Servant.Scotty.Prelude

Instances of ScottyOp for the operations defined in Servant.Prelude, along with some reusable types necessary for the instances.

Defining Resources and standard operations

module Servant.Prelude

Standard response types

module Servant.Response.Prelude

ScottyOp class and standard operations implementations in scotty

class ScottyOp o where

A class that lets you define one or more handler(s) for an operation o.

Associated Types

type Suitable o a i r :: Constraint

Each operation can define its own constraints on:

• the type of the entries, a * the type by which the entries are indexed, i * the result type r of "effectful" database operations (those that addupdatedelete entries)

This is useful because that way, your types will only have to satisfy the constraints specified by the operations your Resource carries, not some global dumb constraints you have to pay for even if you don't care about the operation that requires this constraint.

Methods

runOperation :: (Functor m, MonadIO m, ScottyError e, Suitable o a i r) => Resource c a i r e (o : ops) -> Operation o c a i r -> ScottyT e m ()

Given a Resource and the "database function" (so to speak) corresponding to your operation, do some business in scotty's ScottyT and ActionT monads to define a handler for this very operation.

To provide the "database function" with some Context c you can use withContext to run the operation and context to get the context of your Resource.

To catch exceptions around your db operation in your handler, you can use the excCatcher access the ExceptionCatcher of your Resource and handledWith to catch them and convert them to your error type e. You can then raise the error value if you have a sensible default handler or handle it locally and respond with whatever is appropriate in your case.

Instances

ScottyOp Add

Generate a

 POST /:resourcename

handler for adding entries.

Constraints on @a@, @i@ and @r@:

 type Suitable Add a i r = (FromJSON a, Response (UpdateResponse Add) r)

ScottyOp Delete

Generate a

 DELETE /:resourcename/<index specific stuffs>

handler for deleting entries.

Constraints on @a@, @i@ and @r@:

 type Suitable Delete a i r = (Index i, Response (UpdateResponse Delete) r)

ScottyOp ListAll

Generate a

 GET /:resourcename

handler for listing all entries.

Constraints on @a@, @i@ and @r@:

 type Suitable ListAll a i r = ToJSON a

ScottyOp Update

Generate a

 PUT /:resourcename/<index specific stuffs>

handler for updating an entry.

Constraints on @a@, @i@ and @r@:

 type Suitable Update a i r = (Index i, FromJSON a, Response (UpdateResponse Update) r)

ScottyOp View

Generate a

 GET /:resourcename/<index specific stuffs>

handler for viewing an entry.

Constraints on @a@, @i@ and @r@:

 type Suitable View a i r = (Index i, ToJSON a)

Helpful types, functions, classes and instances

module Servant.Scotty.Arguments

module Servant.Scotty.Response

module Web.Scotty.Trans