https://github.com/zotonic/cowmachine

Webmachine for Zotonic and Cowboy
https://github.com/zotonic/cowmachine

cowboy erlang erlang-library http-server webmachine zotonic

Last synced: 4 days ago
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Webmachine for Zotonic and Cowboy

• Host: GitHub
• URL: https://github.com/zotonic/cowmachine
• Owner: zotonic
• License: apache-2.0
• Created: 2016-07-18T14:50:00.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2024-11-14T07:41:16.000Z (about 2 months ago)
• Last Synced: 2024-12-19T04:07:06.504Z (12 days ago)
• Topics: cowboy, erlang, erlang-library, http-server, webmachine, zotonic
• Language: Erlang
• Size: 4.33 MB
• Stars: 13
• Watchers: 12
• Forks: 5
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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[![Hex.pm version][hexpm version]][hexpm]

[![Hex.pm Downloads][hexpm downloads]][hexpm]

[![Hex.pm Documentation][hexdocs documentation]][hexdocs]

[![Erlang Versions][erlang version badge]][gh]

[![License][license]](https://www.apache.org/licenses/LICENSE-2.0)

# Cowmachine

Webmachine for Zotonic and Cowboy

This is an adaptation of https://github.com/webmachine/webmachine for the Cowboy web server.

Cowmachine is a request handler for Cowboy.

Main differences with Basho’s Webmachine are:

 * Use cowboy instead of mochiweb for the http server

 * Separate dispatching

 * Simplified callbacks

 * Single `process/4` callback for all http methods

 * Caching of some callbacks (like `modified`)

 * More streaming options for returned data

 * Better support for range requests

## Installation

Cowmachine is at Hex, in your `rebar.config` file use:

```erlang

{deps, [

    cowmachine

]}.

```

You can also use the direct Git url and use the development version:

```erlang

{deps, [

    {cowmachine, {git, "https://github.com/zotonic/cowmachine.git", {branch, "master"}}}

]}.

```

## Calling Cowmachine

Cowmachine can be called from your Cowboy middleware:

```erlang

-spec execute(Req, Env) -> {ok, Req, Env} | {stop, Req}

    when Req::cowboy_req:req(), Env::cowboy_middleware:env().

execute(Req, Env) ->

    % Replace below with your own controller module and optionally wrap

    % the request in your own request-context record or map.

    EnvController = Env#{

        cowmachine_controller => mycontroller

    },

    RequestContext = cowmachine_req:init_context(Req, EnvController, #{}),

    % Set options for the cowmachine

    Options = #{

        on_request =>

            fun(Ctx) ->

                % Perform anything after initialization of your request

                % Examples are checking special cookies, changing headers, etc.

                Ctx

            end,

        on_welformed =>

            fun(Ctx) ->

                % Perform anything after well-formedness check of your request

                % Examples are parsing the query args, or authentication

                Ctx

            end,

        on_handled =>

            fun(Ctx) ->

                % Perform anything after processing, before sending the result.

                Ctx

            end

    },

    % Handle the request, returns updated Req and Env for next Cowboy middleware

    cowmachine:request(RequestContext, Options).

```

Or just use the default Cowmachine middleware:

```erlang

    #{

        middlewares => [

            % ... add your dispatcher middlware

            cowmachine

        ],

        request_timeout => 60000,

        env => #{

            % If no dispatcher, default to `mycontroller` as the cowmachine

            % controller.

            cowmachine_controller => mycontroller

        }

    }.

```

## Dispatching

You can use the [Zotonic Dispatch Compiler](https://github.com/zotonic/dispatch_compiler) to match your controller paths against the request.

## Controller

The controller provides the callbacks to handle the request.

The controller is an Erlang module implementing callback functions, only functions that return some non-default value need to be implemented.

For the controller callbacks and more documentation, check the [wiki pages](https://github.com/zotonic/cowmachine/wiki).

## Documentation generation

### Edoc

#### Generate public API

`rebar3 edoc`

#### Generate private API

`rebar3 as edoc_private edoc`

### ExDoc

`rebar3 ex_doc --logo doc/img/logo.png --output edoc -f html`

[hexpm]: https://hex.pm/packages/cowmachine

[hexpm version]: https://img.shields.io/hexpm/v/cowmachine.svg?style=flat-curcle "Hex version"

[hexpm downloads]: https://img.shields.io/hexpm/dt/cowmachine.svg?style=flat-curcle

[hexdocs documentation]: https://img.shields.io/badge/hex-docs-purple.svg?style=flat-curcle

[hexdocs]: https://hexdocs.pm/cowmachine

[gh]: https://github.com/zotonic/cowmachine/actions/workflows/test.yaml

[gh badge]: https://img.shields.io/github/workflow/status/zotonic/cowmachine/Test?style=flat-curcle

[erlang version badge]: https://img.shields.io/badge/Supported%20Erlang%2FOTP-22.0%20to%2024.0-blue.svg?style=flat-curcle

[license]: https://img.shields.io/badge/License-Apache_2.0-blue.svg?logo=apache&logoColor=red "Apache 2.0"