website/www/conservancy/static/admin-media/js/dateparse.js
2010-09-30 10:30:33 -04:00

233 lines
7 KiB
JavaScript

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