6.1 KiB
+++ title = "Host a Website" weight = 85 +++
%feature by ~hanfel-dovned hosts a simple HTML page from an Urbit ship at an associated URL. This tutorial examines how it uses the middleware %schooner library by Quartus to return a web page when contacted by a web browser. You will learn how a basic site hosting app can handle HTTP requests and render a page using an %html mark.
%feature presents a web page from /app/feature-ui at /apps/feature/feature-ui. These paths are both configurable by the developer.
/sur Structure Files
Our primary event in this case is simply an %action to create a page.
/sur/feature.hoon:
|%
+$ action
$% [%new-page html=@t]
==
--
No special mark files are necessary for %feature other than %html.
/app Agent Files
The agent only maintains a state containing the page contents as a cord.
The system only handles pokes: there are no subscriptions or Arvo calls except for the Eyre binding.
/app/feature.hoon:
/- feature
/+ dbug, default-agent, server, schooner
/* feature-ui %html /app/feature-ui/html
|%
+$ versioned-state
$% state-0
==
+$ state-0 [%0 page=@t]
+$ card card:agent:gall
--
%- agent:dbug
^- agent:gall
=| state-0
=* state -
|_ =bowl:gall
+* this .
def ~(. (default-agent this %.n) bowl)
++ on-init
^- (quip card _this)
:_ this(page 'Hello World')
:~
:* %pass /eyre/connect %arvo %e
%connect `/apps/feature %feature
==
==
::
++ on-save
^- vase
!>(state)
::
++ on-load
|= old-state=vase
^- (quip card _this)
=/ old !<(versioned-state old-state)
?- -.old
%0 `this(state old)
==
::
++ on-poke
|= [=mark =vase]
^- (quip card _this)
|^
?+ mark (on-poke:def mark vase)
%handle-http-request
?> =(src.bowl our.bowl)
=^ cards state
(handle-http !<([@ta =inbound-request:eyre] vase))
[cards this]
==
++ handle-http
|= [eyre-id=@ta =inbound-request:eyre]
^- (quip card _state)
=/ ,request-line:server
(parse-request-line:server url.request.inbound-request)
=+ send=(cury response:schooner eyre-id)
::
?+ method.request.inbound-request
[(send [405 ~ [%stock ~]]) state]
::
%'POST'
?. authenticated.inbound-request
:_ state
%- send
[302 ~ [%login-redirect './apps/feature']]
?~ body.request.inbound-request
[(send [405 ~ [%stock ~]]) state]
=/ json (de:json:html q.u.body.request.inbound-request)
=/ action (dejs-action +.json)
(handle-action action)
::
%'GET'
?+ site
:_ state
(send [404 ~ [%plain "404 - Not Found"]])
::
[%apps %feature %public ~]
:_ state
%- send
:+ 200 ~
:- %html page
::
[%apps %feature ~]
?. authenticated.inbound-request
:_ state
%- send
[302 ~ [%login-redirect './apps/feature']]
:_ state
%- send
:+ 200 ~
:- %html feature-ui
==
==
::
++ dejs-action
=, dejs:format
|= jon=json
^- action:feature
%. jon
%- of
:~ new-page+so
==
::
++ handle-action
|= =action:feature
^- (quip card _state)
?- -.action
%new-page
?> =(src.bowl our.bowl)
`state(page html:action)
==
--
++ on-peek on-peek:def
++ on-watch
|= =path
^- (quip card _this)
?+ path (on-watch:def path)
[%http-response *]
`this
==
::
++ on-leave on-leave:def
++ on-agent on-agent:def
++ on-arvo on-arvo:def
++ on-fail on-fail:def
--
Pokes
++on-poke only responds to %handle-http-request, which is dealt with in a |^ barket core.
The most interesting part of the whole app is the ++handle-http arm:
++ handle-http
|= [eyre-id=@ta =inbound-request:eyre]
^- (quip card _state)
=/ ,request-line:server
(parse-request-line:server url.request.inbound-request)
=+ send=(cury response:schooner eyre-id)
::
?+ method.request.inbound-request
[(send [405 ~ [%stock ~]]) state]
::
%'POST'
?. authenticated.inbound-request
:_ state
%- send
[302 ~ [%login-redirect './apps/feature']]
?~ body.request.inbound-request
[(send [405 ~ [%stock ~]]) state]
=/ json (de:json:html q.u.body.request.inbound-request)
=/ action (dejs-action +.json)
(handle-action action)
::
%'GET'
?+ site
:_ state
(send [404 ~ [%plain "404 - Not Found"]])
::
[%apps %feature %public ~]
:_ state
%- send
:+ 200 ~
:- %html page
::
[%apps %feature ~]
?. authenticated.inbound-request
:_ state
%- send
[302 ~ [%login-redirect './apps/feature']]
:_ state
%- send
:+ 200 ~
:- %html feature-ui
::
:: [%apps %feature %state ~]
:: :_ state
:: %- send
:: :+ 200 ~
:: [%json (enjs-state +.state)]
==
==
This arm uses the server library and schooner to produce a response of a server state and associated data. HTTP requests to /apps/feature are checked for login authentication, while /apps/feature/public are not.
POST
In response to a POST request, the default page in the state can be changed. This is the only state change supported by the agent.
GET
A GET request defaults to a 404 error.
/apps/feature/publicreturns200success and the default page in the state./apps/featurereturns200success and the target page, statically compiled on agent build.
/lib/schooner
The Schooner library simplifies raw HTTP handling for Gall agents, in particular for MIME returns.