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Controller

Namespace: Saturn.Endpoint
Parent: Saturn.Endpoint

Module with controller computation expression


Declared Types
Type Description
Action

Type used for plug operation, allowing you to choose for which actions given plug should work

ControllerBuilder<'Key, 'IndexOutput, 'ShowOutput, 'AddOutput, 'EditOutput, 'CreateOutput, 'UpdateOutput, 'PatchOutput, 'DeleteOutput, 'DeleteAllOutput>

Computation expression used to create Saturn controllers - abstraction representing REST-ish endpoint for serving HTML views or returning data. It supports:

  • a set of predefined actions that are automatically mapped to the endpoints following standard conventions
  • embedding sub-controllers for modeling one-to-many relationships
  • versioning
  • adding plugs for a particular action which in principle provides the same mechanism as attributes in ASP.NET MVC applications
  • defining a common error handler for all actions
  • defining a not-found action

The result of the computation expression is a standard Giraffe HttpHandler, which means that it's easily composable with other parts of the ecosytem.

Example:

let commentController userId = subcontroller {
    index (fun ctx -> (sprintf "Comment Index handler for user %i" userId ) |> Controller.text ctx)
    add (fun ctx -> (sprintf "Comment Add handler for user %i" userId ) |> Controller.text ctx)
    show (fun (ctx, id) -> (sprintf "Show comment %s handler for user %i" id userId ) |> Controller.text ctx)
    edit (fun (ctx, id) -> (sprintf "Edit comment %s handler for user %i" id userId )  |> Controller.text ctx)
}

let userControllerVersion1 = controller {
    version 1
    subController "/comments" commentController

    index (fun ctx -> "Index handler version 1" |> Controller.text ctx)
    add (fun ctx -> "Add handler version 1" |> Controller.text ctx)
    show (fun (ctx, id) -> (sprintf "Show handler version 1 - %i" id) |> Controller.text ctx)
    edit (fun (ctx, id) -> (sprintf "Edit handler version 1 - %i" id) |> Controller.text ctx)
}

let userController = controller {
    subController "/comments" commentController

    plug [All] (setHttpHeader "user-controller-common" "123")
    plug [Index; Show] (setHttpHeader "user-controller-specialized" "123")

    index (fun ctx -> "Index handler no version" |> Controller.text ctx)
    add (fun ctx -> "Add handler no version" |> Controller.text ctx)
    show (fun (ctx, id) -> (sprintf "Show handler no version - %i" id) |> Controller.text ctx)
    edit (fun (ctx, id) -> (sprintf "Edit handler no version - %i" id) |> Controller.text ctx)
}
val commentController : userId:'a -> 'b
val userId : 'a
val sprintf : format:Printf.StringFormat<'T> -> 'T
val id : x:'T -> 'T
val userControllerVersion1 : obj
val userController : obj
ControllerState<'Key, 'IndexOutput, 'ShowOutput, 'AddOutput, 'EditOutput, 'CreateOutput, 'UpdateOutput, 'PatchOutput, 'DeleteOutput, 'DeleteAllOutput>

Type representing internal state of the controller computation expression


Values and Functions
Name Description
except(actions)
Signature: actions:Action list -> Action list

Returns list of all actions except given actions.

response ctx input
Signature: ctx:HttpContext -> input:Task<'a> -> Task

controller
Signature: ControllerBuilder<'Key,'IndexOutput,'ShowOutput,'AddOutput,'EditOutput,'CreateOutput,'UpdateOutput,'PatchOutput,'DeleteOutput,'DeleteAllOutput>

Computation expression used to create controllers

subcontroller
Signature: ControllerBuilder<'Key,'IndexOutput,'ShowOutput,'AddOutput,'EditOutput,'CreateOutput,'UpdateOutput,'PatchOutput,'DeleteOutput,'DeleteAllOutput>

Computation expression used to create HttpHandlers representing subcontrollers.