Re: Flowscript and return to pipeline

[Stephan Coboos]

Leszek Gawron wrote:

On Thu, Feb 26, 2004 at 10:22:12AM +0100, Stephan Coboos wrote:
 

I think a solution like this:

<map:match pattern="first">
 <map:call function="getValues" return="true"/>
 <map:transform type="jxt"/>
 <map:serialize/>
</map:match>
   

 

is more easier to understand than this:

<map:match pattern="first">
 <map:call function="getValues"/>
</map:match>
<map:match pattern="second">
 <map:generate type="jxt"/>
 <map:serialize/>
</map:match>
ok, this is possible, too:

<map:match pattern="first">
 <map:act type="getValues"/>
 <map:transform type="jxt"/>
 <map:serialize/>
</map:match>
   

Not easier to understand at all as you are mixing concerns. With 2 lines of
code you have mixed model and view.
 

What are the differences between this two solutions?

<map:match pattern="first">
 <map:call function="getValues" return="true"/>
 <map:transform type="jxt"/>
 <map:serialize/>
</map:match>
and

<map:match pattern="first">
        <map:act type="serverpages" src="get_values.xsp">
                <!-- the action puts the values in request attribute and now you can
            use it from within jxtemplate -->
                <map:generate type="jx" src="values.jx"/>
                <map:serialize type="html"/>
        <map:act>
        <map:generate src="failed-to-get-data.xml"/>
        <map:serialize type="html"/>
</map:match>
Therefore I wrote "why not using flowscript like actions"?

Please note the attribute return="true" in the <map:call/>. This tells cocoon what the flow will always return into the sitemap at this position and is not able to use sendPage or sendPageAndWait. I think this would be a possible way to realize integration of flowscript.

What if getValues function fails to fetch the data? 
Of course another way could be to to use a construct like this:

<map:match pattern="first">
 <map:act type="flowscript">
    <!-- Do something here -->
 </map:act>
 <map:transform type="jxt"/>
 <map:serialize/>
</map:match>
- BSF (you can use Javascript too) - I do not know what state the BSF block is
 in right now as really nobody used it before.
OK. But this seems to be a problem. I have to use this option in a production environment and therefore it has to be stable. 

It should be possible to say: Use flowscript for _all_ your logic problems. The one way should be to use it with sendPage, ... and another way to use it without this functions and instead with a if-else-construct within the pipeline like in actions. So you have one technique which solves the most problems.

Regards
Stephan