The document discusses using headless Drupal as a data server, detailing how browsers and applications interact with it for data retrieval in formats like JSON and XML. It covers the advantages and disadvantages of using headless Drupal with web and mobile applications, emphasizing faster data transfer and the separation of data generation from presentation. It also highlights features of Drupal 7 and 8's services modules, including authentication methods and custom extensibility.

1. Drupal as a Data
Server
Using Headless Drupal

2. First, a look at browsers
 Browsers work with HTML
 The browser makes a request to a URL
 The server returns HTML for that URL
 HTML contains both data and structure
 The browser interprets the HTML as a web page

3. Browser Makes
Request
Drupal generates
HTML
Browser interprets
HTML as web page

4. Headless Drupal
 Some application makes a request to a URL
 The URL returns data (no structure)
 JSON
 XML
 Plist
 etc
 The application processes the data
 Wraps it in HTML
 Saves it to a database
 Inserts it into a view in an app
 etc

5. App Makes
Request to Drupal
Drupal generates
Data
App processes
data

6. Using JavaScript frameworks
with Headless Drupal
 Initial HTML and JS is served from non-Drupal
application
 JavaScript requests data (JSON etc) from Drupal
 Javascript wraps response in HTML and inserts it to
browser
 Advantages:
 Can build applications not requiring page reloads
 Data transfer is pure data (JSON etc) without structure
(HTML), making data transfer much faster
 Disadvantages
 Need to make two systems work together (Drupal + other
system, ex Angular)

7. Using Mobile Apps with
Headless Drupal
 App holds all page structures
 App requests data (JSON etc) from Drupal
 Application inserts data into page structure
 Advantages (over mobile browser app):
 As page structure (layout, fonts etc) do not need to be
downloaded, apps are faster than a mobile website
 Disadvantages
 Often requires separate developer for apps
 Two systems need to be maintained

8. Drupal Process
 Drupal separates data generation from presentation
 When Drupal is used as a webserver, the generated
data is ‘wrapped’ in HTML
 When Drupal is used as a data server (ex REST
server) the data is ‘wrapped’ in a data format (JSON,
XML etc)

9. Drupal
generates
data
Browser App
Data wrapped
in HTML
Data wrapped in
JSON/XML/etc

10. Components of a data server
 Authentication
 The method to identify the user
 Oauth
 OAuth2 (used by Google, Twitter Instagram etc)
 Sessions
 Endpoint
 The URL from which data can be retrieved
 Resources
 Retrieve data or perform an action
 Response formatters
 JSON
 XML
 Plist

11. Drupal 7 – Services module
 The Services module is used to create data servers in Drupal 7
 Services 7.3 ships with:
 Servers
 REST
 XMLRPC
 Authentication
 OAuth
 Sessions
 Resources
 Multiple core resources – node, taxonomy, user etc
 Data Formatters
 Bencode
 JSON
 JSONP
 PHP
 XML

12. Drupal 7 – Services module
 Additional modules can be downloaded to extend
services. Some examples:
 Servers
 SOAP server (https://www.drupal.org/project/soap_server)
 Authentication
 OAuth2 (https://www.drupal.org/project/oauth2_server)
 Resources
 User points (https://www.drupal.org/project/userpoints)
 Data formatters
 REST Server plist
(https://www.drupal.org/project/rest_server_plist)

13. Extending Services
 hook_services_resources()
http://www.drupalcontrib.org/api/drupal/contributions!s
ervices!docs!services.services.api.php/function/hook_
services_resources/7
 Allows for adding new resources and actions
 Systems can provide custom data

14. Drupal 8 – Services is in core
 Drupal 8 ships with:
 HTTP Basic Authentication
 HTTP Authentication
 Username and Password sent as HTTP headers
 Cookie
 Uses cookies

15. Drupal 8 – Services is in core
 Drupal 8 ships with:
 RESTful Services (REST server)

16. Drupal 8 – Services is in core
 Drupal 8 ships with:
 HAL – provides HAL-JSON serialization
 Serialization
 Supports JSON and XML
 Additional methods provided through the Serialization
API

17. Thank you!
 Check out my podcast at https://www.sensei-and-the-
geek.com/