Re: [el-dev] Question about the new OptionalELResolver

[Arjan Tijms <arjan.tijms@xxxxxxxxxxx>]

Hi,

I've been following this discussion here, and recognize the importance of the current concerns.

We do have to remember that we have really little time remaining to resolve this. _expression_ Language is up for review at the end of this month:

See https://www.eclipse.org/lists/jakartaee-platform-dev/msg04409.html

Kind regards,

Arjan Tijms

On Tue, 20 Feb 2024 at 12:43, Mark Thomas via el-dev <el-dev@xxxxxxxxxxx> wrote:

On 13/02/2024 15:31, Paul Nicolucci wrote:
> Hey Mark,
>
> Your proposal seems reasonable to me!

I've started to look at implementing this in Tomcat and have found a
complication. Consider the following _expression_:

${beanA.beanBOpt.map(b -> b.name)}

Should this call Optional.map() which is likely what was intended or
should it call Optional.get().map() which will probably throw a
MethodNotFoundException

I think the answer is that the user has to choose.

Choice A: Don't use OptionalELResolver

Instances of Optional are treated like any other object. The _expression_
above will trigger a call to Optional.map() and return a (possibly
non-empty) Optional.


Choice B: Use OptionalELResolver

Instances of Optional are treated as Optional.get() if present and null
if empty (and any property or method on the Optional is ignored). The
_expression_ above will return null if the Optional is empty. If the
Optional is present then the _expression_ will return the result of
calling Optional.get().map() which may return a value or may throw a
MethodNotFoundException


I'm going to continue my work in Tomcat on this basis and see where
things end up.

Mark
_______________________________________________
el-dev mailing list
el-dev@xxxxxxxxxxx
To unsubscribe from this list, visit https://www.eclipse.org/mailman/listinfo/el-dev