Class: LMS::Canvas

Inherits:
Object
  • Object
show all
Defined in:
lib/lms/canvas.rb

Defined Under Namespace

Classes: CanvasException, InvalidAPIMethodRequestException, InvalidAPIRequestException, InvalidAPIRequestFailedException, InvalidRefreshOptionsException, InvalidTokenException, MissingRequiredParameterException, RefreshToken500Exception, RefreshTokenFailedException, RefreshTokenRequired, TokenException

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(lms_uri, authentication, refresh_token_options = nil) ⇒ Canvas

The authentication parameter must be either a string (indicating a token), or an object that responds to:

- #id
- #token
- #update(hash) -- which should update #token with hash[:token]:noh



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# File 'lib/lms/canvas.rb', line 55

def initialize(lms_uri, authentication, refresh_token_options = nil)
  @per_page = 100
  @lms_uri = lms_uri
  @refresh_token_options = refresh_token_options
  @authentication = if authentication.is_a?(String)
                      OpenStruct.new(token: authentication)
                    else
                      authentication
                    end

  if refresh_token_options.present?
    required_options = [:client_id, :client_secret, :redirect_uri, :refresh_token]
    extra_options = @refresh_token_options.keys - required_options
    unless extra_options.empty?
      raise InvalidRefreshOptionsException,
            "Invalid option(s) provided: #{extra_options.join(', ')}"
    end
    missing_options = required_options - @refresh_token_options.keys
    unless missing_options.empty?
      raise InvalidRefreshOptionsException,
            "Missing required option(s): #{missing_options.join(', ')}"
    end
  end
end

Class Attribute Details

.auth_state_model ⇒ Object

Returns the value of attribute auth_state_model.



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# File 'lib/lms/canvas.rb', line 23

def auth_state_model
  @auth_state_model
end

Instance Attribute Details

#authentication ⇒ Object (readonly)

Returns the value of attribute authentication.



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# File 'lib/lms/canvas.rb', line 48

def authentication
  @authentication
end

Class Method Details

.allow_scoped_path(type) ⇒ Object

These methods allow custom paths to be appended to the API endpoint.



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# File 'lib/lms/canvas.rb', line 314

def self.allow_scoped_path(type)
  [
    "STORE_CUSTOM_DATA",
    "LOAD_CUSTOM_DATA",
    "DELETE_CUSTOM_DATA",
  ].include?(type)
end

.ignore_required(type) ⇒ Object

Ignore required params for specific calls. For example, the external tool calls have required params “name, privacy_level, consumer_key, shared_secret”. However, those params are not required if the call specifies config_type: “by_xml”.



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# File 'lib/lms/canvas.rb', line 306

def self.ignore_required(type)
  [
    "CREATE_EXTERNAL_TOOL_COURSES",
    "CREATE_EXTERNAL_TOOL_ACCOUNTS",
  ].include?(type)
end

.lms_url(type, params, payload = nil) ⇒ Object 



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# File 'lib/lms/canvas.rb', line 322

def self.lms_url(type, params, payload = nil)
  endpoint = LMS::CANVAS_URLs[type]
  parameters = endpoint[:parameters]

  # Make sure all required parameters are present
  missing = []
  if !ignore_required(type)
    parameters.select { |p| p["required"] }.map { |p| p["name"] }.each do |p|
      if p.include?("[") && p.include?("]")
        parts = p.split("[")
        parent = parts[0].to_sym
        child = parts[1].gsub("]", "").to_sym
        missing << p unless (params[parent].present? && params[parent][child].present?) ||
            (payload.present? && payload[parent].present? && payload[parent][child].present?)
      else
        missing << p unless params[p.to_sym].present? ||
            (payload.present? && !payload.is_a?(String) && payload[p.to_sym].present?)
      end
    end
  end

  if !missing.empty?
    raise LMS::Canvas::MissingRequiredParameterException,
          "Missing required parameter(s): #{missing.join(', ')}"
  end

  # Generate the uri. Only allow path parameters
  uri_proc = endpoint[:uri]
  path_parameters = parameters.select { |p| p["paramType"] == "path" }.
    map { |p| p["name"].to_sym }
  args = params.slice(*path_parameters).deep_symbolize_keys
  uri = args.blank? ? uri_proc.call : uri_proc.call(**args)

  # Handle scopes in the url. These API endpoints allow for additional path
  # information to be added to their urls.
  # ie "users/#{user_id}/custom_data/favorite_color/green"
  if allow_scoped_path(type) &&
    scope = params[:scope]&.gsub("../", "").gsub("..", "") # Don't allow moving up in the path
    uri = File.join(uri, scope)
  end

  # Generate the query string
  query_parameters = parameters.select { |p| p["paramType"] == "query" }.
    map { |p| p["name"].to_sym }

  # always allow paging parameters
  query_parameters << :per_page
  query_parameters << :page
  query_parameters << :as_user_id

  allowed_params = params.
    slice(*query_parameters).
    reject { |key, value| value.nil? }

  if allowed_params.present?
    "#{uri}?#{allowed_params.to_query}"
  else
    uri
  end
end

.on_auth(callback = nil, &block) ⇒ Object

callback must accept a single parameter (the API object itself) and return the new authentication object.



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# File 'lib/lms/canvas.rb', line 33

def self.on_auth(callback = nil, &block)
  @@on_auth = callback || block
end

Instance Method Details

#all_accounts ⇒ Object

Get all accounts including sub accounts



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# File 'lib/lms/canvas.rb', line 388

def all_accounts
  all = []
  single_proxy("LIST_ACCOUNTS", {}, nil, true).each do ||
    all << 
    sub_accounts = single_proxy("GET_SUB_ACCOUNTS_OF_ACCOUNT",
                         {
                            account_id: ["id"],
                            recursive: true,
                         },
                         nil,
                         true)
    all = all.concat(sub_accounts)
  end
  all
end

#api_delete_request(api_url, additional_headers = {}) ⇒ Object 



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# File 'lib/lms/canvas.rb', line 133

def api_delete_request(api_url, additional_headers = {})
  url = full_url(api_url)
  refreshably do
    HTTParty.delete(url, headers: headers(additional_headers))
  end
end

#api_error(result) ⇒ Object 



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# File 'lib/lms/canvas.rb', line 229

def api_error(result)
  error = "Status: #{result.headers['status']} \n"
  error << "Http Response: #{result.response.code} \n"
  error << "Error: #{result.response.message} \n"
end

#api_get_all_request(api_url, additional_headers = {}) ⇒ Object 



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# File 'lib/lms/canvas.rb', line 140

def api_get_all_request(api_url, additional_headers = {})
  [].tap do |results|
    api_get_blocks_request(api_url, additional_headers) do |result|
      results.concat(result)
    end
  end
end

#api_get_blocks_request(api_url, additional_headers = {}) ⇒ Object 



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# File 'lib/lms/canvas.rb', line 148

def api_get_blocks_request(api_url, additional_headers = {})
  connector = api_url.include?("?") ? "&" : "?"
  next_url = "#{api_url}#{connector}per_page=#{@per_page}"
  while next_url
    result = api_get_request(next_url, additional_headers)
    yield result
    next_url = get_next_url(result.headers["link"])
  end
end

#api_get_request(api_url, additional_headers = {}) ⇒ Object 



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# File 'lib/lms/canvas.rb', line 126

def api_get_request(api_url, additional_headers = {})
  url = full_url(api_url)
  refreshably do
    HTTParty.get(url, headers: headers(additional_headers))
  end
end

#api_post_request(api_url, payload, additional_headers = {}) ⇒ Object 



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# File 'lib/lms/canvas.rb', line 119

def api_post_request(api_url, payload, additional_headers = {})
  url = full_url(api_url)
  refreshably do
    HTTParty.post(url, headers: headers(additional_headers), body: payload)
  end
end

#api_put_request(api_url, payload, additional_headers = {}) ⇒ Object 



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# File 'lib/lms/canvas.rb', line 112

def api_put_request(api_url, payload, additional_headers = {})
  url = full_url(api_url)
  refreshably do
    HTTParty.put(url, headers: headers(additional_headers), body: payload)
  end
end

#auth_state_model ⇒ Object

instance accessor, for convenience



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# File 'lib/lms/canvas.rb', line 27

def auth_state_model
  self.class.auth_state_model
end

#check_result(result) ⇒ Object

Raises:



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# File 'lib/lms/canvas.rb', line 217

def check_result(result)
  code = result.response.code.to_i

  return result if [200, 201, 202, 203, 204, 205, 206].include?(code)

  if code == 401 && result.headers["www-authenticate"] == 'Bearer realm="canvas-lms"'
    raise LMS::Canvas::RefreshTokenRequired.new("", nil, result, @authentication)
  end

  raise LMS::Canvas::InvalidAPIRequestException.new(api_error(result), code, result)
end

#delete_token(expire_sessions: false) ⇒ Object 



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# File 'lib/lms/canvas.rb', line 188

def delete_token(expire_sessions: false)
  url = full_url("login/oauth2/token", false)
  params = if expire_sessions
              {expire_sessions: true}
            else
              {}
           end
  refreshably do
    HTTParty.delete(url, headers: headers, query: params)
  end
end

#force_refresh ⇒ Object 



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# File 'lib/lms/canvas.rb', line 158

def force_refresh
  @authentication = @@on_auth.call(self)
end

#full_url(api_url, use_api_prefix = true) ⇒ Object 



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# File 'lib/lms/canvas.rb', line 102

def full_url(api_url, use_api_prefix = true)
  if api_url[0...4] == "http"
    api_url
  elsif use_api_prefix
    "#{@lms_uri}/api/v1/#{api_url}"
  else
    "#{@lms_uri}/#{api_url}"
  end
end

#get_next_url(link) ⇒ Object 



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# File 'lib/lms/canvas.rb', line 235

def get_next_url(link)
  return nil if link.blank?
  if url = link.split(",").detect { |l| l.split(";")[1].strip == 'rel="next"' }
    url.split(";")[0].gsub(/[\<\>\s]/, "")
  end
end

#headers(additional_headers = {}) ⇒ Object 



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# File 'lib/lms/canvas.rb', line 96

def headers(additional_headers = {})
  {
    "Authorization" => "Bearer #{@authentication.token}",
  }.merge(additional_headers)
end

#lock ⇒ Object

Obtains a lock (via the API.auth_state_model interface) and yields an authentication object corresponding to self.authentication.id. The object is returned when the block finishes.



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# File 'lib/lms/canvas.rb', line 84

def lock
  auth_state_model.transaction do
    record = auth_state_model.
      lock(true).
      find(authentication.id)

    yield record

    record
  end
end

#multi_proxy(type, params, payload = nil, get_all = false) ⇒ Object 



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# File 'lib/lms/canvas.rb', line 242

def multi_proxy(type, params, payload = nil, get_all = false)
  # Helper methods call several Canvas methods to return a block of data to the client
  if helper = CANVAS_HELPER_URLs[type]
    result = self.send(helper)
    return OpenStruct.new(
      code: 200,
      headers: {},
      body: result.to_json
    )
  end
end

#proxy(type, params, payload = nil, get_all = false, &block) ⇒ Object 



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# File 'lib/lms/canvas.rb', line 298

def proxy(type, params, payload = nil, get_all = false, &block)
  multi_proxy(type, params, payload, get_all) ||
    single_proxy(type, params, payload, get_all, &block)
end

#refresh_token ⇒ Object 



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# File 'lib/lms/canvas.rb', line 200

def refresh_token
  payload = {
    grant_type: "refresh_token"
  }.merge(@refresh_token_options)
  url = full_url("login/oauth2/token", false)
  result = HTTParty.post(url, headers: headers, body: payload)
  code = result.response.code.to_i
  if code >= 500
    raise LMS::Canvas::RefreshToken500Exception.new(api_error(result), code, result, @authentication)
  end

  if code > 201
    raise LMS::Canvas::RefreshTokenFailedException.new(api_error(result), code, result, @authentication)
  end
  result["access_token"]
end

#refreshably ⇒ Object 



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# File 'lib/lms/canvas.rb', line 162

def refreshably
  refresh_attempts = 0

  begin
    result = yield
    check_result(result)
  rescue LMS::Canvas::RefreshTokenRequired => ex
    raise ex if @refresh_token_options.blank?

    refresh_attempts += 1

    @authentication = @@on_auth.call(self)

    if refresh_attempts < 2
      retry
    else
      raise LMS::Canvas::InvalidTokenException.new(
        "Refreshing the token gives an invalid token. The developer key may have been disabled.",
        result&.response&.code&.to_i,
        result,
        @authentication
      )
    end
  end
end

#single_proxy(type, params, payload = nil, get_all = false) ⇒ Object 



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# File 'lib/lms/canvas.rb', line 254

def single_proxy(type, params, payload = nil, get_all = false)
  additional_headers = {
    "Content-Type" => "application/json"
  }
  payload = {} if payload.blank?
  payload_json = payload.is_a?(String) ? payload : payload.to_json
  parsed_payload = payload.is_a?(String) ? JSON.parse(payload) : payload
  parsed_payload = parsed_payload.with_indifferent_access

  method = LMS::CANVAS_URLs[type][:method]
  url = LMS::Canvas.lms_url(type, params, parsed_payload)

  case method
  when "GET"
    if block_given?
      api_get_blocks_request(url, additional_headers) do |result|
        yield result
      end
    elsif get_all
      api_get_all_request(url, additional_headers)
    else
      api_get_request(url, additional_headers)
    end
  when "POST"
    api_post_request(url, payload_json, additional_headers)
  when "PUT"
    api_put_request(url, payload_json, additional_headers)
  when "DELETE"
    api_delete_request(url, additional_headers)
  else
    raise LMS::Canvas::InvalidAPIMethodRequestException "Invalid method type: #{method}"
  end

rescue LMS::Canvas::InvalidAPIRequestException => ex
  error = "#{ex.message} \n"
  error << "API Request Url: #{url} \n"
  error << "API Request Params: #{params} \n"
  error << "API Request Payload: #{payload} \n"
  error << "API Request Result: #{ex.result.body} \n"
  new_ex = LMS::Canvas::InvalidAPIRequestFailedException.new(error, ex.status, ex.result)
  new_ex.set_backtrace(ex.backtrace)
  raise new_ex
end