How to Call a bean from JavaScript 2

otamez · Jul 4, 2003

How to call a bean from Java Script code when button clicked?

Here is a piece of code on how it is the flow

<script language="Javascript">
function validatefields()
{
...Code for validating fields
!!HERE I WANT TO CALL A METHOD FROM MY BEAN!!
}
</script>
<body>
<jsp:useBean id="UpdateBean" class="com.class.web.comp.mybean" scope="session" />
<form name="myform" >
<input type="button" name="SaveProg" value=" Program " onClick="Javascript:validatefields();">
</from>

palbano · Jul 4, 2003

Classic web development problem. In a web application that uses server side code you have code the executes in two different locations (1) The Browser (2) The Server

They are not the same even if you are testing with both on the same physical computer.

<jsp:usebean> creates an instance of the Java class in the Servlet executing in the web server context.

<script language="javascript"> executes in the browser context

The two contexts do not coexist nor for that matter do they even exist at the same point in time as they are synchronous in nature. The only means of communication between the two contexts is to use HTTP REQUEST/RESPONSE data

-pete

sedj · Jul 4, 2003

JSP calls to beans are evaluated at the server, and their values transcribed to HTML at the point where the servlet (all JSP pages are basically evaluated and compiled to servlets byt thekicks out the response to the browser. As palbano says, JSP/Servlets are executed (ie code evaluated) serverside, and JavaScript clientside. The only way to let the two interact is by the medium that is HTML. If you set up in a <FORM> a <INPUT TYPE="hidden" NAME="myvalue" VALUE="whatever"> - this value can be accessed by JSP at server runtime, and also accessed by JavaScript at clientside (document.form[0].myvalue.value) ... hense overcoming your problem of JavaScript interacting with evaluated JSP - simple !!!

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How to Call a bean from JavaScript 2

otamez

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palbano

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sedj

Programmer

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