Class: Flickr

Inherits:
Object show all
Defined in:
lib/acts_as_unvlogable/flickr.rb

Overview

Flickr client class. Requires an API key

Defined Under Namespace

Classes: Photo, PhotoCollection, User

Constant Summary collapse

HOST_URL = 
'https://flickr.com'
API_PATH = 
'/services/rest'
VALID_SIZES =

Flickr, annoyingly, uses a number of representations to specify the size of a photo, depending on the context. It gives a label such a “Small” or “Medium” to a size of photo, when returning all possible sizes. However, when generating the uri for the page that features that size of photo, or the source url for the image itself it uses a single letter. Bizarrely, these letters are different depending on whether you want the Flickr page for the photo or the source uri – e.g. a “Small” photo (240 pixels on its longest side) may be viewed at “www.flickr.com/photos/sco/2397458775/sizes/s/” but its source is at “”. The VALID_SIZES hash associates the correct letter with a label

{ "Square" => ["s", "sq"],
  "Thumbnail" => ["t", "t"],
  "Small" => ["m", "s"],
  "Medium" => [nil, "m"],
  "Large" => ["b", "l"]
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(api_key_or_params = nil, email = nil, password = nil, shared_secret = nil) ⇒ Flickr

To use the Flickr API you need an api key (see www.flickr.com/services/api/misc.api_keys.html), and the flickr client object shuld be initialized with this. You’ll also need a shared secret code if you want to use authentication (e.g. to get a user’s private photos) There are two ways to initialize the Flickr client. The preferred way is with a hash of params, e.g. ‘api_key’ => ‘your_api_key’, ‘shared_secret’ => ‘shared_secret_code’. The older (deprecated) way is to pass an ordered series of arguments. This is provided for continuity only, as several of the arguments are no longer usable (‘email’, ‘password’)



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# File 'lib/acts_as_unvlogable/flickr.rb', line 47

def initialize(api_key_or_params=nil, email=nil, password=nil, shared_secret=nil)
  @host = HOST_URL
  @api = API_PATH
  if api_key_or_params.is_a?(Hash)
    @api_key = api_key_or_params['api_key']
    @shared_secret = api_key_or_params['shared_secret']
    @auth_token = api_key_or_params['auth_token']
  else
    @api_key = api_key_or_params
    @shared_secret = shared_secret
    (email, password) if email and password
  end
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method_id, params = {}) ⇒ Object

Implements everything else. Any method not defined explicitly will be passed on to the Flickr API, and return an XmlSimple document. For example, Flickr#test_echo is not defined, so it will pass the call to the flickr.test.echo method.



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# File 'lib/acts_as_unvlogable/flickr.rb', line 66

def method_missing(method_id, params={})
  request(method_id.id2name.gsub(/_/, '.'), params)
end

Instance Attribute Details

#api_key ⇒ Object (readonly)

Returns the value of attribute api_key.



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# File 'lib/acts_as_unvlogable/flickr.rb', line 12

def api_key
  @api_key
end

#auth_token ⇒ Object (readonly)

Returns the value of attribute auth_token.



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# File 'lib/acts_as_unvlogable/flickr.rb', line 12

def auth_token
  @auth_token
end

#user ⇒ Object

Returns the value of attribute user.



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# File 'lib/acts_as_unvlogable/flickr.rb', line 13

def user
  @user
end

Instance Method Details

#request(method, params = {}) ⇒ Object

Takes a Flickr API method name and set of parameters; returns an XmlSimple object with the response



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# File 'lib/acts_as_unvlogable/flickr.rb', line 71

def request(method, params={})
  url = request_url(method, params)
  response = XmlSimple.xml_in(open(url), { 'ForceArray' => false })
  raise response['err']['msg'] if response['stat'] != 'ok'
  response
end

#request_url(method, params = {}) ⇒ Object

Builds url for Flickr API REST request from given the flickr method name (exclusing the ‘flickr.’ that begins each method call) and params (where applicable) which should be supplied as a Hash (e.g ‘user_id’ => “foo123”)



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# File 'lib/acts_as_unvlogable/flickr.rb', line 81

def request_url(method, params={})
  method = 'flickr.' + method
  url = "#{@host}#{@api}/?api_key=#{@api_key}&method=#{method}"
  params.merge!('api_key' => @api_key, 'method' => method, 'auth_token' => @auth_token)
  signature = signature_from(params) 
  
  url = "#{@host}#{@api}/?" + params.merge('api_sig' => signature).collect { |k,v| "#{k}=" + CGI::escape(v.to_s) unless v.nil? }.compact.join("&")
end

#signature_from(params = {}) ⇒ Object 



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# File 'lib/acts_as_unvlogable/flickr.rb', line 90

def signature_from(params={})
  return unless @shared_secret # don't both getting signature if no shared_secret
  request_str = params.reject {|k,v| v.nil?}.collect {|p| "#{p[0].to_s}#{p[1]}"}.sort.join # build key value pairs, sort in alpha order then join them, ignoring those with nil value
  return Digest::MD5.hexdigest("#{@shared_secret}#{request_str}")
end