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Your Questions Answered #10

Richard Clark — Fri, 09 Jul 2010 12:45:00 +0000

The clinic is getting busy with more HTML5 ailments. This week, we’ll cover using sections within a footer, vs. Flash security, why HTML5 elements are treated as inline, using offline with storage, and marking up block quotes.

Footer with sections

Tommie asked:

Hi, I’ll get to the point right away. I want to use, lets say 3 section elements inside a footer each floating left and inside each of this sections I have some standard information. Is this the right way to go, or should I put my section elements outside the footer and only put copyright text etc. inside the footer?

Thanks!

You could use a

within

. but
is a sectioning root anyway
is flow content and can contain sectioning content. If you want them to appear in the outline within the footer, then it makes perfect sense to do as you suggest.

See more in Jack’s article on the
element. There are also some more examples in the spec.

Cheers, Rich

vs. Flash (security and copyright)

John asked:

I’m seeing lots of opinions that the canvas element might free us of the Adobe Flash monopoly, but what mechanisms can we use to protect our works when using straight HTML and JavaScript?

Right now I’m thinking about simple flash games, but I’m sure this is a concern for others wanting to use (free) HTML methods to perform functions now reserved more for flash.

Thanks for any input.

I’m not sure of any security mechanisms that we can use to protect content. It isn’t really any different than an image or any other type of resource. Having said that, decompilers can circumvent some of Flash’s security measures as well, so you may not be much worse off using .

If we come across anything, we’ll be sure to let you know.

Cheers, Rich

HTML5 tags inline?

Tami asked:

So, I’ve been experimenting with the new HTML5 elements, and one frustration I have is understanding the native display of the new elements, and how it works within the document flow. So far, experimenting with them has shown them to be very unpredictable. At best, they’re kind of behaving like a bastard span. They seem to be behaving like inline elements but that seems like it is wrong. In some cases, setting to display: block gives the expected behavior, but on the footer tag, it’s not interacting with floated elements properly.

So, are these new elements inline or are browsers still just trying to catch up? I tried looking in in the HTML5 working draft spec, but so far I am not understanding the way its written (HTML4’s specs clearly spelled out whether an element was display or inline).

Here’s an article from my personal blog that I wrote a while ago describing why browsers treat HTML5 elements as inline.

Thanks, Bruce.

Offline + Storage

Dear Doctor, I’m trying to work out if HTML5 will be able to do the job that I want. I have a number of documents (PDF, PPT, etc.) that I want to share with people in my team. These documents may change from time to time. Also, the people may not always be connected online.

Would it be possible to “cache” documents in an offline database in the browser so that when they are not connected they can still view them but when they are, they get the latest versions (which also refresh the cache)?

That way I can do a fairly pretty interface for sorting these documents so that they can easily find them.

Thanks in advance for any help you can provide.

You can, but I would strongly encourage you to think carefully about whether it’s worth it.

You can include these “assets” in the manifest, which will make the files available to the offline applications (note that this isn’t storage, just caching, which is what you’re after).

The problem is that when the visitor first hits the page with the manifest — which contains all the PDFs, PPTs, etc. — it will download all of these files. This is the bit that I’d encourage you to consider carefully. To compound that, I believe there’s a 5MB limit on the cache, so you might run into problems if you’re trying to cache more than that.

I’ve not covered offline cache on HTML5 Doctor yet (though it’s on the list), but I have described the process on my 24ways article.

If there are new versions of the cached files, you need to change the contents of the manifest — e.g., include a version number, which will trigger a download of all the assets again. Not ideal, but that’s the current situation.

Hope that helps a bit, Remy

Correct markup with blockquote

Phil asked:

Hi, in HTML 4.0 Strict and XHTML 1.0 Strict, text inside a blockquote element is required to be nested inside another block-level element, e.g. p.

In HTML5 that requirement seems to have been relaxed, as the following element validates successfully:
This is a blockquote.
The HTML5 spec uses the p element in the usage examples, but does not mention whether it is required.

Can you please confirm if this requirement has now been deprecated?

Great question. As I expected, this validates:



blockquote test
Tiger tiger burning bright

We double-checked with the WHATWG mailing list and confirmed that

can contain ‘flow’ content (i.e., text, paragraphs, etc.).

To summarise, it would be valid not to further mark up content within a
, but authors are encouraged to use a
(or other more appropriate element).

Bruce

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 #10 originally appeared on HTML5 Doctor on July 9, 2010.

Your Questions Answered #8

Richard Clark — Wed, 05 May 2010 13:00:55 +0000

We’re back with more of your questions (and our answers) about HTML5. In this article, we’ll discuss using a

at the top of your markup, how to skip to certain parts of a video, styling form elements and attributes, and more.

HTML5
on top

David asked:

Hi!

I wonder if it possible to put the footer on top such as www.perfectfools.com with HTML5 and still make the HTML validate.

Thanks a lot and best regards!

David

HTML elements should always describe their content, so if you think that

is most suitable for your content, then you’re absolutely entitled to use it. Despite its name,

’s position is in no way restricted — visually or ordinally — within a document.

Cheers, Rich

Skip to certain parts of a video file

John Paul asked:

Hello

supposing I have a very long video file in an accompanying video element, without using the controls, how do I skip to certain time stages through the API? Much as one would on a DVD menu, for example.

Apologies if this has been asked already.

JP

You can achieve this using JavaScript and data attributes. Check out these articles from Bruce Lawson and Patrick Lauke from Opera. They’ve used data attributes to add subtitles, but you could just as easily use the attributes to jump to specific parts of a video.

For example, set data-start and data-end attributes on your element. You can then use JavaScript to read the attribute values, set the current position of the video using the currentTime attribute, start playing the video via the play() method, and even stop playing the video by listening for the timeupdate event and stopping the video with pause() once it’s reached a specified time. See the spec for the HTMLMediaElement object for more details.

Cheers, Rich

In addition to this, the recent addition of the track element will make this more easily achievable. We will cover the track element in more detail soon.

s within navigation links

Benjamin asked:

Hey,

I’m currently doing up the new version of my website, and decided to do it in HTML5.

One area I’m confused about is whether or not for navigation links I should be using a h1 or h2 element.

For example:
    
        Actions
    
    
        Sitemap
        Login
        Search
        Enquire
    
Should those span.title elements be wrapped in a h2? My thoughts on why this would be required is for an outline, as navigation should appear in the outline right?

Thanks a bunch.

In theory, yes, navigation should appear in the outline. I personally don’t think it should require a heading, and I know there have been requests to the developers of the outline algorithm to make

show as a ‘Navigation’ element rather than ‘untitled section’.

If you want to use a heading within your

element, using an

would be fine. You don’t really need the

element in there too. The outline would be calculated correctly without it. With current browser implementations, however, I don’t think it would make much difference if you used an

.

You don’t need the elements in the

s. They aren’t required in the outline unless they’re providing a table of contents for the document.

I hope that answers your question. We plan to write an article regarding outlining soon.

Cheers, Rich

Styling supported HTML5 form elements and attributes

Mike asked:

First off, I wanted to say I really appreciate the service this site is doing. I have found this site to be a very valuable resource and is always the first place I look when I have a question about implementing HTML5.

How do I style/edit/change the UI generated feedback for the new HTML5 form elements and attributes. For example, In Opera, is there a standard CSS notation to style the error message so that it doesn’t necessarily show up under the field in red? Where in the DOM is it inserted? Is the message for a required field customizable? Finally, is this information specified in the HTML5 spec or are the implementation details left up to the browsers?

There is currently no way to use CSS to style error messages. As the HTML5 spec isn’t finished yet, it’s a bit early to start specifying new CSS.

The HTML5 spec defines no UI requirements regarding how browsers should display messages.

You can override a browser’s default behaviour with JavaScript. I’m not a scripter, but I reckon you would need to attach an event handler to the error event and have the handler cancel the default action and show a custom error message. I think that as long as you call evt.preventDefault() within the event handler, it should prevent showing the default error message. Then you can add an element into the DOM and style it as you wish, with the default error handling as a fallback for those without JavaScript. If anyone gives this a go and gets it working, we’d be very interested to see the results.

Ta, Bruce

Section headers

Tibor asked:

Hi. I would like to know, how to use section’s headers. Is this code correct?
	header 1


	header 2
or I have to use header element inside every aside, article, section etc.
	
    	header 1
	


	
    	header 2
	
Tibor

Your first example is correct. You only need

to group items within a header. If the header contains only a single

–
element, you don’t need to wrap it in a
.

Thanks, Bruce

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 9

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Your Questions Answered #8 originally appeared on HTML5 Doctor on May 5, 2010.

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.

Related Posts:

Your Questions Answered #8

Your Questions Answered #7

Your Questions Answered #6

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

Your Questions Answered #3

Richard Clark — Thu, 22 Oct 2009 13:52:44 +0000

We’re back with our (semi) regular round up of answering readers HTML5 related questions. Right, let’s not mess about any longer and dive straight in with the questions.

Multiple use of tags

Daniel Davis asked:

Dear Doctor,

Just a quick confirmation please.

Am I right in thinking that nav, like header and footer, can be used more than once in a single page? For example, surrounding a menu at the top of the page and surrounding next/previous buttons at the bottom.
Come to think of it, is it fair to say that all tags except html, head and body can be used more than once?
Thanks in advance, doctor.

I’ll be back soon about my dodgy knee.

You’re correct all the elements you mention can be used more than once a page. If you see this article about the header and this about the footer – they show that you can use them multiple times on a page. Also you don’t really need html, head or body tags, as all browsers will assume them anyway but it’s also safe to leave them included.

— Hope that clears things up Rich and Bruce

HTML5 + Javascript Client Web App

Girish asked:

Is it possible to create a complete client side application using HTML 5 (it will embed chat clients, stock ticker) + JavaScript, and then bundle is with underlining Firefox 3.5 engine, so that user can install it as a desktop app on Linux, and then it runs in its own window using firefox 3.5 engine. The app will store everything in local storage – like url, usernames etc, and will not interact with any local server.

It would pure HTML5 + JavaScript based client web app which would be packaged, and can be installed or launched from startup scripts.

Or instead of using firefox 3.5 engine, we can use Mozilla Prism to convert it to web app, and then bundle it, is it possible?

Technically it should be possible. Certainly the HTML5 offline applications API (via the manifest) gives you all that ability to create a client side app and it run locally without a web connection.

However, the browser is the problem. Prism might be a good way to deploy this as a standalone app, but I don’t know if Prism is running the latest Gecko engine (or whether that comes with the JS engine, etc) – and even if it does – Firefox 3.5 currently has a pretty severe bug with the offline applications: it doesn’t work!

I have logged the bug with Mozilla and I know they’re working (in fact, I believe they’ve fixed it and are now testing).

The alternative is to use Fluid (a Webkit based app) – but again, that’s only if they have updated to the latest Webkit and thus including the offline applications API (that said, quickly looking at the Fluid site, their in-progress version may have the latest Webkit).

Regarding launch from start up scripts – you could achieve this though the custom scheme handlers (but this is just Firefox IIRC): http://www.whatwg.org/specs/web-apps/current-work/multipage/browsers.html#custom-handlers

Equally, there may be an API that you could exploit via the standalone browser, either Prism or Fluid.

— Good luck! Remy

MIME or DOCTYPE, which one prevails

Pedro Estébanez asked:

Hello doctor,

I have found this site a very good resource for web developers and I thank you for your effort.

Now, my question:

There is a lot of discussion about hot to tell the browser we are using HTML5 or XHTML5 by setting the Content-Type HTTP header. But then I don’t know the true role the DOCTYPE plays (apart from keeping quirks mode from being activated and validation).

For example, if I compose my documents as XHTML with an according DOCTYPE and my server serves them as text/html, why XML mode is not triggered in the browser?

Thanks in advance.

Did you see this article on the site from Bruce? HTML5, XML and XHTML5 and this one from Remy HTML5 Boilerplates.

Also see this (linked in Bruce’s article) for some advice on using the right mime type. http://www.webstandards.org/learn/articles/askw3c/sep2003/.

— Cheers Rich

Outline Algorithm

Mike Taylor asked:

In Section 4.4.11.1 of the current HTML5 spec, the outline algorithm is described–yet it’s not super clear in what ways this is useful to users or developers. It would be great if some more light could be shed on the topic!

Thanks for the awesome blog, btw.

The outliner basically allows you to easily see the heading structure of a site. The outline can then figure out from the heading structure where in the outline it should sit, should you want to only parse a section of the code into another site or page for example. (I realise this isn’t totally clear). Also check out the HTML5 Outliner for checking your work.

Bruce covered it a little bit in his section article – “With very few exceptions, section should not be used if there is no natural heading for it. Check your work in the HTML 5 outiner tool. If you see any instances of “untitled section” that corresponds to a section, you’re probably doing it wrong. (It’s fine for a nav or aside element to be untitled, however).”

We’ll try and cover it in more detail in a future post but I hope this helps for now, Rich.

HTML5 and xmlns

Ad Taylor asked:

I hope this isn’t a stupid question BUT …

If I am using the html5 DOCTYPE and I am still using xhtml syntax do I need to define the xmlns in the html tag (i.e. xmlns=”http://www.w3.org/1999/xhtml”)?

Thank you for taking the time to do this.

We said, Not a stupid question, but a simple answer: No!

— Ta Bruce (HTML5 Shrink)

Developing to a changing spec

Sam Rayner asked:

I read the Super Friends Guide to HTML5 Hiccups – http://www.zeldman.com/superfriends/guide/ and it’s worried me a little.

I’ve recently been developing personal projects using HTML5 as I find I learn best ‘on the job’ and wish to become familiar with the new spec by putting it in to practice. However, it sounds like I’ve misinterpreted bits and often used new elements such as footer in the way the Super Friends describe rather than in line with the spec.

I really want to continue enjoying the benefits of HTML5 in my own non-critical web work but it seems I run the risk of having to return to it all at a later date and amend stuff due to changes in the spec.

What do you think the best course of action is? Continue with 5 but keep going back and fixing old projects? – Could become a real hassle.

Continue with 5 and leave non-visual discrepancies as they are (the code may be slightly off but it’s styled fine)? – Goes against all of my natural instincts to do things right.

Return to 4 and use class names as apposed to the new elements for the time being?

I realise this is the risk I take developing with a developing spec but I’m worried if I wait until everything is set in stone I’ll still be using HTML4 years from now!

Thanks a lot,

I understand your concerns with the spec changing from day to day. It’s hard to keep up with (there’s 6 of us and that’s tough enough).

Although I’m sure you’re aware in footers case, its content model has now been changed to allow it to act more like header.

I think essentially you have three choices for your development or a combination of the below currently:

Continue working as you are with new HTML5 elements and change them as the spec becomes more defined

Use HTML4, with HTML5 class names (as you suggested)

Use only the simplified doctype and those elements that will only be benificial in the future or add progressive enchancement (e.g. inline elements such as time.)

Its going to be a while until we can use HTML5 in development projects but in my opinion there isn’t any reason to not use it on personal projects now. You have to judge it on a case by case basis, but whichever parts you do you will be futureproofed to some extent.

— Cheers Rich

HTML5 and Browser Compatibility

A lot of people ask this type of question regularly so here’s a few links that we think are useful.

Can I use

Mollys HTML5 Table

Comparison of Layout Engines Wiki

That about wraps up this round of questions, we’ll be publishing more soon, but in the meantime don’t be afraid to keep asking the doctor about HTML5.

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Your Questions Answered #3 originally appeared on HTML5 Doctor on October 22, 2009.