Use of [ and ] within id or name attribute of <input /> tag

[Martin Lucas-Smith]

I am wanting to know whether [ and ] are XHTML1-valid characters for use
within an id attribute and/or a name attribute.

http://validator.w3.org/check?uri=http://www-thaihydro.geog.cam.ac.uk/riverslice/&ss=1&verbose=1

(e.g. see line 77) suggests that it is valid, but the spec suggests that
it is not.


More detail:

I have a form containing a variety of input elements, including a checkbox
array.

For ease of processing the form, it would be helpful if the name of each
element in the checkbox array could include [ ] e.g.

<input type="checkbox" name="formname[checkbox][number]" />

However, looking at the HTML4 spec, which XHTML1.0Transit ional piggy-backs
onto, the specification suggests that [ and ] are not valid characters for
use within this:

http://www.w3.org/TR/html401/types.html#type-name

"ID and NAME tokens must begin with a letter ([A-Za-z]) and may be
followed by any number of letters, digits ([0-9]), hyphens ("-"),
underscores ("_"), colons (":"), and periods (".")."

However, a page I have online at present which uses [ ] does validate to
XHTML1.0Transit ional:

http://validator.w3.org/check?uri=http://www-thaihydro.geog.cam.ac.uk/riverslice/&ss=1&verbose=1

eg. line 77 contains name="main[function]"

Is [ and ] therefore valid?




Martin Lucas-Smith www.geog.cam.ac.uk/~mvl22

https://www.lucas-smith.co.uk

[Martin Honnen]

Re: Use of [ and ] within id or name attribute of &lt;input /&gt; tag



Martin Lucas-Smith wrote:
[color=blue]
>
> I am wanting to know whether [ and ] are XHTML1-valid characters for use
> within an id attribute and/or a name attribute.
>
> http://validator.w3.org/check?uri=ht...ss=1&verbose=1
>
> (e.g. see line 77) suggests that it is valid, but the spec suggests that
> it is not.
>
>
> More detail:
>
> I have a form containing a variety of input elements, including a checkbox
> array.
>
> For ease of processing the form, it would be helpful if the name of each
> element in the checkbox array could include [ ] e.g.
>
> <input type="checkbox" name="formname[checkbox][number]" />
>
> However, looking at the HTML4 spec, which XHTML1.0Transit ional piggy-backs
> onto, the specification suggests that [ and ] are not valid characters for
> use within this:
>
> http://www.w3.org/TR/html401/types.html#type-name
>
> "ID and NAME tokens must begin with a letter ([A-Za-z]) and may be
> followed by any number of letters, digits ([0-9]), hyphens ("-"),
> underscores ("_"), colons (":"), and periods (".")."
>
> However, a page I have online at present which uses [ ] does validate to
> XHTML1.0Transit ional:
>
> http://validator.w3.org/check?uri=ht...ss=1&verbose=1
>
> eg. line 77 contains name="main[function]"
>
> Is [ and ] therefore valid?[/color]

When you look at

http://www.w3.org/TR/xhtml1/dtds.html#dtdentry_xhtml1-transitional.dtd_input

you will see that the name attribute of <input> is of type CDATA
therefore for XHTML 1.0 transitional the [] in a name attribute value of
an <input> element will pass validation with an XML parser.
The id attribute is defined to be of type ID and that doesn't allow [ or ].
--

Martin Honnen

http://JavaScript.FAQTs.com/

[Martin Lucas-Smith]

Re: Use of [ and ] within id or name attribute of &lt;input /&gt; tag



[Summary: Can anyone point me to a definitive reference of where the
allowed characters for a valid XHTML name attribute (of an input/form) tag
is, so I can make a regexp from this (or even also provide me with a
regexp!)?]


A while ago I posted to this list wanting to know whether [ and ] are
XHTML1-valid characters for use within an id attribute and/or a name
attribute. I need to apply this more generally now beyond just [].

Ultimately, I'm trying to get an regexp for validating a form API-supplied
name for both an input tag (<input name="something " ... /> and for a form
name <form name="something ">, i.e. in PHP



$formName = 'name';

$regexp = '[something]';
if (!ereg ($regexp, $formName)) {
'The form name must consist of characters....
}




I understand that in HTML4, [] and are allowed this is not the case:
[color=blue][color=green]
> > http://www.w3.org/TR/html401/types.html#type-name
> >
> > "ID and NAME tokens must begin with a letter ([A-Za-z]) and may be
> > followed by any number of letters, digits ([0-9]), hyphens ("-"),
> > underscores ("_"), colons (":"), and periods (".")."[/color][/color]


But that in XHTML the allowed characters are different (as I have been
told they include []) :

[color=blue]
> When you look at
> http://www.w3.org/TR/xhtml1/dtds.htm...onal.dtd_input
> you will see that the name attribute of <input> is of type CDATA
> therefore for XHTML 1.0 transitional the [] in a name attribute value of
> an <input> element will pass validation with an XML parser. The id
> attribute is defined to be of type ID and that doesn't allow [ or ]. --[/color]

However, I can't see where exactly the CDATA type is defined for XHTML
Transitional, which is the doctype I'm using? Therefore:


** Can anyone point me to a definitive reference of where the allowed
characters for a valid XHTML name attribute (of an input/form) tag is, so
I can make a regexp from this (or even also provide me with a regexp!)? **



Martin

[Jim Dabell]

Re: Use of [ and ] within id or name attribute of &lt;input /&gt; tag

Martin Lucas-Smith wrote:
[color=blue]
> [Summary: Can anyone point me to a definitive reference of where the
> allowed characters for a valid XHTML name attribute (of an input/form) tag
> is, so I can make a regexp from this (or even also provide me with a
> regexp!)?][/color]
[snip][color=blue]
> I understand that in HTML4, [] and are allowed this is not the case:
>[color=green][color=darkred]
>> > http://www.w3.org/TR/html401/types.html#type-name
>> >
>> > "ID and NAME tokens must begin with a letter ([A-Za-z]) and may be
>> > followed by any number of letters, digits ([0-9]), hyphens ("-"),
>> > underscores ("_"), colons (":"), and periods (".")."[/color][/color][/color]
[snip]

You are confusing data types with attributes. The name attribute for the
<input> element type is clearly listed as being CDATA, not ID or NAME
tokens:

<URL:http://www.w3.org/TR/html401/interact/forms.html#h-17.3>
<URL:http://www.w3.org/TR/html401/interact/forms.html#h-17.4>

The only real restriction on what characters can appear in form control
names is when a form is submitted with GET:

"The "get" method restricts form data set values to ASCII characters."

-- <URL:http://www.w3.org/TR/html401/interact/forms.html#h-17.13.1>

[color=blue]
> However, I can't see where exactly the CDATA type is defined for XHTML
> Transitional, which is the doctype I'm using?[/color]
[snip]

<URL:http://www.w3.org/TR/REC-xml#attdecls>

--
Jim Dabell

[Martin Lucas-Smith]

Re: Use of [ and ] within id or name attribute of &lt;input /&gt; tag


[color=blue][color=green]
> > [Summary: Can anyone point me to a definitive reference of where the
> > allowed characters for a valid XHTML name attribute (of an input/form)
> > tag is, so I can make a regexp from this (or even also provide me with
> > a regexp!)?][/color]
>
> You are confusing data types with attributes. The name attribute for
> the <input> element type is clearly listed as being CDATA, not ID or
> NAME tokens:[/color]

I must confess I don't fully understand how the spec is read :), hence my
question.

[color=blue]
> The only real restriction on what characters can appear in form control
> names is when a form is submitted with GET:
>
> "The "get" method restricts form data set values to ASCII characters."
>
> -- <URL:http://www.w3.org/TR/html401/interact/forms.html#h-17.13.1>[/color]


Erm, I'm strictly referring to what appears as XXX in the following:

<input name="xxx" ... />

Can anyone supply an unambiguous reference/regexp as to what xxx can be
for the page still to validate as XHTML?



Martin