Class: IMS::LTI::ToolConsumer

Inherits:
ToolBase
  • Object
show all
Defined in:
lib/ims/lti/tool_consumer.rb

Overview

Class for implementing an LTI Tool Consumer

Constant Summary

Constants included from LaunchParams

LaunchParams::LAUNCH_DATA_PARAMETERS

Instance Attribute Summary collapse

Attributes inherited from ToolBase

#consumer_key, #consumer_secret

Attributes included from RequestValidator

#oauth_signature_validator

Attributes included from LaunchParams

#custom_params, #ext_params, #non_spec_params

Instance Method Summary collapse

Methods inherited from ToolBase

#post_service_request

Methods included from RequestValidator

#request_oauth_nonce, #request_oauth_timestamp, #valid_request!, #valid_request?

Methods included from LaunchParams

#get_custom_param, #get_ext_param, #get_non_spec_param, #process_params, #roles=, #set_custom_param, #set_ext_param, #set_non_spec_param, #to_params

Methods included from Extensions::Base

#extend_outcome_request, #extend_outcome_response, #outcome_request_extensions, #outcome_response_extensions

Constructor Details

#initialize(consumer_key, consumer_secret, params = {}) ⇒ ToolConsumer

Create a new ToolConsumer

Parameters:

  • consumer_key (String) —

    The OAuth consumer key

  • consumer_secret (String) —

    The OAuth consumer secret

  • params (Hash) (defaults to: {}) —

    Set the launch parameters as described in LaunchParams



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# File 'lib/ims/lti/tool_consumer.rb', line 11

def initialize(consumer_key, consumer_secret, params={})
  super(consumer_key, consumer_secret, params)
  @launch_url = params['launch_url']
end

Instance Attribute Details

#launch_url ⇒ Object

Returns the value of attribute launch_url.



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# File 'lib/ims/lti/tool_consumer.rb', line 4

def launch_url
  @launch_url
end

#nonce ⇒ Object

Returns the value of attribute nonce.



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# File 'lib/ims/lti/tool_consumer.rb', line 4

def nonce
  @nonce
end

#timestamp ⇒ Object

Returns the value of attribute timestamp.



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# File 'lib/ims/lti/tool_consumer.rb', line 4

def timestamp
  @timestamp
end

Instance Method Details

#generate_launch_data ⇒ Object

Generate the launch data including the necessary OAuth information

Raises:



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# File 'lib/ims/lti/tool_consumer.rb', line 39

def generate_launch_data
  raise IMS::LTI::InvalidLTIConfigError, "Not all required params set for tool launch" unless has_required_params?

  params = self.to_params
  params['lti_version'] ||= 'LTI-1p0'
  params['lti_message_type'] ||= 'basic-lti-launch-request'
  uri = URI.parse(@launch_url)

  if uri.port == uri.default_port
    host = uri.host
  else
    host = "#{uri.host}:#{uri.port}"
  end

  consumer = OAuth::Consumer.new(@consumer_key, @consumer_secret, {
          :site => "#{uri.scheme}://#{host}",
          :signature_method => "HMAC-SHA1"
  })

  path = uri.path
  path = '/' if path.empty?
  if uri.query && uri.query != ''
    CGI.parse(uri.query).each do |query_key, query_values|
      unless params[query_key]
        params[query_key] = query_values.first
      end
    end
  end
  options = {
          :scheme => 'body',
          :timestamp => @timestamp,
          :nonce => @nonce
  }
  request = consumer.create_signed_request(:post, path, nil, options, params)

  # the request is made by a html form in the user's browser, so we
  # want to revert the escapage and return the hash of post parameters ready
  # for embedding in a html view
  hash = {}
  request.body.split(/&/).each do |param|
    key, val = param.split(/=/).map { |v| CGI.unescape(v) }
    hash[key] = val
  end
  hash
end

#has_required_params? ⇒ Boolean

Check if the required parameters for a tool launch are set

Returns:

  • (Boolean) 


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# File 'lib/ims/lti/tool_consumer.rb', line 32

def has_required_params?
  @consumer_key && @consumer_secret && @resource_link_id && @launch_url
end

#process_post_request(post_request) ⇒ Object 



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# File 'lib/ims/lti/tool_consumer.rb', line 16

def process_post_request(post_request)
  request = extend_outcome_request(OutcomeRequest.new)
  request.process_post_request(post_request)
end

#set_config(config) ⇒ Object

Set launch data from a ToolConfig

Parameters:



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# File 'lib/ims/lti/tool_consumer.rb', line 24

def set_config(config)
  @launch_url ||= config.secure_launch_url
  @launch_url ||= config.launch_url
  # any parameters already set will take priority
  @custom_params = config.custom_params.merge(@custom_params)
end