---
Luca Burgazzoli
On Wed, Sep 7, 2016 at 12:00 PM, Claus Ibsen <claus.ib...@gmail.com> wrote:
> On Wed, Sep 7, 2016 at 11:39 AM, Luca Burgazzoli <lburgazz...@gmail.com>
> wrote:
>> In line comments.
>>
>> ---
>> Luca Burgazzoli
>>
>>
>> On Wed, Sep 7, 2016 at 10:34 AM, Claus Ibsen <claus.ib...@gmail.com> wrote:
>>> Hi Luca
>>>
>>> Good to see some experiments with this.
>>>
>>> The OUT functions is not needed as end users would only work with the
>>> IN message in the routes. We have deprecated OUT stuff in the Java DSL
>>> in some places.
>>>
>>
>> Removed out and reduced to a single function method, this requires to
>> explicit
>> set the type like:
>>
>> function((Message m) -> m.getBody() )
>> function((Exchange e) -> e.getIn())
>>
>> Is that ok ?
>>
>
> I think we need to tweak this a bit to find the right balance. Would
> like if we could omit the type for normal use-cases. Working on
> Message is a bit shorter than Exchange as you can call getBody /
> getHeader asap. And if you need Exchange there is a getExchange
> method.
>
Agree, so we could complete remove the Exchange variant, an additional
option would be - but I'm thinking aloud here - to override calls such
- body()
- exchange()
- inMessage()
So we then may have something like:
transform()
.inMessage(m -> ...)
transform()
.body(b -> ...)
transform()
.body(Bean.class, b -> ...)
transform()
.body(Bean.class, (b, h) -> ...)
>
>
>
>>> Just a mind that the goal of Camel 2.18 is to be a gentle Java8
>>> upgrade where the APIs are backwards compatible, so end users can take
>>> any existing Java 7 based Camel 2.17 or older and compile as Java 8
>>> and run on Camel 2.18 as-is.
>>>
>>> Therefore we have so far only done Java 8 stuff internally in Camel,
>>> eg inside component implementations and so on.
>>>
>>> But your changes seems non invasive and can be a candidate to include.
>>> But we could consider marking that as "experimental" so we can do API
>>> changes for the next release, and when we get more hands down on Camel
>>> 3.0 where the APIs can be more Java 8 aggressive.
>>>
>>
>> Is there an annotation or documentation convention for that ?
>>
>
> No we dont have that, but we can add to javadoc that its "work in
> progress" or "subject for change" or something. Just so we have
> freedom to change it in the following release(s).
>
>
>
>>> Also mind that a goal of the DSL is also to let Java and XML be 1:1 so
>>> end users can use the same EIPs in either one, and usually an easy
>>> migration between them, as they are similar. Just be more cautious
>>> when working on Java DSL that you dont end up in a situation with
>>> something that is not possible to do in XML.
>>
>> I think in xml it will be more about bean binding/method reference so it
>> should work out of the box but I will test it before merging.
>>
>>
>>> Also we should avoid turning the Java DSL into un-readable and
>>> cluttered/complex DSL as the Spring Integration Java DSL:
>>> https://github.com/spring-projects/spring-integration-samples/blob/master/dsl/cafe-dsl/src/main/java/org/springframework/integration/samples/dsl/cafe/lambda/Application.java
>>>
>>> But this is a great start, and like that its gentle and only about
>>> doing lambda style functions as Camel expressions.
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> On Tue, Sep 6, 2016 at 5:37 PM, Luca Burgazzoli <lburgazz...@gmail.com>
>>> wrote:
>>>> Hello everyone,
>>>> I've started working on CAMEL-7831 to create a Java8 example to use
>>>> Expressions and I've ended up with a simple example - see [1].
>>>> Of course it is only for demonstrative purpose.
>>>>
>>>> Java8 lambda support to Expressions has been added to
>>>> - ExpressionClause to avoid adding overload method for every method
>>>> accepting an Expressions definition
>>>> - ExpressionBuilder so you can use something like transform(function(e ->
>>>> ...))
>>>>
>>>> There are some additional functional interfaces to select the argument
>>>> of the lambda
>>>> - ExchangeFunction
>>>> - MessageFunction
>>>> - BodyFunction
>>>>
>>>>
>>>> Any feedback would be really appreciated.
>>>>
>>>> Regards,
>>>> Luca
>>>>
>>>>
>>>> [1]
>>>> https://github.com/lburgazzoli/apache-camel/blob/CAMEL-7831/examples/camel-example-dsl-java8/src/main/java/org/apache/camel/example/dsl/java8/MyRoute.java
>>>>
>>>>
>>>> ---
>>>> Luca Burgazzoli
>>>
>>>
>>>
>>> --
>>> Claus Ibsen
>>> -----------------
>>> http://davsclaus.com @davsclaus
>>> Camel in Action 2: https://www.manning.com/ibsen2
>
>
>
> --
> Claus Ibsen
> -----------------
> http://davsclaus.com @davsclaus
> Camel in Action 2: https://www.manning.com/ibsen2
