From 75bcaff9384d80fec4e1adb8deb1f82165b8ed24 Mon Sep 17 00:00:00 2001 From: Rob Richard Date: Tue, 7 Jan 2025 13:52:26 -0500 Subject: [PATCH 1/5] Spec edits for incremental delivery, Section 3 --- spec/Section 3 -- Type System.md | 113 ++++++++++++++++++++++++++++++- 1 file changed, 111 insertions(+), 2 deletions(-) diff --git a/spec/Section 3 -- Type System.md b/spec/Section 3 -- Type System.md index 04e4fa450..258e37532 100644 --- a/spec/Section 3 -- Type System.md +++ b/spec/Section 3 -- Type System.md @@ -794,8 +794,8 @@ And will yield the subset of each object type queried: When querying an Object, the resulting mapping of fields are conceptually ordered in the same order in which they were encountered during execution, excluding fragments for which the type does not apply and fields or fragments -that are skipped via `@skip` or `@include` directives. This ordering is -correctly produced when using the {CollectFields()} algorithm. +that are skipped via `@skip` or `@include` directives or postponed via `@defer`. +This ordering is correctly produced when using the {CollectFields()} algorithm. Response serialization formats capable of representing ordered maps should maintain this ordering. Serialization formats which can only represent unordered @@ -1948,6 +1948,14 @@ GraphQL implementations that support the type system definition language must provide the `@deprecated` directive if representing deprecated portions of the schema. +GraphQL implementations may provide the `@defer` and/or `@stream` directives. If +either or both of these directives are provided, they must conform to the +requirements defined in this specification. + +Note: The [Directives Are Defined](#sec-Directives-Are-Defined) validation rule +ensures that GraphQL Operations containing the `@defer` or `@stream` directives +cannot be executed by a GraphQL service that does not support them. + GraphQL implementations that support the type system definition language should provide the `@specifiedBy` directive if representing custom scalar definitions. @@ -2164,3 +2172,104 @@ to the relevant IETF specification. ```graphql example scalar UUID @specifiedBy(url: "https://tools.ietf.org/html/rfc4122") ``` + +### @defer + +```graphql +directive @defer( + label: String + if: Boolean! = true +) on FRAGMENT_SPREAD | INLINE_FRAGMENT +``` + +The `@defer` directive may be provided on a fragment spread or inline fragment +to indicate that execution of the related selection set should be deferred. When +a request includes the `@defer` directive, the result may consist of multiple +responses: the initial response containing all non-deferred data, while +subsequent responses include deferred data. + +The `@include` and `@skip` directives take precedence over `@defer`. + +```graphql example +query myQuery($shouldDefer: Boolean! = true) { + user { + name + ...someFragment @defer(label: "someLabel", if: $shouldDefer) + } +} +fragment someFragment on User { + id + profile_picture { + uri + } +} +``` + +#### @defer Arguments + +- `if: Boolean! = true` - When `true`, fragment _should_ be deferred (see + related note below). When `false`, fragment must not be deferred. Defaults to + `true` when omitted. +- `label: String` - An optional string literal (variables are disallowed) used + by GraphQL clients to identify data from responses and associate it with the + corresponding defer directive. If provided, the GraphQL service must include + this label in the corresponding pending object within the response. The + `label` argument must be unique across all `@defer` and `@stream` directives + in the document. + +### @stream + +```graphql +directive @stream( + label: String + if: Boolean! = true + initialCount: Int = 0 +) on FIELD +``` + +The `@stream` directive may be provided for a field whose type incorporates a +`List` type modifier; the directive enables the backend to leverage technology +such as asynchronous iterators to provide a partial list initially, and +additional list items in subsequent responses. + +The `@include` and `@skip` directives take precedence over `@stream`. + +```graphql example +query myQuery($shouldStream: Boolean! = true) { + user { + friends(first: 10) { + nodes + @stream(label: "friendsStream", initialCount: 5, if: $shouldStream) { + name + } + } + } +} +``` + +#### @stream Arguments + +- `if: Boolean! = true` - When `true`, field _should_ be streamed (see related + note below). When `false`, the field must not be streamed and all list items + must be initially included. Defaults to `true` when omitted. +- `label: String` - An optional string literal (variables are disallowed) used + by GraphQL clients to identify data from responses and associate it with the + corresponding stream directive. If provided, the GraphQL service must include + this label in the corresponding pending object within the result. The `label` + argument must be unique across all `@defer` and `@stream` directives in the + document. +- `initialCount: Int` - The number of list items the service should return + initially. If omitted, defaults to `0`. A field error will be raised if the + value of this argument is less than `0`. + +Note: The ability to defer and/or stream parts of a response can have a +potentially significant impact on application performance. Developers generally +need clear, predictable control over their application's performance. It is +highly recommended that GraphQL services honor the `@defer` and `@stream` +directives on each execution. However, the specification allows advanced use +cases where the service can determine that it is more performant to not defer +and/or stream. Therefore, GraphQL clients _must_ be able to process a response +that ignores the `@defer` and/or `@stream` directives. This also applies to the +`initialCount` argument on the `@stream` directive. Clients _must_ be able to +process a streamed response that contains a different number of initial list +items than what was specified in the `initialCount` argument. From 31116400c744c9099d6c79b7f9ec75c9be14e25f Mon Sep 17 00:00:00 2001 From: Rob Richard Date: Fri, 10 Jan 2025 10:28:23 -0500 Subject: [PATCH 2/5] re-order arguments --- spec/Section 3 -- Type System.md | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/spec/Section 3 -- Type System.md b/spec/Section 3 -- Type System.md index 258e37532..ba488628d 100644 --- a/spec/Section 3 -- Type System.md +++ b/spec/Section 3 -- Type System.md @@ -2177,8 +2177,8 @@ scalar UUID @specifiedBy(url: "https://tools.ietf.org/html/rfc4122") ```graphql directive @defer( - label: String if: Boolean! = true + label: String ) on FRAGMENT_SPREAD | INLINE_FRAGMENT ``` @@ -2221,9 +2221,9 @@ fragment someFragment on User { ```graphql directive @stream( - label: String - if: Boolean! = true initialCount: Int = 0 + if: Boolean! = true + label: String ) on FIELD ``` @@ -2249,6 +2249,9 @@ query myQuery($shouldStream: Boolean! = true) { #### @stream Arguments +- `initialCount: Int` - The number of list items the service should return + initially. If omitted, defaults to `0`. A field error will be raised if the + value of this argument is less than `0`. - `if: Boolean! = true` - When `true`, field _should_ be streamed (see related note below). When `false`, the field must not be streamed and all list items must be initially included. Defaults to `true` when omitted. @@ -2258,9 +2261,6 @@ query myQuery($shouldStream: Boolean! = true) { this label in the corresponding pending object within the result. The `label` argument must be unique across all `@defer` and `@stream` directives in the document. -- `initialCount: Int` - The number of list items the service should return - initially. If omitted, defaults to `0`. A field error will be raised if the - value of this argument is less than `0`. Note: The ability to defer and/or stream parts of a response can have a potentially significant impact on application performance. Developers generally From 32785b8591f994185c2d2eb4383ff0849c7212c3 Mon Sep 17 00:00:00 2001 From: Rob Richard Date: Fri, 10 Jan 2025 12:03:59 -0500 Subject: [PATCH 3/5] Apply suggestions from code review Co-authored-by: Benjie --- spec/Section 3 -- Type System.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/spec/Section 3 -- Type System.md b/spec/Section 3 -- Type System.md index ba488628d..8aa208d67 100644 --- a/spec/Section 3 -- Type System.md +++ b/spec/Section 3 -- Type System.md @@ -2221,7 +2221,7 @@ fragment someFragment on User { ```graphql directive @stream( - initialCount: Int = 0 + initialCount: Int! = 0 if: Boolean! = true label: String ) on FIELD @@ -2249,7 +2249,7 @@ query myQuery($shouldStream: Boolean! = true) { #### @stream Arguments -- `initialCount: Int` - The number of list items the service should return +- `initialCount: Int! = 0` - The number of list items the service should return initially. If omitted, defaults to `0`. A field error will be raised if the value of this argument is less than `0`. - `if: Boolean! = true` - When `true`, field _should_ be streamed (see related From 65d0abed1dc324faa7a7d29c2c395a2f94b3d196 Mon Sep 17 00:00:00 2001 From: Rob Richard Date: Fri, 7 Feb 2025 16:19:46 -0500 Subject: [PATCH 4/5] Address PR feedback --- spec/Section 3 -- Type System.md | 56 +++++++++++++++++++------------- 1 file changed, 34 insertions(+), 22 deletions(-) diff --git a/spec/Section 3 -- Type System.md b/spec/Section 3 -- Type System.md index 8aa208d67..8861f3846 100644 --- a/spec/Section 3 -- Type System.md +++ b/spec/Section 3 -- Type System.md @@ -1953,8 +1953,9 @@ either or both of these directives are provided, they must conform to the requirements defined in this specification. Note: The [Directives Are Defined](#sec-Directives-Are-Defined) validation rule -ensures that GraphQL Operations containing the `@defer` or `@stream` directives -cannot be executed by a GraphQL service that does not support them. +ensures that GraphQL operations can only include directives available on the +schema; thus operations including `@defer` or `@stream` directives can only be +executed by a GraphQL service that supports them. GraphQL implementations that support the type system definition language should provide the `@specifiedBy` directive if representing custom scalar definitions. @@ -2228,20 +2229,21 @@ directive @stream( ``` The `@stream` directive may be provided for a field whose type incorporates a -`List` type modifier; the directive enables the backend to leverage technology -such as asynchronous iterators to provide a partial list initially, and -additional list items in subsequent responses. +`List` type modifier. The directive enables returning a partial list initially, +followed by additional items in subsequent responses. Should the field type +incorporate multiple `List` type modifiers, only the outermost list is streamed. + +Note: The mechanism through which items are streamed is implementation-defined +and may use technologies such as asynchronous iterators. The `@include` and `@skip` directives take precedence over `@stream`. ```graphql example query myQuery($shouldStream: Boolean! = true) { user { - friends(first: 10) { - nodes - @stream(label: "friendsStream", initialCount: 5, if: $shouldStream) { - name - } + friends(first: 10) + @stream(label: "friendsStream", initialCount: 5, if: $shouldStream) { + name } } } @@ -2249,18 +2251,28 @@ query myQuery($shouldStream: Boolean! = true) { #### @stream Arguments -- `initialCount: Int! = 0` - The number of list items the service should return - initially. If omitted, defaults to `0`. A field error will be raised if the - value of this argument is less than `0`. +- `initialCount: Int! = 0` - The number of list items to include initially. If + omitted, defaults to `0`. A field error will be raised if the value of this + argument is less than `0`. When the size of the list is greater than or equal + to the value of `initialCount`, the GraphQL service _must_ initially include + at least as many list items as the value of `initialCount` (see related note + below). - `if: Boolean! = true` - When `true`, field _should_ be streamed (see related - note below). When `false`, the field must not be streamed and all list items - must be initially included. Defaults to `true` when omitted. + note below). When `false`, the field must behave as if the `@stream` directive + is not present—it must not be streamed and all of the list items must be + included. Defaults to `true` when omitted. - `label: String` - An optional string literal (variables are disallowed) used by GraphQL clients to identify data from responses and associate it with the corresponding stream directive. If provided, the GraphQL service must include - this label in the corresponding pending object within the result. The `label` - argument must be unique across all `@defer` and `@stream` directives in the - document. + this label in the corresponding pending object within the response. The + `label` argument must be unique across all `@defer` and `@stream` directives + in the document. + +Note: The +[Defer And Stream Directive Labels Are Unique](#sec-Defer-And-Stream-Directive-Labels-Are-Unique) +validation rule ensures uniqueness of the values passed to `label` on both the +`@defer` and `@stream` directives. Variables are disallowed in the `label` +because their values may not be known during validation. Note: The ability to defer and/or stream parts of a response can have a potentially significant impact on application performance. Developers generally @@ -2269,7 +2281,7 @@ highly recommended that GraphQL services honor the `@defer` and `@stream` directives on each execution. However, the specification allows advanced use cases where the service can determine that it is more performant to not defer and/or stream. Therefore, GraphQL clients _must_ be able to process a response -that ignores the `@defer` and/or `@stream` directives. This also applies to the -`initialCount` argument on the `@stream` directive. Clients _must_ be able to -process a streamed response that contains a different number of initial list -items than what was specified in the `initialCount` argument. +that ignores individual `@defer` and/or `@stream` directives. This also applies +to the `initialCount` argument on the `@stream` directive. Clients must be able +to process a streamed response that contains more initial list items than what +was specified in the `initialCount` argument. From 7c0ba73af33e55e9e1afa9edaa91d986f3d37627 Mon Sep 17 00:00:00 2001 From: Rob Richard Date: Mon, 24 Feb 2025 14:25:21 -0500 Subject: [PATCH 5/5] Address PR feedback --- spec/Section 3 -- Type System.md | 58 ++++++++++++++++---------------- 1 file changed, 29 insertions(+), 29 deletions(-) diff --git a/spec/Section 3 -- Type System.md b/spec/Section 3 -- Type System.md index 8861f3846..23b2f5373 100644 --- a/spec/Section 3 -- Type System.md +++ b/spec/Section 3 -- Type System.md @@ -2185,9 +2185,9 @@ directive @defer( The `@defer` directive may be provided on a fragment spread or inline fragment to indicate that execution of the related selection set should be deferred. When -a request includes the `@defer` directive, the result may consist of multiple -responses: the initial response containing all non-deferred data, while -subsequent responses include deferred data. +a request includes the `@defer` directive, it may return an _incremental stream_ +consisting of an _initial response_ containing all non-deferred data, followed +by one or more _subsequent payloads_ including the deferred data. The `@include` and `@skip` directives take precedence over `@defer`. @@ -2212,11 +2212,11 @@ fragment someFragment on User { related note below). When `false`, fragment must not be deferred. Defaults to `true` when omitted. - `label: String` - An optional string literal (variables are disallowed) used - by GraphQL clients to identify data from responses and associate it with the - corresponding defer directive. If provided, the GraphQL service must include - this label in the corresponding pending object within the response. The - `label` argument must be unique across all `@defer` and `@stream` directives - in the document. + by GraphQL clients to identify data in the _incremental stream_ and associate + it with the corresponding defer directive. If provided, the GraphQL service + must include this label in the corresponding pending object within the + _incremental stream_. The `label` argument must be unique across all `@defer` + and `@stream` directives in the document. ### @stream @@ -2230,7 +2230,7 @@ directive @stream( The `@stream` directive may be provided for a field whose type incorporates a `List` type modifier. The directive enables returning a partial list initially, -followed by additional items in subsequent responses. Should the field type +followed by additional items in subsequent payloads. Should the field type incorporate multiple `List` type modifiers, only the outermost list is streamed. Note: The mechanism through which items are streamed is implementation-defined @@ -2251,22 +2251,22 @@ query myQuery($shouldStream: Boolean! = true) { #### @stream Arguments -- `initialCount: Int! = 0` - The number of list items to include initially. If - omitted, defaults to `0`. A field error will be raised if the value of this - argument is less than `0`. When the size of the list is greater than or equal - to the value of `initialCount`, the GraphQL service _must_ initially include - at least as many list items as the value of `initialCount` (see related note - below). +- `initialCount: Int! = 0` - The number of list items to include initially when + completing the parent selection set. If omitted, defaults to `0`. A field + error will be raised if the value of this argument is less than `0`. When the + size of the list is greater than or equal to the value of `initialCount`, the + GraphQL service _must_ initially include at least as many list items as the + value of `initialCount` (see related note below). - `if: Boolean! = true` - When `true`, field _should_ be streamed (see related note below). When `false`, the field must behave as if the `@stream` directive is not present—it must not be streamed and all of the list items must be included. Defaults to `true` when omitted. - `label: String` - An optional string literal (variables are disallowed) used - by GraphQL clients to identify data from responses and associate it with the - corresponding stream directive. If provided, the GraphQL service must include - this label in the corresponding pending object within the response. The - `label` argument must be unique across all `@defer` and `@stream` directives - in the document. + by GraphQL clients to identify data in the _incremental stream_ and associate + it with the corresponding stream directive. If provided, the GraphQL service + must include this label in the corresponding pending object within the + _incremental stream_. The `label` argument must be unique across all `@defer` + and `@stream` directives in the document. Note: The [Defer And Stream Directive Labels Are Unique](#sec-Defer-And-Stream-Directive-Labels-Are-Unique) @@ -2274,14 +2274,14 @@ validation rule ensures uniqueness of the values passed to `label` on both the `@defer` and `@stream` directives. Variables are disallowed in the `label` because their values may not be known during validation. -Note: The ability to defer and/or stream parts of a response can have a -potentially significant impact on application performance. Developers generally -need clear, predictable control over their application's performance. It is -highly recommended that GraphQL services honor the `@defer` and `@stream` -directives on each execution. However, the specification allows advanced use -cases where the service can determine that it is more performant to not defer -and/or stream. Therefore, GraphQL clients _must_ be able to process a response +Note: The ability to defer and/or stream data can have a potentially significant +impact on application performance. Developers generally need clear, predictable +control over their application's performance. It is highly recommended that +GraphQL services honor the `@defer` and `@stream` directives on each execution. +However, the specification allows advanced use cases where the service can +determine that it is more performant to not defer and/or stream. Therefore, +GraphQL clients _must_ be able to process a _response_ or _incremental stream_ that ignores individual `@defer` and/or `@stream` directives. This also applies to the `initialCount` argument on the `@stream` directive. Clients must be able -to process a streamed response that contains more initial list items than what -was specified in the `initialCount` argument. +to process a streamed field result that contains more initial list items than +what was specified in the `initialCount` argument.