Starting arbitrary jPDL pageflows from a

[igx89]

Say I have the following jPDL pageflows:
PF1: page1.xhtml -> page2.xhtml
PF2: page1.xhtml -> page3.xhtml
PF3: page4.xhtml -> page5.xhtml

What I want to happen is that when the user goes to "controller.seam?flow=PF?", they'll automatically be redirected to the right page and start the right flow. Unfortunately, though that seems a simple task, in reality it's a big pain to do.

Ideally, I'd like to be able to do:

 <page view-id="/controller.xhtml" action="#{controller.getFlow}">
 <param name="flow" value="#{controller.flow}" />

 <navigation>
 <rule if-outcome="PF1">
 <begin-conversation join="true" pageflow="PF1" />
 </rule>
 <rule if-outcome="PF2">
 <begin-conversation join="true" pageflow="PF2" />
 </rule>
 ...
 </navigation>
 </page>

(even that in an ideal world would be more concise, as you can most likely envision)

However, that doesn't work! If the pageflow has a <start-page> node, Seam doesn't like that its view-id is different than the current page (the controller). If the pageflow has a <start-state> node (automatically going to the first page in the flow), Seam complains that it can't do that while in a RENDER_RESPONSE phase.

It would seem the following might get around those issues (though add even more duplicate code):

 <rule if-outcome="PF1">
 <redirect view-id="page1.xhtml" />
 <begin-conversation join="true" pageflow="PF1" />
 </rule>

However, that doesn't work either! Seam doesn't allow multiple elements inside a rule element.

Currently, I'm solving the problem by doing the following; it works, but has lots of ugly duplication (antithema to Seam's goals):

 <page view-id="/controller.xhtml" action="#{controller.getFlow}">
 <param name="flow" value="#{controller.flow}" />

 <navigation>
 <rule if-outcome="PF1">
 <redirect view-id="/page1.xhtml" />
 </rule>
 <rule if-outcome="PF2">
 <redirect view-id="/page1.xhtml" />
 </rule>
 <rule if-outcome="PF3">
 <redirect view-id="/page4.xhtml" />
 </rule>
 </navigation>
 </page>

 <page view-id="/page1.xhtml" action="#{controller.getFlow}">
 <navigation>
 <rule if-outcome="PF1">
 <begin-conversation join="true" pageflow="PF1" />
 </rule>
 </navigation>
 </page>

 <page view-id="/page1.xhtml" action="#{controller.getFlow}">
 <navigation>
 <rule if-outcome="PF2">
 <begin-conversation join="true" pageflow="PF2" />
 </rule>
 </navigation>
 </page>

 <page view-id="/page4.xhtml" action="#{controller.getFlow}">
 <navigation>
 <rule if-outcome="PF3">
 <begin-conversation join="true" pageflow="PF3" />
 </rule>
 </navigation>
 </page>

Should I submit a feature request for a solution to this issue?

[igx89]

(off-topic: I hate the short cut-off on thread titles and/or the painful lack of any "Edit Post" functionality :( )

[pmuir]

Currently supported, you could do this (which helps a bit):

<page view-id="/controller.xhtml">
 <navigation evaluate="#{param.flow}">
 <rule if-outcome="PF1">
 <redirect view-id="/page1.xhtml" />
 </rule>
 <rule if-outcome="PF2">
 <redirect view-id="/page1.xhtml" />
 </rule>
 <rule if-outcome="PF3">
 <redirect view-id="/page4.xhtml" />
 </rule>
</navigation>
</page>

or

<page view-id="/controller.xhtml">
 <navigation>
 <rule if="#{param.flow eq 'PF1'}">
 <redirect view-id="/page1.xhtml" />
 </rule>
 ...
 </navigation>
</page>

Will look at the rest later.

[igx89]

I still need the param element to pass the value onto the page handler for page1.xhtml, so that just rearranges things without reducing code. And, unfortunately, not even that works: the action attribute is needed, otherwise the navigation rules are never evaluated.

[igx89]

Well, I found out that Seam does allow multiple elements inside a root element, but only if they're in the right order! For instance, this doesn't work:

 <rule if-outcome="FP1">
 <redirect view-id="page1.xhtml" />
 <begin-conversation join="true" pageflow="PF1" />
 </rule>

but this does:

 <rule if-outcome="FP1">
 <begin-conversation join="true" pageflow="PF1" />
 <redirect view-id="page1.xhtml" />
 </rule>

So, with that discovery, I was able to greatly reduce the configuration needed, to the point that I'm pretty much satisfied now :). Only unfortunate things are that I still need a controller JavaBean to force the navigation rules to be evaluated on page load and that beginning a pageflow doesn't automatically redirect to its start-page.

The solution:

 <page view-id="/controller.xhtml" action="#{controller.getFlow}">
 <param name="flow" value="#{controller.flow}" />

 <navigation>
 <rule if-outcome="PF1">
 <begin-conversation join="true" pageflow="PF1" />
 <redirect view-id="page1.xhtml" />
 </rule>
 <rule if-outcome="PF2">
 <begin-conversation join="true" pageflow="PF2" />
 <redirect view-id="page1.xhtml" />
 </rule>
 <rule if-outcome="PF3">
 <begin-conversation join="true" pageflow="PF3" />
 <redirect view-id="page4.xhtml" />
 </rule>
 </navigation>
 </page>