Passing a parameter to a javascript function

Question

I have declared a <jsp:usebean> on my jsp to extract a flag from the request. I want to then pass this String as a parameter to a javascript function called on the body onload. What is the best way of doing this? The javascript function is embedded in the jsp - does this mean I can access the variable directly, without even passing it as a parameter? do I use the <%= > syntax to reference the String on the onload? Do I use the <bean:write> the extract the varible within he javascript. Any help appreciated....

Answer 1

JSP runs first on the server, and generates the HTML page with javascript.
The javascript then runs on the client - it can't call any more JSP code, without submitting a request.
In this case, you will want to use JSP to generate the javascript code that you need to run as a string on the page. You should probably use the <%= %> or the <bean:write tag>
eg
  <script>
  <!--
    function loadForm(){
      var userName = "<%= user.getName() %>";
      alert("Hello " + userName);
  //-->
  </script>Note again. The use.getName() function will run on the server and produce static html/javascript like this
var userName = "evnafets";
JSP CODE DOES NOT RUN ON THE CLIENT. You cannot use JSP code to react to button clicks on the form for instance.
Hope this helps,
evnafets