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Posted to users@camel.apache.org by Scott Cranton <sc...@cranton.com> on 2013/02/14 13:38:51 UTC
URI references to Objects in the Registry
I've just noticed the reference syntax that some components use, but
its not clear to me exactly how it works, and more importantly how new
components are supposed to use it correctly... I don't see any
documentation on it, and I've only found some mentions of it in the
JIRA where it was created and in the camel code itself.
Sorry if I missed an earlier thread on this, but I couldn't find it...
It looks like Camel will resolve "#name" values for endpoint uri
properties to the a Registry id instance.
<bean id="bar" class="some.java.clazz"/>
<to uri="someEndpoint:foo?objectProperty=#bar" />
The above syntax will set the Component's configuration, internally
resolving "#bar" to the bean instance from the Camel Registry...
setObjectProperty(some.java.clazz value)
I'm also seeing some cases where it looks like there is magic if you
suffix a property name with "Ref" that will do the same thing...
<to uri="someEndpoint:foo?objectPropertyRef=bar"/>
I assume its the same base Component and Endpoint code that's
resolving this, but I can't find it (yet)...
The confusing bit is that some Processors and Component doc use
different conventions...
It looks like an effort was made to normalize this convention around
version 2.2 or 2.3 timeframe, hence some of the inconsistencies... My
question is what is the current "best practice" and/or what would we
like the convention, both in code and in doc, for version 3
BTW: I like the reference syntax, but it did take me a bit to figure
out "is this a Spring thing" or "Camel magic", and "is it just '#name'
that is magic and/or is suffixing with Ref magic", etc.
Thanks,
Scott
Re: URI references to Objects in the Registry
Posted by Christian Müller <ch...@gmail.com>.
We will harmonize this with Camel 3.0 [1].
[1] https://issues.apache.org/jira/browse/CAMEL-6076
Best,
Christian
On Thu, Feb 14, 2013 at 1:38 PM, Scott Cranton <sc...@cranton.com> wrote:
> I've just noticed the reference syntax that some components use, but
> its not clear to me exactly how it works, and more importantly how new
> components are supposed to use it correctly... I don't see any
> documentation on it, and I've only found some mentions of it in the
> JIRA where it was created and in the camel code itself.
>
> Sorry if I missed an earlier thread on this, but I couldn't find it...
>
> It looks like Camel will resolve "#name" values for endpoint uri
> properties to the a Registry id instance.
>
> <bean id="bar" class="some.java.clazz"/>
>
> <to uri="someEndpoint:foo?objectProperty=#bar" />
>
> The above syntax will set the Component's configuration, internally
> resolving "#bar" to the bean instance from the Camel Registry...
>
> setObjectProperty(some.java.clazz value)
>
> I'm also seeing some cases where it looks like there is magic if you
> suffix a property name with "Ref" that will do the same thing...
>
> <to uri="someEndpoint:foo?objectPropertyRef=bar"/>
>
> I assume its the same base Component and Endpoint code that's
> resolving this, but I can't find it (yet)...
>
> The confusing bit is that some Processors and Component doc use
> different conventions...
>
> It looks like an effort was made to normalize this convention around
> version 2.2 or 2.3 timeframe, hence some of the inconsistencies... My
> question is what is the current "best practice" and/or what would we
> like the convention, both in code and in doc, for version 3
>
> BTW: I like the reference syntax, but it did take me a bit to figure
> out "is this a Spring thing" or "Camel magic", and "is it just '#name'
> that is magic and/or is suffixing with Ref magic", etc.
>
> Thanks,
> Scott
>
--
Re: URI references to Objects in the Registry
Posted by Claus Ibsen <cl...@gmail.com>.
Hi Scott
On Thu, Feb 14, 2013 at 1:38 PM, Scott Cranton <sc...@cranton.com> wrote:
> I've just noticed the reference syntax that some components use, but
> its not clear to me exactly how it works, and more importantly how new
> components are supposed to use it correctly... I don't see any
> documentation on it, and I've only found some mentions of it in the
> JIRA where it was created and in the camel code itself.
>
> Sorry if I missed an earlier thread on this, but I couldn't find it...
>
Yeah Camel has many many pages. Its documented here:
http://camel.apache.org/configuring-camel.html
At the section .. Referring beans from Endpoint URIs.
Maybe we should add a FAQ as well?
And if you have suggestions for other places in the docs to add
reference / note about this, then feel free to change the docs /
suggest.
> It looks like Camel will resolve "#name" values for endpoint uri
> properties to the a Registry id instance.
>
> <bean id="bar" class="some.java.clazz"/>
>
> <to uri="someEndpoint:foo?objectProperty=#bar" />
>
> The above syntax will set the Component's configuration, internally
> resolving "#bar" to the bean instance from the Camel Registry...
>
> setObjectProperty(some.java.clazz value)
>
Yes the # is a reference lookup in the registry and will match with
the bean type as well.
> I'm also seeing some cases where it looks like there is magic if you
> suffix a property name with "Ref" that will do the same thing...
>
There is no magic. There is an option with that name.
> <to uri="someEndpoint:foo?objectPropertyRef=bar"/>
>
They are typically from the earlier days of Camel where we did not
have the # lookup.
Then we needed to have 2 options for the same thing. So you can
configure it as a java type.
And as well sometimes to refer to the registry. And hence we had the
xxx and xxxRef options.
> I assume its the same base Component and Endpoint code that's
> resolving this, but I can't find it (yet)...
>
> The confusing bit is that some Processors and Component doc use
> different conventions...
>
> It looks like an effort was made to normalize this convention around
> version 2.2 or 2.3 timeframe, hence some of the inconsistencies... My
> question is what is the current "best practice" and/or what would we
> like the convention, both in code and in doc, for version 3
>
> BTW: I like the reference syntax, but it did take me a bit to figure
> out "is this a Spring thing" or "Camel magic", and "is it just '#name'
> that is magic and/or is suffixing with Ref magic", etc.
>
> Thanks,
> Scott
You can check the source code for DefaultComponent as thats the one
that usually handles this.
We have some helper classes that does all the hard work
EndpointHelper.setReferenceProperties(getCamelContext(), bean, parameters);
EndpointHelper.setProperties(getCamelContext(), bean, parameters);
--
Claus Ibsen
-----------------
Red Hat, Inc.
FuseSource is now part of Red Hat
Email: cibsen@redhat.com
Web: http://fusesource.com
Twitter: davsclaus
Blog: http://davsclaus.com
Author of Camel in Action: http://www.manning.com/ibsen