[
https://issues.apache.org/activemq/browse/CAMEL-1900?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=53603#action_53603
]
Ashwin Karpe commented on CAMEL-1900:
-------------------------------------
Hi James, Claus, Hadrian and Jon,
I did look at existing DSL definitions closely to see if there was an EIP that
I could use to accomplish my objective.
The nearet ones I came up with considering the processors I had were really two
a> The Enricher component that suitably refactored could altenatively
apply something other than an AggregationStrategy in the following way
from(...).enrich("cache:testcache",
cacheTokenReplacer(...)).to(...)
The trouble however with doing this in an existing DSL is messy
and the most straightforward was
from("http://...";).process(new
CacheBasedTokenReplacer(cache, key, token)).to(...)
b> The other component that seemed to fit the bill was the DataFormat
marshaller/unmarshaller. I toyed with the idea of adding a little data format
which would enrich/modify the original payload . This is guaranteed to work
since org.apache.camel.spi.Dataformat is an interface that can be easily
implemented from outside the camel core. I employed this strategy when I
developed the camel-xmlsecurity data format for encryption/decryption of xml
payloads, tags and tag contents. This was great since I avoided adding the
xml-security jars into the camel-core.
Unfortunately org.apache.model.ProcessorDefinition is a class that
needs to be extended and is not an interface which can be implemented from
different places, which is the root of the problem. I can see why it is this
way and how it helps with intellisense. However the side-effect of this choice
is that model definitions/processors cannot be discreetly added from components
outside the camel-core. I could implement the Block interface that is
implementted by ProcessorDefinition by would end up creating a parallel
ProcessorDefinition class (maybe ok but will have no intellisense).
c> I totally agree your idea of making lookups into a higher level
abstracted lookup pattern which could extend/support lookups on several other
endpoints (JNDI, ehCache, DB, OSGi) etc. But I am unclear on how this can be
accomplished within the camel core without running into the same issues. that
currently are not required to be in the camel-core (e.g ehCache etc).
My suggestion/recommendation would be to upgrade the model setup to something
very similar to DataFomat which make everything extensible and intellisense
friendly...
Please let me know what you think.
> Need to allow adding of model definitions and processors in camel components
> without involving the camel-core
> -------------------------------------------------------------------------------------------------------------
>
> Key: CAMEL-1900
> URL: https://issues.apache.org/activemq/browse/CAMEL-1900
> Project: Apache Camel
> Issue Type: New Feature
> Components: camel-core
> Affects Versions: 2.0-M3
> Reporter: Ashwin Karpe
> Fix For: Future
>
>
> Please see the synopsis of my problem below...
> =================================================================================
> I recently submitted an camel-cache component based on Ehcache to the Apache
> Camel community (CAMEL-1868). The component has an event based Cache consumer
> and a Cache Producer to write to the cache.
>
> I was planning on adding several processors that would do selective cache
> contents based replacement at the payload/token/XPath level. I have the code
> written and working however, I was planning on adding a nice model definition
> to bring it all together via DSL. This is where I ran into a serious problem.
> The problem is the following
>
> a> The processors are in the cache component and I extended the base
> interface processor and I can do the following in unit tests and it works.
> from("cache://TestCache1").
> filter(header("CACHE_KEY").isEqualTo("quote")).
> process (new
> CacheBasedTokenReplacer("cache://TestCache1","cache_key","##tag##")).
> to("direct:next");
> b> I put together a CamelCacheDefinition class (see attached)
> in the camel-cache component (not camel-core)
> that uses package org.apache.camel.model.cache
> and extends ProcessorDefinition<CacheProcessorDefinition> from
> package org.apache.camel.model
> c> I would like the following effect
> from("cache://TestCache1").
> filter(header("CACHE_KEY").isEqualTo("quote")).
>
> applycachevalue("cache://TestCache1","cache_key","##tag##").
> to("direct:next");
>
> The problem is that when I develop the unit test and try to do intellisense,
> I do not see applycachevalue() against ProcessorDefinition (this part I
> understand, since it is not seeing the CacheDefinition entry) since this
> capabilty comes from the processorDefinition in came-core. What I am trying
> to see is
> a> How can I do this without having to modify the
> ProcessorDefinition in camel-core and keep my CacheDefinition in the
> camel-cache component.
> b> I do not wish to add the ehCache dependency in the camel-core
> and bloat the core. Also, the Producer and Consumer ehCache components are
> all related to the processors and I would like to avoid fragmentation of the
> processors from the components.
> b> If not and I do have to move the CacheDefinition into the
> camel-core, can I still keep the processors in camel-cache component and
> intellisense without side-effects ( I suspect I can through the groups setup
> in camel-core but I need to verify)
>
> ======================================================================================
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
