GraphQL.Query.Builder

GraphQL Query Builder .NET

A tool to build GraphQL query from a C# model.

See complete documentation here

See sample here

Upgrading from v2.x? See the migration guide.

Install

dotnet add package GraphQL.Query.Builder

Usage

Basic Query

IGraphQLField<Human> field = new GraphQLField<Human>("humans")
    .AddArguments(new { id = "uE78f5hq" })
    .AddField(h => h.FirstName)
    .AddField(h => h.LastName)
    .AddField(
        h => h.HomePlanet,
        sq => sq.AddField(p => p.Name)
    )
    .AddField<Human>(
        h => h.Friends,
        sq => sq
            .AddField(f => f.FirstName)
            .AddField(f => f.LastName)
    );

string query = new GraphQLOperation(OperationType.Query)
    .AddQuery(field)
    .Build();
// Output:
// query{humans(id:"uE78f5hq"){FirstName LastName HomePlanet{Name} Friends{FirstName LastName}}}

Variables

var idVar = new GraphQLVariable("id", "ID!");

string query = new GraphQLOperation(OperationType.Query, "GetHuman")
    .AddVariable(idVar)
    .AddQuery(
        new GraphQLField<Human>("human")
            .AddArgument("id", idVar.Reference())
            .AddField(h => h.FirstName)
            .AddField(h => h.LastName))
    .Build();
// Output:
// query GetHuman($id:ID!){human(id:$id){FirstName LastName}}

Directives

var showFriends = new GraphQLVariable("showFriends", "Boolean!");

new GraphQLField<Human>("human")
    .AddField(h => h.FirstName)
    .AddField<Human>(
        h => h.Friends,
        sq => sq.AddField(f => f.FirstName),
        GraphQLDirective.Include(showFriends.Reference()));
// Field output:
// human{FirstName Friends @include(if:$showFriends){FirstName}}

Fragments

var nameFields = new GraphQLFragment("NameFields", "Human",
    new GraphQLField<Human>("Human")
        .AddField(h => h.FirstName)
        .AddField(h => h.LastName));

string query = new GraphQLOperation(OperationType.Query)
    .AddQuery(
        new GraphQLField<Human>("hero").AddFragment(nameFields))
    .AddQuery(
        new GraphQLField<Human>("villain").AddFragment(nameFields))
    .AddFragment(nameFields)
    .Build();
// Output:
// query{hero{...NameFields} villain{...NameFields}} fragment NameFields on Human{FirstName LastName}

Multiple Root Fields

string query = new GraphQLOperation(OperationType.Query)
    .AddQuery(new GraphQLField<Human>("hero").AddField(h => h.FirstName))
    .AddQuery(new GraphQLField<Droid>("droid").AddArgument("id", 1).AddField(d => d.Name))
    .Build();
// Output:
// query{hero{FirstName} droid(id:1){Name}}

Mutations

string mutation = new GraphQLOperation(OperationType.Mutation, "CreateHuman")
    .AddQuery(
        new GraphQLField<Human>("createHuman")
            .AddArgument("name", "Luke")
            .AddField(h => h.Id)
            .AddField(h => h.FirstName))
    .Build();
// Output:
// mutation CreateHuman{createHuman(name:"Luke"){Id FirstName}}

Options

// CamelCase field names
var options = new QueryOptions
{
    Formatter = CamelCasePropertyNameFormatter.Format
};

new GraphQLField<Human>("human", options)
    .AddField(h => h.FirstName);
// Field output: human{firstName}

// Control null property handling
var ignoreNullOptions = new QueryOptions
{
    DefaultIgnoreCondition = QueryIgnoreCondition.WhenWritingNull
};