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Re: "Universal HTML"
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Jukka K. Korpela
Apr 6, 2016, 4:53:52 PM4/6/16
to
6.4.2016, 23:22, Stefan Ram wrote:
> When one wants to write HTML that can be displayed in a wide
> range of browsers, including very old ones and HTML5 browsers,
> what should one observe?
That’s a rather broad question. I will try to address the more specific
questions asked.
> One can try to omit all element types that are only available
> under some versions: <tt> is not in HTML5, <section> is not in
> HTML 4.01.
<tt> is still supported by “HTML5 browsers.” The HTML5 spec more or less
recommends this, and even if it didn’t, the browser vendors would win
nothing (and would lose something) by removing the support.
The <section> and </section> tags are ignored by old browsers. It is
usually impossible to detect the difference between this and “support”
to the <section> element. There is no requirement on any particular
handling of that element, except that it is a block element, but even
this does not matter in most contexts (since line breaks will be caused
by other elements anyway).
It’s a different story if you set some styles on <section>. Then old
versions of IE will ignore them, as it does not support styling any
element that it does not know. There is a simple cure to this: just say
“IE, meet <section>”:
<script>
document.createElement('section');
</script>
> But what about the start of the document?
The doctype does not matter, except in the sense of triggering
“standards” vs. “quirks” mode.
> <!DOCTYPE HTML>
This triggers “standards” mode in any browser that has one.
> <html xmlns="http://www.w3.org/1999/xhtml" lang="de" xml:lang="de">
It really does not matter, except to those rare user agents that
recognize and use the lang attribute.
> <head><meta charset="UTF-8" /><title>Beispiel</title><style type="text/css">
> </style></head><body>
What about that? I see no problem here. The <meta charset="UTF-8"> trick
(or <meta charset="UTF-8" /> if you play XHTML) was specifically
invented according to observed browser behavior. Due to certain parsing
oddities, it works well in old browsers, too.
> Or can one safely assume that web browsers will »always«
> support HTML 4.01 (»always« = for the next decades) and thus
> use HTML 4.01 as that »eternal HTML«?
No browser ever supported HTML 4.01, though most browsers currently in
use support almost all of the HTML 4.01 features that are actually used
by HTML authors.
--
Yucca, http://www.cs.tut.fi/~jkorpela/
> When one wants to write HTML that can be displayed in a wide
> range of browsers, including very old ones and HTML5 browsers,
> what should one observe?
That’s a rather broad question. I will try to address the more specific
questions asked.
> One can try to omit all element types that are only available
> under some versions: <tt> is not in HTML5, <section> is not in
> HTML 4.01.
<tt> is still supported by “HTML5 browsers.” The HTML5 spec more or less
recommends this, and even if it didn’t, the browser vendors would win
nothing (and would lose something) by removing the support.
The <section> and </section> tags are ignored by old browsers. It is
usually impossible to detect the difference between this and “support”
to the <section> element. There is no requirement on any particular
handling of that element, except that it is a block element, but even
this does not matter in most contexts (since line breaks will be caused
by other elements anyway).
It’s a different story if you set some styles on <section>. Then old
versions of IE will ignore them, as it does not support styling any
element that it does not know. There is a simple cure to this: just say
“IE, meet <section>”:
<script>
document.createElement('section');
</script>
> But what about the start of the document?
The doctype does not matter, except in the sense of triggering
“standards” vs. “quirks” mode.
> <!DOCTYPE HTML>
This triggers “standards” mode in any browser that has one.
> <html xmlns="http://www.w3.org/1999/xhtml" lang="de" xml:lang="de">
It really does not matter, except to those rare user agents that
recognize and use the lang attribute.
> <head><meta charset="UTF-8" /><title>Beispiel</title><style type="text/css">
> </style></head><body>
What about that? I see no problem here. The <meta charset="UTF-8"> trick
(or <meta charset="UTF-8" /> if you play XHTML) was specifically
invented according to observed browser behavior. Due to certain parsing
oddities, it works well in old browsers, too.
> Or can one safely assume that web browsers will »always«
> support HTML 4.01 (»always« = for the next decades) and thus
> use HTML 4.01 as that »eternal HTML«?
No browser ever supported HTML 4.01, though most browsers currently in
use support almost all of the HTML 4.01 features that are actually used
by HTML authors.
--
Yucca, http://www.cs.tut.fi/~jkorpela/
Thomas 'PointedEars' Lahn
Apr 10, 2016, 7:56:56 AM4/10/16
to
Jukka K. Korpela wrote:
> It’s a different story if you set some styles on <section>. Then old
> versions of IE will ignore them, as it does not support styling any
> element that it does not know. There is a simple cure to this: just say
> “IE, meet <section>”:
> <script>
> document.createElement('section');
> </script>
The “simple cure” introduces a dependency on another technique, client-side
> It’s a different story if you set some styles on <section>. Then old
> versions of IE will ignore them, as it does not support styling any
> element that it does not know. There is a simple cure to this: just say
> “IE, meet <section>”:
> <script>
> document.createElement('section');
> </script>
scripting. Therefore, it is better to not style purely structural HTML5
elements if “old versions of IE” are to be considered.
>> <!DOCTYPE HTML>
>
> This triggers “standards” mode in any browser that has one.
>> <html xmlns="http://www.w3.org/1999/xhtml" lang="de" xml:lang="de">
>
> It really does not matter, except to those rare user agents that
> recognize and use the lang attribute.
other user agents, too. For example, it can be used and is used to apply
stylesheet rules only in the context of a specific (group of) language(s),
and it can be used and is used for selecting content for A/B tests with
Optimizely. BTDT.
>> Or can one safely assume that web browsers will »always«
>> support HTML 4.01 (»always« = for the next decades) and thus
>> use HTML 4.01 as that »eternal HTML«?
>
Nonsense.
PointedEars
--
When all you know is jQuery, every problem looks $(olvable).
Thomas 'PointedEars' Lahn
Apr 10, 2016, 7:57:46 AM4/10/16
to
Jukka K. Korpela wrote:
> It’s a different story if you set some styles on <section>. Then old
> versions of IE will ignore them, as it does not support styling any
> element that it does not know. There is a simple cure to this: just say
> “IE, meet <section>”:
> <script>
> document.createElement('section');
> </script>
The “simple cure” introduces a dependency on another technology, client-side
> It’s a different story if you set some styles on <section>. Then old
> versions of IE will ignore them, as it does not support styling any
> element that it does not know. There is a simple cure to this: just say
> “IE, meet <section>”:
> <script>
> document.createElement('section');
> </script>
scripting, needlessly. Therefore, it is better to not style purely
structural HTML5 elements if “old versions of IE” are to be considered.
>> <!DOCTYPE HTML>
>
> This triggers “standards” mode in any browser that has one.
>
> This triggers “standards” mode in any browser that has one.
It triggers Compatibility Mode in older IEs.
>> <html xmlns="http://www.w3.org/1999/xhtml" lang="de" xml:lang="de">
>
> It really does not matter, except to those rare user agents that
> recognize and use the lang attribute.
>
> It really does not matter, except to those rare user agents that
> recognize and use the lang attribute.
The “lang” attribute can be used to trigger language-specific behavior in
other user agents, too. For example, it can be used and is used to apply
stylesheet rules only in the context of a specific (group of) language(s),
and it can be used and is used for selecting content for A/B tests with
Optimizely. BTDT.
other user agents, too. For example, it can be used and is used to apply
stylesheet rules only in the context of a specific (group of) language(s),
and it can be used and is used for selecting content for A/B tests with
Optimizely. BTDT.
>> Or can one safely assume that web browsers will »always«
>> support HTML 4.01 (»always« = for the next decades) and thus
>> use HTML 4.01 as that »eternal HTML«?
>
>> support HTML 4.01 (»always« = for the next decades) and thus
>> use HTML 4.01 as that »eternal HTML«?
>
Adam H. Kerman
Apr 10, 2016, 8:58:57 AM4/10/16
to
Jukka K. Korpela <jkor...@cs.tut.fi> wrote:
>. . . The doctype does not matter, except in the sense of triggering
>standards vs. quirks mode. . . .
I assumed the purpose of the declaration was to allow a browser
to render tagged text according to a specific standard to allow for
the possibility of no backwards compatibility.
>No browser ever supported HTML 4.01, though most browsers currently in
>use support almost all of the HTML 4.01 features that are actually used
>by HTML authors.
May I have more information? 4.01 is from 1999. I thought you meant it
wasn't implemented immediately. What are examples of 4.01 features that
can't be rendered by the browser in a standard way?
>. . . The doctype does not matter, except in the sense of triggering
>standards vs. quirks mode. . . .
I assumed the purpose of the declaration was to allow a browser
to render tagged text according to a specific standard to allow for
the possibility of no backwards compatibility.
>No browser ever supported HTML 4.01, though most browsers currently in
>use support almost all of the HTML 4.01 features that are actually used
>by HTML authors.
wasn't implemented immediately. What are examples of 4.01 features that
can't be rendered by the browser in a standard way?
Jukka K. Korpela
Apr 10, 2016, 11:19:27 AM4/10/16
to
10.4.2016, 15:58, Adam H. Kerman wrote:
> Jukka K. Korpela <jkor...@cs.tut.fi> wrote:
>
>> . . . The doctype does not matter, except in the sense of triggering
>> standards vs. quirks mode. . . .
>
> I assumed the purpose of the declaration was to allow a browser
> to render tagged text according to a specific standard to allow for
> the possibility of no backwards compatibility.
That’s a common but completely wrong assumption.
> Jukka K. Korpela <jkor...@cs.tut.fi> wrote:
>
>> . . . The doctype does not matter, except in the sense of triggering
>> standards vs. quirks mode. . . .
>
> I assumed the purpose of the declaration was to allow a browser
> to render tagged text according to a specific standard to allow for
> the possibility of no backwards compatibility.
The doctype thing was introduced into HTML just because the designers of
HTML specifications wanted to retrofit HTML, an existing but not
formally defined markup language, into the framework of SGML. In SGML, a
doctype declaration has uses of its own, but none of that ever mattered
in web browsers. They did not not implement HTML as an SGML application.
The doctype string has later been taken into use in triggering one of
two or three browser modes, but these do not relate to HTML versions;
instead, they reflect different levels of adherence to the
specifications of various CSS and some HTML features. In one mode, the
CSS declaration width: 100 is ignored (as it must be according to all
CSS specs); in another mode, it is taken as width: 100px (which is what
the author most probably meant). This has absolutely nothing to do with
HTML versions, and still less with Document Type Definitions (which is
what doctype declarations refer to in SGML).
>> No browser ever supported HTML 4.01, though most browsers currently in
>> use support almost all of the HTML 4.01 features that are actually used
>> by HTML authors.
>
> May I have more information? 4.01 is from 1999. I thought you meant it
> wasn't implemented immediately.
To begin with, try
<em/Hello world/
It is valid HTML 4.01 and equivalent to <em>Hello word</em> but browsers
choke on it.
To take an example from a different level, the align="char" attribute
was never implemented. It would be crucial for proper formatting of
numerical tables with decimal numbers. (And, while it’s not relevant to
the topic, it’s really no excuse that the attribute has a counterpart in
CSS, since that counterpart has not been implemented either.)
--
Yucca, http://www.cs.tut.fi/~jkorpela/
Philip Herlihy
Apr 10, 2016, 12:44:54 PM4/10/16
to
In article <nedqnn$ts8$1...@dont-email.me>, jkor...@cs.tut.fi says...
> numerical tables with decimal numbers. (And, while it?s not relevant to
> the topic, it?s really no excuse that the attribute has a counterpart in
learn something useful from.
:-)
--
Phil, London
>
> 10.4.2016, 15:58, Adam H. Kerman wrote:
>
> > Jukka K. Korpela <jkor...@cs.tut.fi> wrote:
> >
> >> . . . The doctype does not matter, except in the sense of triggering
> >> standards vs. quirks mode. . . .
> >
> > I assumed the purpose of the declaration was to allow a browser
> > to render tagged text according to a specific standard to allow for
> > the possibility of no backwards compatibility.
>
> That?s a common but completely wrong assumption.
> 10.4.2016, 15:58, Adam H. Kerman wrote:
>
> > Jukka K. Korpela <jkor...@cs.tut.fi> wrote:
> >
> >> . . . The doctype does not matter, except in the sense of triggering
> >> standards vs. quirks mode. . . .
> >
> > I assumed the purpose of the declaration was to allow a browser
> > to render tagged text according to a specific standard to allow for
> > the possibility of no backwards compatibility.
>
> the topic, it?s really no excuse that the attribute has a counterpart in
> CSS, since that counterpart has not been implemented either.)
JKK is one contributor whose posts I invariably read, and invariably
learn something useful from.
:-)
--
Phil, London
Adam H. Kerman
Apr 10, 2016, 12:56:40 PM4/10/16
to
>That's a common but completely wrong assumption. . . .
Thank you for the information.
Thank you for the information.
Osmo Saarikumpu
Apr 11, 2016, 11:29:19 AM4/11/16
to
On 10/04/2016 18:19, Jukka K. Korpela wrote:
> 10.4.2016, 15:58, Adam H. Kerman wrote:
>
>> Jukka K. Korpela <jkor...@cs.tut.fi> wrote:
>>> No browser ever supported HTML 4.01, though most browsers currently in
>>> use support almost all of the HTML 4.01 features that are actually used
>>> by HTML authors.
>>
>> May I have more information? 4.01 is from 1999. I thought you meant it
>> wasn't implemented immediately.
>
> No, I meant literally that it was never implemented.
I was under the same impression, but after reviewing the examples you
> 10.4.2016, 15:58, Adam H. Kerman wrote:
>
>> Jukka K. Korpela <jkor...@cs.tut.fi> wrote:
>>> No browser ever supported HTML 4.01, though most browsers currently in
>>> use support almost all of the HTML 4.01 features that are actually used
>>> by HTML authors.
>>
>> May I have more information? 4.01 is from 1999. I thought you meant it
>> wasn't implemented immediately.
>
> No, I meant literally that it was never implemented.
give, now I'm not so sure anymore, at least if the following applies:
browser support === conforming user agent
> To begin with, try
>
> <em/Hello world/
>
> It is valid HTML 4.01 and equivalent to <em>Hello word</em> but browsers
> choke on it.
use them would be conforming SGML documents, but ISTM that there is no
requirement for HTML conformance, as the spec says:
"SGML systems conforming to [ISO8879] are expected to recognize a number
of features that aren't widely supported by HTML user agents. We
recommend that authors avoid using all of these features."
Considering that:
"HTML document is an SGML document that meets the constraints of this
specification."
Coupled with:
"A conforming user agent for HTML 4 is one that observes the mandatory
conditions ("must") set forth in this specification..."
Coupled with the syntax for EM:
Start tag: required, End tag: required.
> To take an example from a different level, the align="char" attribute
> was never implemented.
"If a user agent doesn't support character alignment, behavior in the
presence of this value is unspecified."
And later on the char attribute:
"User agents are not required to support this attribute."
But, maybe I'm missing something obvious, as usual :)
--
Best wishes, Osmo
Jukka K. Korpela
Apr 11, 2016, 1:08:25 PM4/11/16
to
11.4.2016, 18:29, Osmo Saarikumpu wrote:
> On 10/04/2016 18:19, Jukka K. Korpela wrote:
– –
> On 10/04/2016 18:19, Jukka K. Korpela wrote:
>> To begin with, try
>>
>> <em/Hello world/
>>
>> It is valid HTML 4.01 and equivalent to <em>Hello word</em> but browsers
>> choke on it.
>
> IINM, this would be an SGML construct (SGML SHORTTAG) and documents that
> use them would be conforming SGML documents, but ISTM that there is no
> requirement for HTML conformance,
Clause 4.2 says: “HTML 4 is an SGML application conforming to
>>
>> <em/Hello world/
>>
>> It is valid HTML 4.01 and equivalent to <em>Hello word</em> but browsers
>> choke on it.
>
> IINM, this would be an SGML construct (SGML SHORTTAG) and documents that
> use them would be conforming SGML documents, but ISTM that there is no
> requirement for HTML conformance,
International Standard ISO 8879 -- Standard Generalized Markup Language
SGML”. Since processing HTML documents is what a user agent does, by
definition, it is clearly a requirement that SGML rules be obeyed.
> "SGML systems conforming to [ISO8879] are expected to recognize a number
> of features that aren't widely supported by HTML user agents. We
> recommend that authors avoid using all of these features."
> Coupled with the syntax for EM:
>
> Start tag: required, End tag: required.
defined in the DTDs. But that’s not the point here. The point is that in
my example, the second slash “/” is by definition an end tag (called nul
end-tag, NET, in SGML).
>> To take an example from a different level, the align="char" attribute
>> was never implemented.
>
> On this the spec says:
>
> "If a user agent doesn't support character alignment, behavior in the
> presence of this value is unspecified."
>
> And later on the char attribute:
>
> "User agents are not required to support this attribute."
a browser non-conforming. It however means that it does not support (all
of) HTML 4.01.
--
Yucca, http://www.cs.tut.fi/~jkorpela/
Thomas 'PointedEars' Lahn
Apr 11, 2016, 2:20:30 PM4/11/16
to
Ask him for references that support his humble opinion.
PointedEars
--
realism: HTML 4.01 Strict
evangelism: XHTML 1.0 Strict
madness: XHTML 1.1 as application/xhtml+xml
-- Bjoern Hoehrmann
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