Nested InputObjects don't get populated

[pkese]

I've added a small random generator query to star-wars-api example:

 let randoms =
 let inputs = [
 Define.Input ("count", IntType)
 Define.Input ("range", Nullable (Define.InputObject("RandomRange", [
 Define.Input ("min", IntType)
 Define.Input ("max", IntType)
 ])))
 ]
 let renderRandoms (ctx:ResolveFieldContext) (r:Root) =
 // printfn "Random called with count:%A and range:%A" (ctx.Arg "count") (ctx.Arg "range")
 // todo: ranges are not implemented, because ctx.Arg("range") is always empty (read below)
 [ for i in 1..ctx.Arg("count") -> System.Random.Shared.Next() ]

 Define.Field ("random", ListOf IntType, "Render random numbers", inputs, renderRandoms)

and plugged it into existing Query:

 let Query =
 let inputs = [ Define.Input ("id", StringType) ]
 Define.Object<Root> (
 name = "Query",
 fields =
 [ Define.Field ("hero", Nullable HumanType, "Gets human hero", inputs, fun ctx _ -> getHuman (ctx.Arg ("id")))
 Define.Field ("droid", Nullable DroidType, "Gets droid", inputs, (fun ctx _ -> getDroid (ctx.Arg ("id"))))
 Define.Field ("planet", Nullable PlanetType, "Gets planet", inputs, fun ctx _ -> getPlanet (ctx.Arg ("id")))
 Define.Field ("characters", ListOf CharacterType, "Gets characters", (fun _ _ -> characters))
 randoms // <-- here
 ])

Now I can say

query { random(count:5) }

and get

{ "documentId": -804090008,
 "data": {
 "random": [1773619870, 512090916, 1972640319, 301711584, 480788316]
}}

---

Problem

When I call

query { random(count:5, range:{min:10, max:20}) }

The ctx.args("range") is always passed as an empty unpopulated obj() without any type or properties,
whereas ctx.args("count") works as expected.

[xperiandri]

That happens because you need to declare

type Range = { Min: int; Max: int }
let inputs = [
 Define.Input ("count", IntType)
 Define.Input ("range", Nullable (Define.InputObject<Range>("RandomRange", [
 Define.Input ("min", IntType)
 Define.Input ("max", IntType)
 ])))
 ]

As Define.InputObject() equals to Define.InputObject<obj>().
There is no functionality to deserialize into IReadOnlyDictionary<string, obj> if no type parameter is specified.

[xperiandri]

There are 2 options to fix Define.InputObject<obj>:

1. Exception at runtime when schema is created that it is not allowed
2. Deserialize into IReadOnlyDictionary<string, obj>

[pkese]

@xperiandri thanks, I appreciate your help.

Defining a Range type works.
My problem however is that in my real app, I don't have a fixed input type known a compile time (available input values depend on dynamic database schema).

I suppose I could dynamically create a new type and then use reflection to call the Define.InputObject with proper generic instantiation with that dynamic type (is this the right path or is there an easier workarond)?

A nice option (from the library side) besides IReadOnlyDictionary<string, obj> would be to allow Define.InputObject<JsonElement>. Probably anything that can be expressed as an input expression should be 1:1 mappable to Json.

[xperiandri]

Have you tried that? Doesn’t it work?

[pkese]

I've tried with

 let randoms =
 let inputs = [
 Define.Input ("count", IntType)
 Define.Input ("range", Nullable (Define.InputObject<System.Text.Json.JsonElement>("Range", [
 Define.Input ("min", IntType)
 Define.Input ("max", IntType)
 ])))
 ]
 let renderRandoms (ctx:ResolveFieldContext) (r:Root) =
 [ for i in 1..ctx.Arg("count") -> System.Random.Shared.Next() ]

 Define.Field ("random", ListOf IntType, "Render random numbers", inputs, renderRandoms)

... but it's resulting in a runtime error when the app starts:

Unhandled exception. System.TypeInitializationException: The type initializer for 'FSharp.Data.GraphQL.Samples.StarWarsApi.Schema' threw an exception.
 ---> System.TypeInitializationException: The type initializer for '<StartupCode$FSharp-Data-GraphQL-Samples-StarWarsApi>.$Schema' threw an exception.
 ---> System.Collections.Generic.KeyNotFoundException: An index satisfying the predicate was not found in the collection.
 at Microsoft.FSharp.Collections.SeqModule.Find[T](FSharpFunc`2 predicate, IEnumerable`1 source) in D:\a\_work\1\s\src\FSharp.Core\seq.fs:line 840
 at FSharp.Data.GraphQL.ReflectionHelper.matchConstructor(Type t, String[] fields) in /home/peter/work/org/FSharp.Data.GraphQL/src/FSharp.Data.GraphQL.Server/ReflectionHelper.fs:line 168
 at FSharp.Data.GraphQL.Values.compileByType(FSharpList`1 inputObjectPath, InputSource inputSource, InputDef originalInputDef, InputDef inputDef) in /home/peter/work/org/FSharp.Data.GraphQL/src/FSharp.Data.GraphQL.Server/Values.fs:line 92
 at FSharp.Data.GraphQL.Values.compileByType(FSharpList`1 inputObjectPath, InputSource inputSource, InputDef originalInputDef, InputDef inputDef) in /home/peter/work/org/FSharp.Data.GraphQL/src/FSharp.Data.GraphQL.Server/Values.fs:line 255
 at FSharp.Data.GraphQL.Execution.compileObject@665.Invoke(String _arg1, FieldDef fieldDef) in /home/peter/work/org/FSharp.Data.GraphQL/src/FSharp.Data.GraphQL.Server/Execution.fs:line 672
 at Microsoft.FSharp.Collections.MapTreeModule.iterOpt[TKey,TValue](FSharpFunc`3 f, MapTree`2 m) in D:\a\_work\1\s\src\FSharp.Core\map.fs:line 358
 at FSharp.Data.GraphQL.Execution.compileObject(ObjectDef objdef, FSharpFunc`2 executeFields) in /home/peter/work/org/FSharp.Data.GraphQL/src/FSharp.Data.GraphQL.Server/Execution.fs:line 665
 at FSharp.Data.GraphQL.Execution.compileSchema@681.Invoke(Tuple`2 tupledArg) in /home/peter/work/org/FSharp.Data.GraphQL/src/FSharp.Data.GraphQL.Server/Execution.fs:line 691
 at Microsoft.FSharp.Collections.SeqModule.Iterate[T](FSharpFunc`2 action, IEnumerable`1 source) in D:\a\_work\1\s\src\FSharp.Core\seq.fs:line 632
 at FSharp.Data.GraphQL.Execution.compileSchema(SchemaCompileContext ctx) in /home/peter/work/org/FSharp.Data.GraphQL/src/FSharp.Data.GraphQL.Server/Execution.fs:line 681
 at <StartupCode$FSharp-Data-GraphQL-Server>.$Executor.-ctor@95-4.Invoke(SchemaCompileContext ctx)
 at <StartupCode$FSharp-Data-GraphQL-Server>.$Executor.go@85.Invoke(ctx ctx, FSharpList`1 middlewares) in /home/peter/work/org/FSharp.Data.GraphQL/src/FSharp.Data.GraphQL.Server/Executor.fs:line 86
 at <StartupCode$FSharp-Data-GraphQL-Server>.$Executor.go@89-1.Invoke(ctx ctx') in /home/peter/work/org/FSharp.Data.GraphQL/src/FSharp.Data.GraphQL.Server/Executor.fs:line 89
 at FSharp.Data.GraphQL.Server.Middleware.LiveQueryMiddleware.middleware(SchemaCompileContext ctx, FSharpFunc`2 next) in /home/peter/work/org/FSharp.Data.GraphQL/src/FSharp.Data.GraphQL.Server.Middleware/MiddlewareDefinitions.fs:line 167
 ...

[xperiandri]

What about Dictionary?

[xperiandri]

Or dynamic

[pkese]

Define.InputObject<System.Collections.Generic.Dictionary<string,obj>> compiles fine but at query time results in ctx.Arg("range") being an empty sequence.

Similarly Define.InputObject<System.Dynamic.DynamicObject> compiles but at runtime returns a Dynamic object with no members.

[xperiandri]

Thanks for testing!
The input object logic is here
We can check if the type is some known dynamic type or object then switch to a dictionary logic

[pkese]

Thanks @xperiandri, based on your hints, I managed to patch the code in #475 ... and that fixes my issue.

(ignore the link just above this comment: I somehow managed to commit too many files into the pool request, so I closed that request and made a new one).