Active Server Page

Active Server Page

1.What is ASP

2.Create, Process Forms

3.Display, Edit Databases

4.Built-in Objects

Part I: What is ASP?

An abbreviation for Active Server Pages Free and already built into Win2000 Using server-side scripting (The code inside ASP

is mixed in with standard HTML and is NEVER seen by the browser.)

Allows you to dynamically generate browser-neutral content


Runs on Microsoft Internet Information Server (IIS) only

Administrated with FrontPage Explorer

Extension of .asp Default language:

VBScript CGI, PHP, JSP….

Web Browser

Database

Windows NT Server


A simple example The Web Server finds the

file and then processes all the ASP code between <% ... %> before handing back the page. Code between <% ... %> never arrives at the browser.

<%@ Language=“VBScript”%>

<html><head><TITLE>hi.asp</TITLE></head><body bgcolor="#FFFFFF">Today is <%=now%> and all is well<br><%if hour(now())>13 THEN%>Good Morning<%ELSE%>Good Day!<%END IF%></body></html>

Today is 3/1/00 12:22:54 AM and all is wellGood Day!

<html><head><title>hi.asp</title></head><body bgcolor="#FFFFFF"><p>Today is 3/1/00 12:22:54 AM and all is well<br> Good Day! </p></body></html>

Part II: Process Form Input in ASP Forms are the primary way that a user feeds information to the server and collected by ASP objects. A

form is a web page that contains tags that cause the browser to show fields that the user can fill in. Forms can be HTML or ASP files. The form must pass the variables onto a .asp file to process the form. With Get or Post Method

– Get sends form input to the browser as part of the URLE.g., http://lw4fd.law4.hotmail.msn.com/cgi-bin/HoTMaiL?disk=216.33.148.69_d514&login=sungchichu&f=33792&curmbox=ACTIVE&_lang=&fti=yes

– Post sends form input to the browser as part of the Request Tips: a text link to post above form would look like this:

<a href= "javascript:submitform(document.forms['whatever'])">whatever</a>

Form with GET

<form action="x.asp" name="whatever" method=get>....<input type=submit><input type=reset></form>

An ASP script picks up a form field with:<%whatever=request.query

string("whichfield")%>

Part II: Process Form Input in ASP

there is a limit on the number of characters (approximately 4,000 but varies depending on server and browsers

involved. The form will show its

parameter in the browser address window, for example:testform.asp?state=md&city=Germantownwould be the URL in the browser, if the state and city field were populated

It supports many more characters than get (megabytes of data in case of file uploads)

The form will not show its parameter in the browser address window, for example:http://whatever.com/testform.aspwould be the only URL in the browser, regardless of how many fields and how much data is passed.

Form with Post <form action="x.asp"

name="whatever" method="post">....<input type=submit><input type=reset></form>

An ASP script picks up the form field with:<%whatever=request.form("whichfield")%>

Part II: Process Forms in ASP <html><head>

<title>FormTextBox.asp</title></head><body bgcolor="#FFFFFF"><Form action = "FormTextBoxRespond.asp" method="get">Fill Out This Form For Us:<p>Last Name -> <Input NAME="NameLast" size ="10"><br>Country -> <Input NAME="Country" value="USA" size=10><br>State -> <Input NAME="State" MaxLength="2" size=2><br><Input type="submit" value="Give me your data!"><hr></form></body></html>

<html><head><title>FormTextBoxRespond.asp</title></head><body bgcolor="#FFFFFF"><%lname=request.querystring("namelast")cty=request.querystring("country")st=request.querystring("state")

response.write lname & "<br>"response.write cty & "<br>"response.write st & "<br>"%></body></html>

Part II: Create, Process Forms

Leo

USA

20

Part II: Create, Process Forms IF Statement Very often you must determine what to do next based on user input. This is one of the

roles of the IF statement. First we make a form that will ask a user for their first name and last name

If … then else (elseif)end if

<html><head><TITLE>ifrespond.asp</TITLE></head><body bgcolor="#FFFFFF"><%fname=request.querystring("Firstname")lname=request.querystring("Lastname")If fname="George" and lname="Washington" then%>Hi.<p>You must be the first president!<%else%>Hi!<p>Nice to Meet You<%end if%></body></html>

Part II: Create, Process Forms Select Case statement Using IF-THEN can be cumbersome, prone to programmer errors and slower to

execute. A more efficient construct is SELECT CASE (Switch-break in C?). It is optimized for testing one variable against many conditions

Here is the select case that will determine what the form input means.

<%fname=request.querystring("Firstname")lname=request.querystring("Lastname")%>Nice to Meet You <%=fname%> <%=lname%><p><% select case lcase(lname)case "washington","adams"response.write "The first president has same last name<p>"case "jefferson"response.write "The third president has same last name<p>"case "lincoln"response.write "The sixteenth president has same last name<p>"end select%>

Part III: Display, Edit Databases

ActiveX Data Objects(ADO)

Active Server PageADO

OLE DB Layer

ODBC data Provider

3rd partydata provider

SQL Relational Database

None-relational data store


ADODB.Command ADODB.Connection ADODB.Error ADODB.Field ADODB.Parameter ADODB.Property ADODB.Recordset

Set adoCon= Server.CreateObject(“ADODB.Connection”)

Set adoRec= Server.CreateObject(“{ADODB.Recordset”)

adoCon.Open “Yourdatabase”

adoRec.activeConnection=adoCon

adoRec.open SQLstatement

…..

adoRec.close

adoCon.close

set adoRec = nothing

set adoCon = nothing

Part III: Display, Edit Databases Recordset Object Methods AddNew MoveFirst / MoveLast / Move

Previous Open Update Delete Property EOF / BOF CursorType ActiveConnection AbsolutePosition

Connection Object Methods Close Execute Open

Property Attributes CommandTimeout ConnectionTimeout Mode

Part III: Display, Edit Databases display a table from a SQL statement. <% set conntemp=server.createobject("adodb.connection")

conntemp.open myDSNmySQL="select * from publishers where state='NY'"set rstemp=conntemp.execute(mySQL)If rstemp.eof thenresponse.write "No records matched<br>"response.write mySQL & "<br>So cannot make table..."connection.closeset connection=nothingresponse.endend if%><table border=1><% response.write "<tr>"for each whatever in rstemp.fieldsresponse.write "<td><B>" & whatever.name & "</B></TD>"nextresponse.write "</tr>"


DO UNTIL rstemp.eofpubid=rstemp("pubid")name=rstemp("name")company_name=rstemp("company_name") ...…

cellstart="<td align=""top"">"response.write "<tr>"response.write cellstart & pubid & "</td>"response.write cellstart & name & "</td>"response.write "</tr>"rstemp.movenextLOOP%></table><%' Now close and dispose of resourcesrstemp.closeset rstemp=nothingconntemp.closeset conntemp=nothing%>


Select field1, field2, ... from table1, table2, … where selection_criteria

Insert into table_name (fields, …) Values (values…) Insert into table_name Select Select_statement Update table_name set field1=new value, field2=new

value… where… Delete from table_name where… Be Careful!

Part IV: Built-in Objects

There are six kinds of intrinsic objects that make up the IIS object model: Application, ObjectContext, Request, Response, Server, Session

Each has its own Properties, Collections, Methods, Events


Request: gives you access to the user’s HTTP request header and body

By working with form, create dynamic web pages and perform more meaningful server-side actions(such as updating a database) based on input from the user

Properties: TotalBytes Collections: ClientCerficate, Cookies, Form, QueryString,

ServerVariables Methods: BinaryRead Events: None


<form action=“http://mycorp.com/secure.asp” method=post>

<input type=“file” name=“filename”> <br>

<input type=“submit” value=“OK”>

</form>

<% Dim lngTotalByteCount

Dim vntRequestData lngTotalByteCount=Req

uest.TotalBytes vntRequestData=Reque

st.BinaryRead(lngTotalByteCount)

%>


Request.Form has three properties of its own Key: Represents the name of a specific element of the Form Item: Represents the value of a specific element of the

Form Count: Returns the number of elements in the collection strKeyName=Request.Form.Key(3) strKeyValue=Request.Form.Item(strKeyName) Request.Form(str) is just an abbreviated form of

Request.Form.Item(str)


Response: gives you a great deal of control over the HTTP response to the client

Properties: Buffer, CacheControl, Charset, ContentType, Expires, ExpiresAbsolute, IsClientConntected, PICS, Status

Collections: Cookies Methods: Addheader, AppendToLog, BinaryWrite, Clear,

End, Flush, Redirect,, Write Event: None


The following is the same: <%

Response.write “Your name is” Response.write Request.Form(“name”) Response.write “<br>” %>

Your name is <%=Request.Form(“name”)%><br>

Part IV: Built-in Objects An example using Server Object <html><head>

<TITLE>bc.asp</TITLE></head><body bgcolor="#FFFFFF"><% Set bc = Server.CreateObject("MSWC.BrowserType") %> Browser Name: <%=bc.browser %><p> Browser Version: <%=bc.version%><p><% if (bc.frames = TRUE) then %> I noticed you do frames<p><% else %>I noticed you are frame challenged<p><% end if %><% if (bc.tables = TRUE) then %> I noticed you do tables<p><% else %>I noticed you can't do tables<p><% end if set bc=nothing%></body></html>

Date post:	15-Jan-2016
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