Question

I have a table contents many fields

db.define_table('i2l_templates',
    Field('id','id',
          represent=lambda id:SPAN(A(T('View'),_href=URL('view_template',args=id)),' | ',
                                          A(T('Edit'),_href=URL('edit_template',args=id)))),
    Field('user_id', db.auth_user, default=auth.user_id, writable=False,readable=False,
          label=T('User Id')),
    Field('template_name', requires=IS_NOT_EMPTY(), type='string',
          label=T('Template name')),
    Field('template_type', requires=IS_IN_SET(('Letter', 'Invoice', 'Reminder')),
          label=T('Template type')),
    Field('myref_format', requires=IS_NOT_EMPTY(), type='string',
          label=T('My reference')),
    Field('myref_offset', type='integer',
          label=T('My ref. Offset')),
    Field('letterheader', type='integer',
          label=T('Letter Header')),
    Field('invoiceheader', type='integer',
          label=T('Invoice header')),
    Field('reminderheader', type='integer',
          label=T('Reminder Header')),
    format='%(template_name)s',
    migrate=settings.migrate)

so i want to do this
when the user choose a template type Letter, the field letterheader will appear and invoiceheader and reminderheader will still hidden ..
when the user change the type to invoice, the field invoiceheader appears … and so on

Answer 1

to do this use jQuery ..
example:

<script>
jQuery(document).ready(function(){
   jQuery('#i2l_templates_heading__row').hide();
   jQuery('#i2l_templates_headingvalue__row').hide();
   jQuery('#i2l_templates_template_type').change(function(){
        if(jQuery('#i2l_templates_template_type').attr('value')=="{{=T('Invoice')}}")
        {
            jQuery('#i2l_templates_heading__row').show();
            jQuery('#i2l_templates_headingvalue__row').show();
        }
        else {
            jQuery('#i2l_templates_heading__row').hide();
            jQuery('#i2l_templates_headingvalue__row').hide();
        }});
});
</script>