how can i produce tags like those

<input id="person_contact_data__web_addresses__url" class="autofocus" type="text" value="" size="30" name="person[contact_data][web_addresses][][url]"/>
<input id="person_contact_data__phone_numbers__number" class="autofocus" type="text" value="" size="30" name="person[contact_data][phone_numbers][][number]"/>

f.text_field within my form block

and then how can i manipulate them on my controler to add them in the database to Person model ?