deprecated-gotham-restful/README.md

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	<h1>gotham-restful</h1>
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<br/>

**Note:** The `stable` branch contains some bugfixes against the last release. The `master`
branch currently tracks gotham's master branch and the next release will use gotham 0.5.0 and be
compatible with the new future / async stuff.

This crate is an extension to the popular [gotham web framework][gotham] for Rust. It allows you to
create resources with assigned methods that aim to be a more convenient way of creating handlers
for requests.

## Features

 - Automatically parse **JSON** request and produce response bodies
 - Allow using **raw** request and response bodies
 - Convenient **macros** to create responses that can be registered with gotham's router
 - Auto-Generate an **OpenAPI** specification for your API
 - Manage **CORS** headers so you don't have to
 - Manage **Authentication** with JWT
 - Integrate diesel connection pools for easy **database** integration

## Safety

This crate is just as safe as you'd expect from anything written in safe Rust - and
`#![forbid(unsafe_code)]` ensures that no unsafe was used.

## Methods

Assuming you assign `/foobar` to your resource, you can implement the following methods:

| Method Name | Required Arguments | HTTP Verb | HTTP Path      |
| ----------- | ------------------ | --------- | -----------    |
| read_all    |                    | GET       | /foobar        |
| read        | id                 | GET       | /foobar/:id    |
| search      | query              | GET       | /foobar/search |
| create      | body               | POST      | /foobar        |
| change_all  | body               | PUT       | /foobar        |
| change      | id, body           | PUT       | /foobar/:id    |
| remove_all  |                    | DELETE    | /foobar        |
| remove      | id                 | DELETE    | /foobar/:id    |

Each of those methods has a macro that creates the neccessary boilerplate for the Resource. A
simple example could look like this:

```rust
/// Our RESTful resource.
#[derive(Resource)]
#[resource(read)]
struct FooResource;

/// The return type of the foo read method.
#[derive(Serialize)]
struct Foo {
	id: u64
}

/// The foo read method handler.
#[read(FooResource)]
fn read(id: u64) -> Success<Foo> {
	Foo { id }.into()
}
```

## Arguments

Some methods require arguments. Those should be
 * **id** Should be a deserializable json-primitive like `i64` or `String`.
 * **body** Should be any deserializable object, or any type implementing [`RequestBody`].
 * **query** Should be any deserializable object whose variables are json-primitives. It will
   however not be parsed from json, but from HTTP GET parameters like in `search?id=1`. The
   type needs to implement [`QueryStringExtractor`].

Additionally, non-async handlers may take a reference to gotham's [`State`]. If you need to
have an async handler (that is, the function that the method macro is invoked on is declared
as `async fn`), consider returning the boxed future instead. Since [`State`] does not implement
`Sync` there is unfortunately no more convenient way.

## Uploads and Downloads

By default, every request body is parsed from json, and every respone is converted to json using
[serde_json]. However, you may also use raw bodies. This is an example where the request body
is simply returned as the response again, no json parsing involved:

```rust
#[derive(Resource)]
#[resource(create)]
struct ImageResource;

#[derive(FromBody, RequestBody)]
#[supported_types(mime::IMAGE_GIF, mime::IMAGE_JPEG, mime::IMAGE_PNG)]
struct RawImage {
	content: Vec<u8>,
	content_type: Mime
}

#[create(ImageResource)]
fn create(body : RawImage) -> Raw<Vec<u8>> {
	Raw::new(body.content, body.content_type)
}
```

## Features

To make life easier for common use-cases, this create offers a few features that might be helpful
when you implement your web server.  The complete feature list is
 - [`auth`](#authentication-feature) Advanced JWT middleware
 - `chrono` openapi support for chrono types
 - [`cors`](#cors-feature) CORS handling for all method handlers
 - [`database`](#database-feature) diesel middleware support
 - `errorlog` log errors returned from method handlers
 - [`openapi`](#openapi-feature) router additions to generate an openapi spec
 - `uuid` openapi support for uuid

### Authentication Feature

In order to enable authentication support, enable the `auth` feature gate. This allows you to
register a middleware that can automatically check for the existence of an JWT authentication
token. Besides being supported by the method macros, it supports to lookup the required JWT secret
with the JWT data, hence you can use several JWT secrets and decide on the fly which secret to use.
None of this is currently supported by gotham's own JWT middleware.

A simple example that uses only a single secret could look like this:

```rust
#[derive(Resource)]
#[resource(read)]
struct SecretResource;

#[derive(Serialize)]
struct Secret {
	id: u64,
	intended_for: String
}

#[derive(Deserialize, Clone)]
struct AuthData {
	sub: String,
	exp: u64
}

#[read(SecretResource)]
fn read(auth: AuthStatus<AuthData>, id: u64) -> AuthSuccess<Secret> {
	let intended_for = auth.ok()?.sub;
	Ok(Secret { id, intended_for })
}

fn main() {
	let auth: AuthMiddleware<AuthData, _> = AuthMiddleware::new(
		AuthSource::AuthorizationHeader,
		AuthValidation::default(),
		StaticAuthHandler::from_array(b"zlBsA2QXnkmpe0QTh8uCvtAEa4j33YAc")
	);
	let (chain, pipelines) = single_pipeline(new_pipeline().add(auth).build());
	gotham::start("127.0.0.1:8080", build_router(chain, pipelines, |route| {
		route.resource::<SecretResource>("secret");
	}));
}
```

### CORS Feature

The cors feature allows an easy usage of this web server from other origins. By default, only
the `Access-Control-Allow-Methods` header is touched. To change the behaviour, add your desired
configuration as a middleware.

A simple example that allows authentication from every origin (note that `*` always disallows
authentication), and every content type, could look like this:

```rust
#[derive(Resource)]
#[resource(read_all)]
struct FooResource;

#[read_all(FooResource)]
fn read_all() {
	// your handler
}

fn main() {
	let cors = CorsConfig {
		origin: Origin::Copy,
		headers: vec![CONTENT_TYPE],
		max_age: 0,
		credentials: true
	};
	let (chain, pipelines) = single_pipeline(new_pipeline().add(cors).build());
	gotham::start("127.0.0.1:8080", build_router(chain, pipelines, |route| {
		route.resource::<FooResource>("foo");
	}));
}
```

The cors feature can also be used for non-resource handlers. Take a look at [`CorsRoute`]
for an example.

### Database Feature

The database feature allows an easy integration of [diesel] into your handler functions. Please
note however that due to the way gotham's diesel middleware implementation, it is not possible
to run async code while holding a database connection. If you need to combine async and database,
you'll need to borrow the connection from the [`State`] yourself and return a boxed future.

A simple non-async example could look like this:

```rust
#[derive(Resource)]
#[resource(read_all)]
struct FooResource;

#[derive(Queryable, Serialize)]
struct Foo {
	id: i64,
	value: String
}

#[read_all(FooResource)]
fn read_all(conn: &PgConnection) -> QueryResult<Vec<Foo>> {
	foo::table.load(conn)
}

type Repo = gotham_middleware_diesel::Repo<PgConnection>;

fn main() {
	let repo = Repo::new(&env::var("DATABASE_URL").unwrap());
	let diesel = DieselMiddleware::new(repo);

	let (chain, pipelines) = single_pipeline(new_pipeline().add(diesel).build());
	gotham::start("127.0.0.1:8080", build_router(chain, pipelines, |route| {
		route.resource::<FooResource>("foo");
	}));
}
```

### OpenAPI Feature

The OpenAPI feature is probably the most powerful one of this crate. Definitely read this section
carefully both as a binary as well as a library author to avoid unwanted suprises.

In order to automatically create an openapi specification, gotham-restful needs knowledge over
all routes and the types returned. `serde` does a great job at serialization but doesn't give
enough type information, so all types used in the router need to implement `OpenapiType`. This
can be derived for almoust any type and there should be no need to implement it manually. A simple
example could look like this:

```rust
#[derive(Resource)]
#[resource(read_all)]
struct FooResource;

#[derive(OpenapiType, Serialize)]
struct Foo {
	bar: String
}

#[read_all(FooResource)]
fn read_all() -> Success<Foo> {
	Foo { bar: "Hello World".to_owned() }.into()
}

fn main() {
	gotham::start("127.0.0.1:8080", build_simple_router(|route| {
		let info = OpenapiInfo {
			title: "My Foo API".to_owned(),
			version: "0.1.0".to_owned(),
			urls: vec!["https://example.org/foo/api/v1".to_owned()]
		};
		route.with_openapi(info, |mut route| {
			route.resource::<FooResource>("foo");
			route.get_openapi("openapi");
		});
	}));
}
```

Above example adds the resource as before, but adds another endpoint that we specified as `/openapi`
that will return the generated openapi specification. This allows you to easily write clients
in different languages without worying to exactly replicate your api in each of those languages.

However, as of right now there is one caveat. If you wrote code before enabling the openapi feature,
it is likely to break. This is because of the new requirement of `OpenapiType` for all types used
with resources, even outside of the `with_openapi` scope. This issue will eventually be resolved.
If you are writing a library that uses gotham-restful, make sure that you expose an openapi feature.
In other words, put

```toml
[features]
openapi = ["gotham-restful/openapi"]
```

into your libraries `Cargo.toml` and use the following for all types used with handlers:

```rust
#[derive(Deserialize, Serialize)]
#[cfg_attr(feature = "openapi", derive(OpenapiType))]
struct Foo;
```

## Examples

There is a lack of good examples, but there is currently a collection of code in the [example]
directory, that might help you. Any help writing more examples is highly appreciated.

## License

Licensed under your option of:
 - [Apache License Version 2.0](https://gitlab.com/msrd0/gotham-restful/blob/master/LICENSE-Apache)
 - [Eclipse Public License Version 2.0](https://gitlab.com/msrd0/gotham-restful/blob/master/LICENSE-EPL)


 [diesel]: https://diesel.rs/
 [example]: https://gitlab.com/msrd0/gotham-restful/tree/master/example
 [gotham]: https://gotham.rs/
 [serde_json]: https://github.com/serde-rs/json#serde-json----
 [`CorsRoute`]: trait.CorsRoute.html
 [`QueryStringExtractor`]: ../gotham/extractor/trait.QueryStringExtractor.html
 [`RequestBody`]: trait.RequestBody.html
 [`State`]: ../gotham/state/struct.State.html