question regarding the Cocoon 3 API

[Robby Pelssers <Ro...@nxp.com>]

Hi,

Are my following assumptions right?


-          setConfiguration is typically used when using sitemap

-          but for setup(params) method the API states that this is the shared map for all components... so it should not be called directly

but it gets indirectly called when executing pipeline.setup(outputstream, params)?



If it was not intended this way, then https://issues.apache.org/jira/browse/COCOON3-68 applies.



-          But I still can see the need that different components need to be able to be  setup with different maps of parameters. Suppose both components need a "id" parameter but for
the generator this needs to be value 'x' and for e.g. the transformer value 'y'. Then using a shared map will not work.


Kind regards,
Robby






public interface PipelineComponent {

    /**
     * This method is called after pipeline run - regardless if the run was
     * successful or an exception was thrown.
     */
    void finish();

    /**
     * Pass component specific configuration parameters to the pipeline
     * component in a generic way. This is useful in environments that
     * automatically assemble pipelines with their components and can't use the
     * components constructors or setters.
     *
     * @param configuration The {@link Map} of configuration parameters.
     */
    void setConfiguration(Map<String, ? extends Object> configuration);

    /**
     * The shared object map for this pipeline run.
     *
     * @param parameters A {@link Map} of parameters that are available to all
     *            {@link PipelineComponent}s. This is a modifiable map that can
     *            be changed by this pipeline component.
     */
    void setup(Map<String, Object> parameters);
}

Re: question regarding the Cocoon 3 API

[Steven Dolg <st...@indoqa.com>]

Am 15.07.2011 16:12, schrieb Reinhard Pötz:
> On 07/07/2011 12:09 PM, Robby Pelssers wrote:
>> Hi,
>>
>> Are my following assumptions right?
>>
>> -setConfiguration is typically used when using sitemap
>
> yes
>
>> -but for setup(params) method the API states that this is the shared map
>> for all components… so it should not be called directly
>>
>> but it gets indirectly called when executing
>> pipeline.setup(outputstream, params)?
>
> yes, see o.a.c.pipeline.AbstractPipeline#setupComponents
>
>> If it was not intended this way, then
>> https://issues.apache.org/jira/browse/COCOON3-68 applies.
>>
>> -But I still can see the need that different components need to be able
>> to be setup with different maps of parameters. Suppose both components
>> need a “id” parameter but for
>>
>> the generator this needs to be value ‘x’ and for e.g. the transformer
>> value ‘y’. Then using a shared map will not work.
>
> If you use the Java API directly, you can pass any parameter by using 
> the constructor or a custom setter method to your component.
>
> There should be no need to call the setup method yourself.
>
Exactly.
If you use the Pipeline API programmatically you should use the specific 
setters and getters of the pipeline and its components directly.
After all you add them to the pipeline yourself, so you have full 
control over the type and way they are constructed and should be able to 
use specific getters/setters.

The generic methods 'setup' and 'setConfiguration' are offered for 
enviroments that can not or do not want to use the specific 
setters/getters of the pipeline or its components.

Of course it is not possible to supply different values under the same 
key with the generic methods.
The question here should be: Why does my scenario require that?

The two obvious solutions to this are:
1) use different parameter names (one could argue that two different 
parameters must not have the same name when they can occur within the 
same context, otherwise this will result in ambiguity - which is exactly 
the problem here)
2) provide the parameters before adding the components to the pipeline 
(during construction), thereby avoiding having them in the same context 
and resolving the ambiguity

Re: question regarding the Cocoon 3 API

[Reinhard Pötz <re...@apache.org>]

On 07/07/2011 12:09 PM, Robby Pelssers wrote:
> Hi,
>
> Are my following assumptions right?
>
> -setConfiguration is typically used when using sitemap

yes

> -but for setup(params) method the API states that this is the shared map
> for all components… so it should not be called directly
>
> but it gets indirectly called when executing
> pipeline.setup(outputstream, params)?

yes, see o.a.c.pipeline.AbstractPipeline#setupComponents

> If it was not intended this way, then
> https://issues.apache.org/jira/browse/COCOON3-68 applies.
>
> -But I still can see the need that different components need to be able
> to be setup with different maps of parameters. Suppose both components
> need a “id” parameter but for
>
> the generator this needs to be value ‘x’ and for e.g. the transformer
> value ‘y’. Then using a shared map will not work.

If you use the Java API directly, you can pass any parameter by using 
the constructor or a custom setter method to your component.

There should be no need to call the setup method yourself.

-- 
Reinhard Pötz         Founder & Managing Director, Indoqa and Deepsearch
                         http://www.indoqa.com/people/reinhard-poetz.html

Member of the Apache Software Foundation
Apache Cocoon Committer, PMC member                  reinhard@apache.org
________________________________________________________________________

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