Source for file TimeStringParser.class.php

<?php
/**
 * @since 5/24/05
 * @package harmoni.primitives.chronology.string_parsers
 * 
 * @copyright Copyright &copy; 2005, Middlebury College
 * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License (GPL)
 *
 * @version $Id: TimeStringParser.class.php,v 1.3 2006/12/01 16:34:53 adamfranco Exp $
 *
 * @link http://harmoni.sourceforge.net/
 * @author Adam Franco <adam AT adamfranco DOT com> <afranco AT middlebury DOT edu>
 */ 
 
require_once(dirname(__FILE__)."/StringParser.class.php");
//require_once(dirname(__FILE__)."/RegexStringParser.class.php");
 
/**
 * This StringParser can handle Times (12-hour or 24-hour) in the form:
 *        - <hour>:<minute>:<second> <am/pm>
*    <minute>, <second> or <am/pm> may be omitted.  e.g. 1:59:30 pm; 8AM; 15:30
 * 
 * @since 5/24/05
 * @package harmoni.primitives.chronology.string_parsers
 * 
 * @copyright Copyright &copy; 2005, Middlebury College
 * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License (GPL)
 *
 * @version $Id: TimeStringParser.class.php,v 1.3 2006/12/01 16:34:53 adamfranco Exp $
 *
 * @link http://harmoni.sourceforge.net/
 * @author Adam Franco <adam AT adamfranco DOT com> <afranco AT middlebury DOT edu>
 */
class TimeStringParser 
    extends RegexStringParser {
    
/*******************************************************
 * Instance Methods
 *********************************************************/
 
     
     /**
     * Return the regular expression used by this parser
     * 
     * @return string 
     * @access protected
     * @since 5/24/05
     */
    function getRegex () {
        return
"/
^                                        # Start of the line
 
#-----------------------------------------------------------------------------            
    (                                    # One or Two-digit hour
        (?: [1-9])
        |
        (?: 1[0-9])
        |
        (?: 2[0-4])
    )
    
    (?:                                    # Optional :Minute:Seconds component
        :                                # Colon
        ([0-5][0-9])?                    # Two-digit minute
        
        (?:                                # Optional :Seconds component
            :                            # Colon                
            (                            # Two-digit second 
                [0-5][0-9]
                (?: \.[0-9]+)?            # followed by an optional decimal.
            )
        )?
    )?
    
    \s?                                    # Optional space
    
    (am|pm)?                            # Optional AM or PM
    
$
/xi";
     }
    
    /**
     * Parse the input string and set our elements based on the contents of the
     * input string. Elements not found in the string will be null.
     * 
     * @return void 
     * @access private
     * @since 5/24/05
     */
    function parse () {
        preg_match($this->getRegex(), $this->input, $matches);
        
        // Matches:
        // [0] => 3:25:10 pm
        // [1] => 3
        // [2] => 25
        // [3] => 10
        // [4] => pm
        
        if (isset($matches[4]) && strtolower($matches[4]) == 'am' && $matches[1] == '12')
            $this->setHour(0);
        else if (isset($matches[4]) && strtolower($matches[4]) == 'pm' && $matches[1] < 13)
            $this->setHour($matches[1] + 12);
        else
            $this->setHour($matches[1]);
        
        if (isset($matches[2]))
            $this->setMinute($matches[2]);
        
        if (isset($matches[3]))
            $this->setSecond($matches[3]);
    }
}
 
?>