HTML Online Tutorial Contents

Following are the posts for HTML online Tutorial. To learn everything about HTML, just read these posts: HTML Online Tutorial HTML TAGS (2) HTML BASICS (3) HTML ELEMENTS (4) HTML ATTRIBUTES (5) More »

XHTML

XHTML stands for Extensible Hypertext Markup Language. It is also known as XML (Extensible Markup Language). It is a markup language. In XHTML, there are no predefined tags. The user defines the More »

HTML SUMMARY

In this tutorial, you learned: HTML Introduction HTML Tags HTML Basics HTML Elements HTML Attributes HTML Paragraphs HTML Headings HTML Formats HTML Image HTML Links HTML Lists HTML Frames HTML Table After More »

HTML TABLES (13)

HTML Tables are used to arrange data in web pages. HTML allows the use of tables by <table>…</table> tags. Each row in HTML table is recognized by <tr>…</tr> tag. In each row More »

HTML FRAMES (12.2)

Nested frames example: For the following example to work, there are two other simple HTML files : “HMTL11e1 frame a.html” and “HMTL11e1 frame b.html”. your browser will divide your screeub half. The More »

 

Category Archives: ASP

Learn what are ASP Session Objects and how they are used?

Learn what are ASP Session Objects and how they are used?

In this post you will learn what is session object in ASP and how it is used?

The session object is used to store the information of a user session and to change its settings.

Session is usually when a user opens a particular application on a system, do some alterations on it and then close it. The system that you are using recognizes you and knows when you open and close the application. But, if we look for same recognition of user over internet, then there is a problem, because the web server does not recognize the user and has no information about its activities. This is because the HTTP address cannot maintain state.

So, the solution to this issue is provided by the ASP. It creates a unique cookie for every user and is sent to the system user is using. This cookie contains the information which actually provides the identification of the user. The session object is basically this interface.

In other words, session object is used to store user information and change the settings for the user session. The variables which are stored in a session object contains the information about single user and it can be accessed by every page in a particular application. The information which are usually stored on session variables are name, id and the user preferences. The server will always create a new session object for every user which is automatically destroyed when the session is finished.

Session Start

The session for any user starts at three occasions; when a user has requested the ASP file and the Session_OnStart procedure is included in Global.asa file, when any value is stored in a session variable, when the uses has requested an ASP file, and the <object> tag is used to instantiate an object with session by a Global.asa file.

Session end

Any user session will end if he / she has not refreshed the web page in the application for a given time. This time is usually 20 minutes by default. But for some reason you want to change this wait or timeout interval to short or long period than you have to use the property known as Timeout property.

For example, consider a following example, in which we have set the timeout interval of 25 minutes:

The example below sets a timeout interval of 5 minutes:

<%

Session.Timeout=25

%>

But what if you want to end the session suddenly, then you will have to use the method known as Abandon. Consider the following example:

<%

Session.Abandon

%>

But we do not know when the user is going to end his / her session. The session ending time is unpredictable from the user side i.e. we do not know that the last request of the user was the final request or not. Thus, you do not know how long you need to keep the session alive. If you wait too long for the user to continue the session then it will use more of your resources which is not practical. On the other hand, if the session is stopped too soon than the user might have to start gain because when we stopped the session the server deleted all of the information of user session. Therefore, determining and setting a right timeout interval is a challenge. Therefore, we recommend to only store small amounts of data in the session variables.

In the next post, you will learn how to retrieve, store and remove the session variables. You will also learn how to loop through the content and static object collections.

email
ASP online tutorial

ASP Server Side Scripting Online Tutorial Contents

Following is the ASP  Server Side Scripting Online Tutorial Contents:

ASP  Server Side Scripting
Learn about ASP Introduction in ASP tutorial (2)
Learn about Features of ASP, IIS and PWS (3)
Learn about Installation of IIS and PWS (4 ASP)
Learn about Installation of IIS on Windows Server 2003 and Testing your Web (5 ASP)
Learn about Basic ASP Syntax Rules (6 ASP)
Learn about Basic ASP Variables (7 ASP)
Learn about Basic ASP Procedures (8 ASP)
Learn about Basic ASP Forms and Inputs by User (9.1 ASP)
Learn about Basic ASP Forms and Inputs by User (9.2 ASP)
Learn about ASP Cookies (10 ASP)
Learn about ASP Session Objects (11.1 ASP)
Learn about ASP Session Objects (11.2 ASP)
asp 11.2

Learn about ASP Session Objects (11.2 ASP):

Just for revision, the issue discussed in previous post was when to end the session. For example you are using an application for past 20 minutes. Then you stop using it for like an hour. In the meantime this application is using loads of resources on the server for no use. So to reduce the resources, if theserver shuts the session like after the 5 minutes( you have not been using the application). Then you would have to start again if by any chance you come back sooner than an hour.  Therefore to find the right time to end the session is quite difficult and unpredictable. So, to avoid this issue we can store few variables in the session object. By using ASP we can store various variables in the sessions. Following example will set the variable name to “RABIA” and age to “22”. <% Session(“name”)=”RABIA” Session(“age”)=22 %> These or any values stored in session variables can be accessed from any page in an application. Following will print the values of variables:

<% Response.Write(Session(“name”)) Response.Write(Session(“age”)) %> The above code will give following output: RABIA 22 The user preferences are very significant. They can be stored in the session variables. Later on, these preferences can be used to decide what page should be send to user according to his/her preference. Following is the example which shows the text version of page and message that is going to be displayed if the screen resolution is high: <% If Session(“screenres”)=”high” Then %> Displaying the multimedia version due to high resolution <%Else%> Displaying the text version due to low resolution <%End If%> Removing the variables: All session variables are inside the content collection. Any of these variables can be removed by using “Remove method”. Following example will delete the session variable name if the age is greater than 92: <% If Session.Contents(“age”)>92 then Session.Contents.Remove(“name”) End If %> Removing each variable one by one can be troublesome. So to avoid this “RemoveAll” method can be used as shown in the following example where all variables are removed:

<% Session.Contents.RemoveAll() %>

Similarly displaying the variables one by one can be troublesome, so to avoid this using loop to see all the contents collection is possible as shown in following example: <% Session(“name”)=”RABIA” Session(“age”)=22 dim m For Each m in Session.Contents Response.Write(m & “<br />”) Next %>

This will give the following output: Name Age For instance you do not know the number of variables in the session object then you can use the following example to loop through the content collection: <% dim m,s s=Session.Contents.Count Response.Write(“Session variables: ” & s) For m=1 to s Response.Write(Session.Contents(i)) Next %> This will print all the variables as follows: Session variables: 2 RABIA 22 To see that all values are stored in session objects, loop through the staticobject collection is possible. Following is the example that shows how it can be done: <% dim m For Each m in Session.StaticObjects Response.Write(m) Next %>

 

For more visit next posts in this category.To go back to Contents of this tutorial: ASP Active Server Side Scripting Contents

ASP 11.1

Learn about ASP Session Objects (11.1 ASP):

The object which stores information or change settings of a user session is known as Session Object.

A session is the duration in which user opens an application, performs some changes in it and then closes it. During this session your computer knows everything about the opening of an application, changes you made in it and the closing of an application. But the server does not know anything about the session of an application because HTTP does not keep the information of this sort.

ASP solves this problem by using the interface of Session object. ASP basically creates a special cookie and sends it to the user computer to identify the user. This is known as Session Object.

Session Objects comprises of different variables which store information about the single user. But this information is available to every page of an application. Few common type of information stored in session objects are name, id and the user preferences. But the server destroys the session object after creating a new session object.

You must be wondering when a session starts? The session starts when

  1. any user requests an ASP file and there is a Session_On Procedure in the Global_asa file.
  2. There is any value stored in the session variable.
  3. any user requests an ASP file and there is a <Object>Tag in the Global_asa file to instantiate the session object.

The next question which comes in mind after this is When a session ends? So, the answer is that if the user is not using an application for a default period of time than the session will expire. By default this time is 20 minutes. This time can be changed by using the “Timeout” Property of the session. Following is an example where you can change the default time to 40 minutes:


<%

Session.Timeout=40

%>

But if ending the session immediately is needed then you can use “Abandon“ property of session. Following is the property that shows the syntax to end the session immediately:

<%

Session. Abandon

%>

Now the issue is when to end the session. For example you are using an application for past 20 minutes. Then you stop using it for like an hour. In the meantime this application is using loads of resources on the server for no use. So to reduce the resources, if the server shuts the session like after the 5 minutes( you have not been using the application). Then you would have to start again if by any chance you come back sooner than an hour.  Therefore to find the right time to end the session is quite difficult and unpredictable. So, to avoid this issue we can store few variables in the session object.

The next post will explain about Storing, Removing and Retrieval of session variables. Also it will explain the procedure to loop the content collection and the Static Object collection.

For more visit next posts in this category.To go back to Contents of this tutorial: ASP Active Server Side Scripting Contents

ASP Cookies

Learn about ASP Cookies (10 ASP):

A cookie is basically a small file which is embedded on the user computer by the server to identify the user. This cookie is send with every request that user make for a particular page using any web browser. One of the many advantages of ASP is to both retrieve and create different cookie values. Following is the brief method of crating cookies in ASP:

The command that is used to produce cookies is:    “Response.Cookies”. This command should be written before the HTML tags in the file. (<html>).  The syntax for creating cookies is following:

<%

Response.Cookies”name of cookie”=”value of cookie”.

%>

There are different properties that any cookie can have for example the expiry date of the cookie.  Following is the example where a cookie named “website-school” is created with the value “ASP Tutorial” and will expire on 03/01/2012:

<%

Response.Cookies” website-school”=” ASP Tutorial”.

Response.Cookies” website-school”=” ASP Tutorial”.Expires=#January 03,2012#

%>

Now comes the part where you get to learn how to get the cookie. The command which is used to retrieve any created cookie is “Request.Cookies”. You can request the value of cookie and store it in a variable (Cookievariable) and then print it later. Following is the syntax used for this purpose:

<%

Cookievariable=Request.Cookies(”name of cookie”)

Response.write(”name of cookie” & Cookievariable)

%>

The following example will retrieve “website-school” and print its value:

<%

Cookievariable=Request.Cookies(”website-school”)

Response.write(”website-school” & Cookievariable)

%>

Output of this example will be:

website-school = ASP Tutorial

 

Now, some information about cookies with keys….

If any cookie comprises of more than one value, then such cookie is known as a cookie with keys. The syntax for doing so is:

<%

Response.Cookies(”name of cookie”) (“sub name”)=”value of cookie”.

Response.Cookies(”name of cookie”) (“sub name1”)=”value of cookie”.

%>

Following cookie will display cookies with keys of a user containing his name, age and sex:

<%

Response.Cookies(”user1”) (“name”)=”Muntaha”

Response.Cookies(”user1”) (“age”)=”22”

Response.Cookies(”user1”) (“sex”)=”Female”

%>

Reading all cookies send by a server will be very troublesome. Don’t worry there is a solution  to read all the cookies send by a server. But to do this we will use Request.Cookies.HasKeys property.  Following is the syntax to do this:

<script type=”text/javascript”><!–
google_ad_client = “ca-pub-7789281879799866”;
/* webpost */
google_ad_slot = “1930114734”;
google_ad_width = 300;
google_ad_height = 250;
//–>
</script>
<script type=”text/javascript”
src=”http://pagead2.googlesyndication.com/pagead/show_ads.js”>
</script>

<html>
<body>

<%
dim a,b
for each a in Request.Cookies
response.write(“<p>”)
if Request.Cookies(a).HasKeys then
for each b in Request.Cookies(a)
response.write(a &b& “=” & Request.Cookies(a)(b))
response.write(“<br />”)
next
else
Response.Write( “Start”)
end if
response.write “</p>”
next
%>
</body>
</html>

The output of this code will be as following:

Start

user1:name=Muntaha
user1:age=22
user1:sex=Female
Some of the browser does not support cookies. Then passing information via these browser is impossible. So the two alternative ways of passing information are:

  • You can either add Parameters to the URL.
  • Or you can use a form to do so

 

By using the forms, user can enter the information and then clicks the “Send” button. Following is the way with which you can add parameters to the URL:

<form method=”post” action=”none.asp”>
user Name: <input type=”text” name=”name” value=”” />
user age: <input type=”text” name=”age” value=”” />
<input type=”submit” value=”Submit” />
</form>

Similarly the retrieval of these cookies can be done in following way:

<%
name=Request.form(“name”)
age=Request.form(“age”)
response.write(“<p>” & name & ” ” & age & “!</p>”)
%>

Similarly the information can be passed by adding parameters to the URL.

<a href=”none.asp?name=Muntaha & age=22″>Go to none Page</a>

The retrieval of these cookies can be done in following way:


<%
name=Request.form(“name”)
age=Request.form(“age”)
response.write(“<p>” & name & ” ” & age & “!</p>”)
%>

For more visit next posts in this category.To go back to Contents of this tutorial: ASP Active Server Side Scripting Contents