This is server API (go to client)

Module Eliom_parameter

module Eliom_parameter : sig..end

Ad-hoc runtime type representation for service parameters.

See the Eliom manual for more information about service parameters.


type ('a, +'b, +'c) params_type

Abstract type for service parameters. See for example the parameter ~get_param of Eliom_service.​service.

  • 'a is the type for the OCaml type of the parameter as expected by the service handler.
  • 'b is a phantom type, subtype of Eliom_parameter.​suff, stating the kind of the parameter: suffix or not.
  • 'c is the type of the parameter name, usually an instance of Eliom_parameter.​param_name, as used by forms construction functions (e. g. the last parameter of Eliom_registration.Html5.get_form), and specialized form widget (see for example the section Form widget of Eliom_registration.HTML5). )
type suff = [ `Endsuffix | `WithSuffix | `WithoutSuffix ]

This type is used as a phantom type in Eliom_parameter.​params_type to describe whether a parameter is encoded in the path of the URI as a suffix parameter.

Typed parameter's name

type 'a param_name

Abstract type for parameters' name. The 'a type parameter is a phantom type, usually a subtype of Eliom_parameter.​setoneradio, used to denotes the parameter's arity.

type no_param_name

Empty type used to denotes it is not possible to use the parameter in a form. See for example Eliom_parameter.​raw_post_data.

type 'a setoneradio = [ `One of 'a | `Radio of 'a | `Set of 'a ]

A parameter arity could either be:

  • `Set of 'a means: any number of 'a.
  • `One of 'a means: exactly one 'a.
  • `Radio of 'a means: zero or one 'a.
type 'a oneradio = [ `One of 'a | `Radio of 'a ]

Restriction of Eliom_parameter.​setoneradio unary and optional parameters.

type 'a setone = [ `One of 'a | `Set of 'a ]

Restriction of Eliom_parameter.​setoneradio unary and set parameters.

Types helpers

type ('a, 'b) binsum =  | Inj1 of 'a | Inj2 of 'b

Helpers type used for parameters of type binary sum, see Eliom_parameter.​sum.

type 'an listnames = {
  it: 'el 'a. ('an -> 'el -> 'a -> 'a) -> 'el list -> 'a -> 'a;}

Helpers type used to construct forms from lists, see Eliom_parameter.​list.

Basic types of pages parameters

val int : 
  string ->
  (int, [ `WithoutSuffix ], [ `One of int ] param_name)
  params_type

Specifying parameter as int s tells that the service takes an integer as parameter, labeled s.

val int32 : 
  string ->
  (int32, [ `WithoutSuffix ],
   [ `One of int32 ] param_name)
  params_type

Specifying parameter as int32 s tells that the service takes a 32 bits integer as parameter, labeled s.

val int64 : 
  string ->
  (int64, [ `WithoutSuffix ],
   [ `One of int64 ] param_name)
  params_type

Specifying parameter as int64 s tells that the service takes a 64 bits integer as parameter, labeled s.

val float : 
  string ->
  (float, [ `WithoutSuffix ],
   [ `One of float ] param_name)
  params_type

Specifying parameter as float s tells that the service takes a floating point number as parameter, labeled s.

val string : 
  string ->
  (string, [ `WithoutSuffix ],
   [ `One of string ] param_name)
  params_type

Specifying parameter as string s tells that the service takes a string as parameter, labeled s.

val bool : 
  string ->
  (bool, [ `WithoutSuffix ],
   [ `One of bool ] param_name)
  params_type

Specifying parameter as bool s tells that the service takes a boolean as parameter, labeled s. (to use for example with boolean checkboxes)

val file : 
  string ->
  (Eliom_lib.file_info, [ `WithoutSuffix ],
   [ `One of Eliom_lib.file_info ] param_name)
  params_type

Specifying parameter as file s tells that the service takes a file as parameter, labeled s.

val unit : (unit, [ `WithoutSuffix ], unit) params_type

Specifying parameter as unit is used for services that don't have any parameters

val user_type : 
  of_string:(string -> 'a) ->
  to_string:('a -> string) ->
  string ->
  ('a, [ `WithoutSuffix ], [ `One of 'a ] param_name)
  params_type

Specifying parameter as user_type ~of_string ~to_string s tells that the service take a parameter, labeled s, and that the server will have to use of_string and to_string to make the conversion between the OCaml representation of the parameter and it's external representation as a string. It allows one to use whatever type you want for a parameter of the service.

val type_checker : 
  ('a -> unit) ->
  ('a, 'b, 'c) params_type ->
  ('a, 'b, 'c) params_type

Specifying parameter as type_checker check t is equivalent as t but the check function is called after decoding the parameters, allowing you to make more checks on the parameters before the service handler is called. Raise an exception if the parameter is not correct, and the error handler will be called instead of the service handler.

type coordinates = {
  abscissa: int;  ordinate: int;}

The type coordinates represent the data sent by an <input type="image" ...>.

val coordinates : 
  string ->
  (coordinates, [ `WithoutSuffix ],
   [ `One of coordinates ] param_name)
  params_type

Specifying parameter as coordinates s tells that the service takes as parameters the coordinates of a point in an <input type="image" ...>.

val string_coordinates : 
  string ->
  (string * coordinates, [ `WithoutSuffix ],
   [ `One of string * coordinates ]
   param_name)
  params_type

Specifying parameter as string_coordinates s tells that the service takes as parameters the coordinates of a point and the associated string value in an <input type="image" value="..." ...>.

val int_coordinates : 
  string ->
  (int * coordinates, [ `WithoutSuffix ],
   [ `One of int * coordinates ]
   param_name)
  params_type

Same as string_coordinates but for an integer value

val int32_coordinates : 
  string ->
  (int32 * coordinates, [ `WithoutSuffix ],
   [ `One of int32 * coordinates ]
   param_name)
  params_type

Same as string_coordinates but for a 32 bits integer value

val int64_coordinates : 
  string ->
  (int64 * coordinates, [ `WithoutSuffix ],
   [ `One of int64 * coordinates ]
   param_name)
  params_type

Same as string_coordinates but for a 64 integer value

val float_coordinates : 
  string ->
  (float * coordinates, [ `WithoutSuffix ],
   [ `One of float * coordinates ]
   param_name)
  params_type

Same as string_coordinates but for a float value

val user_type_coordinates : 
  of_string:(string -> 'a) ->
  to_string:('a -> string) ->
  string ->
  ('a * coordinates, [ `WithoutSuffix ],
   [ `One of 'a * coordinates ]
   param_name)
  params_type

Same as string_coordinates but for a value of your own type. See Eliom_parameter.​user_type for a description of the of_string and to_string parameters.

Composing types of pages parameters

val ( ** ) : 
  ('a, [ `WithoutSuffix ], 'b) params_type ->
  ('c, [< `Endsuffix | `WithoutSuffix ] as 'e, 'd)
  params_type ->
  ('a * 'c, 'e, 'b * 'd) params_type

The combinator p1 ** p2 allows one to define service that take a pair of parameter. The associated service handler should expect a pair (p1, p2) as parameter.

val prod : 
  ('a, [ `WithoutSuffix ], 'b) params_type ->
  ('c, [< `Endsuffix | `WithoutSuffix ] as 'e, 'd)
  params_type ->
  ('a * 'c, 'e, 'b * 'd) params_type
val sum : 
  ('a, [ `WithoutSuffix ], 'b) params_type ->
  ('c, [ `WithoutSuffix ], 'd) params_type ->
  (('a, 'c) binsum, [ `WithoutSuffix ], 'b * 'd)
  params_type

The combinator sum p1 p2 allows one to define service that expect either the parameter p1 or the parameter p2.

val opt : 
  ('a, [ `WithoutSuffix ], 'b) params_type ->
  ('a option, [ `WithoutSuffix ], 'b) params_type

The combinator opt p allow to define an optional parameter.

val neopt : 
  ('a, [ `WithoutSuffix ], 'b) params_type ->
  ('a option, [ `WithoutSuffix ], 'b) params_type

The combinator neopt p allow to define an optional parameter assumed to be None if empty.

val radio : 
  (string ->
   ('a, [ `WithoutSuffix ], [ `One of 'b ] param_name)
   params_type) ->
  string ->
  ('a option, [ `WithoutSuffix ],
   [ `Radio of 'b ] param_name)
  params_type

Specifying parameter as radio f s tells that the service takes an optional argument labeled s and of type f s. Use radio instead of Eliom_parameter.​opt if you want to use this parameter with a radio button.

val any : 
  ((string * string) list, [ `WithoutSuffix ], unit)
  params_type

Use this if you want to take any parameters. The service will answer to all the request, and get all parameters as an association list of strings.

val set : 
  (string ->
   ('a, [ `WithoutSuffix ], [ `One of 'b ] param_name)
   params_type) ->
  string ->
  ('a list, [ `WithoutSuffix ],
   [ `Set of 'b ] param_name)
  params_type

Use this if you want your service to take several parameters with the same name. The service handler will receive a list of values. To create the form, just use the same name several times. For example set int "i" will match the parameter string i=4&i=22&i=111 and send to the service handler a list containing the three integers 4, 22 and 111. The order is unspecified.

val list : 
  string ->
  ('a, [ `WithoutSuffix ], 'b) params_type ->
  ('a list, [ `WithoutSuffix ], 'b listnames)
  params_type

The service takes a list of parameters. The first parameter of this function is the name of the list. The service handler will receive a list of values. To create the form, an iterator of type Eliom_parameter.​listnames is given to generate the name for each value.

val regexp : 
  Netstring_pcre.regexp ->
  string ->
  to_string:(string -> string) ->
  string ->
  (string, [ `WithoutSuffix ],
   [ `One of string ] param_name)
  params_type

regexp r d s tells that the service takes a string that matches the regular expression r as parameter, labeled s, and that will be rewritten in d. The syntax of regexp is PCRE's one (uses Netstring_pcre, from OCamlnet). For example: regexp (Netstring_pcre.regexp "\[(.* )\]") "($1)" "myparam" will match the parameter myparam=[hello] and send the string "(hello)" to the service handler.

val guard : 
  (string -> ('a, 'b, 'c) params_type) ->
  string -> ('a -> bool) -> ('a, 'b, 'c) params_type

guard construct name pred returns the same parameter as construct name but with ensuring that each value must satisfy pred. For instance: int "age" ((>=) 0)

val suffix : 
  ?redirect_if_not_suffix:bool ->
  ('s, [< `Endsuffix | `WithoutSuffix ], 'sn)
  params_type ->
  ('s, [ `WithSuffix ], 'sn) params_type

Tells that the parameter of the service handler is the suffix of the URL of the current service. e.g. suffix (int "i" ** string "s") will match an URL ending by 380/yo. and send (380, "yo") to the service handler.

For each service with suffix, there is also a service with regular parameters (without suffix) that will be used if you create a form towards a service with suffix. If redirect_if_not_suffix is true (default), this service without suffix will be redirected to the suffix version.

val all_suffix : 
  string ->
  (string list, [ `Endsuffix ],
   [ `One of string list ] param_name)
  params_type

Takes all the suffix, as long as possible, as a (slash separated) string list

val all_suffix_string : 
  string ->
  (string, [ `Endsuffix ],
   [ `One of string ] param_name)
  params_type

Takes all the suffix, as long as possible, as a string

val all_suffix_user : 
  of_string:(string -> 'a) ->
  to_string:('a -> string) ->
  string ->
  ('a, [ `Endsuffix ], [ `One of 'a ] param_name)
  params_type

Takes all the suffix, as long as possible, with a type specified by the user.

val all_suffix_regexp : 
  Netstring_pcre.regexp ->
  string ->
  to_string:(string -> string) ->
  string ->
  (string, [ `Endsuffix ],
   [ `One of string ] param_name)
  params_type

all_suffix_regexp r d s takes all the suffix, as long as possible, matching the regular expression r, name s, and rewrite it in d.

val suffix_prod : 
  ?redirect_if_not_suffix:bool ->
  ('s, [< `Endsuffix | `WithoutSuffix ], 'sn)
  params_type ->
  ('a, [ `WithoutSuffix ], 'an) params_type ->
  ('s * 'a, [ `WithSuffix ], 'sn * 'an) params_type

Tells that the function that will generate the service takes a pair whose first element is the suffix of the URL of the current service, and the second element corresponds to other (regular) parameters. e.g.: suffix_prod (int "suff" ** all_suffix "endsuff") (int "i") will match an URL ending by 777/go/go/go?i=320 and send the value ((777, ["go";"go";"go"]), 320) to the service handler.

val suffix_const : 
  string ->
  (unit, [ `WithoutSuffix ],
   [ `One of unit ] param_name)
  params_type

suffix_const v is used only inside suffixes (do nothing for regular parameters). It tells that the service takes a constant parameter inside the suffix, whose value must be v. It is used for putting constant directory names inside suffix parameters (and thus make suffix parameters not be only suffixes but anywhere you want in the path, e.g. /param1/const/param2).

type 'a ocaml

marshaled OCaml values of type 'a

val ocaml : 
  string ->
  'a Deriving_Json.t ->
  ('a, [ `WithoutSuffix ],
   [ `One of 'a ocaml ] param_name)
  params_type

ocaml s tells that the service is expecting some caml (client side) program to send some value of type 'a, marshaled. As usual s is the name of the parameter.

val raw_post_data : 
  (((string * string) * (string * string) list) option *
   string Ocsigen_stream.t option, [ `WithoutSuffix ],
   no_param_name)
  params_type

When the content type is neither URLencoded form data or multipart data, it is possible to get it as a stream of strings. The first element of the pair is the content-type. This kind of parameter cannot be combined with other ones, and it is not possible to create a form towards a service taking this kind of parameter.

type ('a, +'tipo, +'names) non_localized_params

Non localized parameters

val make_non_localized_parameters : 
  prefix:string ->
  name:string ->
  ?persistent:bool ->
  ('a, [ `WithoutSuffix ], 'b) params_type ->
  ('a, [ `WithoutSuffix ], 'b) non_localized_params

create a new specification for non localized parameters. You must give a name to this set of parameters. Warning: the names must be unique for the whole application. That's why the name is composed by a prefix (the name of your project) and another string (the name of your non localized parameters).

Will fail with exception Failure _ if the name contains a dot. If ?persistent is true, the non localized parameter may remain if you call another service, if this service allows this (default false).

val get_non_localized_get_parameters : 
  ('a, [ `WithoutSuffix ], 'b) non_localized_params ->
  'a option

get_non_localized_get_parameters ~sp p decodes and returns non localized GET parameters specified by p if present.

val get_non_localized_post_parameters : 
  ('a, [ `WithoutSuffix ], 'b) non_localized_params ->
  'a option

get_non_localized_post_parameters ~sp p decodes and returns non localized POST parameters specified by p if present.

type nl_params_set

Use this type to give non localized parameters to a link or a form

val empty_nl_params_set : nl_params_set
val add_nl_parameter : 
  nl_params_set ->
  ('a, [< `WithSuffix | `WithoutSuffix ], 'b)
  non_localized_params ->
  'a -> nl_params_set
val get_nl_params_names : 
  ('b, [< `WithSuffix | `WithoutSuffix ], 'a)
  non_localized_params -> 'a
val get_to_and_from : 
  ('a, 'b, 'c) params_type ->
  (string -> 'a) * ('a -> string)

Given a parameter type, get the two functions that converts from and to strings. You should only use this function on

  • options ;
  • basic types : int, int32, int64, float, string
  • marshal
  • unit
  • string
  • bool