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6.3.1 Partial Updates: Ambiguous Exception #303

Closed cjslep closed 2 months ago

cjslep commented 6 years ago

In the paragraph describing this, it states (emphasis mine):

For client to server interactions, updates are partial; rather than updating the document all at once, any key value pair supplied is used to replace the existing value with the new value. This only applies to the top-level fields of the updated object. A special exception is for when the value is the json null type; this means that this field should be removed from the server's representation of the object.

What is the exception referring to?

Given my track record at misinterpreting the intentions of the spec, I figured I should ask here.

nightpool commented 6 years ago

the latter, I believe

On Sat, Apr 28, 2018, 10:50 AM Cory J Slep notifications@github.com wrote:

In the paragraph describing this, it states (emphasis mine):

For client to server interactions, updates are partial; rather than updating the document all at once, any key value pair supplied is used to replace the existing value with the new value. This only applies to the top-level fields of the updated object. A special exception is for when the value is the json null type; this means that this field should be removed from the server's representation of the object.

What is the exception referring to?

  • Only applying to top-level fields of the updated object. Therefore, you can remove subfields. Note this is the track I wound up going down in go-fed/activity.
  • Replacing a value. Instead of replacing it with null, it should just be deleted. This seemed too obvious to be an exception to me; hence I went for the first interpretation.

Given my track record at misinterpreting the intentions of the spec, I figured I should ask here.

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evanp commented 2 months ago

I think the sentence is pretty clear: ''A special exception is for when the value is the json null type''. I don't know if there's a way to make this clearer. I realize that it seems obvious, but it's the only way to delete a property using this technique.

I think the bigger problem is that properties with null values are elided out of JSON-LD compaction, which means this feature is not very compatible with JSON-LD and the compaction requirements in AS2. I believe we have another issue open for that, so I'm going to recommend just closing this.

trwnh commented 2 months ago

The other issue is #396 but it appears to have been closed without comment

TallTed commented 2 months ago

properties with null values are elided out of JSON-LD compaction

Note that there is a difference between "properties with a value of NULL" and "properties with no value", either of which might be meant by "properties with null values". The latter conveys no information in the worlds of JSON-LD and RDF, and thus is eligible for elision during compaction; the former may convey some information, and thus SHOULD be retained.