
                'month'         => '01',
                'day'           => '01',
                'hour'          => '00',
                'minute'        => '00',
                'second'        => '00',
                'fraction'      => '000000',
            );

        } else {

            /** @link http://stackoverflow.com/a/38334226/5351316 */
            list( $usec, $sec ) = explode( ' ', microtime() );

            $datetime = array(
                'year'          => date( 'Y', $sec ),
                'month'         => date( 'm', $sec ),
                'day'           => date( 'd', $sec ),
                'hour'          => date( 'H', $sec ),
                'minute'        => date( 'i', $sec ),
                'second'        => date( 's', $sec ),
                'fraction'      => substr( $usec, 2, 6 ),
            );
        }

        $parsed = self::parseFromFormat( $format, $date );

        foreach ( $chars as $n => $char ) {

            $lastChar    = isset( $chars[ $n - 1 ] ) ? $chars[ $n - 1 ] : '';
            $skipCurrent = '\\' == $lastChar;

            if ( ! $skipCurrent && isset( $keys[ $char ] ) ) {

                // Existing value exists in supplied parsed date.
                if ( $parsed[ $keys[ $char ][0] ] ) {

                    /*
                     * Replace default datetime interval with the parsed datetime interval only if
                     * an `!` was found within the supplied $format and its position is
                     * greater than the current $format character position.
                     */
                    if ( ! ( FALSE !== $pos && $pos > $n ) ) {

                        $datetime[ $keys[ $char ][0] ] = $parsed[ $keys[ $char ][0] ];
                    }
                }
            }
        }

        // Ensure the datetime integers are correctly padded with leading zeros.
        $datetime['month']  = str_pad( $datetime['month'], 2, '0', STR_PAD_LEFT );
        $datetime['day']    = str_pad( $datetime['day'], 2, '0', STR_PAD_LEFT );
        $datetime['hour']   = str_pad( $datetime['hour'], 2, '0', STR_PAD_LEFT );
        $datetime['minute'] = str_pad( $datetime['minute'], 2, '0', STR_PAD_LEFT );
        $datetime['second'] = str_pad( $datetime['second'], 2, '0', STR_PAD_LEFT );

        // Parse the $datetime into a string which can be parsed by DateTime().
        $formatted = strtr( 'year-month-day hour:minute:second.fraction', $datetime );

        // Sanity check to make sure the datetime is valid.
        if ( ! strtotime( $formatted ) ) {

            return FALSE;
        }

        // Return a new DateTime instance.
        return new DateTime( $formatted );
    }
}

In case you don't need the last 4 fields of the array you may simply use strtotime instead of date_parse_from_format to get the same result. For example:

$textdate = $date;
$datetime = strtotime($textdate);
$datearray = date_parse($datetime);
print_r($datearray);

This works with PHP 5.2