Angular Date Parsing Hackery

date-parser-playing.js

console.clear();

var $locale = locale;

function forEach(coll, fn) {
  var type = Object.prototype.toString.call(coll);
  if(type === '[object Array]') {
    //HACK new browsers only
    coll.forEach(fn);
  } else if(type === '[object Object]') {
    for(var key in coll) {
      fn(coll[key], key, coll);
    }
  }
}

function filter(coll, fn) {
  //HACK: New browsers only
  return coll.filter(fn);
}

function getRegexBody(regex) {
  return (/^\/(.*)\/.*$/g).exec(''+regex)[1];
}

function isFunction(o) {
  return typeof o === 'function';
}

//HACK: only for new browsers
function indexOf(coll, item) {
  return coll.indexOf(coll, item);
}

var ISO_TIME = 'HH:mm:ss',
    ISO_TIME_UTC = ISO_TIME + 'Z',
    ISO_DATE = 'yyyy-MM-dd',
    ISO_DATETIME = ISO_DATE + 'T' + ISO_TIME,
    ISO_DATETIME_UTC = ISO_DATETIME + 'Z'

var subPatterns = [
  ['dd', 'day', /[0-9]{2}/],
  ['d', 'day', /\d+/],
  ['MMMM', 'fullmonth', monthRegExp],
  ['MMM', 'shortmonth', shortMonthRegExp],
  ['MM', 'month', /\d\d/],
  ['M', 'month', /\d+/],
  ['yyyy','year',/\d{4}/],
  ['yy','year',/\d\d/],
  ['y','year',/\d+/],
  ['HH','hours',/\d\d/],
  ['H', 'hours',/\d+/],
  ['hh', 'hours', /\d\d/],
  ['h', 'hours', /\d+/],
  ['mm', 'minutes', /\d\d/],
  ['m', 'minutes', /\d+/],
  ['.sss', 'milliseconds', /\.\d\d\d/],
  [',sss', 'milliseconds', /,\d\d\d/],
  ['ss', 'seconds', /\d\d/],
  ['s', 'seconds', /\d+/],
  ['Z', 'offset', /[+-]\d\d\d\d/]
];

function collectionRegExp(collection) {
  return new RegExp('('+ collection.join('|') + ')');
}

function shortMonthRegExp() {
  return collectionRegExp($locale.DATETIME_FORMATS.SHORTMONTH);
}

function monthRegExp() {
  return collectionRegExp($locale.DATETIME_FORMATS.MONTH);
}

function createMatcher(pattern) {
  var body = pattern,
      map = [],
      runAfter = null;
      
  forEach(subPatterns, function(sp) {
    var pattern = sp[0],
        name = sp[1],
        regexp = sp[2];
        
    if(isFunction(regexp)) {
      body = body.replace(pattern, function(match, index) {
        map[index] = name;
        return '!@#$';
      });
      runAfter = runAfter || {};
      runAfter[name] = regexp();
    } else {
      body = body.replace(pattern, function(match, index) {
        map[index] = name;
        return '(' + getRegexBody(regexp) + ')';
      });
    }
  });
  
  if(runAfter) {
    forEach(runAfter, function(regexp, name) {
      body = body.replace('!@#$', function(match, index) {
        
        console.log(regexp);
        return '(' + getRegexBody(regexp()) + ')';
      });
    });
  }
  
  return {
    map: filter(map, function() { return true; }),
    regexp: new RegExp('^' + body + '$')
  };
}

function parse(str, pattern) {
  var matcher = createMatcher(pattern),
      matches = matcher.regexp.exec(str),
      time;
      
  console.log('test', matcher);
  
  if(matches) {
    time = {};
    console.log(matcher.map);
    forEach(matcher.map, function(name, i) {
      var value = matches[i+1],
          formats = $locale.DATETIME_FORMATS;
          
      if(name === 'shortmonth') {
        time.month = indexOf(formats.SHORTMONTH, value);
      } else if (name === 'fullmonth') {
        time.month = indexOf(formats.MONTH, value);
      } else {
        time[name] = +value;
      } 
    });
    
    return new Date(time.year || 0, 
      time.month ? time.month-1 : 0, 
      time.day || 1,
      time.hours || 0,
      time.minutes || 0,
      time.seconds || 0);
  }
  
  return null;
}

console.log(parse('2013 12 25 01:23:45', 'y MM dd HH:mm:ss'));
console.log(parse('31\u200f//10\u200f//2012', 'dd\u200f//MM\u200f//y'));
console.log(parse('14 Dec 2013', 'dd MMM yyyy'));