AJAX ASP Example

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AJAX ASP Example


AJAX is used to create more interactive applications.

AJAX ASP Example
The following example will demonstrate how a web page can communicate with a
web server while a user type characters in an input field:

Example

Start typing a name in the input field below:
Suggestions:
First name:




Example Explained
In the example above, when a user types a character in the input field, a function
called showHint() is executed.
The function is triggered by the onkeyup event.
Here is the code:

Example

<p>Start typing a name in the input field below:</p>
<p>Suggestions: <span id="txtHint"></span></p>
<form>
First name: <input type="text" onkeyup="showHint(this.value)"></form>
<script>
function showHint(str) {
  if (str.length == 0) {
    document.getElementById("txtHint").innerHTML = "";
    return;
  } else {
    const xmlhttp = new XMLHttpRequest();
    xmlhttp.onload = function() {
      document.getElementById("txtHint").innerHTML = this.responseText;
    }
  xmlhttp.open("GET", "gethint.asp?q=" + str);
  xmlhttp.send();
  }
}
</script>

Try it Yourself »

Code explanation:
First, check if the input field is empty (str.length == 0). If it is, clear the
content of the txtHint placeholder and exit the function.
However, if the input field is not empty, do the following:

Create an XMLHttpRequest object
Create the function to be executed when the server response is ready
Send the request off to an ASP file (gethint.asp) on the server
Notice that q parameter is added gethint.asp?q="+str
The str variable holds the content of the input field








The ASP File - "gethint.asp"
The ASP file checks an array of names, and returns the corresponding name(s) to the
browser:

<%
response.expires=-1
dim a(30)
'Fill up array with names
a(1)="Anna"
a(2)="Brittany"
a(3)="Cinderella"
a(4)="Diana"
a(5)="Eva"
a(6)="Fiona"
a(7)="Gunda"
a(8)="Hege"
a(9)="Inga"
a(10)="Johanna"
a(11)="Kitty"
a(12)="Linda"
a(13)="Nina"
a(14)="Ophelia"
a(15)="Petunia"
a(16)="Amanda"
a(17)="Raquel"
a(18)="Cindy"
a(19)="Doris"
a(20)="Eve"
a(21)="Evita"
a(22)="Sunniva"
a(23)="Tove"
a(24)="Unni"
a(25)="Violet"
a(26)="Liza"
a(27)="Elizabeth"
a(28)="Ellen"
a(29)="Wenche"
a(30)="Vicky"
'get the q parameter from URL
q=ucase(request.querystring("q"))
'lookup all hints from array if length of q>0
if len(q)>0 then
 
hint=""
 
for i=1 to 30
   
if q=ucase(mid(a(i),1,len(q))) then
     
if hint="" then
       
hint=a(i)
     
else
       
hint=hint & " , " & a(i)
     
end if
   
end if
 
next
end if
'Output "no suggestion" if no hint were found
'or output the correct values
if hint="" then
 
response.write("no suggestion")
else
 
response.write(hint)
end if
%>












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Reference: https://www.w3schools.com/js/js_ajax_asp.asp