Re: User Agent Definition

Hi all (since I don't think interest in this is limited to Jeanne, Greg, and I),

Here's another kick at the can... and by can I probably mean giant squid. ;-)

Things to note:

-          I changed "any" to "a" in the first sentence

-          I made webview components a sub-type of stand-alone and provided some possible language for handling them in the conformance section

-          I added a note to "user agent" to try to cover the apps case (both mobile and desktop)


user agent
A user agent is a software that retrieves, renders and facilitates end user interaction with web content. If the software only performs these functions for time-based media, then the term "media player" is used, otherwise, the more general designation "browser" is used. UAAG 2.0 identifies several user agent architectures:

*         stand-alone, non-web-based, browser: These user agents run on non-Web platforms (e.g., desktop and mobile operating systems and cross-OS platforms, such as Java) and perform content retrieval, rendering and end-user interaction facilitation themselves. Examples include: Firefox, Safari, Internet Explorer, Chrome, Opera.

o   Note: A variant of stand-alone user agents are webview components. These software development mechanisms are essentially stand-alone browsers that can be used as programmatic objects to package web content for delivery in non-web-based mobile or desktop applications. Examples include: Android Webview[1], iOS UIWebView [2].

*         embedded user agent, plug-in: These user agents "plug-in" to stand-alone user agents in order to render and facilitate end-user interaction for content types that the stand-alone user agent does not support. Embedded user agents establish direct connections with the platform (e.g. communication via platform accessibility services). Examples include: QuickTime Player, Acrobat Reader, Shockwave Player.

*         web-based user agent: These user agents operate by (a) transforming the web content into a technology that the stand-alone (or embedded) user agent can render and (b) injecting the web-based user agent's own user interface functionality into the content to be rendered. Web-based user agents may be nested. Examples include: Hotmail, Google Docs, FlexPaper.

Note: There is an important distinction to be made between user agents that retrieve, render and facilitate end user interaction with arbitrary web content (in a given technology) and applications that retrieve, render, and facilitate end-user interaction with more restricted data sets. For example, a financial application that retrieves, renders and facilitates user interaction with an XML-encoded stock price history would not be considered a user agent. Instead, if the application is constructed using web technologies, it would make more sense to evaluate it using WCAG 2.0.

For the conformance section(?)

Conformance for "webview components":

*         It is recommended that webview components be evaluated for UAAG 2.0 conformance. This can be done be creating a basic application that contains only the component and whatever functionality is required to provide the component with content to render.

*         If the finished application makes use of webview component to retrieve, render and facilitate end user interaction with arbitrary web content then a UAAG 2.0 evaluation should be performed on the finished application. Otherwise, an evaluation using WCAG 2.0 would be more appropriate (*Ed. Perhaps with a reference to the UAAG 2.0 conformance claim for the webview component in question?).


[1] http://developer.android.com/reference/android/webkit/WebView.html
[2] http://developer.apple.com/library/ios/#documentation/uikit/reference/UIWebView_Class/Reference/Reference.html















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