Re: [xml-dev] Use DTDs!

[Gareth Oakes <goakes@gpsl.co>]

Hi XML Dev,


On 2/05/2016, 21:00, "Michael Kay" <mike@saxonica.com> wrote:

>
>> On 2 May 2016, at 10:20, Henry S. Thompson <ht@markup.co.uk> wrote:
>> 
>> Ghislain Fourny <g@28.io> writes:
>> 
>>> This makes it cumbersome to deal with XML documents that use namespaces as
>>> you need to stick both to (i) static prefixes and to (ii) the elements
>>> where xmlns attributes are used to bind them.
>> 
>> Not so -- Dan Connolly pioneered a simple approach using parameter
>> entities, see e.g.
>> 
>>  https://www.w3.org/2001/XMLSchema.dtd
>> 
>
>And that's not cumbersome?

I totally agree with Michael here. I always thought namespaces were an awkward addition to XML and (not to peel that scab open yet again!) this is one of the reasons.

In general though this makes me realise how DTDs* are awkward in general because of the reliance on parameter entities, making them very unreadable. I have had good experience using Ovidius TreeVision to explore complex DTDs, but as a question to the group, is there a good visual tool** out there to work with DTDs? One that is both read/write and will understand and retain the parameter entities?

As much as it would be nice to use RELAX NG or even W3C Schema for everything, we always seem to be stuck dealing with large and complex DTDs.

* DTDs in this context meaning non-trivial implementations containing many modules, sub-modules, parameter entities, etc.

** Currently supported software in this space seems thin on the ground. Quick search shows that Stylus Studio seems to ship with one - is it fit for purpose?

// Gareth Oakes
// Chief Architect, GPSL
// www.gpsl.co