How do I target elements with an attribute that has any value in CSS?

Question

I know that I can target elements which have a specific attribute in CSS, for example:

input[type=text]
{
    font-family: Consolas;
}

Answer 1

The following will match any anchor tag with a rel attribute defined:

a[rel]
{
    color: red;
}

http://www.w3.org/TR/CSS2/selector.html#pattern-matching

---

Update: To account for the scenario @vsync mentioned, in the comment section (differentiating between emtpy/non-empty values), you could incorporate the CSS :not pseudo-class:

a[rel]:not([rel=""])
{
    color: red;
}

https://developer.mozilla.org/en-US/docs/Web/CSS/:not

Answer 2

Yes in CSS 3 selectors there are several attribute selectors.

E.g.

[att] Represents an element with the att attribute, whatever the value of the attribute.

[att=val] Represents an element with the att attribute whose value is exactly "val".

[att~=val] Represents an element with the att attribute whose value is a whitespace-separated list of words, one of which is exactly "val". If "val" contains whitespace, it will never represent anything (since the words are separated by spaces). Also if "val" is the empty string, it will never represent anything.

[att^=val] Represents an element with the att attribute whose value begins with the prefix "val". If "val" is the empty string then the selector does not represent anything.

[att$=val] Represents an element with the att attribute whose value ends with the suffix "val". If "val" is the empty string then the selector does not represent anything.

[att*=val] Represents an element with the att attribute whose value contains at least one instance of the substring "val". If "val" is the empty string then the selector does not represent anything.

Answer 3

Should add that if a browser sets an attribute by default you may need to work around. This does not appear to be an issue in "modern" brosers, however, this is an issue I have seen, so be sure to check cross-browser performance.

For instance, I discovered that in IE prior to 9, colSpan is set for all TD's in a Table, so any single cell has the hidden colspan value of 1.

So if you were targetting "any TD with colspan attribute" you apply in your webdoc, even the td's having no colspan attribute set, such as any TD being a single cell, will receive the css styling. IE less than 9 will basically style them all!

Only reason to concern over this is all the remaining XP users out there who cannot upgrade above IE8.

So for Example, I have a group of tables where the content may shift from end to end, leaving anywhere from 1 to 7 cells blank either at the end or the beginning.

I want to apply a color to any blank cells at the end or the beginning utilizing the colspan attribute. Using the following will not work in IE less than 9

#my td[colspan] {background-color:blue;}

...all TD's will get styled (funny since the conditional attribute styling was supposedly superior in IE, but I digress...).

Using the following works across all browsers when I set the value of colspan to 'single' for any solitary cell/TD I wish to include in the styling scheme, however its a 'hack' and will not properly validate...

#my td[colspan="single"] {background-color:blue;} /* 'single' could be anything */
#my td[colspan="2"] {background-color:blue;}
#my td[colspan="3"] {background-color:blue;}
#my td[colspan="4"] {background-color:blue;}
#my td[colspan="5"] {background-color:blue;}
#my td[colspan="6"] {background-color:blue;}
#my td[colspan="7"] {background-color:blue;}

Alternatively you should be able to more appropriately address the issue using conditional styling using "if lt IE 9" to override. It would be the correct way to do this, just keep in mind you must hide the "properly constructed css" from IElt9 in the process, and I think the only proper way to do that is with selective style sheets.

Most of us already do that anyway, but regardless, you still do well to consider and test if a browser applies an auto-attribute when it sees none, and how it may handle your otherwise corect syntax for styling on attribute values.

(btw, colspan just happens not to be in the css specification yet [as of css3], so this example throws no validation error.)