I'm trying to do something like the following:
{exp:my_tag my-param2="1" my-param2="2"}
<li>{title}</li>
<li><ul>
{my_fields}
<li>{field_label}: {field_value}</li>
{/my_fields}
</ul></li>
{/exp:my_tag}
Is it possible to do it with a simple TMPL->parse_variables() or should I put in place something more complex?
The parse_variables function handles this natively so there's really no need to complicate things unless you need some additional functionality.
The template class documentation includes some detailed instructions, but basically you just need to add a my_fields array to your main array of variable data.
$vars['title'] = 'My Title';
$vars['my_fields'] = array(
array('field_label' => 'Foo', 'field_value' => 'Something'),
array('field_label' => 'Bar', 'field_value' => 'Something else')
);
$output = $this->EE->TMPL->parse_variables($this->EE->TMPL->tagdata, $vars);
