Introduction to ChicagoBoss:
(ChicagoBoss)http://www.chicagoboss.org] was made by (Evan Miller)[],
it provide to erlang folk a MVC pattern web framework like Ruby On Rail,
to develop scalable web app using Erlang/OTP.
Erlang like Java is a compiled language, an erlang source file is compiled to a beam file.
an run inside the Erlang Virtual Machine like Java compile to bytecode and run inside the JVM
(java virtual machine).
in this serie of article i will talk about ChicagoBoss,
i assume you know erlang or have some knowledge about fonctional programming,
if not i suggest you to visit learnyousomeerlang.org.
Step By Step:
Install erlang:
on linux Ubuntu 14.04, i usualy remove pre installed erlang runtime and use kerl to install erlang from source.
> cd ~
> mkdir bin
> cd bin
> sudo apt-get remove erlang
> sudo apt-get build-dep erlang
> curl -O[https://raw.githubusercontent.com/spawngrid/kerl/master/kerl](https://raw.githubusercontent.com/spawngrid/kerl/master/kerl)
> chmod u+x kerl
> echo "" >> ~/.kerlrc
> ./kerl update releases
> ./kerl build 17.5 17.5
> ./kerl install 17.5 ~/bin/lang/erlang/17.5
> echo "source ~/bin/lang/erlang/17.5/activate" >> ~/.profile
> echo "export PATH=$PATH:$HOME/bin:." >> ~/.profile
after this step, you have a working erlang runtime compiled from source.
just type erl in your shell and you will get the erlang REPL.
Install ChicagoBoss:
>sudo apt-get install git
>mkdir workspace
>cd workspace
>git clone [http://github.com/ChicagoBoss/ChicagoBoss.git](http://github.com/ChicagoBoss/ChicagoBoss.git) -b v0.8.13
Create my first CB project and start developping.
>cd
>cd workspace/ChicagoBoss
>make app PROJECT=first
>cd ../first
>./init-dev.sh
anatomy of an CB app source tree.
first/
├── boss.config
├── init-dev.sh
├── init.sh
├── deps
│ ├── boss
│ ├── boss_db
│ └── ...
├── log
│ ├── console.log
│ ├── crash.log
│ └── error.log
├── Makefile
├── priv
│ ├── first.routes
│ ├── init
│ ├── rebar
│ └── static
├── README.md
├── rebar
├── rebar.cmd
├── rebar.config
├── src
│ ├── controller
│ ├── first.app.src
│ ├── mail
│ ├── view
│ └── websocket
└── start-server.bat
- boss.config is the config file of your application.
- init-dev.sh start your app in developping, auto reload and recompilation.
- init.sh start your app
- deps, here goes all your dependancy application
- log, log file of your application
- priv/first.routes , custom routing file
- priv/init , here goes your init script
- priv/static, here goes your static files
- src/controller, yours app controllers source.
- src/mail, incoming/outgoing mail controller
- src/view//.html
- src/websocket, websocket controller.
Which IDE?
personnaly is use Emacs, some people use Sublime Text, some Erlide, some VIM.
it is up to you, any text editor is fine.
My first controller/view.
convention, a controller is named like this:
/src/__controller.erl
for example i want to create a controller with the name index,
with an action call index,
when the browser go to http://localhost:8001/index/index my app should show
Hello world text.
edit first/src/controller/first_index_controller.erl like
-module(first_index_controller, [Req, SessionId]).
-export([index/3]).
index('GET', [], _ReqCtx) ->
{ok, [{msg, "Hello World!!!"}]}.
the corresponding view:
/src/view//.
for the action index in controller index.
first/src/view/index/index.html
{{ msg }}
curl -X GET[http://localhost:8001/index/index](http://localhost:8001/index/index)
action:
an action in CB is a function with 2 or 3 parameters.
- the first parameter is the method matching the requested method, it is an atom:
'GET', 'POST', 'PUT', 'DELETE', 'HEAD' ... - the second parameter is uri token.
- the third parameter is optional: Request Context, CB will provide to your action
the request context, it is a proplist of usefull value. this list of usefull value can be modified
by the _before fonction or by some boss_filter fonction.
-module(first_index_controller, [Req, SessionId]).
-export([index/3]).
index('GET', [], ReqCtx) ->
lager:info("Request Context: ~p",[ReqCtx]),
{ok, [{msg, "Hello World!!!"}]}.
default action.
what is default action?,
no action cannot be guessed from the requested url,
if you want to provide such feature, you can use the attributes *-default_action().
in your controller module.
if no default action is provided, CB will redirect throw an 404 not found.
curl -X GET[http://localhost:8001/index](http://localhost:8001/index)
then http://loaclhost:8001/index will execute the default action index.
-module(first_index_controller, [Req, SessionId]).
-export([index/3]).
-default_action(index).
index('GET', [], _ReqCtx) ->
{ok, [{msg, "Hello World!!!"}]}.
then http://localhost:8001/index will execute the default action index.
curl -X GET[http://localhost:8001/index](http://localhost:8001/index)