Class: IMS::LTI::OutcomeResponse

Inherits:
Object
  • Object
show all
Includes:
Extensions::Base
Defined in:
lib/ims/lti/outcome_response.rb

Overview

Class for consuming/generating LTI Outcome Responses

Response documentation: www.imsglobal.org/lti/v1p1pd/ltiIMGv1p1pd.html#_Toc309649691

Error code documentation: www.imsglobal.org/gws/gwsv1p0/imsgws_baseProfv1p0.html#1639667

This class can be used by both Tool Providers and Tool Consumers. Each will use it a bit differently. The Tool Provider will use it parse the result of an OutcomeRequest to the Tool Consumer. A Tool Consumer will use it generate proper response XML to send back to a Tool Provider

Tool Provider Usage

An OutcomeResponse will generally be created when POSTing an OutcomeRequest through a configured ToolProvider. See the ToolProvider documentation for typical usage.

Tool Consumer Usage

When an outcome request is sent from a Tool Provider the body of the request is XML. This class parses that XML and provides a simple interface for accessing the information in the request. Typical usage would be:

# create a new response and set the appropriate values
res = IMS::LTI::OutcomeResponse.new
res.message_ref_identifier = outcome_request.message_identifier
res.operation = outcome_request.operation
res.code_major = 'success'
res.severity = 'status'

# set a description (optional) and other information based on the type of response
if outcome_request.replace_request?
  res.description = "Your old score of 0 has been replaced with #{outcome_request.score}"
elsif outcome_request.read_request?
  res.description = "You score is 50"
  res.score = 50
elsif outcome_request.delete_request?
  res.description = "You score has been cleared"
else
  res.code_major = 'unsupported'
  res.severity = 'status'
  res.description = "#{outcome_request.operation} is not supported"
end

# the generated xml is returned to the Tool Provider
res.generate_response_xml

Constant Summary collapse

CODE_MAJOR_CODES = 
%w{success processing failure unsupported}
SEVERITY_CODES = 
%w{status warning error}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Extensions::Base

#extend_outcome_request, #extend_outcome_response, #outcome_request_extensions, #outcome_response_extensions

Constructor Details

#initialize(opts = {}) ⇒ OutcomeResponse

Create a new OutcomeResponse

Parameters:

  • opts (Hash) (defaults to: {}) —

    initialization hash



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# File 'lib/ims/lti/outcome_response.rb', line 60

def initialize(opts={})
  opts.each_pair do |key, val|
    self.send("#{key}=", val) if self.respond_to?("#{key}=")
  end
end

Instance Attribute Details

#code_major ⇒ Object

Returns the value of attribute code_major.



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# File 'lib/ims/lti/outcome_response.rb', line 50

def code_major
  @code_major
end

#description ⇒ Object

Returns the value of attribute description.



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# File 'lib/ims/lti/outcome_response.rb', line 50

def description
  @description
end

#message_identifier ⇒ Object

Returns the value of attribute message_identifier.



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# File 'lib/ims/lti/outcome_response.rb', line 50

def message_identifier
  @message_identifier
end

#message_ref_identifier ⇒ Object

Returns the value of attribute message_ref_identifier.



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# File 'lib/ims/lti/outcome_response.rb', line 50

def message_ref_identifier
  @message_ref_identifier
end

#operation ⇒ Object

Returns the value of attribute operation.



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# File 'lib/ims/lti/outcome_response.rb', line 50

def operation
  @operation
end

#post_response ⇒ Object

Returns the value of attribute post_response.



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# File 'lib/ims/lti/outcome_response.rb', line 50

def post_response
  @post_response
end

#request_type ⇒ Object

Returns the value of attribute request_type.



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# File 'lib/ims/lti/outcome_response.rb', line 50

def request_type
  @request_type
end

#response_code ⇒ Object

Returns the value of attribute response_code.



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# File 'lib/ims/lti/outcome_response.rb', line 50

def response_code
  @response_code
end

#score ⇒ Object

Returns the value of attribute score.



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# File 'lib/ims/lti/outcome_response.rb', line 50

def score
  @score
end

#severity ⇒ Object

Returns the value of attribute severity.



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# File 'lib/ims/lti/outcome_response.rb', line 50

def severity
  @severity
end

Class Method Details

.from_post_response(post_response) ⇒ Object

Convenience method for creating a new OutcomeResponse from a response object

req = IMS::LTI::OutcomeResponse.from_post_response(response)



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# File 'lib/ims/lti/outcome_response.rb', line 69

def self.from_post_response(post_response)
  response = OutcomeResponse.new
  response.process_post_response(post_response)
end

Instance Method Details

#failure? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ims/lti/outcome_response.rb', line 90

def failure?
  @code_major == 'failure'
end

#generate_response_xml ⇒ String

Generate XML based on the current configuration

Returns:

  • (String) —

    The response xml



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# File 'lib/ims/lti/outcome_response.rb', line 134

def generate_response_xml
  builder = Builder::XmlMarkup.new
  builder.instruct!

  builder.imsx_POXEnvelopeResponse("xmlns" => "http://www.imsglobal.org/services/ltiv1p1/xsd/imsoms_v1p0") do |env|
    env.imsx_POXHeader do |header|
      header.imsx_POXResponseHeaderInfo do |info|
        info.imsx_version "V1.0"
        info.imsx_messageIdentifier @message_identifier || IMS::LTI::generate_identifier
        info.imsx_statusInfo do |status|
          status.imsx_codeMajor @code_major
          status.imsx_severity @severity
          status.imsx_description @description
          status.imsx_messageRefIdentifier @message_ref_identifier
          status.imsx_operationRefIdentifier @operation
        end
      end
    end #/header
    env.imsx_POXBody do |body|
      unless unsupported?
        if @operation == OutcomeRequest::READ_REQUEST
          body.tag!(@operation + 'Response') do |request|
            request.result do |res|
              res.resultScore do |res_score|
                res_score.language "en" # 'en' represents the format of the number
                res_score.textString @score.to_s
              end
            end #/result
          end
        else
          body.tag!(@operation + 'Response')
        end #/operationResponse
      end
    end #/body
  end
end

#has_error? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ims/lti/outcome_response.rb', line 102

def has_error?
  @severity == 'error'
end

#has_warning? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ims/lti/outcome_response.rb', line 98

def has_warning?
  @severity == 'warning'
end

#process_post_response(post_response) ⇒ Object 



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# File 'lib/ims/lti/outcome_response.rb', line 74

def process_post_response(post_response)
  self.post_response = post_response
  self.response_code = post_response.code
  xml = post_response.body
  self.process_xml(xml)
  self
end

#process_xml(xml) ⇒ Object

Parse Outcome Response data from XML



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# File 'lib/ims/lti/outcome_response.rb', line 107

def process_xml(xml)
  if xml.include?('#<UUID:0x')              # Blackboard bug!
    m_id = xml.match('#<UUID:(\w+)>')[1].hex.to_i
    xml = xml.sub(/#<UUID:\w+>/, m_id.to_s)
  end
  begin
    doc = REXML::Document.new xml
  rescue => e
    raise IMS::LTI::XMLParseError, "#{e}\nOriginal xml: '#{xml}'"
  end
  @message_identifier = doc.text('//imsx_statusInfo/imsx_messageIdentifier')
  @message_identifier = doc.text('//imsx_messageIdentifier') if @message_identifier.nil?
  @message_identifier = @message_identifier.nil? ? '0' : @message_identifier.to_s
  @code_major = doc.text("//imsx_statusInfo/imsx_codeMajor")
  @code_major.downcase! if @code_major
  @severity = doc.text("//imsx_statusInfo/imsx_severity")
  @severity.downcase! if @severity
  @description = doc.text("//imsx_statusInfo/imsx_description")
  @description = @description.to_s if @description
  @message_ref_identifier = doc.text("//imsx_statusInfo/imsx_messageRefIdentifier")
  @operation = doc.text("//imsx_statusInfo/imsx_operationRefIdentifier")
  @score = doc.text("//readResultResponse//resultScore/textString")
  @score = @score.to_s if @score
end

#processing? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ims/lti/outcome_response.rb', line 86

def processing?
  @code_major == 'processing'
end

#success? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ims/lti/outcome_response.rb', line 82

def success?
  @code_major == 'success'
end

#unsupported? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ims/lti/outcome_response.rb', line 94

def unsupported?
  @code_major == 'unsupported'
end