bgneal@1: /* 'Magic' date parsing, by Simon Willison (6th October 2003)
bgneal@1:    http://simon.incutio.com/archive/2003/10/06/betterDateInput
bgneal@1:    Adapted for 6newslawrence.com, 28th January 2004
bgneal@1: */
bgneal@1: 
bgneal@1: /* Finds the index of the first occurence of item in the array, or -1 if not found */
bgneal@1: if (typeof Array.prototype.indexOf == 'undefined') {
bgneal@1:     Array.prototype.indexOf = function(item) {
bgneal@1:         var len = this.length;
bgneal@1:         for (var i = 0; i < len; i++) {
bgneal@1:             if (this[i] == item) {
bgneal@1:                 return i;
bgneal@1:             }
bgneal@1:         }
bgneal@1:         return -1;
bgneal@1:     };
bgneal@1: }
bgneal@1: /* Returns an array of items judged 'true' by the passed in test function */
bgneal@1: if (typeof Array.prototype.filter == 'undefined') {
bgneal@1:     Array.prototype.filter = function(test) {
bgneal@1:         var matches = [];
bgneal@1:         var len = this.length;
bgneal@1:         for (var i = 0; i < len; i++) {
bgneal@1:             if (test(this[i])) {
bgneal@1:                 matches[matches.length] = this[i];
bgneal@1:             }
bgneal@1:         }
bgneal@1:         return matches;
bgneal@1:     };
bgneal@1: }
bgneal@1: 
bgneal@1: var monthNames = gettext("January February March April May June July August September October November December").split(" ");
bgneal@1: var weekdayNames = gettext("Sunday Monday Tuesday Wednesday Thursday Friday Saturday").split(" ");
bgneal@1: 
bgneal@1: /* Takes a string, returns the index of the month matching that string, throws
bgneal@1:    an error if 0 or more than 1 matches
bgneal@1: */
bgneal@1: function parseMonth(month) {
bgneal@1:     var matches = monthNames.filter(function(item) { 
bgneal@1:         return new RegExp("^" + month, "i").test(item);
bgneal@1:     });
bgneal@1:     if (matches.length == 0) {
bgneal@1:         throw new Error("Invalid month string");
bgneal@1:     }
bgneal@1:     if (matches.length > 1) {
bgneal@1:         throw new Error("Ambiguous month");
bgneal@1:     }
bgneal@1:     return monthNames.indexOf(matches[0]);
bgneal@1: }
bgneal@1: /* Same as parseMonth but for days of the week */
bgneal@1: function parseWeekday(weekday) {
bgneal@1:     var matches = weekdayNames.filter(function(item) {
bgneal@1:         return new RegExp("^" + weekday, "i").test(item);
bgneal@1:     });
bgneal@1:     if (matches.length == 0) {
bgneal@1:         throw new Error("Invalid day string");
bgneal@1:     }
bgneal@1:     if (matches.length > 1) {
bgneal@1:         throw new Error("Ambiguous weekday");
bgneal@1:     }
bgneal@1:     return weekdayNames.indexOf(matches[0]);
bgneal@1: }
bgneal@1: 
bgneal@1: /* Array of objects, each has 're', a regular expression and 'handler', a 
bgneal@1:    function for creating a date from something that matches the regular 
bgneal@1:    expression. Handlers may throw errors if string is unparseable. 
bgneal@1: */
bgneal@1: var dateParsePatterns = [
bgneal@1:     // Today
bgneal@1:     {   re: /^tod/i,
bgneal@1:         handler: function() { 
bgneal@1:             return new Date();
bgneal@1:         } 
bgneal@1:     },
bgneal@1:     // Tomorrow
bgneal@1:     {   re: /^tom/i,
bgneal@1:         handler: function() {
bgneal@1:             var d = new Date(); 
bgneal@1:             d.setDate(d.getDate() + 1); 
bgneal@1:             return d;
bgneal@1:         }
bgneal@1:     },
bgneal@1:     // Yesterday
bgneal@1:     {   re: /^yes/i,
bgneal@1:         handler: function() {
bgneal@1:             var d = new Date();
bgneal@1:             d.setDate(d.getDate() - 1);
bgneal@1:             return d;
bgneal@1:         }
bgneal@1:     },
bgneal@1:     // 4th
bgneal@1:     {   re: /^(\d{1,2})(st|nd|rd|th)?$/i, 
bgneal@1:         handler: function(bits) {
bgneal@1:             var d = new Date();
bgneal@1:             d.setDate(parseInt(bits[1], 10));
bgneal@1:             return d;
bgneal@1:         }
bgneal@1:     },
bgneal@1:     // 4th Jan
bgneal@1:     {   re: /^(\d{1,2})(?:st|nd|rd|th)? (\w+)$/i, 
bgneal@1:         handler: function(bits) {
bgneal@1:             var d = new Date();
bgneal@1:             d.setDate(parseInt(bits[1], 10));
bgneal@1:             d.setMonth(parseMonth(bits[2]));
bgneal@1:             return d;
bgneal@1:         }
bgneal@1:     },
bgneal@1:     // 4th Jan 2003
bgneal@1:     {   re: /^(\d{1,2})(?:st|nd|rd|th)? (\w+),? (\d{4})$/i,
bgneal@1:         handler: function(bits) {
bgneal@1:             var d = new Date();
bgneal@1:             d.setDate(parseInt(bits[1], 10));
bgneal@1:             d.setMonth(parseMonth(bits[2]));
bgneal@1:             d.setYear(bits[3]);
bgneal@1:             return d;
bgneal@1:         }
bgneal@1:     },
bgneal@1:     // Jan 4th
bgneal@1:     {   re: /^(\w+) (\d{1,2})(?:st|nd|rd|th)?$/i, 
bgneal@1:         handler: function(bits) {
bgneal@1:             var d = new Date();
bgneal@1:             d.setDate(parseInt(bits[2], 10));
bgneal@1:             d.setMonth(parseMonth(bits[1]));
bgneal@1:             return d;
bgneal@1:         }
bgneal@1:     },
bgneal@1:     // Jan 4th 2003
bgneal@1:     {   re: /^(\w+) (\d{1,2})(?:st|nd|rd|th)?,? (\d{4})$/i,
bgneal@1:         handler: function(bits) {
bgneal@1:             var d = new Date();
bgneal@1:             d.setDate(parseInt(bits[2], 10));
bgneal@1:             d.setMonth(parseMonth(bits[1]));
bgneal@1:             d.setYear(bits[3]);
bgneal@1:             return d;
bgneal@1:         }
bgneal@1:     },
bgneal@1:     // next Tuesday - this is suspect due to weird meaning of "next"
bgneal@1:     {   re: /^next (\w+)$/i,
bgneal@1:         handler: function(bits) {
bgneal@1:             var d = new Date();
bgneal@1:             var day = d.getDay();
bgneal@1:             var newDay = parseWeekday(bits[1]);
bgneal@1:             var addDays = newDay - day;
bgneal@1:             if (newDay <= day) {
bgneal@1:                 addDays += 7;
bgneal@1:             }
bgneal@1:             d.setDate(d.getDate() + addDays);
bgneal@1:             return d;
bgneal@1:         }
bgneal@1:     },
bgneal@1:     // last Tuesday
bgneal@1:     {   re: /^last (\w+)$/i,
bgneal@1:         handler: function(bits) {
bgneal@1:             throw new Error("Not yet implemented");
bgneal@1:         }
bgneal@1:     },
bgneal@1:     // mm/dd/yyyy (American style)
bgneal@1:     {   re: /(\d{1,2})\/(\d{1,2})\/(\d{4})/,
bgneal@1:         handler: function(bits) {
bgneal@1:             var d = new Date();
bgneal@1:             d.setYear(bits[3]);
bgneal@1:             d.setDate(parseInt(bits[2], 10));
bgneal@1:             d.setMonth(parseInt(bits[1], 10) - 1); // Because months indexed from 0
bgneal@1:             return d;
bgneal@1:         }
bgneal@1:     },
bgneal@1:     // yyyy-mm-dd (ISO style)
bgneal@1:     {   re: /(\d{4})-(\d{1,2})-(\d{1,2})/,
bgneal@1:         handler: function(bits) {
bgneal@1:             var d = new Date();
bgneal@1:             d.setYear(parseInt(bits[1]));
bgneal@1:             d.setMonth(parseInt(bits[2], 10) - 1);
bgneal@1:             d.setDate(parseInt(bits[3], 10));
bgneal@1:             return d;
bgneal@1:         }
bgneal@1:     },
bgneal@1: ];
bgneal@1: 
bgneal@1: function parseDateString(s) {
bgneal@1:     for (var i = 0; i < dateParsePatterns.length; i++) {
bgneal@1:         var re = dateParsePatterns[i].re;
bgneal@1:         var handler = dateParsePatterns[i].handler;
bgneal@1:         var bits = re.exec(s);
bgneal@1:         if (bits) {
bgneal@1:             return handler(bits);
bgneal@1:         }
bgneal@1:     }
bgneal@1:     throw new Error("Invalid date string");
bgneal@1: }
bgneal@1: 
bgneal@1: function fmt00(x) {
bgneal@1:     // fmt00: Tags leading zero onto numbers 0 - 9.
bgneal@1:     // Particularly useful for displaying results from Date methods.
bgneal@1:     //
bgneal@1:     if (Math.abs(parseInt(x)) < 10){
bgneal@1:         x = "0"+ Math.abs(x);
bgneal@1:     }
bgneal@1:     return x;
bgneal@1: }
bgneal@1: 
bgneal@1: function parseDateStringISO(s) {
bgneal@1:     try {
bgneal@1:         var d = parseDateString(s);
bgneal@1:         return d.getFullYear() + '-' + (fmt00(d.getMonth() + 1)) + '-' + fmt00(d.getDate())
bgneal@1:     }
bgneal@1:     catch (e) { return s; }
bgneal@1: }
bgneal@1: function magicDate(input) {
bgneal@1:     var messagespan = input.id + 'Msg';
bgneal@1:     try {
bgneal@1:         var d = parseDateString(input.value);
bgneal@1:         input.value = d.getFullYear() + '-' + (fmt00(d.getMonth() + 1)) + '-' + 
bgneal@1:             fmt00(d.getDate());
bgneal@1:         input.className = '';
bgneal@1:         // Human readable date
bgneal@1:         if (document.getElementById(messagespan)) {
bgneal@1:             document.getElementById(messagespan).firstChild.nodeValue = d.toDateString();
bgneal@1:             document.getElementById(messagespan).className = 'normal';
bgneal@1:         }
bgneal@1:     }
bgneal@1:     catch (e) {
bgneal@1:         input.className = 'error';
bgneal@1:         var message = e.message;
bgneal@1:         // Fix for IE6 bug
bgneal@1:         if (message.indexOf('is null or not an object') > -1) {
bgneal@1:             message = 'Invalid date string';
bgneal@1:         }
bgneal@1:         if (document.getElementById(messagespan)) {
bgneal@1:             document.getElementById(messagespan).firstChild.nodeValue = message;
bgneal@1:             document.getElementById(messagespan).className = 'error';
bgneal@1:         }
bgneal@1:     }
bgneal@1: }