- From: Brian Blakely <anewpage.media@gmail.com>
- Date: Mon, 11 Feb 2013 19:17:25 -0500
- To: "Tab Atkins Jr." <jackalmage@gmail.com>
- Cc: "whatwg@lists.whatwg.org" <whatwg@lists.whatwg.org>
Sure thing. Let me go through the use cases that I see as applicable today, derived from instances where an existing vendor or service currently utilizes a non-standard implementation. * Social network sharing Facebook currently scrapes "OpenGraph tags" from shared pages to create a content snippet. One such tag is og:image, which specifies the image to display in that snippet. Twitter and Google+ use these same tags in addition to their own implementations for developers. For the title and description of the snippet, scrapers will fall back to <title> and the meta description. A canonical image would serve the same purpose, but for visual content. * News aggregation Flipboard, a highly visual, magazine-style news and article reader, displays a hero image from the target page. It does this by parsing and analyzing the <img> elements in a page, sometimes displaying a non-optimal or even vacant result. A canonical image would allow developers to control this kind of representation with more specificity, and provide the 3rd party app with another presentation option. * OS Integration Apple currently parses their own "apple-touch-icon" element that specifies which image will serve as a web application's icon after the user has added to the homescreen. Android's browser uses this same element, while Microsoft uses a similar "msapplication-TileImage". When these element is not specified, a screenshot of the website is used instead or, in Microsoft's case, the favicon. Firefox OS has still another means of implementation for this. A canonical image could either replace or provide an additional fallback for this functionality. * Color In all these cases, a canonical color allows external parsers to provide further branding or additional flourish in their representation of apps and pages. Microsoft's "msapplication-TileColor" and "msapplication-navbutton-color" elements aim to fulfill this purpose in IE by coloring the app's tile on the Windows 8 homescreen and IE's own navigation UI, respectively. On Mon, Feb 11, 2013 at 5:41 PM, Tab Atkins Jr. <jackalmage@gmail.com>wrote: > On Mon, Feb 11, 2013 at 2:33 PM, Brian Blakely <anewpage.media@gmail.com> > wrote: > > * Proposal > > > > Meta elements for defining a canonical image and color to be associated > > with the page(s) in which they are included. This is intended for use by > > user agents and third-party applications (such as social networks), > > referred to collectively as "parsers" in this document. It is inspired > by > > Microsoft's recent work in site pinning and Apple's "standalone" webapp > > implementation in iOS Safari. > > Can you elaborate? I have no idea what UAs and third-party apps would > do with a "canonical image" or "canonical color". > > ~TJ >
Received on Tuesday, 12 February 2013 00:18:12 UTC