On Jul 17, 2004, at 4:06 PM, Ralph Goers wrote:
At 7/17/2004 11:44 AM, you wrote:
Something else. Basically, it's a workflow manager. Once a job is submitted a sequence of events need to occur before the job is accepted and completed. The sequence of events may complete in seconds or they may take several days to complete. Most of the time, they will complete in seconds. Rather then read the job from the database and create a new instance of the job several times in this short span they are stored in a Map. The component needs access to a SourceResolver and several DataSources. It needs to be available to several Poolable components.
i'm unclear about <component> and <component-instance> too :)
The most meaningful difference i noticed is the declaration of the 'role', that would help you to lookup
your component instance from the component/service manager.
so, i'm waiting an explanation too :)
regards
<component> and <component-instance> are avalon constructs. Basically, a component is something you would look up using the ServiceManager via its role. Sometimes the component represents a collection of objects which are all of the same type, such as input modules, source resolvers, etc. In this case, the component is something that just manages the collection, like ExtendedComponentSelector. If you look at the code that access a component-instance you will see that it looks for a role name with the word "Selector" appended to it. Then the selector will be called with the key to the desired instance (i.e - the specific input module, etc.).
If you take a look at cocoon.roles you will notice that these are really just short-hand ways of specifying a component. For example, in cocoon.roles there is a definition for source-factories that names ExtendedSourceFactorySelector as its implementing class and with a name of org.apache.excalibur.source.SourceFactorySelector. This means that in cocoon.xconf, instead of declaring
<component class="org.apache.cocoon.components.ExtendedSourceFactorySelector role="org.apache.excalibur.source.SourceFactorySelector>
we can just put
<source-factories>
Hope this clears it up a little bit.
Thanks, it does. But just to make sure... A Component marked as ThreadSafe and declared with <component> in cocoon.xconf will be a singleton. If I had several implementations of an interface, I could define a role in cocoon.roles, implement a selector, and using that role declare the implementations in cocoon.xconf using <component-instance>.
Glen Ezkovich HardBop Consulting [EMAIL PROTECTED] http://www.hard-bop.com - new and improved site coming soon
A Proverb for Paranoids:
"If they can get you asking the wrong questions, they don't have to worry about answers."
- Thomas Pynchon Gravity's Rainbow
--------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
