Class: LMS::Canvas

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

Defined Under Namespace

Classes: CanvasException, InvalidAPIMethodRequestException, InvalidAPIRequestException, InvalidAPIRequestFailedException, InvalidRefreshOptionsException, MissingRequiredParameterException, RefreshTokenFailedException, RefreshTokenRequired

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



55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
 
# 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.



23
24
25
 
# 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.



48
49
50
 
# 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.



282
283
284
285
286
287
288
 
# File 'lib/lms/canvas.rb', line 282

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”.



274
275
276
277
278
279
 
# File 'lib/lms/canvas.rb', line 274

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

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



290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
 
# File 'lib/lms/canvas.rb', line 290

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)

  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.



33
34
35
 
# 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



354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
 
# File 'lib/lms/canvas.rb', line 354

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 



134
135
136
137
138
139
 
# File 'lib/lms/canvas.rb', line 134

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 



197
198
199
200
201
 
# File 'lib/lms/canvas.rb', line 197

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 



141
142
143
144
145
146
147
 
# File 'lib/lms/canvas.rb', line 141

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 



149
150
151
152
153
154
155
156
157
 
# File 'lib/lms/canvas.rb', line 149

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 



127
128
129
130
131
132
 
# File 'lib/lms/canvas.rb', line 127

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 



120
121
122
123
124
125
 
# File 'lib/lms/canvas.rb', line 120

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 



113
114
115
116
117
118
 
# File 'lib/lms/canvas.rb', line 113

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



27
28
29
 
# File 'lib/lms/canvas.rb', line 27

def auth_state_model
  self.class.auth_state_model
end

#check_result(result) ⇒ Object

Raises:



185
186
187
188
189
190
191
192
193
194
195
 
# File 'lib/lms/canvas.rb', line 185

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, @authentication)
  end

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

#force_refresh ⇒ Object 



159
160
161
 
# File 'lib/lms/canvas.rb', line 159

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

#full_url(api_url, use_api_prefix = true) ⇒ Object 



103
104
105
106
107
108
109
110
111
 
# File 'lib/lms/canvas.rb', line 103

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 



203
204
205
206
207
208
 
# File 'lib/lms/canvas.rb', line 203

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 



96
97
98
99
100
101
 
# File 'lib/lms/canvas.rb', line 96

def headers(additional_headers = {})
  {
    "Authorization" => "Bearer #{@authentication.token}",
    "User-Agent" => "LMS-API Ruby"
  }.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.



84
85
86
87
88
89
90
91
92
93
94
 
# 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 



210
211
212
213
214
215
216
217
218
219
220
 
# File 'lib/lms/canvas.rb', line 210

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 



266
267
268
269
 
# File 'lib/lms/canvas.rb', line 266

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 



172
173
174
175
176
177
178
179
180
181
182
183
 
# File 'lib/lms/canvas.rb', line 172

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
  unless [200, 201].include?(code)
    raise LMS::Canvas::RefreshTokenFailedException.new(api_error(result), code, result)
  end
  result["access_token"]
end

#refreshably ⇒ Object 



163
164
165
166
167
168
169
170
 
# File 'lib/lms/canvas.rb', line 163

def refreshably
  result = yield
  check_result(result)
rescue LMS::Canvas::RefreshTokenRequired => ex
  raise ex if @refresh_token_options.blank?
  @authentication = @@on_auth.call(self)
  retry
end

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



222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
 
# File 'lib/lms/canvas.rb', line 222

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