VOEvent PR RFC: Description content

[Mark Taylor]

On Wed, 12 Jul 2006, Roy Williams wrote:

> > does it assume it's HTML and attempt to format it thus
> > (which will look wrong if it's plain)
> 
> Mark
> 
> I think the above might be a good solution -- that the presentation  
> layer should simply assume that the text may contain HTML tags. But I  
> do not see how this will mess up the plain text. 
> Isn't plain text  also valid HTML?

Strictly, there are plain text strings which are not valid HTML
(hence the existence of HTML validation services).
Loosely, HTML formatters can usually make sense of just about
anything since most HTML documents in practice are so miserably broken 
that they have to.  However, the point is that how a software 
component presents the information to a human (and what it looks like
when it does) is going to differ according to assumptions that you 
make about the form of the input.  Treating something as HTML when 
it's really not will lose whitespace formatting such as line 
breaks and behave strangely in the presence of '&', '<' and '>' 
characters amongst other things.

For a contrived example consider the difference between the following
content formatted as text or as HTML (which, syntactically, it very 
nearly is): 

  <Description><![CDATA[
     This instrument will only present useful data under the constraints:

        100<Br     Bg>200     99<Hr    Hg>50
         45<Br     Bg>35     101<Hr    Hg>1

  ]]></Description>

> I also agree that the scheme could be elaborated by <Description  
> type="LaTeX"> for example. But perhaps we can leave this to a future  
> evolution of the schema if/when somebody wants it?

Al's suggestion of MIME types sounds like a good idea.

> Thank you for your careful reading.

while we're on careful readings... you've missed a closing quote at

   <Param name="epoch" ucd="time.epoch" value="245523.12345 />

in sec 3.3.

Mark

-- 
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b.taylor at bris.ac.uk +44-117-928-8776 http://www.star.bris.ac.uk/~mbt/