Javascript asp tutorial Lesson 9-cookies

Source: Internet
Author: User

Response Cookies in General:

We'll start with the Response Cookies collection. I don't think it cocould be any easier. you simply put the name of the cookie in the argument. the corresponding value is a string. the only time it gets complicated is when you use keys (which I demonstrate below ).

<%@LANGUAGE="JavaScript"%><%var Tomorrow=new Date()Tomorrow.setDate(Tomorrow.getDate() + 1)myExpire = (Tomorrow.getMonth() + 1) + "/" + Tomorrow.getDate() myExpire += "/" + Tomorrow.getFullYear()Response.Cookies("firstCookie") = "I like cookies."Response.Cookies("firstCookie").Expires=myExpireResponse.Cookies("secondCookie") = "ASP Cookies Are Easy."Response.Cookies("secondCookie").Expires=myExpireResponse.Cookies("thirdCookie")("firstKey")="Here's the first Key."Response.Cookies("thirdCookie")("secondKey")="Here's the second Key."Response.Cookies("thirdCookie").Expires=myExpire%><HTML>We're just setting <%=Response.Cookies.Count%> cookies.<BR><A HREF="script09a.asp">Click Here</A> to retrieve these cookies.</HTML>

Click Here to run the script in a new window.

Setting a cookie with ASP is pretty simple. The format is Response. Cookies ("name") = "value" . That "value" can be either a JavaScript string or an ASP native type such as Request. Form ("userEmail ").

Response Cookie Keys:

If on the first page of your ASP application Response. cookies ("myOnlyCookie") is set, and subsequently on page two of your application Response. cookies ("myOnlyCookie") is reassigned a second value, then only the second value will remain. the first value is lost in this circumstance.

The solution is to either use multiple cookies or to use multiple Keys in the SAME cookie.

Response.Cookies("thirdCookie")("firstKey")="Here's the first Key."Response.Cookies("thirdCookie")("secondKey")="Here's the second Key."

The Setting of one or more Keys is pretty simple. It follows this format: Response. Cookies ("name") ("key") = "value" . Again, the "value" can either be a JavaScript string or ASP native type. The advantage of using keys is that you can store multiple Key/Value pairs inside the very same cookie.

Request Cookies:

Generally you will find ASP cookie management to be far easier than Client Side JavaScript cookies. Down below is the script that retrieves the cookies.

<%@LANGUAGE="JavaScript"%><%if (Response.Cookies.Count <= 0){Response.Redirect("script09.asp")}var firstCookie = Request.Cookies("firstCookie"); var secondCookie = Request.Cookies("secondCookie");var thirdCookie2Keys = Request.Cookies("thirdCookie")("firstKey") thirdCookie2Keys += " " + Request.Cookies("thirdCookie")("secondKey");%><HTML>There are <%=Request.Cookies.Count%> Cookies.<BR>1) <%=firstCookie%><BR>2) <%=secondCookie%><BR>3) <%=thirdCookie2Keys%><BR><A HREF="script09b.asp">Click Here</A> to see how we would sort cookiesif we didn't know their names.</HTML>

Click Here to run the script in a new window.

Do I even need to explain "firstCookie" and "secondCookie "? It's so easy. However, I will have to have explain the retrieval of Keys in "thirdCookie ".

We retrieve cookies in almost exactly the same way that we set them, and that goes for Keys as well. If you keep track of your Key names, then retrieving their values is pretty easy.

var thirdCookieFirstKey = Request.Cookies("thirdCookie")("firstKey")

Cookies ing Cookies:

To delete a cookie, give it an expiration date in the past. The following is not in our examples, but it wocould work.

var Yesterday=new Date()Yesterday.setDate(Yesterday.getDate() - 1)myExpire = (Yesterday.getMonth() + 1) + "/" + Yesterday.getDate() myExpire += "/" + Yesterday.getFullYear()Response.Cookies("firstCookie").Expires=myExpire

Cookie Crumbs:

What if you lose track of your cookie names? What if you lose your Keys? First of all, don't do that. But secondly, we have options.

We can use a VBScript Function withFor/eachLoop. We can use Javascript'sNew Enumerator ()Or we can use a pairForLoops. We, however, cannot use JavaScript'sFor/inLoop. This means we have to be creative.

<%@LANGUAGE="JavaScript"%><%if (Response.Cookies.Count <= 0){Response.Redirect("script09.asp")}%><HTML><SCRIPT LANGUAGE="VBScript" RUNAT="Server">Function forEachCookie()dim x,y,zfor each x in Request.Cookiesif Request.Cookies(x).HasKeys thenfor each y in Request.Cookies(x)z = z & x & ":" & y & "=" & Request.Cookies(x)(y) & "; "nextelsez = z & x & "=" & Request.Cookies(x) & "; "end ifnextforEachCookie = zEnd Function</SCRIPT><%Response.Write("<STRONG>Let's use a VBScript function to ")Response.Write("sort out the Cookies and Keys.</STRONG><BR>\r")var longCookie = forEachCookie()if (longCookie){longCookie = longCookie.split("; ")for (i=0;i<=longCookie.length-1;i++){Response.Write(longCookie[ i ] + "<BR>\r")}}Response.Write("<HR>\r")Response.Write("<STRONG>Let's use <I>new Enumerator( )</I> to ")Response.Write("sort out the Cookies and Keys.</STRONG><BR>\r")var myEnum = new Enumerator(Request.Cookies);for (myEnum; !myEnum.atEnd() ; myEnum.moveNext() ){Response.Write(myEnum.item() + "=")n=Request.Cookies(myEnum.item()).Countif (n){for (o=1;o<=n;o++){Response.Write(Request.Cookies(myEnum.item())(o) + " ")}//Begin alternate method of using Enumerator()Response.Write("<BR>\r<STRONG>OR... </STRONG>")Response.Write(myEnum.item() + "=") Response.Write(unescape(Request.Cookies(myEnum.item())))//End alternate method}else{Response.Write(Request.Cookies(myEnum.item()))}Response.Write("<BR>\r")}Response.Write("<HR>\r")Response.Write("<STRONG>Let's use a pair of JavaScript loops to ")Response.Write("sort out the Cookies and Keys.</STRONG><BR>\r")a=Request.Cookies.Countfor (b=1;b<=a;b++){d = Request.Cookies(b).Countif (d){for (c=1;c<=d;c++) { Response.Write(Request.Cookies(b)(c) + " ") }Response.Write("<BR>\r")}else{ Response.Write(Request.Cookies(b) + "<BR>\r")}}%> </HTML>

Click Here to run the script in a new window.

We do the same job three times. you decide for yourself which one you like best. in the first example you can plainly see from the script, I ask a VBScript function to find and break down all the cookies. I then output the data back to the waiting JavaScript variable.

var longCookie = forEachCookie()

What can I say? Don't lose track of your cookies and don't lose track of your Keys. Otherwise you might have to get a VBScript slim jim.

TheNew Enumerator ()Is okay. I use Enumerator two different ways; one way fails to capture the Key names, and the other way successfully captures the key names (but it needsUnescape ()To get the Key values to print normally ).

In round three, I use a pairForLoops, but they're not as functionalFor/inWocould be. (Notice the lack of Key names .)

Misc. Notes:

We didn't useNew String ()In this lesson. But remember, if you want to manipulate the cookie values inside JavaScript functions or methods, then you will need new String ().

var firstCookie = new String(Request.Cookies("firstCookie") )firstCookie = firstCookie.toUpperCase()

Also, if you were to use Client Side scripting to locate cookies, you wowould have noticed that there is an extra cookie. ASP keeps track of its sessions using a cookie.

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.