Sepia Labs presentation on build web services. Presented at 360iDev.

1. Building Web Services
for Mobile Apps
Brent Simmons @brentsimmons
Nick Bradbury @nbradbury
Brian Reischl @brianreischl
Nick Harris @nick_harris
@SepiaLabs
@Glassboard

2. Introductions
Brent Simmons: NetNewsWire and Mars Edit
Nick Bradbury: HomeSite, TopStyle, FeedDemon.
Brian Reischl: 5+ years at NewsGator
Nick Harris: 5+ years at NewsGator

3. Glassboard
- Private Group Messaging
- Available on iOS, Android and WP7

4. History
- Idea formally born in December 2010
- Development began in January 2011
- First beta in mid-May
- Second beta in July
- Initial Release August 2011

5. Platform Details
- Built on Microsoft Windows Azure
- Both WebRoles and Worker Roles
- Table, Queue and Blob Storage
- SQL Azure for diagnostic data

6. Initial API Design
- REST Implementation
- JSON body content when possible
- Multi-part Form otherwise

7. Why REST?
- Main idea of REST is uniquely addressable objects
- Easier for client developers to understand
- Supported with basic frameworks on any platform
- Encourages more universal architecture decisions

8. REST API Examples:
Boards
GET /api/boards
gets the boards for a user
POST /api/boards
creates a new board with the information supplied in the JSON body
GET /api/boards/{board_id}/statuses
gets the latest statuses for the board
GET /api/boards/{board_id}/statuses/{status_id}/comments
gets the latest comments for the status

9. Why REST cont...
- HTTP Status Codes
- Additional HTTP Headers
POST /api/boards/
RESPONSE:
Status Code: 409 Conflict
X-GlassboardPlatform-Exception-Code:
200002
**Error code 200002: A board with this name
already exists for this chairman

10. Why JSON?
- Smaller “on the wire” footprint

11. JSON Example
{
"AttachmentHasThumbnail":true,
"AttachmentId":"XXX-XXXX-XXXX-XXX",
"AttachmentType":0,
"AuthorId":"XXX-XXXX-XXXX-XXX",
"BoardId":"XXX-XXXX-XXXX-XXX",
"CommentCount":0,
"LikeCount":0,
"LikedByUsers":["XXX-XXXX-XXXX-XXX", “XXX-XXXX-XXXX-XXX”],
"Link":"http://www.link.com",
"Location":"+12345 -12345",
"PubDate":"01/01/1001",
"Status":"Hello World",
"StatusId":"XXX-XXXX-XXXX-XXX",
"Updated":"XXX-XXXX-XXXX-XXX"
}

12. XML Output
<StatusInfo>
<AttachmentHasThumbnail>true</AttachmentHasThumbnail>
<AttachmentId> XXX-XXXX-XXXX-XXX </AttachmentId>
<AttachmentType>NONE</AttachmentType>
<AuthorId> XXX-XXXX-XXXX-XXX </AuthorId>
<BoardId> XXX-XXXX-XXXX-XXX </BoardId>
<CommentCount>0</CommentCount>
<LikeCount>2</LikeCount>
<LikedByUsers>
<string xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays"> XXX-XXXX-XXXX-XXX </string>
<string xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays"> XXX-XXXX-XXXX-XXX </string>
</LikedByUsers>
<Link>http://www.link.com</Link>
<Location>+12345 -12345</Location>
<PubDate>01/01/1001</PubDate>
<Status>Hello World</Status>
<StatusId>XXX-XXXX-XXXX-XXX </StatusId>
<Updated>XXX-XXXX-XXXX-XXX </Updated>
</StatusInfo>

13. { <StatusInfo>
"AttachmentHasThumbnail":true, <AttachmentHasThumbnail>true</AttachmentHasThumbnail>
"AttachmentId":"XXX-XXXX-XXXX-XXX", <AttachmentId> XXX-XXXX-XXXX-XXX </AttachmentId>
"AttachmentType":0, <AttachmentType>NONE</AttachmentType>
"AuthorId":"XXX-XXXX-XXXX-XXX", <AuthorId> XXX-XXXX-XXXX-XXX </AuthorId>
"BoardId":"XXX-XXXX-XXXX-XXX", <BoardId> XXX-XXXX-XXXX-XXX </BoardId>
"CommentCount":0, <CommentCount>0</CommentCount>
"LikeCount":0, <LikeCount>2</LikeCount>
"LikedByUsers":["XXX-XXXX-XXXX-XXX", “XXX-XXXX-XXXX-XXX”], <LikedByUsers>
"Link":"http://www.link.com", <string xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays"> XXX-XXXX-XXXX-XXX </string>
"Location":"+12345 -12345", <string xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays"> XXX-XXXX-XXXX-XXX </string>
"PubDate":"01/01/1001", </LikedByUsers>
"Status":"Hello World", <Link>http://www.link.com</Link>
"StatusId":"XXX-XXXX-XXXX-XXX", <Location>+12345 -12345</Location>
"Updated":"XXX-XXXX-XXXX-XXX" <PubDate>01/01/1001</PubDate>
} <Status>Hello World</Status>
{ <StatusId>XXX-XXXX-XXXX-XXX </StatusId>
"AttachmentHasThumbnail":true, <Updated>XXX-XXXX-XXXX-XXX </Updated>
"AttachmentId":"XXX-XXXX-XXXX-XXX", </StatusInfo>
"AttachmentType":0, <StatusInfo>
"AuthorId":"XXX-XXXX-XXXX-XXX", <AttachmentHasThumbnail>true</AttachmentHasThumbnail>
"BoardId":"XXX-XXXX-XXXX-XXX", <AttachmentId> XXX-XXXX-XXXX-XXX </AttachmentId>
"CommentCount":0, <AttachmentType>NONE</AttachmentType>
"LikeCount":0, <AuthorId> XXX-XXXX-XXXX-XXX </AuthorId>
"LikedByUsers":["XXX-XXXX-XXXX-XXX", “XXX-XXXX-XXXX-XXX”], <BoardId> XXX-XXXX-XXXX-XXX </BoardId>
"Link":"http://www.link.com", <CommentCount>0</CommentCount>
"Location":"+12345 -12345", <LikeCount>2</LikeCount>
"PubDate":"01/01/1001", <LikedByUsers>
"Status":"Hello World", <string xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays"> XXX-XXXX-XXXX-XXX </string>
"StatusId":"XXX-XXXX-XXXX-XXX", <string xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays"> XXX-XXXX-XXXX-XXX </string>
"Updated":"XXX-XXXX-XXXX-XXX" </LikedByUsers>
} <Link>http://www.link.com</Link>
{ <Location>+12345 -12345</Location>
"AttachmentHasThumbnail":true, <PubDate>01/01/1001</PubDate>
"AttachmentId":"XXX-XXXX-XXXX-XXX", <Status>Hello World</Status>
"AttachmentType":0, <StatusId>XXX-XXXX-XXXX-XXX </StatusId>
"AuthorId":"XXX-XXXX-XXXX-XXX", <Updated>XXX-XXXX-XXXX-XXX </Updated>
"BoardId":"XXX-XXXX-XXXX-XXX", </StatusInfo>
"CommentCount":0, <StatusInfo>
"LikeCount":0, <AttachmentHasThumbnail>true</AttachmentHasThumbnail>
"LikedByUsers":["XXX-XXXX-XXXX-XXX", “XXX-XXXX-XXXX-XXX”], <AttachmentId> XXX-XXXX-XXXX-XXX </AttachmentId>
"Link":"http://www.link.com", <AttachmentType>NONE</AttachmentType>
"Location":"+12345 -12345", <AuthorId> XXX-XXXX-XXXX-XXX </AuthorId>
"PubDate":"01/01/1001", <BoardId> XXX-XXXX-XXXX-XXX </BoardId>
"Status":"Hello World", <CommentCount>0</CommentCount>
"StatusId":"XXX-XXXX-XXXX-XXX", <LikeCount>2</LikeCount>
"Updated":"XXX-XXXX-XXXX-XXX" <LikedByUsers>
} <string xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays"> XXX-XXXX-XXXX-XXX </string>
{ <string xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays"> XXX-XXXX-XXXX-XXX </string>
"AttachmentHasThumbnail":true, </LikedByUsers>
"AttachmentId":"XXX-XXXX-XXXX-XXX", <Link>http://www.link.com</Link>
"AttachmentType":0, <Location>+12345 -12345</Location>
"AuthorId":"XXX-XXXX-XXXX-XXX", <PubDate>01/01/1001</PubDate>
"BoardId":"XXX-XXXX-XXXX-XXX", <Status>Hello World</Status>
"CommentCount":0, <StatusId>XXX-XXXX-XXXX-XXX </StatusId>
"LikeCount":0, <Updated>XXX-XXXX-XXXX-XXX </Updated>
"LikedByUsers":["XXX-XXXX-XXXX-XXX", “XXX-XXXX-XXXX-XXX”], </StatusInfo>
"Link":"http://www.link.com", <StatusInfo>
"Location":"+12345 -12345", <AttachmentHasThumbnail>true</AttachmentHasThumbnail>
"PubDate":"01/01/1001", <AttachmentId> XXX-XXXX-XXXX-XXX </AttachmentId>
"Status":"Hello World", <AttachmentType>NONE</AttachmentType>
"StatusId":"XXX-XXXX-XXXX-XXX", <AuthorId> XXX-XXXX-XXXX-XXX </AuthorId>
"Updated":"XXX-XXXX-XXXX-XXX" <BoardId> XXX-XXXX-XXXX-XXX </BoardId>
} <CommentCount>0</CommentCount>
<LikeCount>2</LikeCount>
<LikedByUsers>
<string xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays"> XXX-XXXX-XXXX-XXX </string>

14. iOS Client
- Built by Brent Simmons

15. Android Client
- Build by Nick Bradbury

16. What we learned...

17. The Problem...
- Stringent REST implementations have limitations
- Mobile applications have their own limitations
Mobile apps need to be not only useable but useful
as soon as possible - that means new data...

18. The Newsfeed Solution
- Single call to get all new statuses and comments
- One out-bound request on startup
- Data body just a set of existing JSON objects

19. Platform API Future
- More “newsfeed like” REST hybrid calls
- Open to 3rd parties?

20. Q&A
(with your host @jennyblumberg
aka @glassboard
aka @sepialabs)