Hi
Thanks for all the feedback.
Yeah naming in IT is hard, and so is also which operator syntax to use.
{{?foo}} vs {{foo?}} vs {{optional:foo}} vs {{foo:-}}
I think the last one looks like a smiley ;)
And you can also think of using query parameters style:
{{foo?optional=true}}
On Tue, Mar 9, 2021 at 6:16 AM Tadayoshi Sato <sato.tadayo...@gmail.com> wrote:
>
> Ah there is already the "?speedUp" notation to describe it as optional in
> camel-main. Then I'm fine with {{?speedUp}} syntax to maintain consistency
> within Camel.
> https://camel.apache.org/components/latest/others/main.html#_optional_parameters_on_beans
>
> On Mon, Mar 8, 2021 at 2:25 PM Tadayoshi Sato <sato.tadayo...@gmail.com>
> wrote:
>
> > Hi Zoran,
> >
> > Just in case, Properties component already provide the feature of
> > specifying a default value with {{speedUp:other}} syntax:
> > https://camel.apache.org/components/3.7.x/properties-component.html#_syntax
> >
> > So what Claus proposes here is a feature that optionally can assign some
> > value but otherwise leaves it unassigned at all.
> > I see Claus' point that the syntax {{optional:speedUp}} is really
> > confusing as the properties component would then see it as the placeholder
> > "optional" with default value "speedUp".
> >
> > Personally, I second Babak's syntax of {{speedUp?}} as it aligns with JS
> > syntax and REST producer optional parameters Zoran introduced.
> >
> > Best regards,
> > Tadayoshi
> >
> > On Sat, Mar 6, 2021 at 4:41 AM Zoran Regvart <zo...@regvart.com> wrote:
> >
> >> Hi Claus,
> >> I like the bash shell parameter expansion[1], this allows for
> >> specifying the default value if parameter doesn't expand. Something
> >> like {{speedUp:-}} would be optional without a default value, whereas
> >> {{speedUp:-other}} would provide `other` as a default value.
> >>
> >> For the REST producer bits I introduced optional parameters with a
> >> trailing question mark, see[2]. Doing something consistent here would
> >> be good I think.
> >>
> >> zoran
> >>
> >> [1]
> >> https://www.gnu.org/software/bash/manual/html_node/Shell-Parameter-Expansion.html#Shell-Parameter-Expansion
> >> [2]
> >> https://github.com/apache/camel/blob/b040a056ddf1b8f0756516cd47c00f180f128c05/core/camel-core/src/test/java/org/apache/camel/component/rest/RestProducerTest.java#L84
> >>
> >> On Fri, Mar 5, 2021 at 3:04 PM Claus Ibsen <claus.ib...@gmail.com> wrote:
> >> >
> >> > Hi
> >> >
> >> > In Camel 3.9 we are introducing optional property placeholders.
> >> > https://issues.apache.org/jira/browse/CAMEL-16302
> >> >
> >> > The use-case is to allow configuring Camel endpoints (primarily) where
> >> > you can specify some options that may be configured or not (optional).
> >> >
> >> > Currently all property placeholders are mandatory, unless a default
> >> > value is provided. So with the default value, you could do "optional"
> >> > but then you would need to know what the default value would be (if
> >> > there is any).
> >> >
> >> > Optional placeholders is also a feature that we want to have with
> >> > route templates (aka Kamelets). So you can create kamelets with a
> >> > number of options (some are required, and others would be optional).
> >> > And others have default values etc.
> >> >
> >> > The syntax for marking a property placeholder as option is to prefix
> >> > the key name with ?, eg
> >> >
> >> > from("jms:cheese?concurrentConsumers={{?speedUp}}")
> >> >
> >> > Here the concurrent consumers option is optional, as the placeholder
> >> > value starts with a ? in the key name.
> >> >
> >> > Then the Camel end user can configure the property placeholder, such
> >> > as in application.properties
> >> >
> >> > speedUp=5
> >> >
> >> > Or if there are no configuration, then the option is not present and
> >> > the endpoint is resolved as:
> >> >
> >> > from("jms:cheese")
> >> >
> >> >
> >> > The syntax with the ? mark was choose to keep it short. But we are
> >> > open for feedback.
> >> > Another alternative was to prefix with optional:
> >> >
> >> > {{optional:speedUp}}
> >> >
> >> > However the properties component in Camel then assume the key is named
> >> > optional, and the default value is speedUp. So it clashes with this.
> >> > But we could make "optional" a reserved word and do special handling
> >> > for this.
> >> >
> >> > The only concern about using ? is that an endpoint uri already have ?
> >> > for query parameters. And if using more ? would be confusing?
> >> >
> >> >
> >> from("jms:cheese?concurrentConsumers={{?speedUp}}&subscrtiptionName={{someName}}")
> >> >
> >> > Any thoughts?
> >> >
> >> >
> >> > --
> >> > Claus Ibsen
> >> > -----------------
> >> > http://davsclaus.com @davsclaus
> >> > Camel in Action 2: https://www.manning.com/ibsen2
> >>
> >>
> >>
> >> --
> >> Zoran Regvart
> >>
> >
> >
> > --
> > Tadayoshi Sato
> >
>
>
> --
> Tadayoshi Sato
--
Claus Ibsen
-----------------
http://davsclaus.com @davsclaus
Camel in Action 2: https://www.manning.com/ibsen2
