Le 16 mars 2013 à 09:37, Tom Livingston <tom...@gmail.com> a écrit :
> This may shed some light: > > http://stackoverflow.com/questions/8549529/what-is-the-difference-between-screen-and-only-screen-in-media-queries That stack overflow page refers to this passage in the MQ level 3 spec: > The keyword ‘only’ can also be used to hide style sheets from older user > agents. (above example 9) I’ve always found that statement about the ‘only’ keyword in the CSS MQ spec somewhat ambivalent. Inside a stylesheet, a User Agent that only implements CSS2 will treat as invalid the following: @media screen and (color) {} @media (width:200px) {} And ignore everything until the closing ‘}’. See CSS2.1:4.1.7 and 4.2 The only reasonable use case for using the ‘only’ qualifier as a way to hide something from older UA’s is this: @media only screen {} (and specify that the style rules should only be used for screen media) On the other hand, the ‘only’ keyword can eventually be useful to hide a complete stylesheet from an older UA that implements HTML 4 correctly. Linking to a stylesheet along these lines _should_ be accepted by such an UA: <link rel="stylesheet" href="style.css" media="screen and (min-width: 100px)"> (The UA will truncated after the ‘screen’ media type) but this _should_ be ignored: <link rel="stylesheet" href="style.css" media="only screen and (min-width: 100px)"> (the older UA will truncate after the ‘only’ keyword, and decide it is an invalid media type) see list item 2 under http://www.w3.org/TR/1999/REC-html401-19991224/types.html#type-media-descriptors Philippe -- Philippe Wittenbergh http://l-c-n.com ______________________________________________________________________ css-discuss [css-d@lists.css-discuss.org] http://www.css-discuss.org/mailman/listinfo/css-d List wiki/FAQ -- http://css-discuss.incutio.com/ List policies -- http://css-discuss.org/policies.html Supported by evolt.org -- http://www.evolt.org/help_support_evolt/
