in my action class i want to have a map of strings. and in my tml i want to access this map with textfield. something like

```
<t:form>
    <t:textfield value="myMap['key1']"/>
    <t:textfield value="myMap['key2']"/>
...

```

i don't insist on syntax, but is there anything like this currently in tapestry? if not, what do i need to create such conversion in the most easy way? type coercing? custom components? i'm starting to learn tapestry so feel free to be verbose :)