GraphQL DotNet–Default values for arguments

In GraphQL type definitions, each field can take zero or more arguments. Every argument passed to a field needs to have a name and a type. Next to this, it’s also possible to specify default values for arguments.

For example, let’s create a query in our schema that returns all products for a category, if no category is specified we want to return ‘Beverages’:

	type Query {
	allProducts(category:String="Beverages"): [Product!]!
	}

view raw Query.graphql hosted with ❤ by GitHub

But how can you achieve this using GraphQL DotNet using the GraphType first approach?

	public class ProductsQuery: ObjectGraphType<object>
	{
	private readonly IContextProvider _contextProvider;
	public ProductsQuery(IContextProvider contextProvider)
	{
	_contextProvider = contextProvider;
	Name = "Query";
	Field<NonNullGraphType<ListGraphType<ProductType>>>(
	"allProducts",
	arguments: new QueryArguments(
	new QueryArgument<StringGraphType>() {Name="category", DefaultValue = "Beverages"}),
	resolve: context =>
	{
	var service = _contextProvider.Get<IProductService>();
	return service.GetProducgts(context.GetArgument<string>("category"));
	});
	}
	}

view raw ProductsQuery.cs hosted with ❤ by GitHub