I'm struggling with a Flatpickr's (https://chmln.github.io/flatpickr/) onDayCreate event. Is here anyone who knows better how to check if picker's date object matches any date in my array of dates?
I have an array (or array of objects, not really sure how to call this) with dates going like this:
dates: {
"20161029": 3,
"20161030": 0,
"20161031": 0,
"20161101": 4,
"20161102": 4,
"20161103": 4,
"20161104": 5,
"20161105": 1,
"20161106": 0,
"20161107": 4,
"20161108": 3,
"20161109": 3,
"20161110": 4
}
And I would need to check if value is 0, >3 or 5 and add class to that date. Flatpickr has an example but it is using math function to randomize which dates should have new span element (example). But I can't configure my if else to addClass.
I created a dictionary of the classes just for convenience. You can use the keys of your object as a way to retrieve the number associated to a day when the flatpickr is triggering the onCreateDay callback. With the value associated to a day, you can get the class from the dictionary and, if it's not empty, add it to the element.
I've added some explanations to the code in order to highlight some things I consider relevant.
You can check it running the script in this page (full screen if don't see it) or you can check it in this fiddle.
Hope it helps.
var dates = {
20161029: 3,
20161030: 0,
20161031: 0,
20161101: 4,
20161102: 4,
20161103: 4,
20161104: 5,
20161105: 1,
20161106: 0,
20161107: 4,
20161108: 3,
20161109: 3,
20161110: 4
},
classDict = {
0: 'redClass',
1: 'greenClass',
3: 'blueClass',
4: 'greyClass',
5: 'orangeClass'
};
// Better always use a two digit format in your dates obj
function get2DigitFmt(val) {
return ('0' + val).slice(-2);
}
// onDayCreate event, add class to day if date has a class
flatpickr("#dayCreate", {
onDayCreate: function(dObj, dStr, fp, dayElem) {
var date = dayElem.dateObj,
// Note the + 1 in the month.
key = date.getFullYear() + get2DigitFmt(date.getMonth() + 1) + get2DigitFmt(date.getDate()),
value = classDict[dates[key]];
if (value) {
dayElem.className += ' ' + value;
}
}
});
.redClass {
background-color: red !important;
}
.greenClass {
background-color: green !important;
}
.blueClass {
background-color: blue !important;
}
.greyClass {
background-color: grey !important;
}
.orangeClass {
background-color: orange !important;
}
<link rel="stylesheet" href="https://unpkg.com/flatpickr/dist/flatpickr.min.css">
<script src="https://unpkg.com/flatpickr"></script>
<input id="dayCreate" type="text" placeholder="Select Date..">
UPDATE
The idea of the dictionary was to simplify adding/removing classes and avoid ugly switches or long ifs. However, you could easily modify the code in order to filter by value (only values greater than 3 get class) and add any class you want when the condition is met.
For instance (fiddle):
function getClass(value) {
// Here you could put any logic you want. Ifs, add the value to a string, whatever...
return value === 4 ? 'redClass' : 'blueClass';
}
// onDayCreate event, add class to day if date has a class
flatpickr("#dayCreate", {
onDayCreate: function(dObj, dStr, fp, dayElem) {
var date = dayElem.dateObj,
// Note the + 1 in the month.
key = date.getFullYear() + get2DigitFmt(date.getMonth() + 1) + get2DigitFmt(date.getDate()),
value = dates[key];
if (value > 3) {
dayElem.className += ' ' + getClass(value);
}
}
});
As you can see in the solutions I provided, there's no need to loop over the object all the time in order to get the value associated to a date, you can get it in constant time composing the key of the date from the date that flatpickr provides while constructing the day (onCreateDay callback).
UPDATE
According to the documentation (or so it seems), in order to get the date of a ccurrent day inside of the onDayCreate callback, you must use properties of fp (currentYear and currentMonth) and dayElem (textContent).
However, currentMonth returns always the month that the flatpicker is currently showing, not the month of the day (the calendar can be showing november, but the day can be in october or december) so a bit of tinkering is needed to avoid marking incorrect dates.
In this fiddle you can find a solution that doesn't use dateObj and works more like the documentation says.
And here's the code:
// Better always use a two digit format in your dates obj
function get2DigitFmt(val) {
return ('0' + val).slice(-2);
}
function getClass(value) {
// Here you could put any logic you want. Ifs, add the value to a string, whatever...
return value === 4 ? 'redClass' : 'blueClass';
}
// Adjust month depending on the month's day
function getMonth(currentMonth, dayClass) {
return currentMonth + (dayClass.contains('prevMonthDay') ? 0 : (1 + Number(dayClass.contains('nextMonthDay'))));
}
function getDateKey(year, month, day) {
return year + get2DigitFmt(month) + get2DigitFmt(day);
}
// onDayCreate event, add class to day if date has a class
flatpickr("#dayCreate", {
onDayCreate: function(dObj, dStr, fp, dayElem) {
var key = getDateKey(fp.currentYear, getMonth(fp.currentMonth, dayElem.className), dayElem.textContent),
value = dates[key];
if (value > 3) {
dayElem.className += ' ' + getClass(value);
}
}
});
Something like this should do it (intentionally verbose so you can see what's going on):
var dates = {
20161029: 3,
20161030: 0,
20161031: 0,
20161101: 4,
20161102: 4,
20161103: 4,
20161104: 5,
20161105: 1,
20161106: 0,
20161107: 4,
20161108: 3,
20161109: 3,
20161110: 4
};
flatpickr("#dayCreate", {
onDayCreate: function (dObj, dStr, fp, dayElem) {
//because you're working with an object and not an array,
//we'll iterate using its keys
var myDateKeys = Object.keys(dates);
for (var i = 0; i < myDateKeys.length; i++) {
var myDateKey = myDateKeys[i]; // "20161029
var myDateVal = dates[myDateKey]; // 3
var myYear = parseInt(myDateKey.substr(0, 4));
var myMonth = parseInt(myDateKey.substr(4, 2));
var myDay = parseInt(myDateKey.substr(6, 2));
var myDateObj = new Date(myYear + '-' + myMonth + '-' + myDay + ' 00:00:00');
var fDateObj = dayElem.dateObj;
//compare with event date
if (myDateObj.getTime() == fDateObj.getTime()) {
$(dayElem).addClass('myFancyDateClass' + myDateVal);
}
}
}
});
Then add style rules to your page to highlight the dates accordingly:
.myFancyDateClass0{
color: red;
}
.myFancyDateClass1{
color: green;
}
.myFancyDateClass3{
color: blue;
}
.myFancyDateClass4{
color: yellow;
}
.myFancyDateClass5{
color: pink;
}
Thanks nfreeze and acontell for helping me figure this out when I think documentation for that plugin was kind of hard to understand (for me atleast).
Both answers from nfreeze and acontell worked from the start when I figured out my error with the dayElem.dateObj.
The error was due my older version of the plugin. I had 2.0.5 (which is currently the version for bower) and dateObj started working when I manually updated to version 2.0.6.
My way to actually use this was to make new object (for my own purposes for the future use) and then use every items value for class:
var obj = dates,
keys = Object.keys(obj),
notAvailable = {},
fewAvailable = {},
available = {},
value,
date;
var formattedDates = keys.filter(function(key) {
if ( !obj[key]) {
date = moment( key, 'YYYYMMDD' ).format();
value = 'full';
return notAvailable[date] = value;
} else if( obj[key] < 3 ) {
date = moment( key, 'YYYYMMDD' ).format();
value = 'fewAvailable';
return fewAvailable[date] = value;
} else if( obj[key] >= 3 ) {
date = moment( key, 'YYYYMMDD' ).format();
value = 'available';
return available[date] = value;
}
});
var datesForPicker = Object.assign(notAvailable, fewAvailable, available);
And then onCreate event I used that :
flatpickr("#dayCreate", {
onDayCreate: function(dObj, dStr, fp, dayElem) {
var date = moment(dayElem.dateObj).format(),
value = datesForPicker[date];
if( value ){
dayElem.className += ' ' + value;
}
}
});
Use of Moment.js is logical because I already have it in my project, the reason for moment format is to get those dates in the same format. You could do that other ways too.
Related
Highcharts hour data aggregation flow
follows the next rules: 01 AM = 01:00 + 01:15 + 01:30 + 01:45. (example). So all points between current hour and the next one.
I want it to follow the rule: 01 AM = 00:00 + 00:15 + 00:30 + 00:45
I didn't find a possibility to do that in datagrouping options of library.
Now I'm thinking about hack to modify serie.groupedData object (adding 1 hour to time present there), but unfortunately, even though data is modified it still display old values in chart
chartConfiguration.xAxis[0].events = {
setExtremes(event) {
this.series.forEach(serie => {
if (serie.hasGroupedData && serie.currentDataGrouping.unitName == "hour") {
let groupedData = serie.groupedData.map(dataPiece => {
dataPiece.x = dataPiece.x + 3600000;
return dataPiece;
});
serie.update(groupedData);
}
})
}
};
This code changes x value of all the points to one hour earlier if 1 hour data grouping is applied:
chart: {
events: {
render: function() {
if (redrawEnabled) { // prevent infinte recursive loop - this.redraw() calls render event
redrawEnabled = false;
var series = this.series[0],
isHourUnit = series.currentDataGrouping.unitName === 'hour';
if (isHourUnit && !hourOffsetApplied) {
// change the data
series.setData(data.slice().map((p) => [p[0] - hour, p[1]]), false);
hourOffsetApplied = true;
} else if (!isHourUnit && hourOffsetApplied) {
// resotre the original data
series.setData(data, false);
hourOffsetApplied = false;
}
this.redraw();
redrawEnabled = true;
}
}
}
},
Live demo: http://jsfiddle.net/BlackLabel/z850035n/
If you change dataGrouping.units to ['day', [1]] point are displayed without time offset.
function Weekday (name, traffic) {
this.name = name;
this.traffic = traffic;
}
function mostPopularDays(week) {
week = [];
week.push(this.name, this.traffic);
if(week.length > 1){
return week;
}else if(week.length === null || week === []){
return null;
}else {
return week[0];
}
}
var mon = new Weekday("Monday", 200);
mostPopularDays(mon);
/**
* Determines which day of the week had the most nnumber of people visiting the
* pet store. If more than one day of the week has the same, highest amount of
* traffic, an array containing the days (in any order) should be returned.
* (ex. ["Wednesday", "Thursday"]). If the input is null or an empty array, the function
* should return null.
* #param week an array of Weekday objects
* #return a string containing the name of the most popular day of the week if there is only one most popular day, and an array of the strings containing the names of the most popular days if there are more than one that are most popular
*/
I've been seriously learning Javascript for over 2 weeks now then I took this course in EDx and apparently, still can't solve this kind of problem. The code above is my own code and I know its wrong(except the Weekday function). A help would be gladly appreciated.Thanks
The mostPopularDays function never actually uses the provided argument as it is replaced on the first line.
function mostPopularDays(week) {
week = [];
Then there is an out of context this, the function mostPopularDays is not related in any way to the WeekDay, so the this you are referring to is actually the mostPopularDays function itself and not the intended WeekDay you provided.
From what I understand from the text describing the assignment there should be more than one argument to mostPopularDays in order to filter out the most most popular ones ("#param week an array of Weekday objects").
So, your TODO-list is as follows:
rename the argument to mostPopularDays to represent the input to be an array of WeekDay (I'd use weeks (+s) or weekList)
there is no need to push anything into the array from within mostPopularDays.
there is no use for this within mostPopularDays, you want to be referring to an item in the provided array of WeekDay objects
I don't known which ways of traversing an array your course had covered so far, there are several:
for (var i = 0; i < weekList.length; ++i) { ... }
weekList.forEach(function(week) { ... })
(If you've already covered the reducing and sorting of arrays, you may want to look into those, as that would be my preferred choice)
For test you should create objects(days) and array of objects.
Then sort objects and check if there is more than one day you should return.
I also made a condition to give full answer if there is more than one day with highest traffic.
var mon = new Weekday('Monday', 5);
var tue = new Weekday('Tuesday', 3);
var wed = new Weekday('Wednesday',8);
var thu = new Weekday('Thursday', 5);
var fri = new Weekday('Friday', 14);
var sat = new Weekday('Saturday', 14 );
var sun = new Weekday('Sunday', 0);
var weekDays = [mon, tue, wed, thu, fri, sat, sun];
function mostPopularDays(week) {
week.sort(compare);
var mostPopularDay = [];
var mostPopularDayValue = week[0].traffic;
week.forEach(day => {
if(day.traffic == mostPopularDayValue){
mostPopularDay.push(day.name);
}
});
if(mostPopularDay.length>1){
console.log('The most popular days are: '+ mostPopularDay);
} else{
console.log('The most popular day is '+ mostPopularDay);
}
}
function compare(a,b) {
if (a.traffic < b.traffic)
return 1;
if (a.traffic > b.traffic)
return -1;
return 0;
}
function Weekday (name, traffic) {
this.name = name;
this.traffic = traffic;
}
mostPopularDays(weekDays);
This is easy and you can understand quickly.
function mostPopularDays(week) {
if(week.length === 0){
return null;
}
var maxArray = [];
var max = '';
for(i=0; i < week.length; i++){
if(week[i].traffic === max){
maxArray.push(week[i].name);
}else if(week[i].traffic > max){
maxArray = [];
maxArray.push(week[i].name);
max = week[i].traffic;
};
}
if(maxArray.length === 1){
return maxArray[0];
} else {
return maxArray;
}
}
How can I create an array of dates with format DD-MM-YYYY from today and 1 ahead?
I guess it's something like
var dates = [];
var date = moment();
while (date <= date.clone().add(1, 'month')) {
dates.push(date.format('DD-MM-YYYY'));
date = date.clone().add(1, 'd');
}
but is this the best way to do it?
And how can I do the same with minutes? I want an array with ['00:00', '00:05', '00:10', ..., '23:50', '23:55'].
I guess it's something like
var minutes = [];
var time = moment('00:00', 'hh:mm');
while (time < time.clone().add(1, 'day')) {
minutes.push(time.format('hh:mm'));
time = time.clone().add(5, 'minutes');
}
It's not important to use moment.js for this, but I guess it's easier.
Since these can be general functionality, you should make them configurable.
Time Array
For Time array, i guess creating moment object and manipulating its values will be a waste of resource. You can do that with normal loops.
Non moment version
function getDoubleDigits(str) {
return ("00" + str).slice(-2);
}
function formatTime(h, m, is24Hr) {
var tmp = "";
if(is24Hr){
tmp =" " + (Math.floor(h/12) ? "p.m." : "a.m.")
h=h%12;
}
return getDoubleDigits(h) + ":" + getDoubleDigits(m) + tmp;;
}
function getTimeByInterval(interval, is24HrFormat) {
var times = []
for (var i = 0; i < 24; i++) {
for (var j = 0; j < 60; j += interval) {
times.push(formatTime(i, j, is24HrFormat))
}
}
return times.slice(0);
}
console.log(getTimeByInterval(5, false))
console.log(getTimeByInterval(5, true))
Date Array
Since you want dates between 2 dates with a specific interval, its better to make them configurable:
Moment version
I have made even format configurable in this version. This can be done in non-moment version as well but I guess that(how to format date in pure JS) goes out of question's scope and so not doing that.
function getDatesInrange(d1, d2, interval, format){
var dates = [];
while(d1.isBefore(d2)){
dates.push(d1.format(format));
d1.add(interval, "days");
}
console.log(dates)
return dates.slice(0)
}
getDatesInrange(moment(), moment().add(1, "month"), 1, "DD-MM-YYYY")
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.17.1/moment.min.js"></script>
Non Moment Version
function getDatesInrange(d1, d2, interval){
var dates = [];
while(+d1 < +d2){
dates.push(formateDate(d1));
d1.setDate(d1.getDate() + interval)
}
console.log(dates)
return dates.slice(0)
}
function formateDate(date){
return [getDoubleDigits(date.getDate()),
getDoubleDigits(date.getMonth() +1),
date.getFullYear()].join('-')
}
var startDate = new Date();
var endDate = new Date();
endDate.setMonth(endDate.getMonth() + 1);
getDatesInrange(startDate, endDate, 1)
function getDoubleDigits(str) {
return ("00" + str).slice(-2);
}
Nothing wrong with your current implementation idea (except that the current code will cause an infinite loop. The ceiling should be declared separately), but since moment.js can take objects for duration, it's also possible to create a single helper function in which the values are calculated. For some cases this may not be the most efficient way (for times without a date, this could be overkill), but it would keep it versatile. e.g. if the range should stay the same but only the format should change to include a date, only one parameter would have to be changed.
The example below uses an ES6 generator, but the same could be easily converted to return an array instead:
function* createRange(start, duration, interval, format){
let dt= start.clone(), target = start.clone().add(duration);
while(dt < target){
yield dt.format(format);
dt.add(interval || {years:1});
}
}
let dates = createRange(moment(),{month:1}, {days:1}, 'DD-MM-YYYY'),
times= createRange(moment('00:00','HH:mm'),{days:1},{minutes:5}, 'HH:mm');
console.log([...dates]);
console.log([...times]);
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.17.1/moment.min.js"></script>
Of course if certain ranges, such as the month from now, are recurring, they can be put in a separate function which calls the range function.
20.01.2017
23.01.2017
24.01.2017
25.01.2017
26.01.2017
27.01.2017
31.01.2017
01.02.2017
Lets say i have these dates. All those dates are workdays.
Output should be
20.01.2017-27.01.2017
and
31.01.2017-01.02.2017
Since 30 January is workday and so the first period is not continiuing and new period starts.
What is the best way to approach this.
I was thinking taking first date in array and putting it into a new array. Then comparing next date in array to the previous one if it's next day (ignoring weekends). If it is not nextday then take previous date and put it to array as end date and then start a new array of next period.
Get your first date (I'm supossing you have them ordered, as in your example data they are) and store it on a variable for the start date.
Store the same value also in another variable for the end date.
Now loop through your dates checking if current looped date is the next one after your current end date. If it's, store your current looped date into the end date variable and continue to the next loop. If it isn't return current start and end dates and store your currently looped date as a new period start date, go on until loop ends and return current variables.
This would be my approach, though not the shortest or maybe best way of facing this. Just take it as an idea
var array = [
"20.01.2017",
"23.01.2017",
"24.01.2017",
"25.01.2017",
"26.01.2017",
"27.01.2017",
"31.01.2017",
"01.02.2017"
];
var isNextDay = function(day, nextDay) {
var day1 = new Date(day.slice(3, 6) + day.slice(0, 3) + day.slice(6)); //had to format the date this way to make a valid date
day1.setDate(day1.getDate() + 1); //sets the next day, nextday of 30 or 31(last day of month) is 1
var day2 = new Date(nextDay.slice(3, 6) + nextDay.slice(0, 3) + nextDay.slice(6));
if (day1.getTime() === day2.getTime()) {
return true;
} else {
return false;
}
}
var dateGroup = function(dateStrings) {
var res = [];
var aux = dateStrings[0] + "-";
for (var i = 1; i < dateStrings.length; i++) {
if (!isNextDay(dateStrings[i - 1], dateStrings[i])) {
aux += dateStrings[i - 1];
res.push(aux);
aux = dateStrings[i] + "-";
}
}
aux += dateStrings[dateStrings.length - 1];
res.push(aux); //this is because the last one never gets pushed
return res;
}
var output = dateGroup(array);
You can loop over the dates and calculate what the string for the next date should look like, then compare to see if it's the same. If not, end the previous period and start a new one.
You can use a library to parse and format the dates, but simple functions to do the job are just a couple of lines, e.g.
var dates = ['20.01.2017','23.01.2017','24.01.2017',
'25.01.2017','26.01.2017','27.01.2017',
'31.01.2017','01.02.2017'];
/* Parse date in format D/M/YYYY
** #param {string} s - date to parse lke 23.1.2017
** #returns {Date}
*/
function parseDMY(s) {
var b = s.split(/\D/);
return new Date(b[2], b[1]-1, b[0]);
}
/* Format a date in DD/MM/YYYY with supplied separator
** #param {Date} date - date to format
** #param {string} s - separator, default is /
** #returns {string} date formatted as DD/MM/YYYY with supplied separator
*/
function formatDMY(date, s) {
s = s || '/';
function z(n){return (n<10?'0':'')+n}
return [z(date.getDate()),z(date.getMonth()+1),
date.getFullYear()].join(s);
}
/* Create array of date ranges in DD.MM.YYYY-DD.MM.YYYY format
** #param {Array} data - array of date strings in DD.MM.YYYY format
** #returns {Array} array of range strings in DD.MM.YYYY-DD.MM.YYYY format
*/
function createRanges(data) {
var result = [];
var previous;
data.forEach(function(s, i) {
var previous, previousNext, current, range;
// If on first loop, create a range using first value
if (i == 0) {
result.push(s + '-' + s);
// Otherwise, get end date of last range and add one day
} else {
previous = result[result.length-1].split('-')[1];
previousNext = parseDMY(previous);
previousNext.setDate(previousNext.getDate() + 1);
previousNext = formatDMY(previousNext,'.');
// If current date is same as previousNext, update range.
// Otherwise, start a new range
if (s == previousNext) {
range = result[result.length-1];
result[result.length-1] = range.split('-')[0] + '-' + s;
} else {
result.push(s + '-' + s);
}
}
});
// Remove zero day ranges. Could do this by checking last range
// when creating a new one but seems simpler to do it here
result = result.filter(s=>!(s.split('-')[0] == s.split('-')[1]));
return result;
}
console.log(createRanges(dates));
However, a library like moment.js will help with parsing, formatting and arithmetic.
Same as made by Leandro, but made for an array with Date objects and with using moment.js
function groupDates(dates) {
const res = [];
const isNextDay = (day, nextDay) => moment(day).add(1, 'day').isSame(nextDay, 'day');
const format = "DD.MM.YYYY";
let aux = moment(dates[0]).format(format) + "-";
for (let i = 1; i < dates.length; i++) {
if (!isNextDay(dates[i - 1], dates[i])) {
aux += moment(dates[i - 1]).format(format);
res.push(aux);
aux = moment(dates[i]).format(format) + "-";
}
}
aux += moment(dates[dates.length - 1]).format(format);
res.push(aux);
return res;
}
My solution with Luxon lib
const DateTime = luxon.DateTime;
const test = [
"2022-06-23",
"2022-06-24",
"2022-06-25",
"2022-06-26",
"2022-06-27",
"2022-06-28",
"2022-06-29",
"2022-05-02",
"2022-05-03",
"2022-05-05",
"2022-05-04",
"2022-05-06",
"2022-05-07",
"2022-05-08",
];
function getRanges(datesArr) {
const periods = [];
let ix = 0;
const dates = datesArr.map((d) => DateTime.fromSQL(d));
dates.sort();
dates.forEach((date, index) => {
if (index === 0) {
periods.push([
date,
]);
} else if (date.diff(dates[index - 1], [ 'days' ]).days === 1) {
periods[ix].push(date);
} else {
ix += 1;
periods.push([ date ]);
}
})
return periods;
}
console.log(getRanges(test));
<script src="https://cdnjs.cloudflare.com/ajax/libs/luxon/2.4.0/luxon.min.js"></script>
Then you can get first and last elements from each ranges
I have an array of dates formatted as MM/DD/YYYY. I need to find the next closest date in the future starting from today. Say today was 1/22/2016 then 2/19/2016 would return.
2/3/2015
7/5/2015
1/21/2016
2/19/2016
7/1/2016
I've tried doing substrings to get the month, day, year separate and attempting a sort based off those values but surely there has to be a better way.
There is no need for a sorting algorithm. You only need to iterate once and find the closest date that is greater or equals today.
Pseudocode
closest <- infinity
foreach date in dates:
if (date >= now and date < closest) then
closest <- d
return closest
JavaScript
const dates = [
'2/3/2035',
'7/5/2035',
'1/21/2036',
'2/19/2036',
'7/1/2036',
'10/22/2039',
'08/12/2039',
];
const now = new Date();
let closest = Infinity;
dates.forEach(function(d) {
const date = new Date(d);
if (date >= now && (date < new Date(closest) || date < closest)) {
closest = d;
}
});
console.log(closest);
Personally I would use a library such as the very good Moment.JS library, to handle all the horrible complexity of dates.
It has a difference method:
http://momentjs.com/docs/#/displaying/difference/
e.g.
var a = moment([2007, 0, 29]);
var b = moment([2007, 0, 28]);
a.diff(b) // 86400000
It would then be trivial to Math.min() the differences of each date in your list.
There's also a moment.min, which might shortcut this entirely, if all your dates are in the future already:
http://momentjs.com/docs/#/get-set/min/
A naïve implementation would be to parse each date as a string and sort them in ascending order. Then, remove any dates that are in the past, and get the first child of the array of remaining dates. See this jsbin example:
var dates = [
'2/3/2015',
'7/5/2015',
'1/21/2016',
'2/19/2016',
'7/1/2016'
];
// parse each string as a Date object and sort them in ascending order
function sortDates(dates) {
return dates.map(function(date) {
return new Date(date).getTime();
}).sort(function(a, b) {
return a - b;
});
}
var orderedDates = sortDates(dates);
// remove any dates in the past, and get the first child of the array of remaining dates
var nextDate = orderedDates.filter(function(date) {
return (Date.now() - date) > 0;
})[0];
Keep in mind that this depends on the format of the date string that you pass to the Date object (in other words, is 1/12/2015 January 12th, or December 1st? JavaScript will parse it as January 12th.
You can use while loop, new Date()
var dates = ["2/3/2015","7/5/2015","1/21/2016","2/19/2016","7/1/2016"]
, d = "1/22/2016", n = -1, res = null;
while (++n < dates.length && new Date(dates[n]) < new Date(d));
res = dates[n] || d;
console.log(res)
Lots of answers, one more can't hurt.
Date strings should always be manually parsed. A library can help, but if you only have a single format, a simple function is all that's required.
The following uses reduce to loop over the array of dates and finds the closest future date. If no date is in the future, it returns null.
The returned value is the string from the array, not a Date.
function parseMDY(s) {
var b = (s || '').split(/\D/);
return new Date(b[2], b[0]-1, b[1])
}
function getClosestDateToToday(arr) {
var now = new Date();
now.setHours(23,59,59);
return arr.reduce(function (acc, s) {
var d = parseMDY(s);
return d < now? acc : (acc && d > parseMDY(acc)? acc : s);
}, null);
}
var dates = ['2/3/2015', '7/5/2015','1/21/2016',
'2/19/2016','7/1/2016'];
document.write(getClosestDateToToday(dates));
This really depends upon your dates and data structures (the ones shown in original example are not so great for me).
From the other answers...
To take the example from Josh, you could also keep a pointer to which date you are using, or simply shift off of a sorted queue of dates to make it work, but it's really adding noise to your code, disrupting the purpose.
Frederik.L answer is really beautiful code, but it would still have to be executed multiple times, so I cannot recommend it.
Feedback warning
I've been given feedback in comments that Date.parse can behave inconsistently. I'll move to passing a date parsing callback function, and demonstrate Date.UTC usage in the callback for OP-specific date format. Please be careful when defining your own callbacks, and please do not copy-paste.
Suggestion
I'd suggest utilizing Date functions i.e. Date.parse; but also try where possible to get data sources sorted without needing application-level sorting. Then you can store-once and step through the array using array.shift() or similar;
Ideally also YYYY-MM-DD
Four-Digit Year
Two-Digit Month
Two-Digit Day
... (continue from least occurring to most occurring)
sample code
var dates = [
'2/3/2015',
'7/5/2015',
'7/1/2016',
'1/21/2016',
'2/19/2016'
]; // unsorted garbage dates
var DateList = function( dateList, getDate ) {
var sortedDates = dateList.sort( function(a, b) {
return getDate(a) - getDate(b);
});
this.next = function() {
var dt = sortedDates.shift();
sortedDates.push(dt); // comment to remove cyclical nature
return dt;
}
};
// specific implementation parser for this format
var getDisgustingDateFormat = function(dStr) {
var dParts = dStr.split('/');
return new Date(Date.UTC(dParts[2],dParts[0],dParts[1]));
};
var dl = new DateList( dates, getDisgustingDateFormat );
Usage
dl.next(); // "2/3/2015"
dl.next(); // "7/5/2015"
dl.next(); // "1/21/2016"
dl.next(); // "2/19/2016"
dl.next(); // "7/1/2016"
dl.next(); // "2/3/2015"
Hope this helps (Updated for clarity)
What about this version using for of and momentjs:
const getClosestFutureDate = (dates) => {
if (dates.length === 0) {
return null;
}
let minDiff = 0;
for (const date of dates) {
minDiff += minDiff + 30;
var currentDate = moment(date);
if (currentDate.isAfter(moment()) && currentDate.diff(moment(), "days") <= minDiff) {
break;
}
}
return currentDate;
};
Assuming now = 2019-08-21
console.log(getClosestFutureDate(["2019-05-07", "2019-06-01", "2019-07-13", "2019-11-09", "2019-11-10", "2019-11-11"]));
// 2019-11-09
I am fan of momentjs, but this can be easily refactored to use only vanilla Date.
const FindDate = (date, allDate) => {
// moment().diff only works on moment(). Make sure both date and elements in allDate list is in moment
let nearestDate = -1;
allDate.some(d => {
const currentDate = moment(d)
const difference = currentDate.diff(date); // Or date.diff(currentDate) depending on what you're trying to find
if(difference >= 0){
nearestDate = d
}
});
console.log(nearestDate)
}
In Livescript:
x =
* "2/3/2015"
* "7/5/2015"
* "1/21/2016"
* "2/19/2016"
* "7/1/2016"
sim-unix-ts = (date-str) ->
# Simulate unix timestamp like concatenating
# convert "MM/DD/YYYY" to YYYYMMDD (integer)
# so we can simply compare these integers
[MM, DD, YYYY] = date-str.split "/"
MM = "0#{MM}".slice -2 # apply zero padding
DD = "0#{DD}".slice -2 # apply zero padding
parse-int "#{YYYY}#{MM}#{DD}"
today = sim-unix-ts "2/18/2016"
date-list = [sim-unix-ts(..) for x]
# find next date
next-dates = [.. for date-list when .. > today]
next-date = next-dates.0
next-date-orig = x[date-list.index-of next-date]
alert [next-date, next-date-orig]
..in Javascript:
var x, simUnixTs, today, dateList, res$, i$, x$, len$, nextDates, y$, nextDate, nextDateOrig;
x = ["2/3/2015", "7/5/2015", "1/21/2016", "2/19/2016", "7/1/2016"];
simUnixTs = function(dateStr){
var ref$, MM, DD, YYYY;
ref$ = dateStr.toString().split("/"), MM = ref$[0], DD = ref$[1], YYYY = ref$[2];
MM = ("0" + MM).slice(-2);
DD = ("0" + DD).slice(-2);
return parseInt(YYYY + "" + MM + DD);
};
today = simUnixTs("2/18/2016");
res$ = [];
for (i$ = 0, len$ = x.length; i$ < len$; ++i$) {
x$ = x[i$];
res$.push(simUnixTs(x$));
}
dateList = res$;
res$ = [];
for (i$ = 0, len$ = dateList.length; i$ < len$; ++i$) {
y$ = dateList[i$];
if (y$ > today) {
res$.push(y$);
}
}
nextDates = res$;
nextDate = nextDates[0];
nextDateOrig = x[dateList.indexOf(nextDate)];
alert([nextDate, nextDateOrig]);