Re: Is markup allowed in attribute values?

Arnoud (galactus@stack.urc.tue.nl)
Wed, 26 Jun 1996 22:34:26 +0200 (MET DST)


From: Arnoud "Galactus" Engelfriet <galactus@stack.urc.tue.nl>
Message-Id: <199606262034.WAA14131@toad.stack.urc.tue.nl>
Subject: Re: Is markup allowed in attribute values?
To: amc@cs.wustl.edu (Adam M. Costello)
Date: Wed, 26 Jun 1996 22:34:26 +0200 (MET DST)
Cc: www-html@w3.org
In-Reply-To: <9606262021.AA17354@bacon.cs.wustl.edu> from "Adam M. Costello" at Jun 26, 96 08:21:39 pm

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> Is markup allowed in attribute values?  The particular case I'm thinking

No, it's not. An attribute value may only contain character
data. That is, literal text with -sometimes- entities.

> I've read the HTML 2.0 spec, even tried reading the DTD (I don't
> actually know SGML), but it doesn't seem to say one way or another.

Actually the spec does, you just have to know SGML to understand it =).
In the DTD you can see the permitted contents of a tag. For example,
this is the line for META:

<!ELEMENT META - O EMPTY -- Generic Metainformation -->
<!ATTLIST META
        http-equiv  NAME    #IMPLIED  -- HTTP response header name  --
        name        NAME    #IMPLIED  -- metainformation name       --
        content     CDATA   #REQUIRED -- associated information     --
        >

The "content" is defined as CDATA, which means you can only put
character data in there, no entities or markup.

Galactus
who wonders why you can't have entities in the contents of a META.
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