endpoints4s.algebra

Algebra interfaces

Type members

Classlikes

Describes endpoints related to static assets (e.g. medias, scripts, stylesheets, etc.)

Describes endpoints related to static assets (e.g. medias, scripts, stylesheets, etc.)

Provides vocabulary to describe endpoints that use Basic HTTP authentication.

Provides vocabulary to describe endpoints that use Basic HTTP authentication.

This trait works fine, but developers are likely to implement their own authentication mechanism, specific to their application.

Companion:
object
Companion:
class
trait BuiltInErrors extends Errors

Interpreter for the Errors algebra that uses endpoints4s built-in error types:

Interpreter for the Errors algebra that uses endpoints4s built-in error types:

  • Invalid for client errors,
  • and Throwable for server error.

Both types of errors are serialized into a JSON array containing string error values.

Algebra interface for describing request and response entities that use the chunked transfer-encoding.

Algebra interface for describing request and response entities that use the chunked transfer-encoding.

It introduces a type Chunks[A], which models a stream of chunks of type A. It also introduces constructors for chunked request and response entities.

Chunk re-framing can happen during transport and is dependant on the specific implementation. It is known that browser clients re-frame chunks received from the server.

Example:

 val notifications: Endpoint[Unit, Chunks[String]] =
   endpoint(
     get(path / "notifications"),
     ok(textChunksResponse)
   )

Or also:

 val upload: Endpoint[Chunks[Array[Byte]], Unit] =
   endpoint(
     post(path / "upload", bytesChunksRequest),
     ok(emptyResponse)
   )

Enriches the ChunkedEntities algebra with constructors of request and response entities carrying JSON documents.

Enriches the ChunkedEntities algebra with constructors of request and response entities carrying JSON documents.

Example:

 val events =
   endpoint(
     get(path / "events"),
     ok(jsonChunksResponse[Event])
   )
trait Chunks

Algebra interface for describing endpoints made of requests and responses.

Algebra interface for describing endpoints made of requests and responses.

Requests and responses contain headers and entity.

 /**
   * Describes an HTTP endpoint whose:
   *  - request uses verb “GET”,
   *  - URL is made of path “/foo”,
   *  - response has no entity
   */
 val example = endpoint(get(path / "foo"), emptyResponse)

This trait uses BuiltInErrors to model client and server errors.

Algebra interface for describing endpoints made of requests and responses.

Algebra interface for describing endpoints made of requests and responses.

trait Errors

Defines the error types used to model client and server errors.

Defines the error types used to model client and server errors.

The ClientErrors type is used by endpoints4s to model errors coming from the client (missing query parameter, invalid entity, etc.).

The ServerError type is used by endpoints4s to model errors coming from the server business logic.

The badRequest and internalServerError operations defined in Responses define responses carrying entities of type ClientErrors and ServerError, respectively.

Interpreters are expected to use the clientErrorsResponse and serverErrorResponse operations defined here to handle client and server errors, respectively.

See also:
trait Framing

Algebra interface for describing how chunks of chunked transfer-encoding requests and responses should be framed. Being explicit about how chunks are framed solves the issue of re-framing happening during transport.

Algebra interface for describing how chunks of chunked transfer-encoding requests and responses should be framed. Being explicit about how chunks are framed solves the issue of re-framing happening during transport.

trait JsonCodecs extends JsonEntities

Fixes both the JsonRequest and JsonResponse types to be a same JsonCodec type.

Fixes both the JsonRequest and JsonResponse types to be a same JsonCodec type.

This trait is used as an implementation detail (to reuse code between JsonEntitiesFromSchemas and JsonEntitiesFromCodecs) and is not useful to end-users.

Algebra interface for describing JSON entities in requests and responses.

Algebra interface for describing JSON entities in requests and responses.

Generally, this algebra is not directly used, but one of its specialized algebras is used instead: JsonEntitiesFromSchemas or JsonEntitiesFromCodecs.

 /**
   * Describes an HTTP endpoint whose:
   *  - request uses verb “GET”,
   *  - URL is made of the segment “/user” followed by a `String` segment,
   *  - response content type is JSON and contains a `User`
   */
 val example = endpoint(get(path / "user" / segment[UUID]), jsonResponse[User])

Turns a JsonCodec into a Codec.

Turns a JsonCodec into a Codec.

Partially applies the JsonEntities algebra interface to fix the JsonRequest and JsonResponse types to be JsonSchema.

Partially applies the JsonEntities algebra interface to fix the JsonRequest and JsonResponse types to be JsonSchema.

Provides a way to define endpoints that directly expose the low level APIs of the interpreters.

Provides a way to define endpoints that directly expose the low level APIs of the interpreters.

Using this trait is not recommended because endpoints defined using these methods miss the opportunity to share a consistent protocol between client and server interpreters. However, it can be useful for transitioning legacy code.

Example of endpoint definition:

 val someEndpoint = endpoint(post(path, rawRequestEntity), rawResponseEntity)

Endpoint implementation:

 someEndpoint.implementedBy { request =>
   Ok(request.body.asText.getOrElse("Unable to decode request entity"))
 }

XMLHttpRequest call:

 someEndpoint(xhr => "Foo")
   .map(response => println(response.responseText))
trait Methods

Algebra interface for describing endpoints such that one endpoint can handle several types of requests and responses.

Algebra interface for describing endpoints such that one endpoint can handle several types of requests and responses.

Multiplexed request type

Multiplexed request type

trait Requests extends Urls with Methods with SemigroupalSyntax
object Tag
Companion:
class

Algebra interface for describing URLs made of a path and a query string.

Algebra interface for describing URLs made of a path and a query string.

A path is itself made of segments chained together.

A query string is made of named parameters.

 /**
   * Describes an URL starting with a segment containing “articles”, followed
   * by another `String` segment, and a query string containing
   * a mandatory `Lang` parameter named “lang”, and an
   * optional `Int` parameter named “page”.
   *
   * Examples of matching URLs:
   *
   * - /articles/kitchen?lang=fr
   * - /articles/garden?lang=en&page=2
   */
 val example = path / "articles" / segment[String]() /? (qs[Lang]("lang") & qs[Option[Int]]("page"))