Your Questions Answered #5

Richard Clark — Tue, 02 Mar 2010 14:30:55 +0000

We’re back with our first roundup of your questions for 2010. In this article, we’ll be covering a range of topics including sections and sectioning, the element, scaling video, and a proposal for a element.

Headers and sidebars

Ad asked:

Hello,

I have 2 questions:

1. If I have my main navigation above the masterhead would best practise be having the nav tag inside of a header tag with the h1 and h2 in a hgroup? Or should the nav and header tag be separate?

2. I am building a blog in HTML5. It has a blog-like sidebar with articles, contact info and about info in it. Would the best tag to wrap this in be section or aside?

Thank you so much for your time,
Ad Taylor

Placing your

within your

is fine and valid. However, if it makes more sense to leave it outside, then you can do that too. You don’t need to put the inside the

though.

See our articles on

and

for more on this.

Regarding your second question, I would use

(as we’ve done on the HTML5 doctor site) and then use multiple sections within that. Also see Bruce’s article on Designing a blog with HTML5.

Hope that helps.

Cheers, Rich

HTML5 element

Martijn asked:

As you are, according to the slogan, “helping [me] implement HTML5 today,” I thought to bother you people with a spec. related question.

What should an UA do with an image without specified width and height attributes?

The dimension attributes part of the specification keeps stating “if specified” for every rule but doesn’t give any “if not specified”.

The part of the specification defining the img element itself does not state anything of importance about the dimension attributes apart from how the attributes in the DOM should be created by the UA.

Interesting is to note that they have omitted these attributes in all their img element examples.

In the dimension attribute section they go state the following.

– The dimension attributes are not intended to be used to stretch the image.

So we can only use them to make images smaller? This is odd as well so let’s say by stretch they mean to say both expending and shrinking in size. In this case the attributes can only be used for two cases:

1. To state the exact width and height of the image. Something that seems redundant unless not using those attributes means the UA can display the image at any size (which it might, as nothing about this is defined in the spec.).

2. To give a 0 in both attributes. By this I am telling the UA that the image is not to be seen by the user.

Am I missing something or is the specification missing this?

Looking forward to getting your prescription

Kind Regards, Martijn

If no dimension attributes are specified, the browser will leave no space for the image, and once the image has been loaded (after the rest of the page), it will then need to reflow the entire page, as that’s the first time it knows the size of the image. This can cause the content you’re reading scrolling off the page.

If you give the size of the image as attributes in the HTML, the browser will leave space and render the image there once it’s loaded without reflowing the page. On a mobile phone, reflowing the page unnecessarily drains the battery, and users can get vertigo from the page’s text jumping around to accommodate images.

Thanks, Bruce

Section and Sectioning

Yanoo asked:

Hi,

What do you mean when you are talking about “sectioning”? And why don’t header and footer require sectioning?

I think about section and sectioning like about part of something defined. News, comment, page content, sidebar, *header*, and *footer*. Is it bad representation?

Sectioning relates to the headings in some block of related content and defining what is related to what in a hierarchy of headings (

–

). The outlining algorithm can produce a table of contents from the nested

, and

elements.

Headers and footers themselves do not change the outline; a header or footer may contain no headings. If a header or footer does contain a heading, then that heading does come into the outline. See our article on the section element.

Thanks, Bruce

Scaling the Video

Ian asked:

Hi there,

Not sure if this question is an appropriate one, but any help would be really appreciated.

I’m going about updating my video website, chutney.ie, and would love to implement HTML5. I am interested in replicating the scaling effect/style used on the Mozilla welcome page.

Not being overly knowledgeable in this area, I would love to know how to begin — is this effect a Flash based animation, or something that can be achieved with HTML alone?

Again, any nudge in the right direction would be great.

Many thanks,

Ian

I’m not sure how Mozilla did it, but you can use some of the Webkit and Mozilla transforms on the element. For example, you can cause the video to grow on hover — see this example in Chrome, Safari, or Opera. You can also use the :target pseudoclass to initiate animations. Alternatively, you can use a JavaScript onClick event to create the same effect.

You can also combine and to provide some interesting results (laying the over the ). For more on the element and what it can do, please read the Introduction to HTML5 Video on dev Opera written by Bruce Lawson and Patrick Lauke.

Cheers, Rich

We need a tag

John wrote in and proposed a field element:

Hey there. First off thanks for the site. I was excited to find it. I spent a little time on the W3C site and honestly couldn’t figure out how to submit suggestions there. So going to submit mine to you guys and maybe you can pass it on (if it is good) or point me to someone that can help. Ok to the point:

We are getting nice new tags to with HTML5 (nav, footer, etc) to help us create more semantic code. I think what we really need is a field tag — after all what are fieldsets sets of?

Everyone wraps up their labels and inputs with some element. Some of us do this with UL, some people do it with DT/DD, some with DIVs and some people out there insist that a form is tabular data.

We are all just bastardizing these elements because there is no clear semantic wrapper for field elements of a form.

I think you get the point. I’m trying to keep this email short. If you think there is anything to this argument, I have a more detailed summary (with example code) at:

http://john.mirick.me/2009/10/what-is-really-set-of-shouldnt-we-have.html

I would love to hear your thoughts on this.

Thanks!
John

While a field element would be nice — it would stop the argument over how best to mark-up forms — you have to ask yourself whether or not it actually adds any semantic or functional value to an HTML document. Yes, wrapping inputs and their labels in a field would make things easier to read and drop the need for the for attribute on the label (since the relationship can be assumed), but doing so would not be backwards compatible. In theory, we could continue to add for until there is a suitable time to drop it, but again I question the value of such a tag.

The purpose of wrapping form input/label pairs is generally to ease styling. My personal stance is that unless there are case studies showing how such an element can add more value to HTML forms, this proposal won’t make it very far.

Regards, Mike

Got a question for us?

That wraps up this round of questions. If you’ve got a query about the HTML5 spec or how to implement it, you can get in touch with us and we’ll do our best to help.

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Your Questions Answered #5 originally appeared on HTML5 Doctor on March 2, 2010.

Legend not such a legend anymore

Remy Sharp — Fri, 31 Jul 2009 12:00:26 +0000

Lately I decided I was going to recreate the interactive features of the details element using JavaScript (apparently the same day as fellow Brightonian Jeremy Keith).

However I ran in to some very serious issues with the tag, so serious, in it’s current state, it’s unusable.

Overview of the details element

The details element, by default, is a collapsed element whose summary, or label, is the first child legend (if no legend is used, the UA provides a default, such as “Details”), with a triangular button to indicate it’s current open state.

If you include the open attribute, then the element is open by default. In theory, you could attach a click event to the legend, and switch the open attribute.

The markup would roughly be this:


  Terms & Conditions
  You agree to xyz, etc.

Here’s the details test page I was working from: HTML 5 details test

The issues

The biggest problem, and the show stopper for me, is that the browser’s treatment of the legend element completely breaks this markup pattern – this is true for all the major browsers: Opera, Safari, Firefox and IE (tested in all the latest and some older browsers). I’ll go in these issues in detail in a moment.

Legend treatment

Surprisingly Firefox is the worst one out in these issues, the rest of the browsers have fairly same treatment of the issue. In the screenshots, I’ve included a fieldset and nested legend for reference.

Internet Explorer

IE7 & IE8 closes the legend element it encounters when it’s not inside a fieldset element and move it’s contents out to an adjacent text node.

What’s also strange, is that looking at the DOM it also creates another empty(?) closed legend element after that text node. It doesn’t have any effect, but just looked odd:

Opera

Opera (9 & 10b) is very similar to IE in it’s treatment of the legend in the details element, except it doesn’t create the second closing legend node. It just closes the legend, and creates the adjacent text node.

Safari

Safari simply strips the legend all together out of the DOM. So much so, that if you open the web inspector, then the error console, you’ll see it warning out that it’s encountered an illegal element, ignoring it, then encountering the closing tag, so it ignores that too. You’re left with just the text node.

Firefox

The best for last. Firefox goes one step beyond the other browsers. It assumes you’ve forgotten to include the fieldset element. So when it hits the legend element, Firefox inserts an opening fieldset up until it finds (I believe) the closing fieldset element, which obviously it doesn’t so the result is the rest of the DOM, after the first illegally placed legend ends up eaten by fieldset element, which leaves my DOM in a mess:

Impact on other elements

details isn’t the only element that reuses the legend element for labelling, the figure element also is supposed to support the legend element. The result is obviously going to be the same.

Conclusion

We can’t style the legend element when the text is being thrown out by all the browsers, and Firefox’s DOM mangling is just too painful to look at.

This basically means that we can’t, in any reasonable amount of time, use the legend element inside both the details and figure element in the spec’s current state.

For me, I’ll be using an alternative element, probably just a p element styled to look like a legend, but that’s really not the point. Ideas anyone?

It turns out we weren’t the only ones looking at this and Ian Hickson has responded on the issue:

My plan here is to continue to wait for a while longer to see if the parsing issues can get ironed out (the HTML5 parser in Gecko for instance solves this problem for Firefox). If we really can’t get past this, we’ll have to introduce a new element, but I’m trying to avoid going there.

It’s fine to think that Gecko will update, but it’s IE that I’m worried about, they won’t turn out their render engine, and the result is we’ll have to avoid using the legend in any element other than fieldset.

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Legend not such a legend anymore originally appeared on HTML5 Doctor on July 31, 2009.

HTML5 Boilerplates

Remy Sharp — Fri, 17 Jul 2009 13:30:45 +0000

Without going into the discussion of why HTML 5 is available today and not 2022, this article is going to give you a series of HTML 5 boilerplates that you can use in your projects right now.

HTML 5 in 5 seconds

It’s über easy to get your markup to validate as HTML 5 — just change your DOCTYPE from whatever it is now to this:

That's it! It doesn't require anything more than that.

Google are doing it already. Check out their homepage, written all in one line:

HTML 5 - Google Search


  my birthday

Now after we’ve applied the fix, it’s correctly styled in IE:

One hit solution

For everyone’s convenience, I wrote a single JavaScript file that can be included to create all the HTML 5 elements (and the element) for IE.

Download the IE HTML 5 enabling script

Include the script in your tag, and you’ll be able to style the elements appropriately in IE:

Note that I’ve used a conditional comment to only apply this to IE 8 and below. It’s my hope that IE 9 and onwards will support HTML 5 elements, but when that day comes, make sure to double check the conditional!

Conditions & Gotchas

There are a couple of things to be aware of when using the HTML 5 shiv.

JavaScript required

This obviously means that your design now depends on JavaScript. Personally, I feel that if you’ve used semantic markup for your site and the elements can’t be styled, the content is still completely readable.

Here’s a screenshot of the Full Frontal web site, written using HTML 5 elements, rendered in IE with and without JavaScript enabled:

You can see in the second screenshot that the content isn’t perfect, but it’s still readable — it cascades down correctly, much as if CSS were disabled.

A little head is always good

If you create the new element and don’t use a tag (which is perfectly valid HTML 5), IE will put all those created elements inside the tag. Pretty crazy, but you can easily avoid this by always using both the and tags in your markup. Leif Halvard explains further with demos.

Firefox 2 and Camino 1 rendering bug

Both Firefox 2 and Camino 1 have a bug in the Gecko rendering engine (specifically versions prior to 1.9b5):

Firefox 2 (or any other Gecko-based browser with a Gecko version pre 1.9b5) has a parsing bug where it will close an unknown element when it sees the start tag of a “block” element p, h1, div, and so forth.

According to the W3 Schools stats, Firefox 2 only has around 3% of the market — perhaps low enough to justify ignoring it. It’s safe to assume that Camino 1 commands an even smaller percentage of the market.

By ignoring this issue, however, a site can look quite bad in these browsers. So how can we fix it?

The bug surfaces when Gecko doesn’t recognise an element. Explained roughly, when Gecko parses an unrecognised element, it removes the element’s contents and puts them next to the element.

Take, for example, the following code:


  Title
  ...

This will be parsed in Gecko (prior to version 1.9b5) as if the markup were actually as follows:


  
  Title
  
  ...

The visual result is similar to the above screenshot of IE running without JavaScript (though subtly different, as the DOM tree is actually in a different order than you as the author intended).

The fix

There are two approaches to fixing this issue, and so far I've only successfully used the non-JavaScript approach.

The JavaScript solution

The first approach is to use JavaScript to traverse the DOM tree, rearranging elements as issues are encountered. Simon Pieters has a small working example of how this can be done (towards the bottom of the page). In practise, however, I personally found it didn't work for my markup. The problem is definitely solvable using JavaScript, but this solution still needs work to handle all permutations of markup.

The XHTML solution

The second approach is to serve Gecko XHTML. I've found this to be the easier approach if you're either generating a page dynamically (using something like PHP) or if you can create your own .htaccess file to use Apache's mod_rewrite.

The first change to your markup is to add the xmlns attribute to your tag:

Next, we need to sniff the user agent string (typically a bad approach, but justifiable when targeting such a specific group of users). If the Gecko build is less than 1.9, then we need to set the Content-type header to application/xhtml+xml.

If you want to use mod_rewrite in an .htaccess file (or the httpd.conf file), you need the following rules:

RewriteCond %{REQUEST_URI} \.html$
RewriteCond %{HTTP_USER_AGENT} rv:1\.(([1-8]|9pre|9a|9b[0-4])\.[0-9.]+).*Gecko
RewriteRule .* - [T=application/xhtml+xml]

This rule sends the proper Content-type header to all Gecko based browsers where version is less than 1.9, or "rv:1.9pre" or "rv:1.9a" or "rv:1.9bx" where x is less than 5.

If you don't want to use the mod_rewrite approach, you'll need to manually send the header in your server side scripts. Here's a solution for a PHP script:

if (preg_match('/rv:1\.(([1-8]|9pre|9a|9b[0-4])\.[0-9.]+).*Gecko/', $_SERVER['HTTP_USER_AGENT'])) {
  header('Content-type: application/xhtml+xml');
}

This snippet needs to be included before anything has been printed by your script — i.e., as early as possible.

Gotcha: Yellow Screen of Death

The Yellow Screen of Death shows up whenever there's an XML error on the page. If we're serving markup as XML and telling the browser to interpret it strictly as XML, then we can't serve any characters it doesn't recognise or else it's going to bork:

Below are a few ways to avoid XML parsing errors.

Create strict markup

You need to ensure your markup is squeaky clean — but that's easy, because you're already a Markup Jedi, right?

Use XML entities

HTML entities are a no-no. Sorry, but • isn't going to fly anymore. You need to use XML entities, the numerical representation of these characters.

I've built an entity lookup tool that shows the HTML entity and the XML value of that entity. For example, • is 8226, so the XML entity is •.

Sanitise user generated content

If your site relies on any user generated content (e.g., blog comments), then you need to sanitise the output to ensure there are no validation issues to trigger the Yellow Screen of Death.

This issue alone may justify further investigation of a JavaScript solution.

Worth the trouble?

All that said, Firefox has a very good automated upgrade path. Looking at the stats on W3Schools, it's safe to say that the number of users with this Gecko bug is rapidly diminishing.

HTML5 Doctor » Structure

Your Questions Answered #5

Headers and sidebars