I have trouble with wordwrap of source in my template toolkit files with embedded javascript.

Solution: with the plus sign (+) I splitt the string in more than one line!

<script type="text/javascript">
   $(document).ready(function() {
    $("#lxversion").change(function() {
        var lxverval = $(this).val();
         <% FOREACH lxver IN rzconfig.rz.${vienv}.lx.ver.keys.sort %>
           if (lxverval == "<% lxver %>") {
               $("#lxmodel").html(''+
                 <% FOREACH model IN rzconfig.rz.${vienv}.lx.ver.$lxver.model.keys.sort %>
                   <% IF rzconfig.rz.${vienv}.lx.ver.$lxver.model.$model.default == "true" %>
                     '<option value="<% model %>" selected><% model %></option>'+
                   <% ELSE %>
                     '<option value="<% model %>"><% model %></option>'+
                   <% END %>
                 <% END %>'');
           }
         <% END %>
        $('#lxmodel').selectpicker('refresh');
    });
   });
</script>

It is better to read than

$("#lxmodel").html('<% FOREACH model IN rzconfig.rz.${vienv}.lx.ver.$lxver.model.keys.sort %><% IF rzconfig.rz.${vienv}.lx.ver.$lxver.model.$model.default == "true" %><option value="<% model %>" selected><% model %></option><% ELSE %><option value="<% model %>"><% model %></option><% END %><% END %>');