[ZPT] structure in tal:attributes?

[alan runyan]

hi.

I think I'm missing something.  I am trying to do the following:
<a href="#" tal:attributes="href
string:invokeFactory?type_name=$Type&id=$unique_id">click here</a>

but TALParser turns it into valid xml $Type&amp;id=$unique_id which is not
something I want.  I have tried
tal:define="urlInvokeFactory
string:invokeFactory?type_name=$Type&id=$unique_id"
and then tal:attributes="href structure urlInvokeFactory" and I'm getting a
TAL error ;(

I think I'm missing something ;)

thanks,
~runyaga