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Module Eliom_services

module Eliom_services: sig..end

This module allows to define services.


exception Wrong_session_table_for_CSRF_safe_coservice

val sync : ('a -> 'b -> 'c -> 'd) -> 'a -> 'b -> 'c -> 'd Lwt.t

This function may be used for services that cannot be interrupted (no cooperation point for threads). It is defined by let sync f sp g p = Lwt.return (f sp g p)

type cookie =

|Set of Ocsigen_lib.url_path option * float option * string * string * bool
|Unset of Ocsigen_lib.url_path option * string

Type used for other cookies to set or unset. The float option is the timestamp for the expiration date. The strings are names and values.

val cookie_table_of_eliom_cookies :
   ?oldtable:Ocsigen_http_frame.cookieset ->
    sp:Eliom_sessions.server_params ->
    cookie list -> Ocsigen_http_frame.cookieset

Conversion fonction from Eliom cookies to server cookies. If ?oldtable is present, cookies are added to this table


Types of services


type suff = [ `WithSuffix | `WithoutSuffix ]

type servcoserv = [ `Coservice | `Service ]

type getpost = [ `Get | `Post ]

type attached_service_kind = [ `External | `Internal of servcoserv * getpost ]

type get_attached_service_kind = [ `External | `Internal of servcoserv * [ `Get ] ]

type post_attached_service_kind = [ `External | `Internal of servcoserv * [ `Post ] ]

type internal = [ `Internal of servcoserv * getpost ]

type registrable = [ `Registrable | `Unregistrable ]

You can call register function only on registrable services

type +'a a_s

type +'a na_s

type service_kind =
   [ `Attached of attached_service_kind a_s
    | `Nonattached of getpost na_s ]

type get_service_kind =
   [ `Attached of get_attached_service_kind a_s
    | `Nonattached of [ `Get ] na_s ]

type post_service_kind =
   [ `Attached of post_attached_service_kind a_s
    | `Nonattached of [ `Post ] na_s ]

type internal_service_kind =
   [ `Attached of internal a_s
    | `Nonattached of getpost na_s ]

type attached = [ `Attached of attached_service_kind a_s ]

type nonattached = [ `Nonattached of getpost na_s ]

type ('a, 'b, +'c, +'d, +'e, +'f, +'g) service

Type of services.* 'get is the type of GET parameters

  • 'post is the type of POST parameters
  • 'kind is a subtype of Eliom_services.service_kind (attached or non-attached service, internal or external, GET only or with POST parameters)
  • 'tipo is a phantom type stating the kind of parameters it uses (suffix or not)
  • 'getnames is the type of GET parameters names
  • 'postnames is the type of POST parameters names
  • 'registrable is a phantom type, subtype of Eliom_services.registrable, telling if it is possible to register a handler on this service.



Registration of named modules


This functionality allows to register module initialization functions for Eliom modules which will be executed when the corresponding module is initialized in ocsigen.conf.

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

This function is used to specify the initialization function for Eliom modules linked dynamic or statically into the server. register_eliom_module name f registers the initialization function f for module name. The f function will be invoked when the module is initialized in the configuration file using <eliom name="name"> ... </eliom>, which is equivalent to <eliom module="name.cmo"> ... </eliom> with the exception that it does not load the module using Dynlink.


Definitions of services



Main services


val new_service :
   ?sp:Eliom_sessions.server_params ->
    ?https:bool ->
    path:Ocsigen_lib.url_path ->
    ?keep_nl_params:[ `All | `None | `Persistent ] ->
    get_params:('a, [< suff ] as 'b, 'c)
    Eliom_parameters.params_type ->
    unit ->
    ('a, unit,
    [> `Attached of
    [> `Internal of [> `Service ] * [> `Get ] ] a_s ],
    'b, 'c, unit, [> `Registrable ])
    service

new_service ~path:p ~get_params:pa () creates an Eliom_services.service associated to the path p, taking the GET parameters pa.

If ~https is true, all links towards that service will use https.

Warning: If you use this function after the initialisation phase, you must give the ~sp parameter, otherwise it will raise the exception Eliom_common.Eliom_function_forbidden_outside_site_loading.

val new_external_service :
   prefix:string ->
    path:Ocsigen_lib.url_path ->
    ?keep_nl_params:[ `All | `None | `Persistent ] ->
    get_params:('a, [< suff ] as 'b, 'c)
    Eliom_parameters.params_type ->
    post_params:('d, [ `WithoutSuffix ], 'e) Eliom_parameters.params_type ->
    unit ->
    ('a, 'd, [> `Attached of [> `External ] a_s ], 'b, 'c, 'e,
    [> `Unregistrable ])
    service

Creates an service for an external web site. Allows to creates links or forms towards other Web sites using Eliom's syntax.

The parameter labelled ~path is the URL path, and each element of the list will be URL-encoded.

The parameter labelled ~prefix contains all what you want to put before the path. It usually starts with "http://" plus the name of the server. The whole URL is constructed from the prefix, the path and parameters. The prefix is not encoded. An empty prefix can be used to make a link to another site of the same server.

val new_post_service :
   ?sp:Eliom_sessions.server_params ->
    ?https:bool ->
    fallback:('a, unit,
    [ `Attached of
    [ `Internal of [ `Coservice | `Service ] * [ `Get ] ]
    a_s ],
    [< suff ] as 'b, 'c, unit, [< `Registrable ])
    service ->
    ?keep_nl_params:[ `All | `None | `Persistent ] ->
    post_params:('d, [ `WithoutSuffix ], 'e) Eliom_parameters.params_type ->
    unit ->
    ('a, 'd,
    [> `Attached of
    [> `Internal of [ `Coservice | `Service ] * [> `Post ] ]
    a_s ],
    'b, 'c, 'e, [> `Registrable ])
    service

Creates an service that takes POST parameters. fallback is the a service without POST parameters. You can't create an service with POST parameters if the same service does not exist without POST parameters. Thus, the user can't bookmark a page that does not exist.


Attached coservices


val new_coservice :
   ?name:string ->
    ?csrf_safe:bool ->
    ?csrf_session_name:string ->
    ?csrf_secure_session:bool ->
    ?max_use:int ->
    ?timeout:float ->
    ?https:bool ->
    fallback:(unit, unit,
    [ `Attached of
    [ `Internal of [ `Service ] * [ `Get ] ] a_s ],
    [ `WithoutSuffix ], unit, unit, [< registrable ])
    service ->
    ?keep_nl_params:[ `All | `None | `Persistent ] ->
    get_params:('a, [ `WithoutSuffix ], 'b) Eliom_parameters.params_type ->
    unit ->
    ('a, unit,
    [> `Attached of
    [> `Internal of [> `Coservice ] * [> `Get ] ] a_s ],
    [ `WithoutSuffix ], 'b, unit, [> `Registrable ])
    service

Creates a coservice. A coservice is another version of an already existing main service, where you can register another handler. The two versions are automatically distinguished using an extra parameter added automatically by Eliom. It allows to have several links towards the same page, that will behave differently, or to create services dedicated to one user. See the tutorial for more informations. Coservices can be named if the ?name optional parameter is present or anonymous (in that case, a coservice number will be generated).

The ~timeout parameter specifies a timeout (in seconds) after which the coservice will disappear. This amount of time is computed from the creation or the last call to the service.

The ~max_use parameter specifies that the service can be used only a fixed number of times.

If ~csrf_safe is true, it will create a "CSRF-safe" service (the default is false). (In that case ~name is ignored). It means that the registration of the service will not actually take place when register is called, but delayed and performed each time a form is created. This allows to protect against CSRF attacks, and should be use with a short timeout (and max_use). (And you should probably use POST coservices in that case). In that case, you can register the CSRF safe service either in the global service table or in the session service table. But the actual registration, that will occure when creating a link or a form, will always take place in a session service table. This table is specified by the ~csrf_session_name and ~csrf_secure_session parameters (that correspond to ~session_name and ~secure for the delayed registration); it is default session table if they are absent. Parameters ?session_name and ?secure of register_for_session must have the same values as the one declared while creating the CSRF safe coservice, otherwise the registration will fail with .

val new_post_coservice :
   ?name:string ->
    ?csrf_safe:bool ->
    ?csrf_session_name:string ->
    ?csrf_secure_session:bool ->
    ?max_use:int ->
    ?timeout:float ->
    ?https:bool ->
    fallback:('a, unit,
    [ `Attached of
    [ `Internal of [< `Coservice | `Service ] * [ `Get ] ]
    a_s ],
    [< suff ] as 'b, 'c, unit, [< `Registrable ])
    service ->
    ?keep_nl_params:[ `All | `None | `Persistent ] ->
    post_params:('d, [ `WithoutSuffix ], 'e) Eliom_parameters.params_type ->
    unit ->
    ('a, 'd,
    [> `Attached of
    [> `Internal of [> `Coservice ] * [> `Post ] ] a_s ],
    'b, 'c, 'e, [> `Registrable ])
    service

Creates a coservice with POST parameters


Non attached coservices


val new_coservice' :
   ?name:string ->
    ?csrf_safe:bool ->
    ?csrf_session_name:string ->
    ?csrf_secure_session:bool ->
    ?max_use:int ->
    ?timeout:float ->
    ?https:bool ->
    ?keep_nl_params:[ `All | `None | `Persistent ] ->
    get_params:('a, [ `WithoutSuffix ], 'b) Eliom_parameters.params_type ->
    unit ->
    ('a, unit, [> `Nonattached of [> `Get ] na_s ],
    [ `WithoutSuffix ], 'b, unit, [> `Registrable ])
    service

Creates a non-attached coservice, that is, services that do not correspond to a precise path in the URL. Links towards such services will not change the URL, just add extra parameters. Non-attached coservices can be named if the ?name optional parameter is present or anonymous (in that case, a coservice number will be generated). See the tutorial for more informations.

val new_post_coservice' :
   ?name:string ->
    ?csrf_safe:bool ->
    ?csrf_session_name:string ->
    ?csrf_secure_session:bool ->
    ?max_use:int ->
    ?timeout:float ->
    ?https:bool ->
    ?keep_nl_params:[ `All | `None | `Persistent ] ->
    ?keep_get_na_params:bool ->
    post_params:('a, [ `WithoutSuffix ], 'b) Eliom_parameters.params_type ->
    unit ->
    (unit, 'a, [> `Nonattached of [> `Post ] na_s ],
    [ `WithoutSuffix ], unit, 'b, [> `Registrable ])
    service

Creates a non attached coservice with POST parameters. If the optional parameter ~keep_get_na_params is false, GET non-attached parameters won't be kept in the URL (if any) when you create a POST form to this coservice. Default is true. See also Eliom_mkforms.ELIOMFORMSIG.post_form.


Predefined services


val static_dir :
   sp:Eliom_sessions.server_params ->
    (string list, unit,
    [> `Attached of
    [> `Internal of [> `Service ] * [> `Get ] ] a_s ],
    [ `WithSuffix ], [ `One of string list ] Eliom_parameters.param_name,
    unit, [> `Unregistrable ])
    service

A predefined service that correponds to the directory where static pages are. This directory is chosen in the config file (ocsigen.conf). This service takes the name of the static file as a parameter (a string list, slash separated).

val https_static_dir :
   sp:Eliom_sessions.server_params ->
    (string list, unit,
    [> `Attached of
    [> `Internal of [> `Service ] * [> `Get ] ] a_s ],
    [ `WithSuffix ], [ `One of string list ] Eliom_parameters.param_name,
    unit, [> `Unregistrable ])
    service

The same, but forcing https

val static_dir_with_params :
   sp:Eliom_sessions.server_params ->
    ?keep_nl_params:[ `All | `None | `Persistent ] ->
    get_params:('a, [ `WithoutSuffix ], 'b) Eliom_parameters.params_type ->
    unit ->
    (string list * 'a, unit,
    [> `Attached of
    [> `Internal of [> `Service ] * [> `Get ] ] a_s ],
    [ `WithSuffix ], [ `One of string list ] Eliom_parameters.param_name * 'b,
    unit, [> `Unregistrable ])
    service

Like static_dir, but allows to put GET parameters

val https_static_dir_with_params :
   sp:Eliom_sessions.server_params ->
    ?keep_nl_params:[ `All | `None | `Persistent ] ->
    get_params:('a, [ `WithoutSuffix ], 'b) Eliom_parameters.params_type ->
    unit ->
    (string list * 'a, unit,
    [> `Attached of
    [> `Internal of [> `Service ] * [> `Get ] ] a_s ],
    [ `WithSuffix ], [ `One of string list ] Eliom_parameters.param_name * 'b,
    unit, [> `Unregistrable ])
    service

The same, but forcing https

val void_coservice' :
   (unit, unit, [> `Nonattached of 'a na_s ], [ `WithoutSuffix ],
    unit, unit, [> `Unregistrable ])
    service

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, [> `Nonattached of 'a na_s ], [ `WithoutSuffix ],
    unit, unit, [> `Unregistrable ])
    service

The same, but forcing https.

val void_hidden_coservice' :
   (unit, unit, [> `Nonattached of 'a na_s ], [ `WithoutSuffix ],
    unit, unit, [> `Unregistrable ])
    service

Same as void_coservice' but keeps non attached GET parameters.

val https_void_hidden_coservice' :
   (unit, unit, [> `Nonattached of 'a na_s ], [ `WithoutSuffix ],
    unit, unit, [> `Unregistrable ])
    service

The same, but forcing https.


Misc


val preapply :
   service:('a, 'b, [> `Attached of 'd a_s ] as 'c,
    [< suff ], 'e, 'f, 'g)
    service ->
    'a ->
    (unit, 'b, 'c, [ `WithoutSuffix ], unit, 'f, [> `Unregistrable ])
    service

creates a new service by preapplying a service to 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 add_non_localized_get_parameters :
   params:('a, [ `WithoutSuffix ], 'b) Eliom_parameters.non_localized_params ->
    service:('c, 'd, 'e, 'f, 'g, 'h, 'i) service ->
    ('c * 'a, 'd, 'e, 'f, 'g * 'b, 'h, 'i) service

Adds non localized GET parameters to a service

val add_non_localized_post_parameters :
   params:('a, [ `WithoutSuffix ], 'b) Eliom_parameters.non_localized_params ->
    service:('c, 'd, 'e, 'f, 'g, 'h, 'i) service ->
    ('c, 'd * 'a, 'e, 'f, 'g, 'h * 'b, 'i) service

Adds non localized POST parameters to a service

val unregister :
   ?sp:Eliom_sessions.server_params ->
    ('a, 'b,
    [< `Attached of [> `Internal of 'c * [> `Get ] ] a_s
    | `Nonattached of 'd na_s ],
    'e, 'f, 'g, 'h)
    service -> unit

Unregister a service from global table

val unregister_for_session :
   sp:Eliom_sessions.server_params ->
    ?session_name:string ->
    ?secure:bool ->
    ('a, 'b,
    [< `Attached of [> `Internal of 'c * [> `Get ] ] a_s
    | `Nonattached of 'd na_s ],
    'e, 'f, 'g, 'h)
    service -> unit

Unregister a service from session table


Using your own error pages


val set_exn_handler :
   ?sp:Eliom_sessions.server_params ->
    (Eliom_sessions.server_params -> exn -> Ocsigen_http_frame.result Lwt.t) ->
    unit

Allows to use your own error pages (404, or any exception during page generation).

Warning: If you use this function after the initialisation phase, you must give the ~sp parameter, otherwise it will raise the exception Eliom_common.Eliom_function_forbidden_outside_site_loading.