Class: Watts::Resource

Inherits:

Object

• Object
• Watts::Resource

Defined in:

lib/watts.rb

Overview

HTTP is all about resources, and this class represents them. You’ll want to subclass it and then define some HTTP methods on it, then use your application’s resource method to tell it where to find these resources. (See Watts::App.resource().) If you want your resource to respond to GET with a cheery, text/plain greeting, for example: class Foo < Watts::Resource get { || “Hello, world!” } end

Or you could do something odd like this: class RTime < Watts::Resource class << self; attr_accessor :last_post_time; end

get { || “The last POST was #last_post_time.” } post { || self.class.last_post_time = Time.now.strftime(‘%F %R’) [204, {}, []] }

def last_post_time self.class.last_post_time || “…never” end end

It is also possible to define methods in the usual way (e.g., ‘def get …’), although you’ll need to add them to the list of allowed methods (for OPTIONS) manually. Have a look at the README and doc/examples.

Direct Known Subclasses

HTMLViewResource

Constant Summary

HTTPMethods =

Set.new(%i(get post put delete head options trace connect))

Instance Attribute Summary

• #app ⇒ Object

  Returns the value of attribute app.

• #env ⇒ Object

  Returns the value of attribute env.

Class Method Summary

• .auto_head ⇒ Object

  This method generates a HEAD that just calls #get and only passes back the headers.

• .for_html_view(klass, method) ⇒ Object

  This method is for creating Resources that simply wrap first-class HTML views.

Instance Method Summary

• #default_http_method(*args) ⇒ Object

  By default, we return “405 Method Not Allowed” and set the Allow: header appropriately.

• #head(*args) ⇒ Object

  HEAD responds the same way as the default_method, but does not return a body.

• #initialize(env) ⇒ Resource constructor

  Every resource, on being instantiated, is given the Rack env.

• #options(*args) ⇒ Object

  The default options method, to comply with RFC 2616, returns a list of allowed methods in the Allow header.

• #request ⇒ Object

Constructor Details

#initialize(env) ⇒ Resource

Every resource, on being instantiated, is given the Rack env.

# File 'lib/watts.rb', line 288

def initialize(env)
	if app = env.delete(:watts_app)
		self.app = app
	end
	self.env = env
end

Instance Attribute Details

#app ⇒ Object

Returns the value of attribute app.

# File 'lib/watts.rb', line 285

def app
  @app
end

#env ⇒ Object

Returns the value of attribute env.

# File 'lib/watts.rb', line 285

def env
  @env
end

Class Method Details

.auto_head ⇒ Object

This method generates a HEAD that just calls #get and only passes back the headers. It’s sub-optimal when GET is expensive, so it is disabled by default.

# File 'lib/watts.rb', line 276

def self.auto_head
	head { |*a|
		status, headers, = get(*a)
		[status, headers, []]
	}
end

.for_html_view(klass, method) ⇒ Object

This method is for creating Resources that simply wrap first-class HTML views. It was created with Hoshi in mind, although you can use any class that can be instantiated and render some HTML when the specified method is called. It takes two arguments: the view class, and the method to call to render the HTML.

# File 'lib/watts.rb', line 266

def self.for_html_view klass, method
	c = Class.new HTMLViewResource
	c.view_class = klass
	c.view_method = method
	c
end

Instance Method Details

#default_http_method(*args) ⇒ Object

By default, we return “405 Method Not Allowed” and set the Allow: header appropriately.

# File 'lib/watts.rb', line 316

def default_http_method(*args)
	s = 'Method not allowed.'
	[405,
		{ 'Allow' => http_methods.join(', '),
		  'Content-Type' => 'text/plain',
		  'Content-Length' => s.bytesize.to_s,
		},
		['Method not allowed.']]
end

#head(*args) ⇒ Object

HEAD responds the same way as the default_method, but does not return a body.

# File 'lib/watts.rb', line 328

def head(*args)
	r = default_http_method
	r[2] = []
	r
end

#options(*args) ⇒ Object

The default options method, to comply with RFC 2616, returns a list of allowed methods in the Allow header. These are filled in when the method-defining methods (i.e., get() et al) are called.

# File 'lib/watts.rb', line 298

def options(*args)
	[
		200,
		{
			'Content-Length' => '0', # cf. RFC 2616
			'Content-Type' => 'text/plain', # Appease Rack::Lint
			'Allow' => http_methods.join(', ')
		},
		[]
	]
end

#request ⇒ Object

# File 'lib/watts.rb', line 310

def request
	@request ||= Rack::Request.new(env)
end