It's necessary to put hidden tree of elements inside html-element hidden to attach them to form: hidden tree of elements will be sent to server together with elements, generated by controls.
<form>
<hidden>
<aaa#bbb attribute=value>
<ccc#ddd attribute2=value2>
</aaa>
</hidden>
</form>
| <aaa#bbb attribute=value> <ccc#ddd attribute2=value2> </aaa> |
<form>
<hidden>
<a#ref a1=v1>
</hidden>
<input name=a2 value=v2>
<input name=a3 type=file>
<hidden>
<b b1=bb/>
</a>
</hidden>
</form>
| <a#ref a1=v1 a2=v2 a3=filename.ext> <b b1=bb/> </a> <?file attr=a3 value=filename.ext xml:size=7>Y29udG</file> |
<form>
<hidden>
<data a1=v1>
</hidden>
<tr id=order#ref repeat=template>
<td><input type=text name=row[order].product></td>
<td><input type=text name=row[order].quantity></td>
<td><button type=remove>Remove This Row</button></td>
</tr>
<tr>
<td><button type=add template=order>Add Row</button></td>
</tr>
<hidden>
</data>
</hidden>
</form>
| <data a1=v1> <order#ref product=p1 quantity=q1> <order#ref product=p2 quantity=q2> <order#ref product=p3 quantity=q3> </data> |
<input type=hidden>
should be abolished.
If tag hidden is inside alternative block, then hidden data will be sent only if radio/checkbox-button is pressed.