I see, sounds good, thanks for the clarification.
Am Di., 26. Sept. 2023 um 03:29 Uhr schrieb Yunfeng Zhou <
flink.zhouyunf...@gmail.com>:
> Hi Alexis,
>
> Thanks for the clarification. I found the second constructor on
> Flink's master branch here[1], and maybe it was that we had been
> commenting on different versions of Flink, and the second constructor
> has not been introduced in the version you use. From the source code I
> can see that the OutputTag need not be anonymous so long as the type
> extraction process passes, while making it anonymous guarantees the
> success of this step, so you are right that you need not bother about
> this matter so long as your tests and jobs can pass. Besides, I wonder
> whether being a static field influences the anonymity of a variable.
> To my understanding, making it anonymous means coding `new
> OutputTag<Long>("foobar"){}` instead of `new
> OutputTag<Long>("foobar")`. It doesn't matter whether the prefix is
> `private OutputTag<Long> tag = new OutputTag<Long>("foobar"){}` or
> `private static OutputTag<Long> tag = new
> OutputTag<Long>("foobar"){}`. They should be independent from each
> other and OutputTag's document is correct from this aspect.
>
> [1]
> https://github.com/apache/flink/blob/master/flink-core/src/main/java/org/apache/flink/util/OutputTag.java#L82
>
> Best,
> Yunfeng
>
> On Mon, Sep 25, 2023 at 10:57 PM Alexis Sarda-Espinosa
> <sarda.espin...@gmail.com> wrote:
> >
> > Hi Yunfeng,
> >
> > Thanks for the response. I hadn't even seen the other constructor, but
> it seems that the single-arg constructor works fine even if the output tag
> is declared as "static final", at least in my use case. I imagine Flink
> would complain about unknown types if it really can't figure it out
> automatically, so maybe I can just let it be as long as tests pass, but I
> was wondering if Flink really needs a non-static field to analyze type
> information here. Who knows, maybe there are some scenarios where it's
> really a must.
> >
> > Regards,
> > Alexis.
> >
> > Am Mo., 25. Sept. 2023 um 05:17 Uhr schrieb Yunfeng Zhou <
> flink.zhouyunf...@gmail.com>:
> >>
> >> Hi Alexis,
> >>
> >> If you create OutputTag with the constructor `OutputTag(String id)`,
> >> you need to make it anonymous for Flink to analyze the type
> >> information. But if you use the constructor `OutputTag(String id,
> >> TypeInformation<T> typeInfo)`, you need not make it anonymous as you
> >> have provided the type information.
> >>
> >> The second constructor is introduced after the document and the first
> >> constructor, and I think the document might have been outdated and not
> >> match with OutputTag's current behavior. A ticket and PR could be
> >> added to fix the document. What do you think?
> >>
> >> Best,
> >> Yunfeng
> >>
> >> On Fri, Sep 22, 2023 at 4:55 PM Alexis Sarda-Espinosa
> >> <sarda.espin...@gmail.com> wrote:
> >> >
> >> > Hello,
> >> >
> >> > very quick question, the documentation for side outputs states that
> an OutputTag "needs to be an anonymous inner class, so that we can analyze
> the type" (this is written in a comment in the example). Is this really
> true? I've seen many examples where it's a static element and it seems to
> work fine.
> >> >
> >> > Regards,
> >> > Alexis.
> >> >
>
