Using the Model API

The following example demonstrates the core model API to create a model for a simple service. The service, MessageOfTheDay has a single resource Message. The resource has an identifier for the date, but the read operation does not make the date member required and so will return the message for the current date.

This API acts as a set of generic data objects and as such has a tendency to be verbose in the construction of models. The need to create a lot of Identifier and ShapeID instances, for example, does impact the readability. It is important to note, that while the Smithy specification describes both absolute and relative shape identifiers, relative identifiers are not supported in the semantic model. All names in the semantic model must be resolved to an absolute name.

#![allow(unused_variables)]
fn main() {
use atelier_core::model::identity::{HasIdentity, Identifier};
use atelier_core::model::shapes::{
    HasTraits, MemberShape, Operation, Resource, Service, Shape,
    ShapeKind, Simple, StructureOrUnion, TopLevelShape,
};
use atelier_core::model::values::Value;
use atelier_core::model::{Model, NamespaceID};
use atelier_core::prelude::PRELUDE_NAMESPACE;
use atelier_core::Version;

let prelude: NamespaceID = PRELUDE_NAMESPACE.parse().unwrap();
let namespace: NamespaceID = "example.motd".parse().unwrap();

// ----------------------------------------------------------------------------------------
let mut date = TopLevelShape::new(
    namespace.make_shape("Date".parse().unwrap()),
    ShapeKind::Simple(Simple::String),
);
date
    .apply_with_value(
        prelude.make_shape("pattern".parse().unwrap()),
        Value::String(r"^\d\d\d\d\-\d\d-\d\d$".to_string()).into()
    )
    .unwrap();

// ----------------------------------------------------------------------------------------
let shape_name = namespace.make_shape("BadDateValue".parse().unwrap());
let mut body = StructureOrUnion::new();
body.add_member(
    "errorMessage".parse().unwrap(),
    prelude.make_shape("String".parse().unwrap()),
);
let mut error = TopLevelShape::new(shape_name, ShapeKind::Structure(body));
error
    .apply_with_value(
        prelude.make_shape("error".parse().unwrap()),
        Some("client".to_string().into()),
    )
    .unwrap();

// ----------------------------------------------------------------------------------------
let shape_name = namespace.make_shape("GetMessageOutput".parse().unwrap());
let mut output = StructureOrUnion::new();
let mut message = MemberShape::new(
    "message".parse().unwrap(),
    prelude.make_shape("String".parse().unwrap()),
);
message
    .apply(prelude.make_shape("required".parse().unwrap()))
    .unwrap();
let _ = output.add_a_member(message);
let output = TopLevelShape::new(
    namespace.make_shape("GetMessageOutput".parse().unwrap()),
    ShapeKind::Structure(output),
);

// ----------------------------------------------------------------------------------------
let shape_name = namespace.make_shape("GetMessageInput".parse().unwrap());
let mut input = StructureOrUnion::new();
input.add_member(
    "date".parse().unwrap(),
    date.id().clone(),
);
let input = TopLevelShape::new(
    namespace.make_shape("GetMessageInput".parse().unwrap()),
    ShapeKind::Structure(input),
);

// ----------------------------------------------------------------------------------------
let mut get_message = Operation::default();
get_message.set_input_shape(&input);
get_message.set_output_shape(&output);
get_message.add_error_shape(&error);
let mut get_message = TopLevelShape::new(
    namespace.make_shape("GetMessage".parse().unwrap()),
    ShapeKind::Operation(get_message),
);
get_message
    .apply(prelude.make_shape("readonly".parse().unwrap()))
    .unwrap();

// ----------------------------------------------------------------------------------------
let mut message = Resource::default();
message.add_identifier(Identifier::new_unchecked("date"), date.id().clone());
message.set_read_operation_shape(&get_message);
let message = TopLevelShape::new(
    namespace.make_shape("Message".parse().unwrap()),
    ShapeKind::Resource(message),
);

// ----------------------------------------------------------------------------------------
let mut service = Service::new("2020-06-21");
service.add_resource_shape(&message);
let mut service = TopLevelShape::new(
    namespace.make_shape("MessageOfTheDay".parse().unwrap()),
    ShapeKind::Service(service),
);
service
    .apply_with_value(
        prelude.make_shape("documentation".parse().unwrap()),
        Value::String("Provides a Message of the day.".to_string()).into(),
    )
    .unwrap();

// ----------------------------------------------------------------------------------------
let mut model = Model::new(Version::V10);
model.add_shape(message);
model.add_shape(date);
model.add_shape(get_message);
model.add_shape(input);
model.add_shape(output);
model.add_shape(error);

println!("{:#?}", model);
}