Develop Reference

Unable to sort array of dates pulled from innerText

I’m currently trying to pull dates from the DOM (formatted as 1563595200) into an array in Javascript. The next step is to sort the array properly from closest date to farthest away and cannot figure it out.
Example of element:
<span class="meta-item date">1563595200</span>
Javascript:
var className = document.getElementsByClassName('date');
var classnameCount = className.length;
var IdStore = new Array();
for(var j = 0; j < classnameCount; j++){
var dateString = className[j].innerText;
IdStore.push(dateString);
}
console.log(IdStore);
var IdStore = IdStore.sort(function(a,b){
// Turn your strings into dates, and then subtract them
// to get a value that is either negative, positive, or zero.
return new Date(b.date) - new Date(a.date);
});
console.log(IdStore);
}
storeid();
I expect it to be sorted from nearest date to farthest away but the sorting function isn't doing anything.

You should not be re-declaring a variable here. Remove the var keyword when you are assigning the sort function to IdStore
IdStore = IdStore.sort(function(a,b){

Lokijs remove item by value

I have this small db i have created in loki js
var db = new loki('loki.json');
var children = db.addCollection('children');
I have added some items and now i am trying to remove an item by the value.
I am storing my values like this
var date = new Date();
var timestamp = date.getTime();
children.insert({name:pn,ts:timestamp});
and removing like this
var results = children.find();
console.log('before removal',results);
children.chain().find({'name':field_val}).remove();
console.log('after removal',results);
This is the result screenshot
My removal code does not work since it does not remove all items and does not remove in the correct order.
How can i remove an item by value?.

i think it should be children.chain().find({'name':field_val}).remove();

Javascript in Zapier to return multiple values for posting to Airtable database

I am trying to write some javascript in Zapier which will read two dates and then return an array of all dates between those dates in such a way that they can then be used to create multiple dated records in Airtable (a database). From the Zapier help it says that if you return an array of objects then the following steps will be processed for each.
I have managed to get code which returns the data I wan but it can't be correct because if I try to create the database records only one is created - with all the dates in (so it will only work if output to a text field - not a date). Here's my code attempt:
var fromDate = new Date(inputData.from);
var toDate = new Date(inputData.to);
var output =[];
var i = 1;
do {
var useDate = new String(fromDate.toISOString())
output.push(useDate);
console.log(fromDate);
fromDate.setDate(fromDate.getDate() + 1);
i++
}
while (fromDate <= toDate);
console.log(output);
return{output};
The subsequent step does see the output variable - but it is treated as one value as I said above.
Does anyone have any ideas?

Thanks Juan
That sorted it - or at least it did after removing the return - here is the working code:
var fromDate = new Date(inputData.from);
var toDate = new Date(inputData.to);
var output =[];
var i = 1;
do {
var useDate = new String(fromDate.toISOString())
var dateObject = {};
dateObject.date = useDate;
output.push({dateObject});
fromDate.setDate(fromDate.getDate() + 1);
i++
}
while (fromDate <= toDate);

It looks like you're returning an object, not an array of objects:
return{output};
Also, your do/while statement is creating an array of strings, not objects. In your do block, instead of pushing the useDate string to the output array, you should construct a simple object and push that to the output array.
So instead of pushing '2016-09-28T00:00:00.000Z' each time the loop runs, you should push something like {date: '2016-09-28T00:00:00.000Z'}.
Your do block should look something like this:
do {
var useDate = new String(fromDate.toISOString());
var dateObject = {};
dateObject.date = useDate;
output.push(dateObject);
fromDate.setDate(fromDate.getDate() + 1);
i++
}
This way, output will be an array of objects:
[
{
"date": "2016-09-28T00:00:00.000Z"
},
{
"date": "2016-09-29T00:00:00.000Z"
},
{
"date": "2016-09-30T00:00:00.000Z"
}
]

Sorting an array in javascript based on date

I'm trying to parse multiple subreddit feeds in a Google Script. I can call this Google Script (redditFeeds()) and it returns the title, link, and date to my spreadsheet. However, I want to sort the posts by date so I can see the most recent posts first. I've tried using sort() on the array in various ways and can't get anything sort by descending date. I've even tried converting the date to a Date object and that didn't fix it.
function redditFeeds() {
var entries_array = [];
var subreddit_array = ['https://www.reddit.com/r/funny/top/.rss','https://www.reddit.com/r/news/top/.rss']
for (var s = 0; s < subreddit_array.length; s++) {
var xml = UrlFetchApp.fetch(subreddit_array[s]).getContentText();
var document = XmlService.parse(xml);
var root = document.getRootElement();
var atom = XmlService.getNamespace('http://www.w3.org/2005/Atom');
var entries = document.getRootElement().getChildren('entry', atom);
for (var i = 0; i < entries.length; i++) {
var title = entries[i].getChild('title', atom).getText();
var title = entries[i].getChild('link', atom).getText();
var link = entries[i].getChild('link', atom).getAttribute('href').getValue();
var date = entries[i].getChild('updated', atom).getValue();
entries_array.push([title, link, date]);
}
}
//return entries_array;
//doesn't work
//entries_array.sort(function(a,b) {
// return a.date - b.date;
//});
//also not working
return entries_array.sort(function(a,b) {
new Date(a.date).getTime() - new Date(b.date).getTime();
});
}

I think you want the below, assuming entries_array looks like I think it does. I have no idea what start was supposed to be in your code... I think each entry in entries_array is an array with three members in it, the third being some sort of representation of a date. If it's one that can be parsed by new Date, then this code should work:
return entries_array.sort(function (a, b) {
return new Date(a[2]) - new Date(b[2]);
});
If that's not right, please share what entries_array looks like.

I see a return missing, in the inner sort function and you should not need the getTime()
return entries_array.sort(function(a,b) {
return new Date(a.start) - new Date(b.start);
});

An easy way of sorting date objects is by converting them into UNIX time stamps using dateObj.getTime(). This creates an integer of the seconds since midnight on New Years day 1970. It's very useful if you are working in multiple time zones.

Javascript - create array between two date objects

Question
I am attempting to build an array between two JS objects. It appears that my objects are being created correctly, and in fact that the code below is running.
The unexpected behavior is that every object in my output array is transforming to match the last date that I looped through. i.e. if I loop, whatever my todate_dateobjis, I get an entire array of just that value.
I have to do some debugging wrt the actual start/end dates being correct, but I can handle that -- what I'm stymied by is the behavior described above.
I am very new to javascript. I imagine this is some issue with mutation? Any guidance would be appreciated.
I left the console logs in just because why take them out?
Code
function build_dateobjs_array(fromdate_dateobj, todate_dateobj) {
// return an array of dateojects from fromdate to todate
var current_date = fromdate_dateobj;
var return_array = []
while (current_date <= todate_dateobj) {
return_array[return_array.length] = current_date; // I have read that this is generally faster that arr.push()
var tomorrow = new Date(current_date.getTime() + 86400000);
console.log('tomorrow: ', tomorrow);
current_date.setTime(tomorrow);
console.log('current_date: ', current_date)
console.log("build_dateobjs_array : ", return_array);
};
return return_array;
};

Date objects are mutable. This line:
current_date.setTime(tomorrow);
...changes the state of the Date object that current_date refers to, which you never change.
So you're storing the same object repeatedly in return_array. Instead, make a copy of the Date:
return_array[return_array.length] = new Date(+current_date);
Also, it's probably best to change
var current_date = fromdate_dateobj;
to
var current_date = new Date(+fromdate_dateobj);
so you're not modifying the Date that was passed in.
Side note: There's no need for the round-trip to milliseconds, simply:
function build_dateobjs_array(fromdate_dateobj, todate_dateobj) {
// return an array of dateojects from fromdate to todate
var current_date = new Date(+fromdate_dateobj);
var return_array = [];
while (current_date <= todate_dateobj) {
return_array[return_array.length] = new Date(+current_date);
current_date.setDate(current_date.getDate() + 1);
};
return return_array;
}
(There's also no reason to put a ; at the end of a function declaration.)