authoring txtml : collections

A collection is a namespace for states. In any given TXTML application, there will likely be states with names like "intro" and "success". By specifying a unqiue namespace, it is much easier to avoid loading a state into the engine with a name that already exists. A collection is a prefix in front of the state name separated by a colon. A collection can be specified in two ways, in the header or as an attribute of the state element itself. A collection specified in the header applies to all states in the document if a collection is not specified in the state. For example, the following are equivalent:

<txtml version="1.6">

     <state name="collection_a:state_1">
          ...
     </state>
     
</txtml>


and

<txtml version="1.6" collection="collection_a">

     <state name="state_1">
          ...
     </state>>

</txtml>


whereas in the following example, state 1 is in collection a, and state 2 is in collection b

<txtml version="1.6" collection="collection_a">

     <state name="state 1">
          ...
     </state>

     <state name="collection_b:state_2">
          ...
     </state>

</txtml>