<entry-title>Value Excerption Pattern: Parsing 'value' from an empty element</entry-title> This page is targetted at those already experienced with microformats.
Please carefully note, this page is about a pre-draft, experimental and unfinished microformats proposal. You cannot use this pattern on your live pages, it is not supported by any stable parser and you should not assume that this pattern will be finalized as-is! We're just asking for help in testing this thoroughly. Thank you.
- 1 The proposed parsing rules
- 2 Example Tests
- 3 Evil Tests
- 4 Response
- 5 Related Pages
This is a special page to introduce and gather results to widespread testing of a proposed extension to the value-excerption pattern.
This pattern can be used to resolve some long standing issues with including machine-data in microformats; it's imperative we test thoroughly before adding it to any pattern specification. Following are a number of example tests. Please try them out.
The pattern we're testing looks a little something like this. Those experienced with microformats should immediately see what we're trying to do:
<p class='tel'> <span class='type'> <span class='value-title' title='cell'></span> mobile </span> <span class='value'>+44 7773 000 000</span> </p>
<p class='dtstart'> <span class='value-title' title='2009-01-06T22:54:00-0800'></span> January 6th, in the evening </p>
It allows you to include machine-form data alongside the human form, without polluting visible formatted content with undesired machine form data.
This covers cases where a microformat uses a fixed format of data that is either inappropriate for visible inclusion in a page (such as a full date-time and timezone string), or where an American-English keyword is needed — such as
cell instead of ‘mobile’ in a British English page, or any number of non-English translations.
This pattern is based on rendering behavior in browsers whereby an empty element — that is one containing no text-nodes or other child elements — remains in the DOM tree (for parsing) but is not rendered visibly to a page. This allows an element to be included in the document with a
title attribute (as in the example), but without a tooltip being exposed to users, and without the data being read out by screen readers.
You can use
value-title on non-empty elements as well; whatever makes most sense to your publishing scenario. This page is dedicated to the empty-element version though, since that offers up the consumption unknowns.
Based on everything we know up to this point, we believe this pattern will work. But, it's wide ranging and the web is broad, and we want to be sure. Please, help us out testing this pattern proposal. Examples tests are below, please push them or your own variants into publishing systems, content management systems, editor applications and tools. Check that it comes out the other side with the data intact, and exposed (or hidden) as expected: Render it in desktop browsers, mobile browers, screen readers, in braille… anything you can test, we want to know about! We need to see any quirks, oddities and so on.
Also, by all means provide thoughts on the publishing flow for this. An empty element is an uncommon structure outside of forms and scripts, but the reasoning is as follows: ‘Machine formatted data’ is not metadata, it is content. Therefore, it's structurally appropriate to have it as a sibling to the human-formatted content.
Note that valid HTML is a cornerstone of microformats. Inventing new attributes, depending on unstable drafts of HTML5, using non-standard DOCTYPEs or XML extensions is not an applicable option. We're trying to achieve something as gracefully as we can within the limitations of HTML4, and without harming user experience.
The proposed parsing rules
The current, likely incomplete, parsing rules and restrictions for this pattern are as follows:
- Only one
value-titleelement may be included as a child of a property. No splitting or concatenation, no combining with other value-excerption elements.
- An empty
value-titleelement must be the first-child of the property (not including any preceding whitespace). To alleviate the negative impact of non-visible data, the value should be as near as possible to declaring the property.
- The machine-data value must represent the same data as the visible text; the parent property must not contain arbitrary data. Validator tools will be encouraged to verify this where possible (for example, some programming languages have access to powerful date parsing algorithms that can compare human dates to the ISO form).
- The empty element can be any element, but a generic
spanis most appropriate. You could use
bif you want to save bytes, or an
input type=hiddenif it makes sense to you. That choice will not matter to parsers. You are in complete control of that publishing decision. As per usual µf documentation,
spanwill be used for generic examples.
value-titleproperty does not have to be empty. If you do want a tool-tip to expose a useful data-form, you can. e.g.
<span class='value-title' title='2008'>last year</span>is valid too.
The following snippets are example tests for the new pattern. You can use them as is, or use them as a base for your own tests with your own content. If you write your own tests, please document them under ‘additional test cases’ so that any failing tests can be checked for validity.
hAtom#1: An hAtom
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html lang="en"> <head> <title>Value Excerption Pattern Test hAtom#1</title> </head> <body> <div class="hentry"> <h1 class="entry-title">An introduction to Microformats</h1> <p> Published on <span class="published updated"> <span class="value-title" title="2009-01-09T11:33:00-0800"></span> January 9th, around lunchtime</span> by <span class="author vcard"> <a class="url fn" href="http://example.com"> Joe Blogger</a></span>. </p> <p class="entry-content">Wow, microformats are really useful! You can learn loads about them on the <a href="http://microformats.org/wiki">microformats wiki</a>. </p> </div> </body> </html>
hCal#1: An hCalendar
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html lang="en"> <head> <title>Value Excerption Pattern Test hCal#1</title> </head> <body> <div class="vevent"> <h1 class="summary">Value Exception Test Day!</h1> <p class="description">Come help <span class="organizer vcard"> <a class="fn url org" href="http://microformats.org">microformats.org</a> </span> test a new value-excerption pattern for sanity and robustness! </p> <p>Help out by running some tests at <span class="dtstart"> <span class="value-title" title="2009-01-12T12:00:00-0800"></span> midday on Monday January 12th</span>. </p> <p>See <a href="url" href="http://microformats.org/wiki/value-excerption-pattern-issues/empty-value-element-test">the wiki</a> for more details! </p> </div> </body> </html>
hCard#1: An hCard
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html lang="en"> <head> <title>Value Excerption Pattern Test hCard#1</title> </head> <body> <!-- Behind Test --> <div class="vcard"> <h1 class="fn">Ben Ward</h1> <p>Ben Ward's birthday is <span class="bday"> <span class="value-title" title="1984-02-09"></span> February 9th </span>. You should throw him a party! Or call his <span class="tel"> <span class="type"><span class="value-title" title="cell"></span>mobile</span> on <span class="value">415.123.123</span></span> to wish him well! </p> </div> <!-- End Test --> </body> </html>
hAudio#1: An hAudio
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html lang="en"> <head> <title>Value Excerption Pattern Test hAudio#1</title> </head> <body> <h1>Song of the year?</h1> <!-- Behind Test --> <p class="haudio">Did you hear ‘<span class="fn">Heavy Water</span>’ on <span class="contributor">Foals</span> ‘<span class="album">Antidodes</span>’ record <span class="published"> <span class="value-title" title="2008"></span> last year </span>? It's <span class="duration"> <span class="value-title" title="PT04M32S"></span> 4 and a half minutes long </span>, you should make time to hear it!</p> </div> <!-- End Test --> </body> </html>
If you believe there is an error in any of these tests, or in any others that people contribute, please post on the mailing list.
If you want to give existing microformat parsers a good run out, construct ‘evil’ tests using nesting, combination and interpolation of different microformats.
hAtom + hCalendar
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html lang="en"> <head> <title>Value Excerption Pattern Test hAtomhCalEvil#1</title> </head> <body> <div class="hentry vevent"> <h1 class="entry-title summary">An introduction to Microformats</h1> <p> Published on <span class="published updated"> <span class="value-title" title="2009-01-09T11:33:00-0800"></span> January 11th, late afternoon</span> by <span class="author organizer vcard"> <a class="url fn" href="http://example.com"> Joe Blogger</a></span>. </p> <p class="entry-content description"> <span class="dtstart"> <span class="value-title" title="2009-01-14T19:00:00"></span> this coming Wednesday at 7 </span> is not the date of a completely fictional microformats event. If it existed, it would promise to be informative and get you up to speed on microformats.org for 2009! Now you've learned to work with microformats a little, why not attend and get involved! Why not? Because this event is a test case, not for real. </p> </div> </body> </html>
- Don't like the empty element? Don't like the use of the title attribute? Please file general issues concerning the proposed pattern on the main value excerption brainstorming page, or discuss them on the mailing list.
- Add results of tests and responses to these tests themselves on this page.
Misplaced responses will be moved, and having to do so will make Ben growly, so, y'know, please try to keep the wiki tidy.
List successfully tested environments here. Add new environments as new list items, and expand existing list items with your name and platform variants to indicate verified successes.
|MediaWiki/Linux||Publishing||Safari 3.2.1 (Mac OSX 10.5)||User:BenWard||The empty |
|Safari 3.2.1||Consuming||Mac OSX 10.5,||User:BenWard||Empty-span remains in DOM. Web Inspector reports the element has width and height of ‘0px’. No tooltip due to zero-dimensions.|
|Firefox 3.0||Consuming||Mac OSX 10.5,||User:BenWard||Empty-span remains in DOM. Firebug reports the element has width of '0px' and height of ‘16px’. No tooltip due to zero-width.|
|Opera 9.92||Consuming||Mac OSX 10.5,||User:BenWard||Empty-span remains in DOM. Dragonfly reports the element has width of '0px' and height of ‘0px’. No tooltip due to zero-dimensions.|
For failures, please provide as much information as you can. The precise impact of the error, whether the behavior could be regarded as a bug in the software you're testing, whether it works in subsequent releases, whether you changed any settings in the software to produce the result, and if so, whether enabling/disabling that setting should be regarded a showstopper if this pattern were certified.
Since we want more detail, please expand failures into headed sections rather than cramming into a table.
For example, take this entirely plausible scenario as a template:
Example: Fake Publisher 3.1ß
- Windows Vista
- Test By
- When trying to enter an empty span in my HTML editor, which I wrote myself whilst I was high, the application immediately crashes, performs
rm -rf /on all UNIX boxes connected to my local network (which also appears to cause Android phones within Bluetooth range to do the same…), and then causes all attached peripherals to combust. I was not able to reproduce, as my house was now on fire. I think using a self closing XHTML tag instead might work-around the problem because as we know, it's been proved by Real Scienticians that XML is always better than HTML. Alternatively, it may be a bug in the beta software.
- This is a beta release, and a bug has been filed.
- This product has a known history of flammability bugs.
- The user must explicitly enable the ‘Endanger My Life’ checkbox under the ‘Advanced Mislabelled Checkboxes’ tab of the ‘Complicated Preferences’ preferences pane.
- You get the idea.