Toward HyperDrupal

1. Introduction

Ryan Szrama, Community Dev at Commerce Guys

So why am I not giving my usual Commerce presentation?

Why talk about REST and Hypermedia?

Maybe I'm attracted to constrained systems...

And niche development communities...

The promise of REST is the API equivalent
of a wiki walk, each response asking,
"Would you like to know (or do) more?"

2. The World Wide Web

• URI
• HTTP
• HTML

URI

HTTP Request

  # Request
  GET /page/1 HTTP/1.1
  Host: www.example.com
  Accept: text/html
            

HTML

  # Response
  HTTP/1.1 200 Ok
  Content-Type: text/html;charset=UTF-8

  ...

  <p>This is a wonderful example, no?</p>

  <a href="...">See more examples.</a>

  ...
            

3. HTTP-based APIs

XML-RPC / SOAP

Use HTTP purely as a transport mechanism.

  <?xml version="1.0"?>
  <soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope">
    <soap:Header>
    </soap:Header>
    <soap:Body>
      <m:GetStockPrice xmlns:m="http://www.example.org/stock">
        <m:StockName>IBM
      </m:GetStockPrice>
    </soap:Body>
  </soap:Envelope>
            

• xURI
• xHTTP
• xHypermedia

Why do more?

RPC URI-tunneling

  POST /api/user/1/delete

  POST /api/user/1/update
            

• ✔URI
• xHTTP
• xHypermedia

HTTP-based Type I / II

Use HTTP methods and response codes:

  # A Type I message uses a generic media type
  GET /api/user/1
  Accept: application/json

  PUT /api/user/1
  DELETE /api/user/1
  POST /api/user

  # A Type II message is self-descriptive
  GET /api/user/1
  Accept: application/hal+json
            

• ✔URI
• ✔HTTP
• xHypermedia

REST

Hypermedia API responses include the controls I need to
navigate or manipulate application resources.

  <maze version="1.0">
    <collection href="/maze/maze/">
      <link rel="maze" href="/maze/maze/five-by-five/" />
    </collection>
  </maze>
            

• ✔URI
• ✔HTTP
• ✔Hypermedia

The Richardson Maturity Model

4. Toward HyperDrupal

Drupal 7 and earlier

Using the Services module, most Drupal based
web services are a combination of RPC URI-Tunneling
and HTTP-based Type I APIs.

  # Login is an example of RPC URI-Tunneling
  POST /user/login

  # While other resources are HTTP-based Type I
  GET /user/1
  DELETE /node/3
            

Drupal 8

Drupal core ships with a REST module that supports:

• Entities as resources with unique URIs
• Representations in different formats
• Manipulation via the HTTP interface
• Self-descriptive messages via HAL

Next Steps

Next steps involve both education and code:

• Communicate the constraints and the promise of REST
• Enrich our (HAL and other) responses with hypermedia
• Document REST server and client best practices
• Develop tools that make it even easier

Practical Example

Commerce Mobile:

The promise of REST is the API equivalent
of a wiki walk, each response asking,
"Would you like to know (or do) more?"

The opportunity for Drupal is to become
the new de facto solution for building
restful web services.

http://drupal.org/project/hyperdrupal