W3C home > Mailing lists > Public > public-html@w3.org > September 2007

Re: HDP: Revised "Support Existing Content" Principle

From: Marghanita da Cruz <marghanita@ramin.com.au>
Date: Tue, 18 Sep 2007 06:53:37 +0000
Message-ID: <46EF424B.3000802@ramin.com.au>
To: Maciej Stachowiak <mjs@apple.com>
Cc: "public-html@w3.org WG" <public-html@w3.org>


Maciej Stachowiak wrote:
> 
> On Sep 17, 2007, at 7:24 PM, Marghanita da Cruz wrote:
> 
>> Maciej Stachowiak wrote:
>>> On Sep 17, 2007, at 6:21 PM, Marghanita da Cruz wrote:
>>>> To me, handling of poor markup by browsers is an example of
>>>> the "Degrade Gracefully" Principle rather than the
>>>> support existing content principle.
>>> That's not the intent of the principle. "Degrade Gracefully" says 
>>> nothing about the interaction of existing markup with either new or 
>>> old browsers. It's all about new documents authored to conform to 
>>> HTML5 being able to work reasonably in pre-HTML5 browsers.
>>
>> Sorry, but "Degrade Gracefully" is a concept that has been around as 
>> long as the Web - the concept is that instead of providing an syntax 
>> error the browser should attempt to interpret and display the content.
> 
> That concept is also referred to as error recovery and is covered by the 
> "Handle Errors" principle.
> 
>> So, old browsers will most likely degrade gracefully rather than 
>> report a syntax error, when they start seeing HTML5 code they do not 
>> recognise.
> 
> They won't report a syntax error because browsers never report a syntax 
> error. But they may fail in ways that are more serious or less serious. 
> And the design of new features affects how bad the failure will be.
> 
>> There isn't much point in specifying what you want an old brower to do 
>> with HTML5.
> 
> This principle is about new content that is designed to degrade 
> gracefully in older browsers. It's not about specifying anything for 
> behavior of old browsers - as you point out, it's too late to do 
> anything about that. But the language can be designed to make it easier 
> to create new content that works well in old browsers. The spec has 
> conformance requirements for both implementations and documents, and 
> this principle is mainly about document conformance.
> 
see my comments in the degrade gracefully principle
m
-- 
Marghanita da Cruz
http://www.ramin.com.au
Phone: (+61)0414 869202
Received on Tuesday, 18 September 2007 07:23:02 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Wednesday, 9 May 2012 00:16:07 GMT