unable to read cookie first time in javascript - javascript

I am using Javascript to set the cookie and read the value from cookie.I am using the code available at http://www.w3schools.com/js/js_cookies.asp for creating and reading the value of cookie.when the page loads i am checking that whether that cookie exists or not .Every thing is working fine except it is not reading the cookie when i set it first time and try to read in next page load .it is setting the cookie but does not read only first time .
Here is my code :-
function setCookie(c_name, value, exdays) {
var exdate = new Date();
exdate.setDate(exdate.getDate() + exdays);
var c_value = escape(value) + ((exdays == null) ? "" : "; expires=" + exdate.toUTCString());
document.cookie = c_name + "=" + c_value;
}
//To get the cookie:-
function getCookie(c_name) {
var i, x, y, ARRcookies = document.cookie.split(";");
for (i = 0; i < ARRcookies.length; i++) {
x = ARRcookies[i].substr(0, ARRcookies[i].indexOf("="));
y = ARRcookies[i].substr(ARRcookies[i].indexOf("=") + 1);
x = x.replace(/^\s+|\s+$/g, "");
if (x == c_name) {
return unescape(y);
}
}
}
//to Delete the cookie:-
function cookieDelete(c_name) {
setCookie(c_name, "delete", -1);
}
And on page load i am using it like :-
$(document).ready(function () {
var aZ = getCookie("menuSave");
if (aZ) {
//do Some thing here
}
else {
setCookie("menuSave", "mysp", null);
}
});

You need to add a 'path' to your cookie. For example:
document.cookie = 'ppkcookie2=yet another test; expires=Fri, 27 Jul 2001 02:47:11 UTC; path=/';
The path represents the relative path in your website which the cookie will be readable.
path=/ means it'll be readable on your whole website.
path=/common/ means it'll be readable only in /common/ folder (and its subfolders)

This might not be the answer to your problem but yet a alternative easier solution, hope it helps!
save menu
localStorage.setItem("menusave","vale");
load value
localStorage.getItem("menusave");
Just trying to help!

Since you have marked the question as asp.net,
You can set the cookies as follows:
HttpCookie aCookie = new HttpCookie("lastVisit");
aCookie.Value = DateTime.Now.ToString();
aCookie.Expires = DateTime.Now.AddDays(1);
Response.Cookies.Add(aCookie);
And read it back like:
if(Request.Cookies["lastVisit"] != null)
Label1.Text = Server.HtmlEncode(Request.Cookies["lastVisit"].Value);
Refer MSDN Cookies overview

When you pass null for the expiration days it makes your cookie into a session cookie that will not persist very long.
Change this:
setCookie("menuSave", "mysp", null);
to this to give it an actual expiration date:
setCookie("menuSave", "mysp", 7);
If you want to retrieve the cookie from any page besides the exact same page that set it, you will also need to set a path value in the cookie that allows the cookie to be retrieved on more than just the exact page that set it.

Related

Storing and Retrieving a JSON Obj from a Cookie

I have looked at many SO and haven't been able to figure out how to actually make this work using pure JS. My problem is that I need to add a 2 different urls to a json array and store it into a cookie for access across subdomains (i looked into the iframe local storage thing and it won't work for this application and the json array will be rather small so 4k cookie limit is plenty).
Now what I have is the following:
function getProject(){
var url_str = window.location.href;
var ProjectImgId = url_str.split('projectId=')[1];
ProjectImgId = ProjectImgId.split('&')[0];
var UserId = url_str.split('flashId=')[1];
var ImageURL = 'https://project-api.artifactuprising.com/project/' + ProjectImgId + '/thumbnail?user=' + UserId;
var RecentProjects = {"url" : url_str, "img" : ImageURL};
return RecentProjects;
}
The above will run on a certain page load. I want to be able to do the following with this: retrieve any existing Projects and if there isn't a match on the url, I wan to push the RecentProjects to the cookie array.
Here is where I am getting stumped. I am following w3 School's cookie set up which has worked for me in the past but I am unable to figure out how to push and pull this data using stringify and parse.
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 + ";path=/";
}
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 recent = getCookie("yourRecentProjects");
if (recent != "") {
// this is where I would want to parse the JSON and then check if the getProject.url value is in the current cookie json and if it is not, push it.
} else {
recent = getProject();
if (recent != "" && recent != null) {
setCookie("yourRecentProjects", recent, 365);
}
}
}
I am pretty stumped. I have figured out how to do all this using local storage, then i realized this doesn't work across subdomains so great learning experience but not a solution. Any help would be appreciated.
well, the cookie isn't json, it's just a string with a bunch of key values.
not 100% what you are looking to do with the data, but as an example, this is taken from the MDN, example #3, as for how to parse that string to find a specific value: https://developer.mozilla.org/en-US/docs/Web/API/Document/cookie:
function doOnce() {
if (!document.cookie.split('; ').find(row => row.startsWith('doSomethingOnlyOnce'))) {
alert("Do something here!");
document.cookie = "doSomethingOnlyOnce=true; expires=Fri, 31 Dec 9999 23:59:59 GMT";
} }
String.prototype.split() creates an array of substring segments that are delimited by the value you pass in, the Array.prototype.find() will look at each value in the array until it either finds the substring that starts with that value, or returns undefined if it finds nothing.
In you case, you'd do document.cookie.split("") to create the array of key value substrings, which at that point you can unpack the data in many ways. maybe you are just looking for the existence of the url value, in which case Array.prototype.includes() is what you are looking for.

Using JavaScript and cookies to create user authentication and a notes app

I'm trying to create a simple notepad app (basic CRUD) using just JavaScript and it has to have a login/signup function, I've managed to create code to get a cookie, if the cookie doesn't exist it sets one and then deletes one after an expiry date.
Here is my cookie code:
function getCookie(usersCookie){
if (document.cookie.length > 0){
begin = document.cookie.indexOf(usersCookie+"=")
if (begin != -1){
begin += usersCookie.length+1;
end = document.cookie.indexOf(";", begin);
if (end == -1) end = document.cookie.length;
return unescape(document.cookie.substring(begin, end));
}
}
}
function setCookie(usersCookie, value, expiredays){
var ExpireDate = new Date ();
ExpireDate.setTime(ExpireDate.getTime() + (expiredays * 24 * 3600 * 1000));
document.cookie = usersCookie + "=" + escape(value) + ((expiredays == null) ? "" : "; expires =" + ExpireDate.toGMTString());
}
function delCookie (usersCookie){
if (getCookie(usersCookie)){
document.cookie = usersCookie + "=" + "; expires=Thu, 14-Jan-15 00:00:01 GMT";
}
}
What I need to know now is how I save arrays to the cookie to access later since I can use this for the rest of the app, I'm replacing the DB with Cookies, I'm aware this is the worst way to do something like this, this is purely a self learning exercise to get used to using cookies.
Thanks in advance
you can use JSON.stringify
var arr = [1,2,3,4];
var output = JSON.stringify(arr)
outputs
"[1,2,3,4]"
save this value in cookie and while fetching back use JSON.parse
arr = JSON.parse( output );

How do cookies recognize name, expiration date, path

I am new to JavaScript and cookies, so I have this weird question as different websites had different format. So I had confusion on how the cookies read and access the different parts of it, i.e. how do cookies recognize names from path or expiration date? Do we always have to specify "username=...;path=/;" for it to recognize it or does it automatically find it based on the format?
And the main question that I am trying to figure is how I can add a value to the cookie creation code, such as a " document.cookie="username=John;visit=1;" and use that visit part to tell the hit count by adding 1 to it every time the page loads.
Thank you!
I use two functions (maybe the original code was from here or here) for getting and setting cookies, here are they:
function setCookie(cookieName, content, expires, path) {
var date = new Date();
date.setDate(date.getDate() + expires);
var cookie = escape(content) + (expires == null ? "" : "; expires=" + date.toUTCString()) + (path != null ? "; path=" + path : "");
document.cookie = cookieName + "=" + cookie;
return true;
}
function getCookie(cookieName) {
var cookie = document.cookie,
begin = cookie.indexOf(" " + cookieName + "=");
if (begin == -1) begin = cookie.indexOf(cookieName + "=");
if (begin == -1) cookie = null;
else {
begin = cookie.indexOf("=", begin) + 1;
var end = cookie.indexOf(";", begin);
if (end == -1) end = cookie.length;
cookie = unescape(cookie.substring(begin, end));
}
return cookie;
}
With them you can easily do what you want:
Handle the page loads (eg <body onload="pageLoad()">)
Add a script element to the head part of the page, and the two funtions above
Add the following function inside the script element:
function pageLoad() {
var cCont = getCookie('hitCount');
var count = 0;
if (cCont != null) count = parseInt(count + '');
setCookie('hitCount', (count + 1) + '', null, null);
}
If you want to get the hit count, you can use the count variable, or use the getCookie function again.
Your first question is not totally clear to me, but read this page, there are nice examples and code samples. This is another good presentation of cookies.

Simply Javascript Cookie

I simply want to display a notification in javascript once someone open the page for the first time (1yr expiredate).
var CookieDate = new Date;
CookieDate.setFullYear(CookieDate.getFullYear( ) +1);
document.cookie = 'info=true; expires=' + CookieDate.toGMTString( ) + ';';
After that i try to read the cookie with
var x = document.cookie;
if x == "true" {..}else{...}
but i never get anything
even if i try to go with
var x = document.cookie;
alert(x)
this ends up empty.
(Jquery is no option)

Can a userscript delete cookies from a given domain?

Can Greasemonkey delete cookies from a given domain? If so, how?
There are major limitations on what Greasemonkey can delete. Other tools may be better for what you want, see below. But, if all of these conditions are met:
The cookies you want to delete are on the current page's domain.
They are not "Secure cookies".
You loop through the possible paths, including /, a blank path, etc.
No cookies are set by javascript, after the page loads.
The thing tracking you really is a "cookie". Many websites use a variety of other techniques, including LSO's, local storage, etc.
THEN, the following code will delete them:
//--- Loop through cookies and delete them.
var cookieList = document.cookie.split (/;\s*/);
for (var J = cookieList.length - 1; J >= 0; --J) {
var cookieName = cookieList[J].replace (/\s*(\w+)=.+$/, "$1");
eraseCookie (cookieName);
}
Where eraseCookie() is:
(Note that this eraseCookie gets many more cookies by attempting all possible paths and the most likely sub-domains.)
function eraseCookie (cookieName) {
//--- ONE-TIME INITS:
//--- Set possible domains. Omits some rare edge cases.?.
var domain = document.domain;
var domain2 = document.domain.replace (/^www\./, "");
var domain3 = document.domain.replace (/^(\w+\.)+?(\w+\.\w+)$/, "$2");;
//--- Get possible paths for the current page:
var pathNodes = location.pathname.split ("/").map ( function (pathWord) {
return '/' + pathWord;
} );
var cookPaths = [""].concat (pathNodes.map ( function (pathNode) {
if (this.pathStr) {
this.pathStr += pathNode;
}
else {
this.pathStr = "; path=";
return (this.pathStr + pathNode);
}
return (this.pathStr);
} ) );
( eraseCookie = function (cookieName) {
//--- For each path, attempt to delete the cookie.
cookPaths.forEach ( function (pathStr) {
//--- To delete a cookie, set its expiration date to a past value.
var diagStr = cookieName + "=" + pathStr + "; expires=Thu, 01-Jan-1970 00:00:01 GMT;";
document.cookie = diagStr;
document.cookie = cookieName + "=" + pathStr + "; domain=" + domain + "; expires=Thu, 01-Jan-1970 00:00:01 GMT;";
document.cookie = cookieName + "=" + pathStr + "; domain=" + domain2 + "; expires=Thu, 01-Jan-1970 00:00:01 GMT;";
document.cookie = cookieName + "=" + pathStr + "; domain=" + domain3 + "; expires=Thu, 01-Jan-1970 00:00:01 GMT;";
} );
} ) (cookieName);
}
Optional function, for information or debug:
function listCookies () {
var cookieList = document.cookie.split (/;\s*/);
for (var J = 0, numCookies = cookieList.length; J < numCookies; ++J) {
console.log ("Cookie ", J, ": ", cookieList[J]);
}
}
Your GM script can also use iFrame tricks to delete cookies on third-party domains, but GM is not the best way to handle cookies, in general.
Don't be fooled by any other claims, Greasemonkey and javascript simply cannot delete a cookie unless all of the conditions, listed at the top of this answer, are met. Note that javascript and Greasemonkey cannot even see all the cookies on a page.
Greasemonkey is not the best tool for this, although it may be adequate for select situations.
Here are some far more powerful solutions:
Use Selective Cookie Delete. It keeps the cookies you want and deletes the rest. It does this at the push of a very handy button or automatically when Firefox closes. Both white-lists and black-lists are supported.
Use BetterPrivacy for sneakier LSO's.
Run CCleaner at least once a week, to exorcise a broad spectrum of tracking and cruft.
For powerful, custom, fully-automated cookie removal that does not have the severe limitations that Greasemonkey has, and that runs more often than Selective Cookie Delete, you can write your own browser extension.
You should be able to delete cookies for the currently open site. Have a look at the Cookie Zapper script, this may do what you want and if not the source will probably point you in the right direction.

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