This is server API (go to client)

Module Eliom_service

module Eliom_service : sig..end

Creation and manipulation of Eliom services.


See the Eliom manual for a detailed introduction to the concept of Eliom services.

The main functions to create services are in modules Eliom_service.​Http (default), Eliom_service.​Ocaml (for services returning OCaml values) and Eliom_service.​App (for services belonging to an Eliom client-server app).

Type definitions for services

Services kind

The type service_kind describe all four kind of services:

  • external (attached) services
  • (internal) attached services
  • (internal) attached coservices
  • (internal) non-attached coservices
type internal_attached_service_kind = [ `AttachedCoservice | `Service ]

An internal attached service could either be a `Service or a `AttachedCoservice.

type internal_service_kind = [ `AttachedCoservice | `NonattachedCoservice | `Service ]

An internal service could either be an internal attached service or a `NonattachedCoservice.

type service_kind = 
  [ `AttachedCoservice | `External | `NonattachedCoservice | `Service ]

An attached service could either be an internal Eliom service or an abstraction for an `External service.

Attached or Non-attached

type a_s

The abstract type for attached service representation.

type na_s

The abstract type for non-attached service representation.

type attached_kind = [ `Attached of a_s ]
type non_attached_kind = [ `Nonattached of na_s ]
type attached = [ `Attached of a_s | `Nonattached of na_s ]

POST or GET parameters

type service_method = [ `Delete | `Get | `Post | `Put ]

The kind of a service is `Post when there is at least one POST parameters. It is `Get otherwise.

Common subtypes of service_method

type get_service_kind = [ `Get ]

Restriction of service_method to GET services.

type post_service_kind = [ `Post ]

Restriction of service_method to POST services.

type put_service_kind = [ `Put ]

Restriction of service_method to PUT services.

type delete_service_kind = [ `Delete ]

Restriction of service_method to DELETE services.

Kind of parameters

type suff = [ `WithSuffix | `WithoutSuffix ]

The kind of parameters for a service is `WithSuffix when it have a suffix parameter, for examples Eliom_parameter.​suffix or Eliom_parameter.​suffix_prod. Otherwise it is `WithoutSuffix.

Registrable service

type registrable = [ `Registrable | `Unregistrable ]

A service is `Registrable only if it isn't a pre-applied service, see Eliom_service.​preapply.

Abstract type of services

type 
  ('get, 'post, +[< service_method ]
   , +[< attached ], +[< service_kind ]
   , +[< suff ], 'gn, 'pn
   , +[< registrable ], +'ret)
service

Type of services.

type http_service = [ `Http ]

Types of groups of services.

type appl_service = [ `Appl ]
type 'a ocaml_service
type non_ocaml_service = [ `Appl | `Http ]

The type non_ocaml_service is used as phantom type parameters for the Eliom_registration.​kind. It used to type functions that operates over service that do not returns OCaml values, like appl_self_redirect.

type 'rt rt

Helper for typing OCaml services. In some cases, you may need to write the return type of the service manually. Instead of writing the full type of the service, (which may be huge), add a type constraint for parameter ?rt of service creation functions (like <<a_api subproject="server"|fun Eliom_service.Http.service>>), using the following value.

val rt : 'rt rt

Registration of services

module Http : sig..end

Default module for creating services

module App : sig..end

Module for creating services returning applications

module Ocaml : sig..end

Module for creating services that return OCaml values

module Unsafe : sig..end

Module for creating services without specifying the return type

Static loading of Eliom modules

This functionality allows one to register initialization functions for Eliom modules which will be executed when the corresponding module is loaded in ocsigenserver.conf. If the module is loaded dynamically, you probably don't need this. But if the module is linked statically, some computations, like service registrations must be delayed.

val register_eliom_module : string -> (unit -> unit) -> unit

The function register_eliom_module mod f is used to register the initialization function f to be executed when then module mod is loaded by Ocsigen server. The module mod could either be a dynamically loaded module or linked statically into the server: in each case, the f function will be invoked when the module is initialized in the configuration file using <eliommodule ...> ... </eliommodule>. If register_eliom_module is called twice with the same module name, the second initialization function will replace the previous one.

Predefined services

Static files

val static_dir : 
  unit ->
  (string list, unit, [< service_method > `Get ],
   [< attached > `Attached ],
   [< service_kind > `Service ], [ `WithSuffix ],
   [ `One of string list ] Eliom_parameter.param_name,
   unit, [< registrable > `Unregistrable ],
   [> http_service ])
  service

The predefined service static_dir allows one to create links to static files. This service takes the name of a static file as a parameter (a string list, slash separated). The actual directory in filesystem where static pages will be found must be set up in the configuration file with the staticmod extension.

val https_static_dir : 
  unit ->
  (string list, unit, [< service_method > `Get ],
   [< attached > `Attached ],
   [< service_kind > `Service ], [ `WithSuffix ],
   [ `One of string list ] Eliom_parameter.param_name,
   unit, [< registrable > `Unregistrable ],
   [> http_service ])
  service

Same as Eliom_service.​static_dir but forcing https link.

val static_dir_with_params : 
  ?keep_nl_params:[ `All | `None | `Persistent ] ->
  get_params:('a, [ `WithoutSuffix ], 'an) Eliom_parameter.params_type ->
  unit ->
  (string list * 'a, unit, [< service_method > `Get ],
   [< attached > `Attached ],
   [< service_kind > `Service ], [ `WithSuffix ],
   [ `One of string list ] Eliom_parameter.param_name * 'an,
   unit, [< registrable > `Unregistrable ],
   [> http_service ])
  service

Like static_dir, but allows one to put GET parameters

val https_static_dir_with_params : 
  ?keep_nl_params:[ `All | `None | `Persistent ] ->
  get_params:('a, [ `WithoutSuffix ], 'an) Eliom_parameter.params_type ->
  unit ->
  (string list * 'a, unit, [< service_method > `Get ],
   [< attached > `Attached ],
   [< service_kind > `Service ], [ `WithSuffix ],
   [ `One of string list ] Eliom_parameter.param_name * 'an,
   unit, [< registrable > `Unregistrable ],
   [> http_service ])
  service

Same as Eliom_service.​static_dir_with_params but forcing https link.

Void non-attached coservices

val void_coservice' : 
  (unit, unit, [< service_method > `Get ],
   [< attached > `Nonattached ],
   [< service_kind > `NonattachedCoservice ],
   [ `WithoutSuffix ], unit, unit,
   [< registrable > `Unregistrable ],
   [> non_ocaml_service ])
  service

The service void_coservice' is a predefined non-attached action with special behaviour: it has no parameter at all, even non-attached parameters. Use it if you want to make a link to the current page without non-attached parameters. It is almost equivalent to a POST non-attached service without POST parameters, on which you register an action that does nothing, but you can use it with <a> links, not only forms. It does not keep non attached GET parameters.

val https_void_coservice' : 
  (unit, unit, [< service_method > `Get ],
   [< attached > `Nonattached ],
   [< service_kind > `NonattachedCoservice ],
   [ `WithoutSuffix ], unit, unit,
   [< registrable > `Unregistrable ],
   [> non_ocaml_service ])
  service

Same as Eliom_service.​void_coservice' but forcing https.

val void_hidden_coservice' : 
  (unit, unit, [< service_method > `Get ],
   [< attached > `Nonattached ],
   [< service_kind > `NonattachedCoservice ],
   [ `WithoutSuffix ], unit, unit,
   [< registrable > `Unregistrable ],
   [> non_ocaml_service ])
  service

Same as Eliom_service.​void_coservice' but keeps non attached GET parameters.

val https_void_hidden_coservice' : 
  (unit, unit, [< service_method > `Get ],
   [< attached > `Nonattached ],
   [< service_kind > `NonattachedCoservice ],
   [ `WithoutSuffix ], unit, unit,
   [< registrable > `Unregistrable ],
   [> non_ocaml_service ])
  service

Same as Eliom_service.​void_hidden_coservice' but forcing https.

Miscellaneous

val preapply : 
  service:('a, 'b, [< service_method ] as 'c,
   [< attached > `Attached ] as 'd,
   [< service_kind ] as 'g,
   [< suff ], 'e, 'f,
   [< registrable ], 'return)
   service ->
  'a ->
  (unit, 'b, 'c, 'd, 'g, [ `WithoutSuffix ], unit, 'f,
   [< registrable > `Unregistrable ], 'return)
  service

The function preapply ~service paramaters creates a new service by preapplying service to the GET parameters. It is not possible to register a handler on an preapplied service ; preapplied services may be used in links or as fallbacks for coservices

val attach_coservice' : 
  fallback:(unit, unit, [< `Get ], [< attached_kind ],
   [< `AttachedCoservice | `Service ], [< suff ],
   unit, unit, [< registrable ], 'return1)
   service ->
  service:('get, 'post, [< service_method ] as 'a,
   [< non_attached_kind ],
   [< `NonattachedCoservice ], [< `WithoutSuffix ] as 'b, 'gn,
   'pn, [< registrable ], 'return)
   service ->
  ('get, 'post, 'a, [< attached > `Attached ],
   [< service_kind > `AttachedCoservice ], 'b, 'gn, 'pn,
   [< registrable > `Unregistrable ], 'return)
  service

attach_coservice' ~fallback ~service attaches the non-attached coservice service on the URL of fallback. This allows to create a link to a non-attached coservice but with another URL than the current one. It is not possible to register something on the service returned by this function.

val add_non_localized_get_parameters : 
  params:('p, [ `WithoutSuffix ], 'pn)
   Eliom_parameter.non_localized_params ->
  service:('a, 'b, [< service_method ] as 'c,
   [< attached ] as 'd,
   [< service_kind ] as 'g,
   [< suff ] as 'h, 'e, 'f,
   [< registrable ] as 'i, 'return)
   service ->
  ('a * 'p, 'b, 'c, 'd, 'g, 'h, 'e * 'pn, 'f, 'i, 'return)
  service

The function add_non_localized_get_parameters ~params ~service Adds non localized GET parameters params to service. See the Eliom manual for more information about non localized parameters.

val add_non_localized_post_parameters : 
  params:('p, [ `WithoutSuffix ], 'pn)
   Eliom_parameter.non_localized_params ->
  service:('a, 'b, [< service_method ] as 'c,
   [< attached ] as 'd,
   [< service_kind ] as 'g,
   [< suff ] as 'h, 'e, 'f,
   [< registrable ] as 'i, 'return)
   service ->
  ('a, 'b * 'p, 'c, 'd, 'g, 'h, 'e, 'f * 'pn, 'i, 'return)
  service

Same as Eliom_service.​add_non_localized_get_parameters but with POST parameters.

val unregister : 
  ?scope:[< Eliom_common.scope ] ->
  ?secure:bool ->
  ('a, 'b, [< service_method ],
   [< attached ],
   [< service_kind
   > `AttachedCoservice `NonattachedCoservice `Service ],
   [< suff ], 'f, 'g, [< registrable ],
   'return)
  service -> unit

The function unregister service unregister the service handler previously associated to service with Eliom_registration.​Html5.​register, Eliom_registration.App.register or any other Eliom_registration.*.register functions. See the documentation of those functions for a description of the ~scope and ~secure optional parameters.