GreyWyvern wrote:
> And lo, Blinky the Shark didst speak in alt.www.webmaster:
>
>> Can't for the life of me figure out how to get a hr into a js write.
>>
>> http://blinkynet.net/humor/index.html
>>
>> I'd like a *scripted* <hr> just before the first line created by the
>> fist little script do that it separates the quote of the day from the
>> page intro above it. The reason I want it to be part of the script is
>> so if scripts are disabled and the separator isn't needed, it's not
>> rendered. (The nonscripted <hr> *after* the quote of the day will be
>> all the separation I need between the intro and the list.)
>>
>> I've been able to make this work just fine with "<hr />" being the first
>> element in the first document.write:
>>
>> document.write("<hr />" + "foo")
>>
>> But validation fails with a you-can't-use-a-<hr>-there error.
>
> /me boggles at all the other responses in this thread.
>
> XHTML is not just HTML with a few fancy markup changes. The way the
> markup is *interpreted* changes as well. XHTML is meant to be valid XML
> and thus must follow all the rules as XML.
>
> One of the rules is that you can't just include text containing angle
> brackets or ampersands without them being interpreted as markup and
> entities. Unless you comment it out, or strictly define it as CDATA
> (character data), the XML parser will assume it is PCDATA (parsed
> character data), or IOW: markup.
>
> The element which which you're having problems is this one:
>
>
><script type="text/javascript">
> document.write("<hr \/>" + "Today's alleged Yogi-ism:")
></script>
>
>
> If this were normal HTML, the parser would recognise the script element as
> special and switch to the JS parser for all the contents. The XML parser
> doesn't do this. In XHTML, the script element is *not* special and
> elements found inside it are interpreted as actual elements, whether they
> are inside document.write's or not.
>
> So, in order to get it to validate, you need to tell the parser that
> what's inside the script element is special. You can do this in one of
> two ways, but there are caveats about both.
>
> 1) Simply use SGML comments to hide the code:
>
>
><script type="text/javascript"><!--
> document.write("<hr \/>" + "Today's alleged Yogi-ism:")
> --></script>
>
>
> There are two issues with this though. The first is, though browsers you
> view this in will interpret this bit of code the way you think it should
> work, that's only because you are serving XHTML code to the HTML tag-soup
> parser by using the text/html MIME-type. *Technically* the XML parser is
> allowed to ignore *anything* within SGML comments, *even code*. So
> interpreted as real XML, the above snippet is entirely equivalent to:
>
>
><script type="text/javascript"></script>
>
>
> The second issue is that the double hyphen is a special sequence within
> SGML comments which tell it the comment is ending. Unfortunately, the
> double hyphen is also used in Javascript as the decrement operator (x--).
> So commenting out your code this way precludes you from using the
> decrement operator at all or else some of your code may appear as text,
> and/or your document will not validate. This second issue affects plain
> HTML as well.
>
> 2) Use the XML <![CDATA[ ... ]]> structure to mark the boundaries of your
> code.
>
>
><script type="text/javascript"><![CDATA[
> document.write("<hr \/>" + "Today's alleged Yogi-ism:")
> ]]></script>
>
>
> This is the preferred way to do things in XML, but it won't work in your
> document. Why not? Because you are serving it with a text/html
> MIME-type. This means that markup which *should* be parsed with the XML
> parser is being parsed with the HTML tag-soup parser instead. This is
> precisely why, in your existing document, the JS still works, even though
> the document doesn't validate as XHTML.
>
> In order for the above to function properly in both an HTML and XHTML
> context, you'd need to use a comment system like so[1]:
>
>
><script type="text/javascript"><!--//--><![CDATA[//><!--
> ...
> //--><!]]></script>
>
>
> That's pretty crazy, eh?
>
> So, to summarize: Your markup is being delivered to the browser using the
> text/html MIME-type. This allows it to render as you think it should
> because the HTML tag-soup parser is being used. However, the W3C
> validator is interpreting your XHTML markup as if it were served with the
> correct MIME-type: application/xhtml+xml OR text/xml
>
> This is leading to validation errors which are only errors of context.
> The code is being rendered by browsers in one context, while the validator
> is viewing it in another. I would recommend that if you don't yet fully
> understand the difference between these two contexts, you should return to
> plain HTML4, since that is exactly how you are telling browsers to
> interpret your XHTML markup anyway.
>
>
> One last thing to note, in XHTML sent with one of the proper MIME-type's
> above, certain JS methods which have the potential to allow easy breakage
> of the strict XML rules have been disabled. This includes
> document.write() and also innerHTML() and its relatives. So the code you
> are trying to use, even if you did try switching to the correct
> MIME-types, would not even work, instead throwing JS errors.
>
> An equivalent would be (commented to work in both text/html and text/xml):
>
>
><script type="text/javascript" id="replaceMe"><!--//--><![CDATA[//><!--
> var hr = document.createElement('hr');
> var thisElem = document.getElementById('replaceMe');
> var parentElem = thisElem.parentNode;
> parentElem.replaceChild(hr, thisElem);
> parentElem.appendChild(document.createTextNode("To day's alleged
> Yogi-ism:"));
> //--><!]]></script>
>
>
> Or the somewhat simpler to understand, but won't work in IE 5.5 and
> earlier[2]:
>
>
><script type="text/javascript" id="replaceMe"><!--//--><![CDATA[//><!--
> var frag = document.createDocumentFragment();
> var hr = document.createElement('hr');
> frag.appendChild(hr);
> frag.appendChild(document.createTextNode("Today's alleged
> Yogi-ism:"));
> var thisElem = document.getElementById('replaceMe');
> thisElem.parentNode.replaceChild(frag, thisElem);
> //--><!]]></script>
>
>
> More complicated, yesh. However the purpose is to enforce, as much as
> possible, dynamically added code to be valid XML in itself.
>
> If this is all too much for you to handle, then you should seriously
> consider a step back from XHTML and stick with HTML. Like I said, it's
> more than just a few extra rules tacked onto HTML 4.01; XHTML is an
> entirely different way to parse documents.
>
> HTML is entirely sufficient for most web documents of any kind.
>
>> So I look at W3Schools, which I think I've seen recommended here for
>> tutorials -- I'm obviously new to js.
>>
>> Barely into the js tute, I see:
>>
>> <q>
>>
>> A JavaScript statement like this: document.write("<h1>" + name +
>> "</h1>") can write a variable text into an HTML page
>>
>> </q>
>>
>> Now if they can get a <h1> in there, why can't I get a <hr> in, using the
>> same method? Yes, I tried it with and without closing tags. Validator
>> won't have anything do do with it.
>
> It is simply because you are using an XHTML DOCTYPE. The validator is
> expecting you to follow the rules as if you were using one of the correct
> MIME-types.
>
>> Is there a *simple* way to do that I want? No, I'm not going to do
>> twelve lines of code for one hr.
>
> Yesh, change the DOCTYPE back to HTML 4.01. Simple.
>
> Grey
>
> [1] http://www.hixie.ch/advocacy/xhtml
>
> [2] IE 5.5 and earlier do not support the DocumentFragment object.

Thanks. Based on your input, it looks like I will remove the <hr> and
not rewrite the entire site.

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