Editing Include Javascript in the workflow (section)

==Custom input renderer==

You can overwrite the input renderer for the field you wish to modify. This gives you access to information used to render the field.

<source lang="perl">
          {
            'name' => 'courses',
            'type' => 'text',
	    'multiple' => 1,
	    'text_index' => 1,
	    'render_input' => sub {
                    my ( $field, $repository, $current_value, $dataset, $staff, $hidden_fields, $object, $basename ) = @_;
                    
                    my $dom = $field->render_input_field_actual( $repository, $current_value, $dataset, $staff, $hidden_fields, $object, $basename );
                    my $script = $repository->xml->create_element("script", type=>"text/javascript");
                    my $perl = "print STDERR 'This will be printed to the error log.';
                    $script->appendChild($repository->xml->create_text_node('
// your javascript here '." which can have $perl interlaced "
                    ));
             }
          },
</source>

===Example custom input renderer===
Below is an example of a custom renderer.  This is for a multiple select form element, where some of the options have become deprecated.  The code will add a message to a warning box if either when the page loads or whilst the user is selecting options they choose an option that is deprecated.  However, it will not prevent them from choosing this option.
<source lang="perl">
          {
            'name' => 'divisions',
            'type' => 'subject',
            'multiple' => 1,
            'top' => 'divisions',
            'browse_link' => 'divisions',
            'render_input' => sub {
              my ( $field, $repository, $current_value, $dataset, $staff, $hidden_fields, $object, $basename ) = @_;
              my $messagebox = $repository->xml->create_element("div", id=>$basename."_messagebox", class=>"ep_msg_warning_content_no_table", style=>"display: none;");
              my $messagelist = $repository->xml->create_element("div", id=>$basename."_messagelist");
              $messagebox->appendChild($messagelist);
              my $dom = $field->render_input_field_actual( $repository, $current_value, $dataset, $staff, $hidden_fields, $object, $basename );
              my $script = $repository->make_javascript('var selectmenu = document.getElementById("'.$basename.'");
window.addEventListener("load", function(){ setDivisionsMessage(selectmenu) });
selectmenu.addEventListener("click", function(){ setDivisionsMessage(selectmenu); });
function setDivisionsMessage(selectmenu){
        var messagebox = document.getElementById("'.$basename.'_messagebox");
        var messagelist = document.getElementById("'.$basename.'_messagelist");
        messagelist.innerHTML = "";
        var historical_divisions = [ "cen_sis", "cen_mpm", "fac_acc", "fac_fin", "fac_ms", "fac_mar", "fac_om", "fac_ob", "fac_sts", "fac_sei" ];
        for (var i=0, j=selectmenu.options.length; i<j; i++) {
                if (selectmenu.options[i].selected && historical_divisions.indexOf(selectmenu.options[i].value) != -1){
                        var message = document.createElement("li");
                        message.appendChild(document.createTextNode(selectmenu.options[i].innerHTML + " is a historical centre. Please consider choosing a different centre."));
                        messagelist.appendChild(message);
                }
        }
        messagebox.style.display = (messagelist.children.length > 0 ? "block" : "none");
}
');
              my $superdom = $repository->xml->create_element("div");
              $superdom->appendChild($messagebox);
              $superdom->appendChild($dom);
              $superdom->appendChild($script);
              return $superdom;
            }
          },
</source>