[ANN] Jellyfish 0.5.0 released

# [Jellyfish](https://github.com/godfat/jellyfish)

by Lin Jen-Shin ([godfat](http://godfat.org))

## DESCRIPTION:

Pico web framework for building API-centric web applications, either
Rack applications or Rack middlewares. Under 200 lines of code.

## DESIGN:

* Learn the HTTP way instead of using some pointless helpers
* Learn the Rack way instead of wrapping Rack functionalities, again
* Learn regular expression for routes instead of custom syntax
* Embrace simplicity over convenience
* Don't make things complicated only for _some_ convenience, but
  _great_ convenience, or simply stay simple for simplicity.

## FEATURES:

* Minimal
* Simple
* No templates
* No ORM
* No `dup` in `call`
* Regular expression routes, e.g. `get %r{^/(?<id>\d+)$}`
* String routes, e.g. `get '/'`
* Custom routes, e.g. `get Matcher.new`
* Build for either Rack applications or Rack middlewares

## WHY?

Because Sinatra is too complex and inconsistent for me.

## REQUIREMENTS:

* Tested with MRI (official CRuby) 1.9.3, Rubinius and JRuby.

## INSTALLATION:

    gem install jellyfish

## SYNOPSIS:

### Hello Jellyfish, your lovely config.ru

``` ruby
require 'jellyfish'
class Tank
  include Jellyfish
  get '/' do
    "Jelly Kelly\n"
  end
end
use Rack::ContentLength
use Rack::ContentType, 'text/plain'
run Tank.new
```

### Regular expression routes

``` ruby
require 'jellyfish'
class Tank
  include Jellyfish
  get %r{^/(?<id>\d+)$} do |match|
    "Jelly ##{match[:id]}\n"
  end
end
use Rack::ContentLength
use Rack::ContentType, 'text/plain'
run Tank.new
```

### Custom matcher routes

``` ruby
require 'jellyfish'
class Tank
  include Jellyfish
  class Matcher
    def match path
      path.reverse == 'match/'
    end
  end
  get Matcher.new do |match|
    "#{match}\n"
  end
end
use Rack::ContentLength
use Rack::ContentType, 'text/plain'
run Tank.new
```

### Different HTTP status and custom headers

``` ruby
require 'jellyfish'
class Tank
  include Jellyfish
  post '/' do
    headers       'X-Jellyfish-Life' => '100'
    headers_merge 'X-Jellyfish-Mana' => '200'
    body "Jellyfish 100/200\n"
    status 201
    'return is ignored if body has already been set'
  end
end
use Rack::ContentLength
use Rack::ContentType, 'text/plain'
run Tank.new
```

### Redirect helper

``` ruby
require 'jellyfish'
class Tank
  include Jellyfish
  get '/lookup' do
    found "#{env['rack.url_scheme']}://#{env['HTTP_HOST']}/"
  end
end
use Rack::ContentLength
use Rack::ContentType, 'text/plain'
run Tank.new
```

### Crash-proof

``` ruby
require 'jellyfish'
class Tank
  include Jellyfish
  get '/crash' do
    raise 'crash'
  end
end
use Rack::ContentLength
use Rack::ContentType, 'text/plain'
run Tank.new
```

### Custom error handler

``` ruby
require 'jellyfish'
class Tank
  include Jellyfish
  handle NameError do |e|
    status 403
    "No one hears you: #{e.backtrace.first}\n"
  end
  get '/yell' do
    yell
  end
end
use Rack::ContentLength
use Rack::ContentType, 'text/plain'
run Tank.new
```

### Custom controller

``` ruby
require 'jellyfish'
class Heater
  include Jellyfish
  get '/status' do
    temperature
  end

  def controller; Controller; end
  class Controller < Jellyfish::Controller
    def temperature
      "30\u{2103}\n"
    end
  end
end
use Rack::ContentLength
use Rack::ContentType, 'text/plain'
run Heater.new
```

### Sinatra flavor controller

Currently support:

* Indifferent params

``` ruby
require 'jellyfish'
class Tank
  include Jellyfish
  def controller; Jellyfish::Sinatra; end
  get %r{^/(?<id>\d+)$} do
    "Jelly ##{params[:id]}\n"
  end
end
use Rack::ContentLength
use Rack::ContentType, 'text/plain'
run Tank.new
```

### Jellyfish as a middleware

``` ruby
require 'jellyfish'
class Heater
  include Jellyfish
  get '/status' do
    "30\u{2103}\n"
  end
end

class Tank
  include Jellyfish
  get '/' do
    "Jelly Kelly\n"
  end
end

use Rack::ContentLength
use Rack::ContentType, 'text/plain'
use Heater
run Tank.new
```

### One huge tank

``` ruby
require 'jellyfish'
class Heater
  include Jellyfish
  get '/status' do
    "30\u{2103}\n"
  end
end

class Tank
  include Jellyfish
  get '/' do
    "Jelly Kelly\n"
  end
end

HugeTank = Rack::Builder.new do
  use Rack::ContentLength
  use Rack::ContentType, 'text/plain'
  use Heater
  run Tank.new
end

run HugeTank
```

### Raise exceptions

``` ruby
require 'jellyfish'
class Protector
  include Jellyfish
  handle Exception do |e|
    "Protected: #{e}\n"
  end
end

class Tank
  include Jellyfish
  handle_exceptions false # default is true, setting false here would
make
                          # the outside Protector handle the exception
  get '/' do
    raise "Oops, tank broken"
  end
end

use Rack::ContentLength
use Rack::ContentType, 'text/plain'
use Protector
run Tank.new
```

### Chunked transfer encoding (streaming)

You would need a proper server setup.
Here's an example with Rainbows and fibers:

``` ruby
class Tank
  include Jellyfish
  class Body
    def each
      (0..4).each{ |i| yield "#{i}\n"; Rainbows.sleep(0.1) }
    end
  end
  get '/chunked' do
    Body.new
  end
end
use Rack::Chunked
use Rack::ContentType, 'text/plain'
run Tank.new
```

## CONTRIBUTORS:

* Lin Jen-Shin (@godfat)

## LICENSE:

Apache License 2.0

Copyright (c) 2012, Lin Jen-Shin (godfat)

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

<http://www.apache.org/licenses/LICENSE-2.0>

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied.
See the License for the specific language governing permissions and
limitations under the License.

## CHANGES:

### Jellyfish 0.5.0 -- 2012-10-18

### Incompatible changes

* Some internal constants are removed.
* Renamed `Respond` to `Response`.

### Enhancements

* Now Jellyfish would always use the custom error handler to handle
the
  particular exception even if `handle_exceptions` set to false. That
is,
  now setting `handle_exceptions` to false would only disable default
  error handling. This behavior makes more sense since if you want the
  exception bubble out then you shouldn't define the custom error
handler
  in the first place. If you define it, you must mean you want to use
it.

* Eliminated some uninitialized instance variable warnings.

* Now you can access the original app via `jellyfish` in the
controller.

* `Jellyfish::Controller` no longer includes `Jellyfish`, which would
remove
  those `DSL` methods accidentally included in previous version
(0.4.0-).