Re: [xml-dev] Evolution of a markup language: replace recurringpatterns

[Stephen Green <stephengreenubl@gmail.com>]

Perhaps I should elaborate: with XML Data Islands (you don't hear much
about them these days)
the XML was held in the HTML of the web page but you had to use
javascript to get at it and do
things with it. Originally this tended to mean using an ActiveX XML
parser like MSXML in the web
page and nowadays you can probably rely on the browser's DOM to get at
elements and attributes
with the Javascript. All this gets a bit messy (especially if ActiveX
XML parsers go through constant
updates) but maybe libraries like jQuery can help smotth out user
experience for a web developer.
XForms was supposed to improve the user experience still more, I
think, but I'm not sure it did. It
should be possible to replace the Javascript and 'XML data island'
with an XForm and its 'model'
but I did find myself that I still needed some javascript even with an
XForm to anything my customer
wanted and it meant instead of ActiveX you still needed addins subject
to the same constant updates
and downloads. This was perhaps evidence of browsers not supporting
XML very well, and the
impression I got back then was it was semi-intentional (perhaps
something to do with big vendors
protecting IP and business models???). Not that I'd want to make any
allegations but there would
have been some very cool things which should have been possible but
they might have flown in
the face of what vendors wanted for the Web (and server sales, etc).

----
Stephen D Green



On 23 December 2010 09:46, Stephen Green <stephengreenubl@gmail.com> wrote:
>>
>> How has XML evolved? Can you cite examples of where usage patterns have been observed and then equivalent declarative solutions have been provided?
>>
>
> I don't think you can say XML itself has evolved since, by design,
> there has only been one version in a decade. However, I think
> a classic XML-related example of the progress from Javascript to
> declarative markup has been the evolution from XML Data Islands
> to XForms.
>
> Regards
>
> ----
> Stephen D Green
>
>
>
> On 22 December 2010 14:50, Costello, Roger L. <costello@mitre.org> wrote:
>> Hi Folks,
>>
>> In this book [1] the author says that the members of the HTML5 working group have identified recurring JavaScript patterns and then created corresponding markup:
>>
>>   When JavaScript was introduced into web browsers, it
>>   was immediately seized upon for two tasks: Image rollovers
>>   and Form enhancements. When CSS came along with its
>>   :hover pseudo-class, web designers no longer needed to reach
>>   for JavaScript just to achieve a simple rollover effect.
>>
>>   This is a recurring trend. If a pattern is popular enough, it
>>   will almost certainly evolve from requiring a scripted solution
>>   to something more declarative.
>>
>>   ...
>>
>>   Following the same migratory pattern from scripted to declarative
>>   solutions, the [HTML5] specification introduces many new form
>>   enhancements.
>>
>>   ...
>>
>>   HTML5--it's paving a cowpath ...
>>
>>
>> Another way of saying this is: HTML5 has migrated imperative code to declarative markup.
>>
>> This is exciting.
>>
>>
>> The book gives this example of migrating imperative code to declarative markup:
>>
>>    Here's a common DOM Scripting pattern, often used for
>>    search forms:
>>
>>    1. When a form field has no value, insert some placeholder text into it.
>>
>>    2. When the user focuses on that field, remove the placeholder text.
>>
>>    3. If the user leaves the field and the field still has no value, reinstate the
>>       placeholder text.
>>
>>    In an HTML5 document, you can simply use the placeholder attribute:
>>
>>    <input id="hobbies" name="hobbies" type="text" placeholder="Owl stretching">
>>
>>
>> The HTML language is evolving by diligently observing usage patterns and then creating equivalent markup. Thus, there is a slow but steady progression away from the need for imperative code to declarative solutions.
>>
>> Cool.
>>
>> How has XML evolved? Can you cite examples of where usage patterns have been observed and then equivalent declarative solutions have been provided?
>>
>> /Roger
>>
>> [1] "HTML5 For Web Designers" by Jeremy Keith, p. 40-43.
>>
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>