Widgets

Marcos Caceres (QUT) :: WDS ::26 September, 2007

Interaction designer/developer by trade

Joined W3C Web Apps Formats WG in 2006

Edit:

Widgets 1.0 Requirements

Widgets 1.0 Specification (with Anne van Kesteren, Opera Software)

XBL 2.0 Primer (with Lachlan Hunt)

Doing a PhD on widgets

05/27/09

What are Widgets and Widget Engines?

Problem (lack of standards)

How to address the problem

Widget 1.0 Spec

Packaging

Runtime instances

05/27/09

A single function application

Made from web technologies (easy to build)

Usually access local info or web services

Types:

Desktop

Mobile

Web

Physical

05/27/09

DESKTOP WIDGETS

WEB WIDGETS

05/27/09 Yahoo! Widgets and Sidebar iGoogle Gadgets

MOBILE WIDGETS

PHYSICAL WIDGET

05/27/09 Webwag WidgetStation

Software on which widgets run.

Dashboard, Sidebar, Yahoo, Google Gadgets

05/27/09 Dashboard (Apple Inc.) Yahoo! Widgets engine

05/27/09 Widget: “An end-user's conceptualisation of an interactive single purpose application for displaying and/or updating local data or data on the Web, packaged in a way to allow a single download and installation on a user's machine or mobile device.” [Widget-reqs]

Make a web page

Zip it up

Publish it online (or send it out)

… or at least it should be that easy.

05/27/09

To make a widget more useful:

Ajax (web 2.0 stuff)

Web services

RSS/podcasts

Web APIs/mashups

Access to device

Camera, SMS, etc

05/27/09

Anyone

Enterprise uses

Eg: SAP

05/27/09 SAP Prototype Widget [SAP] “… in the U.S. marketing spending on mobile widgets will reach [US]$500 million by 2010, up from about $2 million [in March 2007]” [BusinessWeek] “ 2007: year of the Widget?” [Newsweek]

No interoperability across widget engines

Security issues not fully resolved

Are all user needs met?

Enterprise requirements

Internationalisation

Accessibility

How will they work on phones?

Mobility

Persistent storage? Keeping costs down.

05/27/09

PACKAGING

Format and Media Type

Automatic Updates

Auto-discovery

Embedding in HTML

Digital Signature

WIDGET INSTANCE

Initialisation (bootstrapping)

Metadata/Preferences

DOM APIs and Events

Cross-widget communication

Rendering

Security model

05/27/09

Format

Zip (version 2)

Deflate or uncompressed

Excludes support for:

64Bit

Encryption

Splitting

Unicode 

Maximize interoperability

Media Type

application/widget

Extension

*.wgt

05/27/09

Keep widget up to date

Widget engine periodically checks for updates:

Is the Version number

HTTP Caching control

Etags, Last modified date

What happens when there is no caching info?

What happens when a widget is auto generated?d

05/27/09

AUTO-DISCOVERY

Auto-discovery enables a browser to identify and install a widget that is associated with an web page.

<a rel="widget“ href=“my.wgt“>Widget</a>

EMBEDDING IN HTML

HTML4/XHTML

Using <object>

HTML5?

We will be approaching HTML-WG.

<widget src=“my.wgt”>

<div>…Fallback content…</div>

</widget?>

We are still investigating how to do this.

05/27/09

XML Digital Signature

Sign everything in a package

Signed Info

Crypto algorithm

Signed value

Key info

Digital certificate

Manifest

The files

<?xml version="1.0" encoding="UTF-8"?>

<Signature xmlns="http://www.w3.org/2000/09/xmldsig#">

<SignedInfo>

<CanonicalizationMethod

Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>

<SignatureMethod

Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" />

<Reference URI="#References"

Type="http://www.w3.org/2000/09/xmldsig#Manifest">

<DigestMethod

Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>

<DigestValue>725x3fVasdfvBGFGjhjyDSFvUk=</DigestValue>

</Reference>

</SignedInfo>

<SignatureValue>MC0E~LE=</SignatureValue>

<KeyInfo>

<X509Data>

<X509Certificate>MI...lVN</X509Certificate>

</X509Data>

</KeyInfo>

<Manifest Id="References">

<Reference URI="config.xml">

<DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" />

<DigestValue>j6...8nk=</DigestValue>

</Reference>

<Reference URI="index.html">

<DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>

<DigestValue>lm...34=</DigestValue>

</Reference>

<Reference URI="pictures/picture1.gif">

<DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>

<DigestValue>pq...56=</DigestValue>

</Reference>

</Manifest>

</Signature>

05/27/09

BOOTSTRAPPING

Automatically finding the start folder and file:

HTML, XML, SVG support (?)

Internationalized context

/en/,/en-au/ ,/en-us/

Automatically launching the start file and configuring the application

METADATA

config.xml

Metadata/Preferences

Widget (id, version, width, height, start)

title

Author (url, email)

description

License

Namespace  :

http://www.w3.org/ns/widgets

05/27/09

Leverage JavaScript+XHR

Widget Object

openURL(url);

preferenceForKey(key)

setPreferenceForKey(value, key)

Extensions to window

resizeTo, resizeBy, moveTo, moveBy

Events

state change, modal priorities

Cross widget communication

HTML 5’s model

05/27/09

SECURITY MODEL

No yet specified.

Should we lock it down or open it up?

Disk access?

Cross-domain requests?

Plugins? Flash? Java? Executables?

RENDERING

Handling transparency in irregularly shaped widgets

05/27/09

[email_address]

Widget images (Microsoft Vista Sidebar)

References

[HTML5]

http://www.whatwg.org/specs/web-apps/current-work/

[BusinessWeek]

Kharif, O. (2007, March 27). Widgets Gone Wireless. Retrieved 5 21, 2007: http://www.businessweek.com/technology/content/mar2007/tc20070327_532303.htm