Develop Reference

How do delete elements from page based on cookie value?

I want to create a button on my webpage, which when clicked, sets a cookie with a specified value. The cookie should be valid for the entire domain, all its directories and sub-domains.
The code I'm using now is this:
function setCookie(cname, cvalue, exdays)
{
var d = new Date();
d.setTime(d.getTime() + (365*24*60*60*1000));
var expires = "expires="+ d.toUTCString();
document.cookie = cname + "name1" + cvalue + "value1" + expires + ";path=/";
}
Then, once the cookie and its value is set, I want that button to get deleted from the page. Also, next time the page loads, I want to check if the cookie and the value exists and if not, show the button or else, delete the button.
The button in context has an id: delete
I'm using this code to check for cookie and its value:
function getCookie(name1)
{
var name = name1 + "value1";
var decodedCookie = decodeURIComponent(document.cookie);
var ca = decodedCookie.split(';');
for(var i = 0; i <ca.length; i++)
{
var c = ca[i];
while (c.charAt(0) == ' ')
{
c = c.substring(1);
}
if (c.indexOf(name) == 0)
{
return c.substring(name.length, c.length);
}
}
return "";
}
I've found these codes from here: https://www.w3schools.com/js/js_cookies.asp
I'm going to use this code to delete the element if the cookie and its value is present:
function removeElement(elementId)
{
var element = document.getElementById(delete);
element.parentNode.removeChild(element);
}
I've taken this code from here: https://www.abeautifulsite.net/adding-and-removing-elements-on-the-fly-using-javascript
I don't know how to link those 2 fuctions to carry out the required action.

Here is a working solution for you. Take a look at the comments inside the Code.
Are u new to JS? in this case you should take a look at codecademy. Its for free and you will learn the basics very fast.
Note that SO does not allow you to check or set cookies. For that reason the runable code below will cause an error. Here is a working fiddle.
if (getCookie('myCookie')) removeElement('myButton'); // remove if cookie is set
if (document.getElementById('myButton')) document.getElementById('myButton').onclick = function() { // bind function to clickevent
setCookie('myCookie', 'myValue', 1); // set cookie
removeElement('myButton'); // remove button
}
function setCookie(cname, cvalue, exdays) { // your setCookie Funktion
var d = new Date();
d.setTime(d.getTime() + (365 * 24 * 60 * 60 * 1000));
var expires = "expires=" + d.toUTCString();
document.cookie = cname + '=' + cvalue + '; '+ expires + ";path=/"; // reset to w3schools solution
}
function getCookie(name) { // your getCookie Funktion
// removed 'var name = ...' because you wont find your cookie if you changing the name here
var decodedCookie = decodeURIComponent(document.cookie);
var ca = decodedCookie.split(';');
for (var i = 0; i < ca.length; i++) {
var c = ca[i];
while (c.charAt(0) == ' ') {
c = c.substring(1);
}
if (c.indexOf(name) == 0) {
return c.substring(name.length, c.length);
}
}
return "";
}
function removeElement(elementId) { // your removeElement Function
var element = document.getElementById(elementId); // variable delete was undefined, if your buttons id was delete you had to write it in ''
element.parentNode.removeChild(element);
}
<button type="button" id="myButton">
click me
</button>

Going by your requirements you just want to delete a specific button if the cookie is present.
In this case you will need to do 2 things.
Call the getCookie and based on the return value call the removeElement at the end of the setCookie method.
Note: I am assuming your setCookie method is synchronous.
Load the button by default and do the same as Step 1 once the page is loaded.
To summarize, your mrthods should look like this:
setCookie method:
function setCookie(cname, cvalue, exdays){
var d = new Date();
d.setTime(d.getTime() + (365*24*60*60*1000));
var expires = "expires="+ d.toUTCString();
document.cookie = cname + "name1" + cvalue + "value1" + expires + ";path=/";
if(getCookie(cname)) removeElement('delete');
}
After Loading the document:
document.onload = ()=>{
if(getCookie(cname)) removeElement('delete');
}

Display popup once per browser session not working

I want to display a popup once in per browser session in a day. So I collect this below script from here. But this script dose bot display anything anytime. Please help me to solved it.
Note: without script popup display well for every page start. But I just want once for my site per browser session.
Cookie script:
function setCookie(cname, cvalue, exdays) {
var d = new Date();
d.setTime(d.getTime() + (exdays*24*60*60*1000));
var expires = "expires="+d.toUTCString();
document.cookie = cname + "=" + cvalue + "; " + expires;
}
function getCookie(cname) {
var name = cname + "=";
var ca = document.cookie.split(';');
for(var i=0; i<ca.length; i++) {
var c = ca[i];
while (c.charAt(0)==' ') c = c.substring(1);
if (c.indexOf(name) == 0) return c.substring(name.length,c.length);
}
return "";
}
function checkCookie() {
var user = getCookie("ccname");
if (user != "") {
} else {
$(".socialbox").fadeIn();
$(".smallcontainers").fadeIn()
user = "mysocial";
setCookie("ccname", user, 1);
}
}

Can I define JavaScript global variables to use across multitple pages?

I want to define a global variable in JavaScript that I can use across multiple html pages. Please suggest.

This is not possible instead you can use cookies to store the variables and retrive them in another html pages.
Use this function to set your cookies
function setCookie(cname, cvalue, exdays)
{
var d = new Date();
d.setTime(d.getTime() + (exdays*24*60*60*1000));
var expires = "expires="+d.toUTCString();
document.cookie = cname + "=" + cvalue + "; " + expires;
}
and use this function to retrive cookies
function getCookie(cname) {
var name = cname + "=";
var ca = document.cookie.split(';');
for(var i=0; i<ca.length; i++) {
var c = ca[i];
while (c.charAt(0)==' ') c = c.substring(1);
if (c.indexOf(name) == 0) return c.substring(name.length,c.length);
}
return "";
}

cookie is expired when browser closed for a html file locating on harddrive

It is a html file with Javascript which is located on my computer (not real home page).
I am using following JavaScript code to add a cookie, the cookie is stil alive when I don't close the browser but when I close the browse the cookie does not exist any more. How do I make the cookie survive in 4 days even when you close the browser?
function setCookie(cname, cvalue, exdays) {
var d = new Date();
d.setTime(d.getTime() + (exdays*24*60*60*1000));
var expires = "expires="+d.toUTCString();
document.cookie = cname + "=" + cvalue + "; " + expires;
}
setCooike("name", "test", 4);
function getCookie(cname) {
var name = cname + "=";
var ca = document.cookie.split(';');
for(var i=0; i<ca.length; i++) {
var c = ca[i];
while (c.charAt(0)==' ') c = c.substring(1);
if (c.indexOf(name) == 0) return c.substring(name.length,c.length);
}
return "";
}
getCookie("name") returns ""??

This is likely a setting in your browser to clear your cookies when you close it. So it cannot be resolved by code, some users will have this setting enabled and won't want to use cookies so you should plan for that situation.

How do you create a cookie in JavaScript without JQuery?

So what I'm saying is that can you create a cookie without using JQuery and only JavaScript.
Do you have an answer?

I have these simple function to do that
function createCookie(name,value,days) {
if (days) {
var date = new Date();
date.setTime(date.getTime()+(days*24*60*60*1000));
var expires = "; expires="+date.toGMTString();
}
else var expires = "";
document.cookie = name+"="+value+expires+"; path=/";
}
function readCookie(name) {
var nameEQ = name + "=";
var ca = document.cookie.split(';');
for(var i=0;i < ca.length;i++) {
var c = ca[i];
while (c.charAt(0)==' ') c = c.substring(1,c.length);
if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
}
return null;
}
function eraseCookie(name) {
createCookie(name,"",-1);
}
Now, calling functions
createCookie('ppkcookie','testcookie',7);
var x = readCookie('ppkcookie')

Create cookies with javascript
JavaScript can create, read, and delete cookies with the document.cookie property.
With JavaScript, a cookie can be created like this:
document.cookie = "username=John Doe";
You can also add an expiry date (in UTC time). By default, the cookie is deleted when the browser is closed:
document.cookie="username=John Doe; expires=Thu, 18 Dec 2013 12:00:00 UTC";
With a path parameter, you can tell the browser what path the cookie belongs to. By default, the cookie belongs to the current page.
document.cookie="username=John Doe; expires=Thu, 18 Dec 2013 12:00:00 UTC; path=/";
All together code:
function setCookie(cname, cvalue, exdays) {
var d = new Date();
d.setTime(d.getTime() + (exdays*24*60*60*1000));
var expires = "expires="+d.toUTCString();
document.cookie = cname + "=" + cvalue + "; " + expires;
}
function getCookie(cname) {
var name = cname + "=";
var ca = document.cookie.split(';');
for(var i=0; i<ca.length; i++) {
var c = ca[i];
while (c.charAt(0)==' ') c = c.substring(1);
if (c.indexOf(name) == 0) return c.substring(name.length, c.length);
}
return "";
}
function checkCookie() {
var user = getCookie("username");
if (user != "") {
alert("Welcome again " + user);
} else {
user = prompt("Please enter your name:", "");
if (user != "" && user != null) {
setCookie("username", user, 365);
}
}
}