Gotcha: must set document.location.hash only at end of page in Mozilla

I just came across a different behaviour between IE and Mozilla Firefox: scripts at the former seem to execute after the page has fully rendered, while the later they seem to execute when they’re met by the page parser or something like that.

The HTML script tag has a defer attribute for running scripts after page has rendered, but that is available only for script tags that load an external script, not for embedded scripts in the HTML page. So this seems like one of those different interpretations that usually plague "standards". 

So, at the following JSP code, I was creating a table of student entries with a named anchor (bookmark) at each of the entries (each named per student id), so that when coming back from another page to that one I could tell it to scroll down to a given student automatically.

The issue was that if I placed the script that set document.location.hash to the student id, then at IE it worked OK, but at Mozilla Firefox it just moved to the top of the page even though the URL at the address bar of the browser had the hash entry (e.g. #55555) at the end and would scroll down correctly if I pressed Refresh button there.

Moving the script to the end of the page made it work for both IE and Mozilla Firefox. Don’t you love HTML’s "debug everywhere"?

 

<%@ page contentType="text/html" session="true" pageEncoding="UTF-8" %>

<%
response.setHeader("Cache-Control", "no-cache, no-store"); //HTTP 1.1
response.setHeader("Pragma", "no-cache"); //HTTP 1.0
response.setDateHeader ("Expires", -1); //prevents caching at the proxy server
%>

…

<%@ page import="javax.portlet.*" %>
<%@ page import="java.util.ResourceBundle" %>

<%@ taglib uri="http://java.sun.com/portlet" prefix="portlet" %>
<%@ taglib uri="http://java.sun.com/jstl/fmt" prefix="fmt" %>

<%
  RenderRequest renderRequest = (RenderRequest) request.getAttribute("javax.portlet.request");
  RenderResponse renderResponse = (RenderResponse) request.getAttribute("javax.portlet.response");
          
…

  String studentId = (String)renderRequest.getAttribute(Constants.JSP_RENDER_STUDENTID);
  if (studentId == null) studentId = "";
…

  <%
       for(int i = 0; i < proposalsCount_supervisor; i++) {
        IProposalListItem proposal = proposals_supervisor.getProposalListItem(i); 
   %>
  <a name="<%=proposal.getStudentId()%>"></a>
   <div class="dissertation_subsection<%=(i%2)%>">

     <div>
     ….

   <%}%>

….

<script type="text/javascript"> <%– MAKE SURE THIS IS PLACED AT THE END, ELSE IT WON’T WORK AT MOZILLA –%>
document.location.hash="<%=studentId%>"; //scroll to previously examined student
<%– alert(document.location.hash); –%>
</script>