Thanks for the pointer, Konrad: that page clearly states:
"Each resource has a resource type which is used by the Servlet and
Script resolver to find the appropriate Servlet or Script to handle the
request for the Resource."
The javadocs are not very precise, but they do not mention that it is
possible to return null.
I would assume that all our resource providers implement this already
like this that always a type is returned. getResourceType is marked with
@NotNull as well.
I personally think that every resource should have a type to identify
what this is about, it's like a mime type just specified differently.
I also think that if we now start to allow null as a return value, there
will be code that simply blows up because it does not expect that the
method returns null. So this would be a breaking change.
In summary, we have documented it in our docs and javadocs to always
return something, so we should keep it like that.
Unless of course there is something fundamentally wrong with it which
justifies a breaking change
Regards
Carsten
On 09.01.2020 14:09, Konrad Windszus wrote:
I tend to agree with the statement that the resource type should be optional.
Not every resource should be rendered and having no resource type set on those
resources feels natural to me.
Enforcing a non-null resource type for every resource is more complicated as each
resource provider must be aware of it (even if you rarely have to deal with it
explicitly). For super types we explicitly have the default
"sling/servlet/default". I think we should make it the implicit resource type
as well (in case none is set, i.e. is null)
In case there are issues in the code like NPEs for such resources, I would
rather fix those.
In any case the documentation at
https://sling.apache.org/documentation/the-sling-engine/resources.html#resource-properties
should be clarified.
Konrad
On 9. Jan 2020, at 14:00, Stefan Seifert <[email protected]> wrote:
i've created a ticket concerning the Sling API that the method
Resource.getResourceType should be marke das @Nullable, i always thought it was
a bug and that the resource type is optional [1].
carsten pointed out that the resource type is mandatory. the javadocs are not
precise on this, i've also found no clear statement in the sling docs (I might
not have found it).
technically there is always a resource type when the JCR resource provider is
used (fallback to JCR primary type if sling:resourceType is not set), but
that's not implicitly the case for other resource providers or synthetic
resources.
if we think a resource type should be never null, we should return a default
value for resources that do not have one, and update the documentation.
WDYT?
stefan
[1] https://issues.apache.org/jira/browse/SLING-8975
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Carsten Ziegeler
Adobe Research Switzerland
[email protected]
