Problems about the Spectrum Data Model from the view of a Web Service programmer

[Matthew Graham]

Hi,

Yet again I find myself in the position of agreeing with Alasdair: there 
is nothing wrong with mixed content. In fact,  it is used elsewhere in 
the IVOA already (either in Registry resource records or VOEvent - I 
can't remember which offhand but have definitely come across it) so if 
we don't want to use it, we should be consistent right across the IVOA - 
a radical idea I know!

    Cheers,

    Matthew

Alasdair Allan wrote:
>
> Gerard wrote:
>> I think irrespective of this, we might in the IVOA attempt to not use 
>> mixed
>> content in serialisations of data and metadata simply beacues of 
>> examples as
>> Alasdair mentions.
>
> Actually I was arguing precisely the opposite point, I don't really 
> see anything wrong with mixed content.
>
>> We can do without and it will be much simpler to
>> transform between different representations (code, databasesof a given
>> underlying model if every data element is explcitily named.
>
> Every data element is explicitly named in both examples I gave you.
>
>> Mixed content will allow things that are hard to make sense of in an
>> automated fashion, like
>>
>> <tag1>34<tag2>35</tag2>36<tag3>hello</tag3>76</tag1>
>
> Err, no that's easier to make sense of in an automated fashion than it 
> is to read, although re-arranging your example into a more human 
> parsable version,  it's perfectly easy to understand as well...
>
> <tag1>
>    34 36 76
>   <tag2>35</tag2>
>   <tag3>hello</tag3>
> </tag1>
>
> In other words,
>
>     tag1         = [ 34, 36, 76 ]
>     tag1.tag2     = 35
>     tag1.tag3     = hello
>
>> Such mixed content is fine fore (X)HTML documents, but imho should be
>> avoided if possible for serialisations that are to be read by machines.
>
> Why? I don't understand why you'd find the above ambiguous?
>
> Al.
>