Library
Module
Module type
Parameter
Class
Class type
Create a Cohttp session manager given an appropriate backend.
module IO : Session.S.IO
type +'a io = 'a B.io
The type of a blocking computation that will produce a value of type 'a
type backend = B.t
The type of a handle on the store.
type key = B.key
The type of a session key.
type value = B.value
The type of a session value.
type period = B.period
The type of a session expiry period.
type t = private {
key : key;
They key for the session in the backend and in cookies.
*)mutable value : value;
The value for the session stored in the backend.
*)mutable expiry_period : period;
The period from now in seconds that the session will expire.
*)mutable modified : bool;
Whether the session data or expiry have been modified
*)}
The session type.
This type is marked private, so the record fields can be accessed and pattern-matched as usual. However, values of this type cannot be constructed directly. To create a new session, use generate
. To retrieve an existing session
, use of_key
or of_header
. To modify t.expiry_period
or t.value
, use set
. Finally, use to_cookie_hdrs
to smartly generate Set-Cookie
and related headers.
of_key backend key
fetches the session associated with key
from the backend, if present and unexpired.
val of_header :
backend ->
string ->
Cohttp.Header.t ->
(t option, Session.S.error) result io
of_header backend cookie_key header
retrieves the session key from the cookies in header
. If cookie_key
is not present in any cookies in header
, then this function will return None
. If a session key is found, it will call {!val:of_key} backend key
. If both lookups were successful, then this function will return Some session
. If no key was found in header
, it will return None
.
of_header_or_create ?expiry backend cookie_key default header
retrieves the session key from the cookies in header
. If cookie_key
is not present in any cookies in the header
or if the session is not a valid one, a new session will be using expiry
for the expiration period and default
as the value.
val to_cookie_hdrs :
?discard:bool ->
?path:string ->
?domain:string ->
?secure:bool ->
?http_only:bool ->
string ->
t ->
(string * string) list
to_cookie_hdrs cookie_key session
will generate response headers to communicate session changes to the client. This function takes into account the t.modified
field of the session type, and will not generate headers if they are not needed.
clear_hdrs cookie_key
will generate response headers to communicate that the client should evict the session with key cookie_key
.
generate ?expiry backend value
will allocate a new session in the backend backend
. The session will expire expiry
seconds from now, defaulting to default_period backend
if one is not explicitly specified.
clear backend session
removes session
from backend
. The backend may choose to persist the session value beyond this call, but any subsequent operations involving key
should behave as if key
is not present in the backend.
The value
and t.expiry_period
of session
will be zero'd out, and the t.modified
flag will be set. Calling to_cookie_hdrs
on a cleared session will generate the appropriate headers directing the client to clear the associated cookie.
set ?expiry ?value backend session
sets the value
for the session associated key
in backend
and sets the session to expire expiry
seconds from now. If expiry
is not provided, the expiry period reported by default_period backend
will be used instead. If no value is provided, then only the expiry will be updated.