graphql-dotnet-upload

This repository contains an experimental implementation of the GraphQL multipart request spec based on ASP.NET Core.

Installation

You can install the latest version via NuGet.

PM> Install-Package GraphQL.Upload.AspNetCore

Usage

Register the middleware in your Startup.cs (in this case we're also using graphql-dotnet/server).

public void ConfigureServices(IServiceCollection services)
{
  services.AddSingleton<MySchema>()
          .AddGraphQLUpload()
          .AddGraphQL();
}

public void Configure(IApplicationBuilder app)
{
  app.UseGraphQLUpload<MySchema>()
     .UseGraphQL<MySchema>();
}

Register a FormFileConverter within your MySchema.cs.

public class MySchema : Schema
{
    public MySchema()
    {
        Query = new Query();
        Mutation = new Mutation();
        RegisterValueConverter(new FormFileConverter());
    }
}

Use the upload scalar in your resolvers. Files are exposed as IFormFile.

Field<StringGraphType>(
    "singleUpload",
    arguments: new QueryArguments(
        new QueryArgument<UploadGraphType> { Name = "file" }),
    resolve: context =>
    {
        var file = context.GetArgument<IFormFile>("file");
        return file.FileName;
    });

Testing

Take a look at the tests and the sample and run some of the cURL requests the spec lists if you are curious.

CMD:

curl localhost:54234/graphql ^
	-F operations="{ \"query\": \"mutation ($file: Upload!) { singleUpload(file: $file) { name } }\", \"variables\": { \"file\": null } }" ^
	-F map="{ \"0\": [\"variables.file\"] }" ^
	-F 0=@a.txt

Bash:

curl localhost:54234/graphql \
	-F operations='{ "query": "mutation ($file: Upload!) { singleUpload(file: $file) { name } }", "variables": { "file": null } }' \
	-F map='{ "0": ["variables.file"] }' \
	-F 0=@a.txt

This middleware implementation only parses multipart requests. The sample app uses additional middleware that handles other cases (e.g. POST with application/json).

Roadmap

• Make sure the implementation behaves according to the spec
• Add convenience extension methods for ServiceCollection and ApplicationBuilder that register the neccessary types
• Feature parity with the reference implementation
• End to end sample with web based client