如何使用 JavaScript 创建会话？

Question

How to create session in JavaScript ?

I try like this:

<script type="text/javascript" >
{
Session["controlID"] ="This is my session";
}
</script> 

Why I looking for session?

I make a request for XML using AJAX. XML response I want to store in session and this session I want to pass to the server page(.asp). I mean to write something like:

<% response.write session("MySession")%>

Answer 1

You can store and read string information in a cookie.

If it is a session id coming from the server, the server can generate this cookie. And when another request is sent to the server the cookie will come too. Without having to do anything in the browser.

However if it is javascript that creates the session Id. You can create a cookie with javascript, with a function like:

function writeCookie(name,value,days) {
    var date, expires;
    if (days) {
        date = new Date();
        date.setTime(date.getTime()+(days*24*60*60*1000));
        expires = "; expires=" + date.toGMTString();
            }else{
        expires = "";
    }
    document.cookie = name + "=" + value + expires + "; path=/";
}

Then in each page you need this session Id you can read the cookie, with a function like:

function readCookie(name) {
    var i, c, ca, nameEQ = name + "=";
    ca = document.cookie.split(';');
    for(i=0;i < ca.length;i++) {
        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 '';
}

The read function work from any page or tab of the same domain that has written it, either if the cookie was created from the page in javascript or from the server.

To store the id:

var sId = 's234543245';
writeCookie('sessionId', sId, 3);

To read the id:

var sId = readCookie('sessionId')

Answer 2

You can use Local storage.

local storage is same as session. the data will be removed when you close the browser.

<script> 
localStorage.setItem('lastname','Smith');

alert(localStorage.getItem('lastname'));
</script>

Edit: @Naveen comment below is correct. You can use session storage instead. ( https://www.w3schools.com/jsref/prop_win_sessionstorage.asp ) Thanks.

<script> 
sessionStorage.setItem('lastname','Smith');

alert(sessionStorage.getItem('lastname'));
</script>

Answer 3

I assume you are using ASP.NET MVC (C#), if not then this answer is not in your issue.

Is it impossible to assign session values directly through javascript? No, there is a way to do that.

Look again your code:

<script type="text/javascript" >
{
Session["controlID"] ="This is my session";
}
</script> 

A little bit change:

<script type="text/javascript" >
{
  <%Session["controlID"] = "This is my session";%>
}
</script>

The session "controlID" has created, but what about the value of session? is that persistent or can changeable via javascript?

Let change a little bit more:

<script type="text/javascript" >
{
  var strTest = "This is my session"; 
  <%Session["controlID"] = "'+ strTest +'";%>
}
</script>

The session is created, but the value inside of session will be "'+ strTest +'" but not "This is my session". If you try to write variable directly into server code like:

<%Session["controlID"] = strTest;%>

Then an error will occur in you page "There is no parameter strTest in current context...". Until now it is still seem impossible to assign session values directly through javascript.

Now I move to a new way. Using WebMethod at code behind to do that. Look again your code with a little bit change:

<script type="text/javascript" >
{
 var strTest = "This is my session"; 
 PageMethods.CreateSessionViaJavascript(strTest);
}
</script> 

In code-behind page. I create a WebMethod:

[System.Web.Services.WebMethod]
public static string CreateSessionViaJavascript(string strTest)
{
    Page objp = new Page();
    objp.Session["controlID"] = strTest; 
    return strTest;
}

After call the web method to create a session from javascript. The session "controlID" will has value "This is my session".

If you use the way I have explained, then please add this block of code inside form tag of your aspx page. The code help to enable page methods.

<asp:ScriptManager EnablePageMethods="true" ID="MainSM" runat="server" ScriptMode="Release" LoadScriptsBeforeUI="true"></asp:ScriptManager>

Source: JavaScript - How to Set values to Session in Javascript

Happy codding, Tri

Answer 4

I think you misunderstood the concept of session, session is a server side per-user-data-store which allows you to save user data on the server side.

thus, you have 2 options, resort to use cookies, which will give the illusion of session(but not quite the same), you can access cookies very simply by document.cookie .

but, if you want your server be aware of the session, you need to use some sort of server request probably the best way is to use AJAX to do this.

I would recommend you to re-read the definition of sessions.

Answer 5

You can try jstorage javascript plugin, it is an elegant way to maintain sessions check this http://www.jstorage.info/

include the jStorage.js script into your html

<script src="jStorage.js"></script>

Then in your javascript place the sessiontoken into the a key like this

$.jStorage.set("YOUR_KEY",session_id);

Where "YOUR_KEY" is the key using which you can access you session_id , like this:

var id = $.jStorage.get("YOUR_KEY");

Answer 6

You can use sessionStorage it is similar to localStorage but sessionStorage gets clear when the page session ends while localStorage has no expiration set.

See https://developer.mozilla.org/en-US/docs/Web/API/Window/sessionStorage

Answer 7

function writeCookie(name,value,days) {
    var date, expires;
    if (days) {
        date = new Date();
        date.setTime(date.getTime()+(days*24*60*60*1000));
        expires = "; expires=" + date.toGMTString();
            }else{
        expires = "";
    }
    document.cookie = name + "=" + value + expires + "; path=/";
}

Answer 8

You can store and read string information in a cookie.

If it is a session id coming from the server, the server can generate this cookie. And when another request is sent to the server the cookie will come too. Without having to do anything in the browser.

However if it is javascript that creates the session Id. You can create a cookie with javascript, with a function like:

The read function work from any page or tab of the same domain that has written it, either if the cookie was created from the page in javascript or from the server.

Answer 9

You can use the name attr:

<script type="text/javascript" >
{
window.name ="This is my session";
}
</script> 

You still have to develop for yourself the format to use, or use a wrapper from an already existing library (mootools, Dojo etc).
You can also use cookies, but they are more heavy on performance, as they go back and forth from the client to the server, and are specific to one domain.

Answer 10

If you create a cookie and do not specify an expiration date, it will create a session cookie which will expire at the end of the session.

See https://stackoverflow.com/a/532660/1901857 for more information.

Answer 11

localStorage and jstorage are your best bets. localStorage is built in and jstorage offers lots of functionalites

See localStorage browser support on caniuse .

Answer 12

<script type="text/javascript">
function myfunction()
{
    var IDSes= "10200";
    '<%Session["IDDiv"] = "' + $(this).attr('id') + '"; %>'
    '<%Session["IDSes"] = "' + IDSes+ '"; %>';
     alert('<%=Session["IDSes"] %>');
}
</script>

link

Answer 13

这是我所做的并且它起作用了，在 PHP 中创建了一个会话，并使用 xmlhhtprequest 来检查每次加载 HTML 页面时是否设置了会话，并且它适用于 Cordova。

Answer 14

Use HTML5 Local Storage. you can store and use the data anytime you please.

<script>
    // Store
    localStorage.setItem("lastname", "Smith");

    // Retrieve
    var data = localStorage.getItem("lastname");

</script>