/// <summary>
/// Adds a connection field.
/// Example usage:
/// <code>
/// this.AddConnectionField<Order, ObjectType<Order>>(context =>
/// {
/// return new Connection<Order>(orderRepository.GetOrders());
/// });
/// </code>
/// </summary>
/// <typeparam name="T">The type of the model.</typeparam>
/// <typeparam name="TT">The type of the GraphQL type (i.e. ObjectType<Model>)</typeparam>
/// <param name="type"></param>
/// <param name="resolve">The resolving func that retuns a connection model.</param>
/// <param name="name">The name of the field.</param>
public static FieldType AddConnectionField <T, TT>(this ComplexGraphType <object> type, Func <ResolveFieldContext <object>, object> resolve, string name = null, QueryArgument[] arguments = null) where T : class where TT : ComplexGraphType <object>, IGraphType <T>
{
// create name if non is given
var lowerCaseName = name != null ? name : $"{typeof(T).Name.ToFirstLower()}s";
// build argument list... first default ones
var args = new QueryArguments(
new QueryArgument <IdGraphType> {
Name = "after"
},
new QueryArgument <IntGraphType> {
Name = "first"
},
new QueryArgument <IdGraphType> {
Name = "before"
},
new QueryArgument <IntGraphType> {
Name = "last"
});
// construct order by type
// create a class type "additionsType" and add a property for each item in "arguments"
// if any custom arguments are set
if (arguments != null)
{
var additionsType = TypeExtensions.CreateAdditionsTypeForType(typeof(T), arguments.Select(a => a.Name).ToArray());
// create a type like OrderByType<T, additionsType> and use it below
var orderByType = typeof(OrderByType <,>).MakeGenericType(new[] { typeof(T), additionsType });
args.Add(new QueryArgument(orderByType)
{
Name = "orderBy"
});
}
else
{
args.Add(new QueryArgument <OrderByType <T> > {
Name = "orderBy"
});
}
// ... then add an optional argument for each property of T
var properties = typeof(T).GetExactProperies();
foreach (var property in properties.Where(p => p.PropertyType.IsSimpleType()))
{
var propertyName = property.Name.ToFirstLower();
args.Add(new QueryArgument(property.PropertyType.MapToGraphType())
{
Name = propertyName
});
}
// .. then add custom added arguments
if (arguments != null)
{
args.AddRange(arguments);
}
// create field
return(type.Field <ConnectionType <T, TT> >(lowerCaseName, $"The {lowerCaseName} connection.", args, resolve));
}
