Introduction to ASP• What is ASP?– ASP stands for Active Server Pages.– ASP is a program that runs inside IIS.– IIS stands for Internet Information Services.– ASP is Microsoft’s solution to building advanced Web sites.
Processing of an HTML PageRequestBrowser Web ServerMemory-HTML fileHTML FileWhen a browser requests an HTML file, the server returns the file
Processing of an ASP PageRequestBrowser Web ServerMemory-ASP FileHTML File ProcessingWhen a browser requests an ASP file, IIS passes the request to theASP engine. The ASP engine reads the ASP file, line by line, andexecutes the scripts in the file. Finally, the ASP file is returned to thebrowser as plain HTML.
ASP Syntax– An ASP file normally contains HTML tags, just as astandard HTML file.– In addition, an ASP file can contain server sidescripts, surrounded by the delimiters <% and %>.Server side scripts are executed on the server, andcan contain any expressions, statements, procedures,or operators that are valid for the scripting languageyou use.– The response.write command is used to write output toa browser
ASP Variables• Variables– Variables are used to store information– This example demonstrates how to create a variable,assign a value to it, and insert the variable value into atext.<html><body><%Dim namename=“Tripti Arora"Response.Write("My name is: " & name)%></body></html>
ASP Variables• Arrays– Arrays are used to store a series of related data items.– This example demonstrates how you can make an arraythat stores names.<%Dim name(5)name(0) = "Jan Egil"name(1) = "Tove"name(2) = "Hege"name(3) = "Stale"name(4) = "Kai Jim"name(5) = "Borge"For i = 0 to 5Response.Write(name(i) & "<br />")Next%></body></html>
Including Files• The #include Directive– It is possible to insert the content of another fileinto an ASP file before the server executes it, withthe server side #include directive.– The #include directive is used to create functions,headers, footers, or elements that will be reused onmultiple pages.
Including Files• How to Use the #include Directive– Here is a file called "mypage.asp":<html><body><h3>Words of Wisdom:</h3><p><!--#include file="wisdom.inc"--></p><h3>The time is:</h3><p><!--#include file="time.inc"--></p></body></html>– Here is the "wisdom.inc" file:"One should never increase, beyond what is necessary,the number of entities required to explain anything."– Here is the "time.inc" file:<%Response.Write(Time)%><!-- #include virtual="somefilename“ - ->Or<!--#include file ="somefilename"-->Syntax
Including Files• Source code in a browser, it will look somethinglike this:<html><body><h3>Words of Wisdom:</h3><p>"One should never increase, beyond whatis necessary, the number of entitiesrequired to explain anything."</p><h3>The time is:</h3><p>11:33:42 AM</p></body></html>
ASP Forms and User Input• User Input– To get information from forms, you can use theRequest Object– Example<form method="GET" action="tizagGet.asp">FirstName <input type="text" name=“fname"/>LastName <input type="text" name=“lname"/><input type="submit" /></form>– There are two ways to get form information: TheRequest.QueryString command and theRequest.Form command.
• Request.QueryString– This collection is used to retrieve the values of thevariables in the HTTP query string.– The form data we want resides within the RequestObjects QueryString collection– Information sent from a form with the GET method isvisible to everybody (in the address field) and the GETmethod limits the amount of information to send.– If a user typed “Bill" and "Gates" in the form exampleabove, the url sent to the server would look like this:http://www.asp.com/pg.asp?fname=Bill&lname=GatesRequest Object - Collections
Request Object - CollectionsRequest.QueryString– The ASP file "pg.asp" contains the following script:<body>Welcome<%response.write(request.querystring("fname"))response.write(request.querystring("lname"))%></body>– The example above writes this into the body of adocument:Welcome Bill Gates
Request Object - Collections• Request.Form– It is used to retrieve the values of form elementsposted to the HTTP request body, using the POSTmethod of the <Form> Tag.– Information sent from a form with the POST methodis invisible to others.– The POST method has no limits, you can send a largeamount of information.– If a user typed "Bill" and "Gates" in the form exampleabove, the url sent to the server would look like this:http://www.asp.com/pg.asp
Request Object - Collections• Request.Form– The ASP file "pg.asp" contains the following script:<body>Welcome<%response.write(request.form("fname"))response.write(" ")response.write(request.form("lname"))%></body>– The example above writes this into the body of adocument:Welcome Bill Gates
ASP Session• The Session Object– The Session object is used to store informationabout each user entering the Web-Site and areavailable to all pages in one application.– Common information stored in session variablesare user’s name, id, and preferences.– The server creates a new Session object for eachnew user, and destroys the Session object whenthe session expires or is abandoned or the userlogs out.
ASP Session• Store and Retrieve Variable Values– The most important thing about the Sessionobject is that you can store variables in it, like this:<%Session("TimeVisited") = Time()Response.Write("You visited this site at:"&Session("TimeVisited"))%>Here we are creating two things actually: a key and a value. Abovewe created the key "TimeVisited" which we assigned the valuereturned by the Time() function.Display:You visited this site at: 8:26:38 AM
Session Object - Properties• SessionID– The SessionID property is a unique identifier that isgenerated by the server when the session is firstcreated and persists throughout the time the userremains at your web site.– Syntax:<%Session.SessionID%>Example:<% Dim mySessionIDmySessionID = Session.SessionID%>
ASP Cookies• Like ASP Sessions, ASP Cookies are used to store informationspecific to a visitor of your website. This cookie is stored tothe users computer for an extended amount of time. If you setthe expiration date of the cookie for some day in the future itwill remain their until that day unless manually deleted by theuser.• Creating an ASP cookie is exactly the same process ascreating an ASP Session. We must create a key/value pairwhere the key will be the name of our "created cookie". Thecreated cookie will store the value which contains the actualdata.
Create Cookies<%create the cookieResponse.Cookies("brownies") = 13%>To get the information we have stored in the cookie wemust use the ASP Request Object that provides a nicemethod for retrieving cookies we have stored on theusers computer.
Retrieving Cookies<%Dim myBrownieget the cookiemyBrownie = Request.Cookies("brownies")Response.Write("You ate " & myBrownie & "brownies")%>• Display:You ate 13 brownies