GraphQL.EntityFrameworkCore.DynamicLinq

Add EntityFramework Core Dynamic IQueryable support to GraphQL.

Info

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MyGet (preview)

How To

With this project you can easily expose all properties from the EF Entities as searchable fields on the GraphQL query.

Entity Type

public class Room
{
    [Key]
    public int Id { get; set; }
    public int Number { get; set; }
    public string Name { get; set; }
    public bool AllowedSmoking { get; set; }
    public RoomStatus Status { get; set; }
}

GraphQL Type

public class RoomType : ObjectGraphType<Room>
{
    public RoomType()
    {
        Field(x => x.Id);
        Field(x => x.Name);
        Field(x => x.Number);
        Field(x => x.AllowedSmoking);
        Field<RoomStatusType>(nameof(RoomModel.Status));
    }
}

Execute the Query

Filter on allowedSmoking

query {
  rooms (allowedSmoking: false) {
    name
    number
    allowedSmoking
    status
  }
}

OrderBy name

It's also possible to add support for an OrderBy field, just add the .SupportOrderBy(); in the code.

query {
  rooms (orderBy: "name desc") {
    name
    number
    status
  }
}

Paging

It's also possible to add support for Paging, just add the .SupportPaging(); in the code.

query {
  roomsWithPaging (page: 1, pageSize: 2) {
    id
    name
    number
    status
  }
}

How to use

Add the required dependency injections

public void ConfigureServices(IServiceCollection services)
{
+    services.Configure<QueryArgumentInfoListBuilderOptions>(Configuration.GetSection("QueryArgumentInfoListBuilderOptions"));
+    services.AddGraphQLEntityFrameworkCoreDynamicLinq();
}

Update your GraphQL Query

public class MyHotelQuery : ObjectGraphType
{
    public MyHotelQuery(MyHotelRepository myHotelRepository, IQueryArgumentInfoListBuilder builder)
    {
1       var roomQueryArgumentList = builder.Build<RoomType>()
2           .Exclude("Id")
3           .SupportOrderBy()
4           .SupportPaging();

        Field<ListGraphType<RoomType>>("rooms",
5           arguments: roomQueryArgumentList.ToQueryArguments(),

            resolve: context => myHotelRepository.GetRoomsQuery()
6               .ApplyQueryArguments(roomQueryArgumentList, context)
                .ToList()
        );
    }
}

1. Use the IQueryArgumentInfoListBuilder to build all possible arguments based on the fields from the GraphQL type (e.g. RoomType)
2. Optionally include/exclude some properties which should not be searchable (this can also be a wildcard like *Id)
3. Optionally add support for OrderBy (argument-name will be OrderBy)
4. Optionally add support for Paging (argument-names will be Page and PageSize)
5. Call the .ToQueryArguments() to create a new QueryArguments object.
6. Call the ApplyQueryArguments extension method to apply the search criteria (optionally the OrderBy and Paging)

Example

See example projec: examples/MyHotel for more details.

References

• Microsoft.EntityFrameworkCore.DynamicLinq
• EntityFramework Core IQueryable
• GraphQL
• My example project is based on ebicoglu/AspNetCoreGraphQL-MyHotel.