W3C home > Mailing lists > Public > www-style@w3.org > July 2004

Re: [CSS21] Error handling of missing style sheets

From: Justin Wood <jw6057@bacon.qcc.mass.edu>
Date: Thu, 15 Jul 2004 01:20:43 -0400
Message-ID: <40F6142B.5010102@bacon.qcc.mass.edu>
To: Mark Moore <mark.moore@notlimited.com>
Cc: www-style@w3.org

Mark Moore wrote:

>According to section 3.2:
>
><blockquote>
>2.	For each source document, it must attempt to retrieve all associated
>style sheets that are appropriate for the supported media types. If it
>cannot retrieve all associated style sheets (for instance, because of
>network errors), it must display the document using those it can retrieve.
></blockquote>
>
>
>According to section 3.3:
>
><blockquote>
>In general, this document does not specify error handling behavior for user
>agents (e.g., how they behave when they cannot find a resource designated by
>a URI). 
>
>However, user agents must observe the rules for handling parsing errors. 
>
>Since user agents may vary in how they handle error conditions, authors and
>users must not rely on specific error recovery behavior.
></blockquote>
>
>
>I would suggest changing 3.2 to clarify whether partial style sheets (e.g.
>network error occurs during retrieval) should be discarded or used.  I would
>recommend they be discarded.
>  
>
I disagree, if there is a netword error, I'd rather my stylesheets be at 
the least 'allowed' to be used for what was received, in { ... } breaks 
(inside) the whole { ... } is discarded based on parsing error!  if a UA 
chooses to discard whole sheet, ok.  if it chooses to allow what it 
already received, great.  But I do not feel we should force this on any UA.

>I would suggest two changes to 3.3:
>
>1) Change the second sentence to mention handling of missing style sheets
>(e.g. " However, user agents must observe the rules for handling parsing
>errors and unretrievable style sheets.")
>  
>
This would remove the intent of the second sentence and become 
excessively repetative, we "provide no rules for missing style sheets" 
(unrecoverable).  but parsing rules are an entirely different story.

>2) Clarify whether the specified parsing errors, or missing style sheets are
>expected or permitted to raise any exception to the User.
>  
>

"Expected" -- Never (imo);  and permitted -- Always (since we do not 
force any error handling conditions, if a UA chooses to msg the user in 
some way available to them let them), though imo a UA should not pop-up 
warnings about missing stylesheets, do we pop-up warnings about missing 
background images (IE or Mozilla as my example)?

Thanks for listening
~Justin Wood, (non W3C WG member, stated as such, so my words are not 
interpreted as a claim of  'fact')
Received on Thursday, 15 July 2004 01:22:26 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 27 April 2009 13:54:31 GMT