XML Attribute Mapping?

[wiggles]

I was wondering if there was talk of using xml for sub-flow attribute mapping rather then full-blown classes? Maybe something like:

<webflow id="mySubflow" start-state="setupForm">
 <in-param name="city"/>
 <in-param name="state"/>
 ...
</webflow>

<webflow id="myRootFlow" start-state="setupForm">
 ...
 <subflow-state id="mySubflow" flow="mySubflow">
  <param-mapping parent="homeCity" child="city"/>
  <param-mapping parent="homeState" child="state"/>
 </subflow-state>
 ...
</webflow>

[Keith Donald]

Yes, great idea. Could you open a JIRA issue so it doesn't get lost?

[wiggles]

Done and done.

[Keith Donald]

I'm thinking something like this:

	<subflow-state id="enterPassengerInformation" flow="passenger">
		<attribute-mapper>
			<input-mapping attribute="$&#123;requestScope.passenger.id&#125;"/>
			<output-mapping attribute="some_flow_attribute"/>
		</attribute-mapper>
	</subflow-state>

[wiggles]

Are you talking about that subflow-state syntax in addition to specifying parameters in the subflow itself? Because you need to specify the local key, as well as the foreign key to map it to for each input and output parameter. I actually forgot the output of the flow and subflow-state in my example. How about this:

<webflow id="mySubflow" start-state="setupForm">
 <!-- Don't really need anything here. -->
 ...
</webflow>

<webflow id="myRootFlow" start-state="setupForm">
 ...
 <subflow-state id="mySubflow" flow="mySubflow">
  <attribute-mapper>
   <in-mapping parent="$&#123;requestScope.person.city&#125;" child="city"/>
   <in-mapping parent="$&#123;requestScope.person.state&#125;" child="state"/>
   <out-mapping child="firstName" parent="$&#123;requestScope.person.firstName&#125;"/>
   <out-mapping child="lastName" parent="$&#123;requestScope.person.lastName&#125;"/>
  </attribute-mapper>
 </subflow-state>
 ...
</webflow>

Looks like you could do something like ParameterizableAttributeMapper.

[Keith Donald]

Oops, yea I see what you mean.

Here ya go:

<subflow-state id="enterPassengerInformation" flow="passenger"> 
      <attribute-mapper> 
         <input name="passengerId" value="$&#123;requestScope.passenger.id&#125;"/> 
         <input name="someInputAttributeName"/>
         <input name="someOtherInputAttributeName" as="someAdaptedInputAttributeName"/>
         <input value="$&#123;requestScope.someAttribute&#125;" as="someAdaptedInputAttributeName"/>
         <output name="someOutputAttributeName"/> 
         <output name="someOutputAttributeName" as="someAdaptedOutputAttributeName"/>
      </attribute-mapper> 
</subflow-state>

Those are all the useful combos I can think of. Others?

Yes, the xml would just be a convenient way to configure a ParameterizableAttributeMapper.

It doesn't make since to map output mappings from request scope, though :-) Only flowScope makes sense for output mappings. This is because the request scope is shared on a "per request" basis, regardless of what flow session is active...

Now, you could map a input request attribute down into flowScope of a subflow, as shown below. This is arguably better than relying on shared requestScope attributes.

[wiggles]

I like that syntax a lot. Does <input name="" value="" as=""/> make sense? If you have a value, why do you need a name?

I didn't know that requests could overlap flows. Very good to know.

[Keith Donald]

Damn man you're quick ;-), no name does not make sense there--only value/as --- thanks :-)

[wiggles]

I noticed that you've done some work with this. Is it complete, because I'm having some trouble getting it to work.

[Keith Donald]

It's still a WIP for PR3 -- at least value expressions are.

What is the problem you're seeing? Basic attribute mapping using static attribute names should work.