Application Factory

ApplicationFactory is a factory of a web application. Enkan has no configuration files.
So all of the configuration are written in ApplicationFactory.

In ApplicationFactory routing and using middleware should be described.

Routing

Kotowari’s routing has the features like RoR routing. There are recognizing and generating.

Defining routes

Routes class has the define method for the mapping between the path and the controller method.

Routes routes = Routes.define(r -> {
    r.get("/").to(HomeController.class, "index");
    r.scope("/admin", admin -> {
        admin.resource(UserController.class);
    });
}).compile();

In the example above, r is a RoutePatterns class for defining each route.
It provides useful methods as follows:

Method	Description
get	If HTTP request method is GET, the request is mapped to the given controller method.
post	If HTTP request method is POST, the request is mapped to the given controller method.
put	If HTTP request method is PUT, the request is mapped to the given controller method.
patch	If HTTP request method is PATCH, the request is mapped to the given controller method.
delete	If HTTP request method is DELETE, the request is mapped to the given controller method.
resource	Creating a resourceful route.
scope	Grouping the multiple routes and prepend the path to each sub-routes.

resource method will generate routes as follows:

HTTP verb	Path	Controller method
GET	/	index
GET	/:id	show
GET	/new	newForm
POST	/	create
GET	/:id/edit	edit
PUT	/:id	update
DELETE	/:id	delete

And scope can be nested.

Routes routes = Routes.define(r ->
    r.scope("/admin", admin ->
        admin.scope("/user", user ->
            user.get("/list").to(AdminUserController.class, "list")))
).compile();

Above example routes the /admin/user/list request to the list method of AdminUserController class.

Generates path

UrlRewriter#urlFor methods can generate the path string from the given parameters.

Routes routes = Routes.define(r -> {
    r.get("/a/b/").to(TestController.class, "index");
    r.get("/a/b/:id").to(TestController.class, "show");
}).compile();

// Generates "/a/b/"
routes.generate(OptionMap.of("controller", TestController.class, "action", "index"));

// Generates "/a/b/1"
routes.generate(OptionMap.of("controller", TestController.class, "action", "show", "id", 1));

Middleware

To use and configure the middleware, call use() method in Application.
The middleware executes in the order they are called use().

    app.use(new DefaultCharsetMiddleware());
    app.use(new MetricsMiddleware<>());
    app.use(NONE, new ServiceUnavailableMiddleware<>(new ResourceEndpoint("/public/html/503.html")));
    app.use(envIn("development"), new StacktraceMiddleware());

Predicates

If the use method takes two arguments, its first argument is a Predicate.
Predicate is a condition whether or not the middleware is applied.

Standard predicates as follows:

Type	Description
NonePredicate	Not applied to all requests
AnyPredicate	Applied to all requests
PathPredicate	Applied to a request that matches the given path pattern and request method
AuthenticatedPredicate	Applied to a request that has valid UserPrincipal
PermissionPredicate	Applied to a request that its UserPrincipal contains the given permissions
EnvPredicate	Applied to a request that the given environment matches the ENKAN_ENV environment variable.