- From: Rune Lillesveen <rune@opera.com>
- Date: Fri, 21 Oct 2011 11:14:52 +0200
- To: www-style@w3.org, "Peter Beverloo" <beverloo@google.com>
On Thu, 20 Oct 2011 19:12:01 +0200, Peter Beverloo <beverloo@google.com> wrote: > The CSS Device Adapt specification defines a parsing algorithm[1] for > the meta-element viewport content, which has been based on WebKit's > implementation that shipped with iOS4. This algorithm only accepts > commas as separators between properties. First, it's in a non-normative section, and we want UAs to move towards an @viewport implementation. That being said, it's there to suggest a mapping between viewport meta and @viewport in a transition phase. > In reality, web authors are using both commas as semi-colons. A wide > range of websites, including CNN[2], Flickr[3] and Reddit[4] depend on > this behavior, which has led at least Mozilla and Microsoft to > implement it and, in case of the latter, write about it[5]. Yes, and they have to add some combination of scale properties to compensate for the fact that "width=device-width;" is the same as "width=0" in Safari and Opera (see comments for the mentioned sites below). > I think the specification should adapt to reflect what authors are > doing. While it's unfortunate that the divergence between commas and > semi-colons happened, it's important for compatibility among mobile > browsers. Two alternative proposed changes: 1. Keep the algorithm as it is and mention that some implementations accept ';' as a separator in addition to ','. 2. Modify the algorithm to include ';' as a separator and say that it's based on the Safari implementation with the ';' added as a recognized separator. > [1] http://dev.w3.org/csswg/css-device-adapt/#parsing-algorithm > [2] http://m.cnn.com Does not give me a viewport meta in Opera. > [3] http://m.flickr.com "width=device-width; initial-scale=1.0; maximum-scale=1.0; user-scalable=0;" Works in Safari because the over-constraining scale values cause the width to end up at device-width anyway. This would not have worked in Safari or Opera: "width=device-width; user-scalable=0;". > [4] http://www.reddit.com/.compact (or http://m.reddit.com/) Same as for m.flickr.com. > [5] > http://blogs.msdn.com/b/iemobile/archive/2010/11/22/the-ie-mobile-viewport-on-windows-phone-7.aspx -- Rune Lillesveen Layout Group Manager Core Technology Department Opera Software ASA
Received on Friday, 21 October 2011 09:15:34 UTC