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Type:
Bug
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Status: Closed
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Priority:
Major
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Resolution: Fixed
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Affects Version/s: V4.0_WD01
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Fix Version/s: V4.0_WD01
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Component/s: ABNF, Protocol, URL Conventions
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Labels:None
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Environment:
[Applied]
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Proposal:
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Resolution:
$expand allows nesting query options after the name of the navigation properties to be expanded.
When expanding only references $select, $expand, and $levels don't make sense as neither structural nor navigation properties are represented in references.
Originally it was a virtual property, but with ODATA-276 we changed it to a path suffix everywhere:
GET ~/Orders(1)/Items/$ref
GET ~/Orders?$expand=Items/$ref
I like the similarity.
I don't understand the issue with the current syntax NavProp(<nested options>)/$ref.
$ref just means "return entity references in place of the entities". Like a cast operator. Some of the nested options ($filter in particular) are meaningful (I only want references for related entities that match a particular criteria). Some of the nested options aren't meaningful and may be optimized out ($expand, $select) but that's okay; they are well defined, just not useful if followed by a /$ref.
| Field | Original Value | New Value |
|---|---|---|
| Proposal |
Change syntax to $epand=NavProp/$ref(<nested options>) and define a different set following $ref than the one directly following the navigation property Rationale: this allows parsing from left to right. The current positioning of NavProp(...)/$ref makes that impossible, and is hard to read anyway. |
Change syntax to $epand=NavProp/$ref(<nested options>) and define a different set following $ref than the one directly following the navigation property: expand = '$expand' EQ expandItem *( COMMA expandItem ) expandItem = [ qualifiedEntityTypeName "/" ] navigationProperty [ "/" qualifiedEntityTypeName ] [ ref OPEN expandRefOption *( SEMI expandRefOption ) CLOSE / OPEN expandOption *( SEMI expandOption ) CLOSE ] expandRefOption = filter / search / skip / top / inlinecount expandOption = expandRefOption / select / orderby / expand / levels Rationale: we now express in the ABNF what is meaningful and thus allowed after /$ref. Also this allows parsing from left to right. And putting /$ref before the parens makes it a bit more obvious. Just try reading $expand=Items($filter=something very complicated and lengthy and I'll only tell you afterwards that I only want)/$ref&andsoon |
| Environment | [Proposed] | [Resolved] |
| Status | New [ 10000 ] | Open [ 1 ] |
| Resolution | Fixed [ 1 ] | |
| Status | Open [ 1 ] | Resolved [ 5 ] |
| Assignee | Ralf Handl [ ralfhandl ] |
| Environment | [Resolved] | [Applied] |
| Reporter | Ralf Handl [ ralfhandl ] | Ralf Handl [ handl ] |
| Assignee | Ralf Handl [ ralfhandl ] | Ralf Handl [ handl ] |
Also see
ODATA-340; wouldn't it make more sense to simply not allow $ref in expand but rather treat it as a 'special' property allowed in the $select? Could we even use in combination with other properties potentially?