Isn't "text-overflow: ellipsis" valid CSS?

Question

This code triggers an error when run through the W3C CSS Validator:

p{
    text-overflow: ellipsis;
}

I get:

Line     Code context      Error/Warning
2        p                 Parse Error [empty string]

Is it just a bug in the validator or am I missing something really obvious?

Haya

Answer 1

This is a bug in the CSS validator, it has been already reported. text-overflow:ellipsis is a valid rule, however the W3C CSS validator is unfortunately prone to errors (see bug list).

However, note that the current working draft lists some text-overflow values as feature at risk:

The Working Group has identified the following features as at risk of being removed from CSS Basic User Interface Module Level 3 when exiting CR. Implementors are urged to implement these features, if they wish to see these features remain in this specification. All other features are either defined in a normative reference (e.g. CSS 2.1 [CSS21] or Selectors [SELECT]) or are believed to have two or more implementations, and thus will not be dropped without returning to last call.

• [...]
• text-overflow property value: <string>
• text-overflow property 2-value syntax and definition.

While this doesn't affect the ellipsis value, it could be the source of the bug in the validator:

Parse Error [empty string]

References

• W3C: CSS Basic User Interface Module Level 3 (CSS3 UI): (WD-20120117)
  • Features at risk
  • 8.2. Overflow Ellipsis: the ‘text-overflow’ property

Heribertoheringer

With regard to it being at risk...I read it that certain variations of text-overflow are at risk, not the whole thing. User agent support should justify keeping at least the basic ellipsis implementation. – Camey

@TimMedora: Yes, addressed this concern and made it more clear. Only some features property values are at risk, not the property itself. ellipsis isn't at risk, however, since the validator prints [empty String] as error, I suspect that those properties are creating the validator's behavior. – Heribertoheringer

This error has been around for a very long time. I last ran into it myself in 2010-ish, way before this recent LCWD. Frankly I don't know what they're doing with the validator. I hope they're rewriting it. – Revolve

Answer 2

It's valid based on MDN's reference, which also links to the spec: http://dev.w3.org/csswg/css3-ui/#text-overflow

Out of curiosity, I ran one of my own sites through the validator. I noted that it listed a few things that I would not consider errors, such as properly prefixed vendor extensions and data URIs.

Camey

Vendor extensions are not valid because they're not part of the standard. However, they are defined in the grammar so implementations can use them. – Revolve