Javascript 日期解析/检查函数

DEFAULT_DATE_RULE = {r:/^(/d{4})//(/d{2})//(/d{2})$/, y:1, m:2, d:3};
function checkDateValueA(val, checkList, begin, end, format, checkBlank) {
if (val == null ||val == "" ) return !checkBlank;
//judge format of value
var dateVal = _parseDate(val, format);
var dateBegin = null;
var dateEnd = null;

if(!dateVal) return false;
if (checkList == null || checkList.length == 0) return true;

var nVal = Date.parse(dateVal);

var KW_BEGIN = "begin";
var KW_END = "end";
if( checkList.length == 2) {
dateBegin = _parseDate(begin, format);
dateEnd = _parseDate(end, format);
if(!dateBegin || !dateEnd) return false;
if ((nVal < Date.parse(dateBegin)) || (nVal > Date.parse(dateEnd))) return false;
} else {
if( checkList[0] == KW_BEGIN) {
dateBegin = _parseDate(begin, format);
if(!dateBegin) return false;
if(nVal < Date.parse(dateBegin)) return false;
} else if( checkList[0] == KW_END){
dateEnd = _parseDate(end, format);
if(!dateEnd) return false;
if(nVal > Date.parse(dateEnd)) return false;
}
}
return true;
}
function checkDateFormatA(val, format, checkBlank) {
if (val == ""||val == null) return !checkBlank;
return (_parseDate(val, format) != null);
}
function _getDateRule(format){
if(!format || format == "") return DEFAULT_DATE_RULE;
var retVal = {};
var rSet = {
"YYYY"	:["y","(//d{4})"],
"YY"	:["y","(//d{2})"],
"MM"	:["m","(//d{2})"],
"DD"	:["d","(//d{2})"]
};

var rStr = "";
for(k in rSet){
rStr = (rStr == "")? k : rStr + "|" + k;
}
var m = format.match(new RegExp(rStr, "g"));
if(!(m instanceof Array) || (m.length != 3)) return null;
if(format.replace(new RegExp(rStr, "g"), "").match(//w/)) return null;
for(i=0; i<m.length; i++){
retVal[rSet[m[i]][0]] = i+1;
}

if(!retVal.y || !retVal.m || !retVal.d) return null;
rStr = format;

for(k in rSet){
rStr = rStr.replace(new RegExp(k),rSet[k][1]);
}
retVal.r = new RegExp("^" + rStr + "$");
return retVal;
}
function _validateDate( y, m, d ) {
var rule = [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
if (d < 1) return false;
if (m == 2) {
if ((( y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0)) {
if (d > 29) return false;
} else {
if (d > 28) return false;
}
} else if (!rule[m-1] || d > rule[m-1]) return false;
return true;
}
function _convertYear(y){
var nY = y * 1;
if(nY < 100){
return ( nY>69 ? "19" : "20") + y;
}
return y;
}
function _parseDate(val, format){
if(val == null) return null;
var rule = _getDateRule(format);
if(!rule) return null;
var m = val.match(rule.r);
if(!m) return null;
var nY = _convertYear(m[rule.y]) * 1;
var nM = m[rule.m] * 1;
var nD = m[rule.d] * 1;
if(_validateDate(nY, nM, nD)){
return (new Date(nY, nM-1, nD));
}
return null;
}