[whatwg] Allowing ">" in attribute values

Thu Jun 24 00:43:25 PDT 2010

On Thu, 24 Jun 2010 04:13:56 +0200, Benjamin M. Schwartz  
<bmschwar at fas.harvard.edu> wrote:
> The HTML5 spec appears to allow ">" inside an attribute value.  For
> example, the following page (note the body tag) passes the experimental
> HTML5 validator at w3c.org:
>
> <!DOCTYPE HTML><html><head><title></title></head>
> <body class="3>2">
> </body></html>
>
> I think ">" should be disallowed inside attribute values.   It is
> disallowed in XHTML [1].  It is disallowed in HTML 4.01 [2].  Disallowing
> it in HTML5 would avoid unnecessary divergence, and also sometimes
> simplify parsing.

Why would it simplify parsing? It's rather nice to allow it for the  
<iframe srcdoc> feature.

> [1] according to the validator in XHTML 1.1 Strict mode.
>
> 'character ">" is not allowed in the value of attribute'
>
> [2] http://www.w3.org/TR/REC-html40/charset.html#h-5.3.2
>
> "Similarly, authors should use ">" (ASCII decimal 62) in text instead
> of ">" to avoid problems with older user agents that incorrectly perceive
> this as the end of a tag (tag close delimiter) when it appears in quoted
> attribute values."
>
> It is also disallowed by the HTML 4.01 Strict validator.

-- 
Anne van Kesteren
http://annevankesteren.nl/