List all active subscriptions for this application.
@param options (see Koala::HTTPService.make_request)
@return [Array] a list of active subscriptions
# File lib/koala/realtime_updates.rb, line 82 def list_subscriptions(options = {}) @api.graph_call(subscription_path, {}, "get", options) end
Subscribe to realtime updates for certain fields on a given object (user, page, etc.). See {developers.facebook.com/docs/reference/api/realtime the realtime updates documentation} for more information on what objects and fields you can register for.
@note Your callback_url must be set up to handle the verification request or the subscription will not be set up.
@param object a Facebook ID (name or number) @param fields the fields you want your app to be updated about @param callback_url the URL Facebook should ping when an update is available @param verify_token a token included in the verification request, allowing you to ensure the call is genuine
(see the docs for more information)
@param options (see Koala::HTTPService.make_request)
@raise A subclass of Koala::Facebook::APIError if the subscription request failed.
# File lib/koala/realtime_updates.rb, line 56 def subscribe(object, fields, callback_url, verify_token, options = {}) args = { :object => object, :fields => fields, :callback_url => callback_url, }.merge(verify_token ? {:verify_token => verify_token} : {}) # a subscription is a success if Facebook returns a 200 (after hitting your server for verification) @api.graph_call(subscription_path, args, 'post', options) end
The Facebook subscription management URL for your application.
# File lib/koala/realtime_updates.rb, line 141 def subscription_path @subscription_path ||= "#{@app_id}/subscriptions" end
Unsubscribe from updates for a particular object or from updates.
@param object the object whose subscriptions to delete.
If no object is provided, all subscriptions will be removed.
@param options (see Koala::HTTPService.make_request)
@raise A subclass of Koala::Facebook::APIError if the subscription request failed.
# File lib/koala/realtime_updates.rb, line 73 def unsubscribe(object = nil, options = {}) @api.graph_call(subscription_path, object ? {:object => object} : {}, "delete", options) end
Public: As a security measure, all updates from facebook are signed using X-Hub-Signature: sha1=XXXX where XXX is the sha1 of the json payload using your application secret as the key.
Example:
# in Rails controller # @oauth being a previously defined Koala::Facebook::OAuth instance def receive_update if @oauth.validate_update(request.body, headers) ... end end
# File lib/koala/realtime_updates.rb, line 127 def validate_update(body, headers) unless @secret raise AppSecretNotDefinedError, "You must init RealtimeUpdates with your app secret in order to validate updates" end if request_signature = headers['X-Hub-Signature'] || headers['HTTP_X_HUB_SIGNATURE'] and signature_parts = request_signature.split("sha1=") request_signature = signature_parts[1] calculated_signature = OpenSSL::HMAC.hexdigest('sha1', @secret, body) calculated_signature == request_signature end end
As a security measure (to prevent DDoS attacks), Facebook sends a verification request to your server after you request a subscription. This method parses the challenge params and makes sure the call is legitimate.
@param params the request parameters sent by Facebook. (You can pass in a Rails params hash.) @param verify_token the verify token sent in the {subscribe subscription request}, if you provided one
@yield verify_token if you need to compute the verification token
(for instance, if your callback URL includes a record ID, which you look up and use to calculate a hash), you can pass meet_challenge a block, which will receive the verify_token received back from Facebook.
@return the challenge string to be sent back to Facebook, or false if the request is invalid.
# File lib/koala/realtime_updates.rb, line 99 def self.meet_challenge(params, verify_token = nil, &verification_block) if params["hub.mode"] == "subscribe" && # you can make sure this is legitimate through two ways # if your store the token across the calls, you can pass in the token value # and we'll make sure it matches ((verify_token && params["hub.verify_token"] == verify_token) || # alternately, if you sent a specially-constructed value (such as a hash of various secret values) # you can pass in a block, which we'll call with the verify_token sent by Facebook # if it's legit, return anything that evaluates to true; otherwise, return nil or false (verification_block && yield(params["hub.verify_token"]))) params["hub.challenge"] else false end end
Create a new RealtimeUpdates instance. If you don’t have your app’s access token, provide the app’s secret and Koala will make a request to Facebook for the appropriate token.
@param options initialization options. @option options :#app_id the application’s ID. @option options :#app_access_token an application access token, if known. @option options :secret the application’s secret.
@raise ArgumentError if the application ID and one of the app access token or the secret are not provided.
# File lib/koala/realtime_updates.rb, line 25 def initialize(options = {}) @app_id = options[:app_id] @app_access_token = options[:app_access_token] @secret = options[:secret] unless @app_id && (@app_access_token || @secret) # make sure we have what we need raise ArgumentError, "Initialize must receive a hash with :app_id and either :app_access_token or :secret! (received #{options.inspect})" end # fetch the access token if we're provided a secret if @secret && !@app_access_token oauth = Koala::Facebook::OAuth.new(@app_id, @secret) @app_access_token = oauth.get_app_access_token end @api = API.new(@app_access_token) end