Context URL of single-valued containment navigation property

[ralfhandl]

Section 10.3 Entity states that

Context URL template:
{context-url}#{entity-set}/$entity

and

If the entity is contained, then entity-set is the top-level entity set or singleton followed by the path to the containment navigation property of the containing entity.

Is the suffix /$entity only relevant for collection-valued containment, or also for single-valued containment?

Clarify and add single-valued example.

[HeikoTheissen]

Is the suffix /$entity only relevant for collection-valued containment, or also for single-valued containment?

Also for single-valued containment. The suffix is omitted for singletons, but these are always top-level in the container. A single-valued containment navigation property contains a single entity, not a singleton.

(By contrast, a non-containment navigation property can target a singleton through a suitable navigation property binding.)

[ralfhandl]

I disagree: a singleton is basically a single-valued containment navigation property of the entity container.

They behave the same in all other aspects, why should their context URL behave differently?

[HeikoTheissen]

They behave the same in all other aspects, why should their context URL behave differently?

Because [OData-CSDL, section 13.3] says:

Singletons are top-level single-valued resources.

Perhaps change that?

[ralfhandl]

That statement is correct. And single-valued containment navigation properties are nested single-valued resources.

So rather clarify the section on context URL and use the service-relative path of the single-valued resource as its context URL, consistently without the suffix /$entity.

[ralfhandl]

@mikepizzo and @Hubert-Heijkers would expect same treatment as singletons, without suffix /$entity