How to store and retrieve an undefined guid with Javascript?

Question

My chrome extension reads an RSS feed that is updated quite often with new posts. What I want to do is assign every guid to an array that holds and then helps determine whether or not each post is new, and so ought to be passed on (as a notification to me).

    $.get('rss-feed', function(data) {
    var $xml = $(data);
    $xml.find("item").each(function() {
        var $this = $(this),
            item = {
                title: $this.find("title").text(),
                link: $this.find("link").text(),
                description: $this.find("description").text(),
                pubDate: $this.find("pubDate").text(),
                guid: $this.find("guid").text()
        }

The guid is then assigned to a variable:

    var latestID = item.guid.slice(-8);

This is where the problem takes place. The very same post keeps being posted as a new one. Is it because it has an undefined value?

    if (latestID == ids[0]) {

    } else if (latestID != ids[0]) {

        var firstNotification = {
            type: "basic",
            title: jobType[0] + ": " + jobWords[1] + " words",
            iconUrl: "icon48.png",
            message: jobPay[0] + "\nID: " + latestID + " Date: " + item.pubDate.slice(17,25),
            requireInteraction: true,
            buttons: [{
                    title: "Go to site!"
                }],
        };

        latestID = ids[0];
    }

Corrected indentation of code and added the missing closing bracket `}`. — Iván Nokonoko, Oct 19 '18 at 13:43

score 0 · Answer 1 · edited Oct 21 '18 at 13:56

0

You can use local storage to save the value locally and check

window.localStorage.setItem("somename",item.guid.slice(-8));

Then you can retrieve wherever you want using,

var prevId = window.localStorage.getItem("somename");

You can compare now

edited Oct 21 '18 at 13:56

marc_s

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answered Oct 19 '18 at 13:29

Jeswin Rebil

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Using localStorage seems a bit over the top in this context. Don't you think it's possible to pull it off just with conditionals and storing them right away in an array? – user2359938 Oct 19 '18 at 13:46
You have used .each function, are you assigning the value in latestID inside the .each function or outside? – Jeswin Rebil Oct 19 '18 at 13:50
Yes, everything runs inside it. Do you think that's the issue? – user2359938 Oct 19 '18 at 14:09
yes that is the issue always it will assign the last value – Jeswin Rebil Oct 19 '18 at 17:28

How to store and retrieve an undefined guid with Javascript?

1 Answers1