Re: Question to XForms authors and implementors: Multiple help, hint, alert elements per form control?

Hi Leigh,

> We have proposed that a future erratum for XForms 1.1 note in the prose
> that multiple such elements per form control is at best not interoperable,
> and further that the schema definitions for which it can be conveniently
> disallowed be changed to do so.

Can I suggest that we don't be too restrictive? I would think that all
we need to do is to work out what it takes to make things
interoperable, were people to have multiple elements.

For example, we could simply say that authors can count on the first
occurrence of one of these elements being processed, but after that,
it will be application specific.

But doing this, we don't rule out any innovations that people might
come up with.


> Are any implementors assigning special meaning to multiple help, hint, and alert elements?

We don't give it special meaning, but we don't disallow multiple
elements, either.

When processors allow multiple elements to appear, then it creates
some interesting possibilities. For example, CSS can be used to
determine which of the elements gets displayed.

One illustration of this would be to have different labels and alerts
depending on whether you are using a mobile or desktop device:

  @media screen {
    .handheld { display: none; }
  }
  @media handheld {
    .screen { display: none; }
  }

  <xf:intput ref="name">
    <xf:label class="handheld">Age</xf:label>
    <xf:label class="screen">Age at next birthday</xf:label>

    <xf:alert class="handheld">Age is required</xf:alert>
    <xf:alert class="screen"
      >You must enter your age. Come on...don't be shy.</xf:alert>
  </xf:input>

You could also have the label determined by the state of the control:

  .valid .reenter { display: none; }
  .invalid .enter { display: none; }

  <xf:intput ref="name">
    <xf:label class="enter">Age at next birthday</xf:label>
    <xf:label class="reenter">Please re-enter your age</xf:label>
  </xf:input>

Slightly contrived examples, I realise. :)

But I'm simply trying to illustrate that there are areas to explore,
and I don't think we gain anything by closing off this avenue of
exploration by tightening up the schema.

Regards,

Mark

--
Mark Birbeck, webBackplane

mark.birbeck@webBackplane.com

http://webBackplane.com/mark-birbeck

webBackplane is a trading name of Backplane Ltd. (company number
05972288, registered office: 2nd Floor, 69/85 Tabernacle Street,
London, EC2A 4RR)

Received on Thursday, 10 December 2009 11:10:25 UTC