Create example for Microsoft Graph

docs/README.md

@@ -5,7 +5,6 @@ Makes http fun again!
 ## Table of contents
 - [Parsing JSON](#parsing-json)
 - [Working with SSL](#working-with-ssl)
-- [Multipart Post](#multipart-post)
 
 ## Parsing JSON
 If the response Content Type is `application/json`, HTTParty will parse the response and return Ruby objects such as a hash or array. The default behavior for parsing JSON will return keys as strings. This can be supressed with the `format` option. To get hash keys as symbols:
@@ -104,21 +103,4 @@ class Client
     # get("resources", verify_peer: false)
   end
 end
-```
-
-## Multipart Post
-
-Sending a `multipart/form-data` post request with HTTParty is easy, for example to request a bearer token from Microsoft's Graph API:
-
-```ruby
-HTTParty.post(
-  "https://login.microsoftonline.com/tenant_id/oauth2/v2.0/token",
-  body: {
-    multipart: true,
-    client_id: 'id',
-    client_secret: 'secret',
-    scope: 'https://graph.microsoft.com/.default',
-    grant_type: 'client_credentials'
-  }
-)
 ```

examples/microsoft_graph.rb

@@ -0,0 +1,52 @@
+require 'httparty'
+
+class MicrosoftGraph
+  MS_BASE_URL = "https://login.microsoftonline.com".freeze
+  TOKEN_REQUEST_PATH = "oauth2/v2.0/token".freeze
+
+  def initialize(tenant_id)
+    @tenant_id = tenant_id
+  end
+
+  # Make a request to the Microsoft Graph API, for instance https://graph.microsoft.com/v1.0/users
+  def request(url)
+    return false unless (token = bearer_token)
+
+    response = HTTParty.get(
+      url,
+      headers: {
+        Authorization: "Bearer #{token}"
+      }
+    )
+
+    return false unless response.code == 200
+
+    return JSON.parse(response.body)
+  end
+
+  private
+
+  # A post to the Microsoft Graph to get a bearer token for the specified tenant.  In this example
+  # our Rails application has already been given permission to request these tokens by the admin of
+  # the specified tenant_id.  
+  # 
+  # See here for more information https://developer.microsoft.com/en-us/graph/docs/concepts/auth_v2_service
+  #
+  # This request also makes use of the multipart/form-data post body.
+  def bearer_token
+    response = HTTParty.post(
+      "#{MS_BASE_URL}/#{@tenant_id}/#{TOKEN_REQUEST_PATH}",
+      body: {
+        multipart: true,
+        client_id: Rails.application.credentials[Rails.env.to_sym][:microsoft_client_id],
+        client_secret: Rails.application.credentials[Rails.env.to_sym][:microsoft_client_secret],
+        scope: 'https://graph.microsoft.com/.default',
+        grant_type: 'client_credentials'
+      }
+    )
+
+    return false unless response.code == 200
+
+    JSON.parse(response.body)['access_token']
+  end
+end