Attention.xml Technology Overview

Attention.xml Technology Overview

Tantek Çelik

Senior Technologist, Technorati, Inc.

http://technorati.com/

Attention.xml Technology Overview

• Background
  • From XML to "lossless XHTML"
  • Building Blocks
• Attention.xml
  • Why?
  • Readers
  • Social Networks
  • Participation
  • Open Issues

History

• HTML began structural
• became presentational during browser wars
• explosive growth because of error tolerance
• table abuse, font tagitis, spacer gifs => backlash

Purification Efforts - XML, CSS

• XML for stricter structure
  • data abstraction appeal
  • draconian error handling
  • schema freedom - new elements for everyone!
• CSS for cleaner, richer presentation
  • enhanced layout and typography
  • graceful fallbacks
  • media/device awareness

What worked?

• XHTML: HTML rebuilt in XML
• CSS richness taught designers good markup
  • CSS Zen Garden
• RSS: ultrasimple XML

What failed?

• schema explosion
• tag vs. attribute arguments
• "boil the ocean" ontology ratholes
• namespace "silos" encouraged NIH
• XML not human readable
• XML didn't work on "the Web"

Expand what worked

• Re-use rather than re-invent
• XHTML is XML
• parsable, modular
• XHTML supports CSS
• everyone already has viewers

XHTML Building Blocks

• applications use common concepts
• links
• lists
• hashtables
• XHTML primitives for "lossless XHTML"

XHTML Building Blocks - Links

• <a href="url">label</a>

• link relationships with

  rel="..."

• 'rel' is extensible and multivalued

  rel="relationship1 relationship2" 

XHTML Building Blocks - Link examples

• blog permalinks

  • <a rel="bookmark" href="blogarchive">... 

• human relationships - social networks
  • XFN (XHTML Friends Network)

    <a rel="friend colleague met" href="personURL">... 

• agreement/reviews/motions
  • VoteLinks

    rel="vote-for" or "vote-against" or "vote-abstain"

XHTML Building Blocks - Lists

• Programs have arrays, XHTML has lists
• ordered array

  <ol><li>

• unordered collection

  <ul><li>

• Nest to arbitrary depths, thus outlines

  <ol><li>
      <ul><li>
          <ol><li>...
  

XHTML Building Blocks - Definition Lists

• these correspond approximately with dictionaries
• hashtables

   <dl>
      <dt>key</dt>
          <dd>value</dd>
   </dl>

• uniqueness constraints not explicit

Using XHTML Building Blocks

• represent existing behavior using these building blocks
• links: XFN, Vote Links
  • add 'rel' to your blogroll links, e.g.

    <a rel="met colleague" href="http://scott.example.com">scott</a>

  • add 'rel' to discussion links, e.g.

    <a rel="vote-against" href="http://bad.example.com">yuck</a>

• outlines: XOXO
• dictionaries: XMDP

Building New Blocks - Principles

• map existing data structures into XHTML equivalents
• enable new stylable building blocks
• re-use schemas, don't reinvent!
• readily exchange data by using 1:1 mappings
• For more info, see microformats

Building New Blocks - More...

• citations, quotes, arrays/tables, etc.
• People
  • RFC 2426 vCard <-> hCard
• Events
  • RFC 2445 iCalendar <-> hCalendar
• For these and more, see past presentation:
  • 2004-09-28 Kevin Marks & Tantek Çelik at SD Forum:
  • Semantic XHTML: Can your website be your API?

Attention.xml: Why?

• Feed overload
• The "5 minute" problem
• No need to reread
• What are my friends paying attention to?
• Collaborative reviewing & organizing
• What new thing should I be reading?

Attention.xml: Format Foundation

• XOXO - well structured outlines and properties
• Common Aggregator Use Cases
• Synchronization
• Social Networks
• Participation

Attention.xml: Groups / Feeds / Items

• Groups - containers for Feeds
• Feeds
  • title, url, alturls, etag, lastupdated
• Items
  • title, permalink, type, etag, lastupdated
• Similar to OPML
  • Typical OPML export = degenerate Attention.xml

Attention.xml: Adding & Removing Feeds

• Groups - containers for Feeds
• Feeds
  • title, url, alturls, etag, lastupdated
  • dateadded, dateremoved
• Items
  • title, permalink, type, etag, lastupdated

Attention.xml: Labeling Groups & Feeds

• Groups - containers for Feeds
  • title
• Feeds
  • title, url, alturls, etag, lastupdated
  • dateadded, dateremoved
  • userfeedtitle
• Items
  • title, permalink, type, etag, lastupdated

Attention.xml: Reading

• Groups
  • title
• Feeds
  • title, url, alturls, etag, lastupdated
  • dateadded, dateremoved
  • userfeedtitle
  • lastread, readtimes - fifo queue when / how long
• Items
  • title, permalink, type, etag, lastupdated
  • lastread, duration, followedlinks

Attention.xml: Social Network

• Groups
  • title
• Feeds
  • title, url, alturls, etag, lastupdated
  • dateadded, dateremoved
  • userfeedtitle
  • lastread, readtimes - fifo queue when / how long
  • rel/XFN
• Items
  • title, permalink, type, etag, lastupdated
  • lastread, duration, followedlinks

Attention.xml: Participation

• Groups
  • title
• Feeds
  • title, url, alturls, etag, lastupdated
  • dateadded, dateremoved
  • userfeedtitle
  • lastread, readtimes - fifo queue when / how long
  • rel/XFN, rel/VoteLink, tags
• Items
  • title, permalink, type, etag, lastupdated
  • lastread, duration, followedlinks
  • rel/VoteLink, tags

Attention.xml: Status

• Stable, Open, Specification (+ FAQ, wiki)
  • http://developers.technorati.com/wiki/attentionxml
• Open Source
  • XOXO parsing, serialization (Python, Perl, plus PHP etc. coming)
• OPML scraper
  • http://technorati.com/attention.html
• Attention Synchronization
  • Technorati AttentionQuery web service API
• NetNewsWire exporter
  • AppleScript Attention.xml export for NetNewsWire

Attention.xml: Coming Soon

• More open source sample code
• Rich Attention.xml samples
• Attention.xml validator
• Technorati Toolbar(s)
  • Attention.xml gathering/syncing while browsing
• Popular Aggregator Implementations
  • On both client and server

Attention.xml: Open Issues

• Privacy
• Attention Subsetting?
• Scalability
  • How many simultaneous users, feeds, clients?
• Insufficient or Excessive?
  • Feature Creep!
• How do you encourage sharing?

Attention.xml: Q & A

• What Next?