Scroll to previously in focus element on the page

Introduction

When the same page returns from the server, how do we scroll to the previously in focus element on the page? Example: If selecting a value from the dropdown placed way below on a page refreshes the page, by default the first field will receive the focus or scroll position set to zero. It forces the user to scroll down to the previous position and causes a lot of frustration.

With simple hidden fields, we can come back to the same position and set the focus on the same field or the next field. This will allow the user to continue from the place where they left off.

Add two hidden fields under the FORM tag:

<input type=&quot;hidden&quot; name = &quot;previousElement&quot;>
<input type=&quot;hidden&quot; name = &quot;previousScrollPosition&quot;>

Add this JavaScript code under the script tag or in your .js file:

function sendScrollPosition() {
    document.forms[0].elements["previousScrollPosition"].value = 
      document.body.scrollTop;
    return true;
} 
function setfocuselement(ele){
    if(document.forms[0] == null) return false;
    if(document.forms[0].elements["previousElement"] != null) {
        document.forms[0].elements["previousElement"].value=
          ele.name || event.srcElement.name;
    }
}

if(document.getElementsByName("previousScrollPosition").length > 0) {


    document.body.scrollTop = 
      document.forms[0].elements["previousScrollPosition"].value;
}

var prvElement= document.forms[0].elements["previousElement"];

if(prvElement != null && prvElement.value != null ) {

    document.forms[0].elements[prvElement.value].focus();
}

When you submit the page, you need to call these two JavaScript functions. You can add these JavaScript functions to the onchange, onblur, or onclick events and finally submit the page to the server.

Server Side

When you render the ASP or JSP page, you need to take both the previousScrollPosition, previousElement values from the Request object and populate both the hidden fields.

<form action=&quot;demo_form2.asp&quot; method=&quot;post&quot;>
First name:
<input type=&quot;text&quot; name=&quot;name&quot; value=&quot;Donald&quot; />
<br />
Last name:
<input type=&quot;text&quot; name=&quot;name&quot; value=&quot;Duck&quot; />
<br />

<input type=&quot;hidden&quot; name = &quot;previousElement&quot; 
  value=&quot;<%Request.Form(&quot;previousElement&quot;)%>&quot;> 
<input type=&quot;hidden&quot; name = &quot;previousScrollPosition&quot; 
  value=&quot;<%Request.Form(&quot;previousScrollPosition&quot;)%>&quot;>
<input type=&quot;submit&quot; value=&quot;Submit&quot; />
</form>

You need to make sure that the form fields are available in the FORM before calling or using the JavaScript functions.

If you have multiple fields with the same name, then you need to send the index of the field to the server and get the field list using the document.getElementsbyName("elementName") function and loop through it to select the correct index and set the focus.

Setting focus on the next element or skipping hidden or disabled fields while doing setfocus is a complex JavaScript action. I will show it in a different article.