I've been playing with the Aria selectors https://developer.chrome.com/blog/puppetaria/ and with page.accessibility.snapshot(). Both pierce shadown-doms but neither pierce frames. I found a design doc that states this was a deliberate decision (along with a question mark).
For the aria selector it's a pain but you can work around it by using page.frames()..$()
For page.accessibility.snapshot() there is no work around exposed via the puppeteer api but there is a cdp command that would make it possible.
I guess my question is does that sound correct in terms of state of affairs and what would the reason be for not including frames in the accessibility tree? I see the same behaviour in devtools but that can't be true for the speech browsers as they do see inside frames!
I'm thinking raise a bug/feature to add something like frame.accessibility.snapshot() or is this a bug in chrome that it doesn't return iframes in the full tree.
Same with aria/selectors is there a good reason to keep frames separate or should I be asking for that to be looked at again?
Related
I was just stumbling upon Chapter 7.2 of the W3C HTML5 spec, where it is said
A node (in particular elements and text nodes) can be marked as inert.
Source: http://www.w3.org/TR/html5/single-page.html#inert-subtrees
Unfortunately, the specification does not say how to do it. Does anybody know?
I've already tried setting the "inert[='true']" attribute to an element ... does not work.
It seems to me, as this might be a HTML5 feature that nobody cared to implement or use so far ... caniuse.com does not even know of it ... but maybe I'm wrong?
It looks like the inert attribute may have been removed from the standard.
Early 2014. Posts about it seem to have dried up online so it is probably safe to assume we won't be able to use it.
The attribute inert exists in HTML 5.1.
HTML 5.1 has now progressed to a W3C recommendation, which is is essentially an endorsement that the proposal is ready for deployment to the public, so we should see the major browser makers starting to implement the recommendations if they haven't done so already.
Whilst caniuse has no information on browser support for the inert subtree yet, but I have raised an issue asking for it to be added.
I've written a quick fiddle which lets you see if your browser supports it (though Chromium/Chrome/Safari and FF do not at the time of writing).
There is a polyfill that could mimic the inert behavior to a node and its corresponding subtree. There is also a YouTube video on Google Chrome Developer's Channel showing this polyfill in action and displaying the power and uses for this behavior.
On buzgilla there is an excellent response explaining why it wasn't and won't be implemented in Firefox as an attribute.
There's no such attribute. If we implement this concept it'll be as part of <dialog>.
It's really confusing, this attribute with pointer-events would have been perfect and helpful for a lot of situations
As far as I understand, the only real advantage of HTML5 semantic markup is for search engines and web crawlers to interpret the document better.
Since intranet applications have nothing to do with search engines or web crawlers, what are the advantages of using semantic markup in HTML5?
There is no straightforward example to point out, but the website (even intranet) can be consumed by different user agents (on different devices).
You are probably familiar with Skype (and the iOS Safari) making phone-number-like words clickable. In the future I can easily imagine mobile browsers being smarter to assist the user in completing tasks on the page, like importing a clearly indicated contact to the address book.
Screenreaders for blind people?
While there is not a whole lot of immediate benefit for non-disabled people, it is still good practice. Does your company not have any externally facing sites? If it does, do those people not look at internal page code? Good practices spread just like bad ones.
see also: http://en.wikipedia.org/wiki/Semantic_HTML
Simply said there the only rule you have to follow if you create your html documents is that it is valid html, otherwise you will have the problem that the browser would try to correct your broken syntax which may result in defects of the visual representation of your content.
In modern browsers you can use display to given any element - with some limitations e.g. with input element - the same visual look and behavior then any other element.
So if you ask what are the advantages of using semantic markup in HTML5 you should ask, why to use any of the semantic markup if it is possible to have the same result using css.
The short answer is, no one will stop you if it is your own project where you are responsible to - except the client that probably gives you requirements.
It is similar to asking: Language xyz provides comments and there is a syntax for doc-comments, but why should I use them?.
Using the semantics wisely increases the readability and thus maintainability. You are not required to use every possibility of semantics at all costs.
Using them will help you to get into the code again if you haven't looked at it for a longer time, e.g. to distinguish between the elements that encapsulate logical parts and elements that are used for styling. Especially if you use a template engine to create your code or to search for certain elements in multiple files.
Even if you are now the only one who works on the code it may happen that if the project grows that you need other people to work on the code. Or for the situation, you for some reason are not available, someone else needs to maintain your code, a good markup is essential.
Using the correct markup and additions like WAI-ARIA is not only essential for handicapped people, but also allows the browser to recognize the meaning of elements, allowing to e.g. improve the keyboard navigation. Especially in a productive environment where you need to type much, it is often faster to navigate with keyboard then using a trackpad or a mouse.
I am thinking about starting to use some HTML5 elements in my sites. With the varying lack of support for HTML5 in Internet Explorer I was considering using HTML5shiv. I have read that I would need to set the CSS for various unrecognised elements to be block level and also the possibility of issues with loading HTML5 elements via ajax.
I would like to know what issues others have encountered when using this script. Thanks.
If you're going to dynamically load HTML5 elements you'll need the innershiv. You'll also need to bear in mind that if the IE user has JavaScript disabled, it won't work at all.
I've found the existing solution to be highly unreliable when used in real world scenarios - it's fine for noddy little "hello world" examples but as soon as the pages start getting more complex then you will find that styles will stop applying on some requests etc.
It's not a very nice answer, but the truth is that if you need to support older IE versions then you basically can't rely on being able to style HTML5 elements reliably. If you can get away with using the elements but use superflous markup (divs etc.) to do things like layout then you might get away with it, but then it depends what you consider to be the lesser of the two evils : Loads of noddy markup or no IE support.
I have just started considering using the HTML 5 api for a Rails/JQuery project, so I can use that great data- attribute to store values.
I am worried though about browser compatibility issues. I have two questions (basic questions):
In order to use HTML 5, do people need to upgrade their browsers? How does that work?
Is there an up-to-the-day chart of what features each browser layout engine supports, more up-to-date than this Wikipedia article on comparing HTML layout engines and this When can I use... HTML 5 page?
Is it going to be an issue with people using IE6 for example? Lots of non-computer saavy people I've talked to who want to get an internet presence themselves use, and the people they talk to use, still, IE6!
If it's not an issue, and you can use HTML 5 on old browsers, how do you? Or what docs should I look at :)? Thanks.
Update: I will post some interesting links as I find them below.
FindMeByIP: "A simple app which reveals your browsers' support for CSS3 and HTML5 features in an easy to read format using Modernizr." - Browser Support for CSS3 and HTML5
It is not useful to consider HTML5 as a single entity, that browsers either ‘support’ or ‘don't support’. HTML5 is:
an attempt to codify widespread existing practice beyond the limits of what the previous W3 HTML and DOM standards had covered, such as IE and Firefox extensions that the other browsers have copied, and long-standing ‘DOM Level 0’ behaviours that everyone took for granted but weren't written into any spec before.
a random selection of new extensions not yet in widespread use, which it is hoped browser manufacturers will support. Some have already succeeded, heading into all new browsers already; some have been spun off into their own specifications (which is much more manageable for everyone), some are controversial, and some no-one cares about at all.
It has been, IMO, an enormous mistake to try to cover these two bases at once. I would have preferred an HTML 3.2-style ‘catch-up’ standard plus many separate extension specifications. But there's nothing can be done about it now.
HTML5 is also:
Not finished. The specification is massive, complicated, incomplete, and likely to change in details (or maybe more than that) before it becomes a proper standard. No-one can say they ‘support HTML5’ yet, because no-one knows yet what ‘HTML5’ is actually going to be.
In practical terms: there are some parts of HTML5 that have long been in use. There are some parts that you can use safely on modern browsers. There are some parts that you can use on new browsers except for IE. There are many parts you can use with fallback workarounds or ‘graceful degradation’. There are some parts you may never be able to use. For now you will have to learn each separately, because there won't be a browser that supports absolutely everything in HTML5 for many, many years. If ever. Add the extra features you like gradually as you go along and they're supported by a greater share of browsers; there will be no ‘big bang’ where everyone updates their browser at once.
As for data- attributes, well, yeah, you can kind of get away with using them, in that most browsers have always allowed any old attributes to go through anyway. This is typical of several HTML5 extensions, the browser doesn't need to explicitly ‘support’ it for it to work.
But since there are other ways of passing data (classes, comments, script blocks, etc.), I'm not wholly convinced it's worth dropping (universally supported, validatable against a fixed standard) HTML4/XHTML1 pages just for that one feature yet.
You might want to check out diveintohtml5.ep.io and modernizr.com.
Modernizr is a small and simple JavaScript library that helps you take advantage of emerging web technologies (CSS3, HTML 5) while still maintaining a fine level of control over older browsers that may not yet support these new technologies.
Here's an interactive chart of html feature support:
http://a.deveria.com/caniuse/
As you can see, there are a lot of browsers that support quite a few of the H5 features.
If you're using jQuery, concerned about interoperability, and the only reason you're investigating HTML5 is to use the data-* attribute set, then I would consider switching back to a better-supported doctype and using jQuery's $().data() method, which allows you to bind arbitrary pieces of data to DOM nodes, similar to how the data- attribute set does.
Example:
<button id="set">Click me!</button>
$('button#set').click(function(){
if($(this).data('name')){
alert('Clickin\' again so soon, ' + $(this).data('name') + '?');
}else{
$(this).data('name', prompt('Hey good lookin\', what\'s your name?', ''));
}
});
Try it out!
My answer might not be the one you would like but I would say - don't. Don't use HTML 5 just yet.
Use Protovis. It uses javascript and HMTL5. No Flash here. More important, Protovis has BSD license. So you can use it in commercial projects. Although D3 is the a newer project that authors of Protovis are working on.
Although this is an old(ish) question, the topic of browser support will always be relevant. There's no right way or wrong way to approach it, but take a look through one of the many browser feature support tables that show you what percentage of users will see a certain feature and then be brutal.
Don't try to please everyone. Don't kill yourself to catch a few percent of the Luddite's who are still using IE7. Next year, substitute that for IE8. Personally, I would be happy to lose 8% in order to spend that time on forward thinking practices rather than catering for those who don't know what an upgrade is.
Maybe your site will cause people to upgrade. These people will come round eventually.
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(I'd like this to be the definitive community wiki. I seeded it from my own answer to this question.)
Specify Everything
A lot of cross-browser issues amount to this: you didn't specify something, and different browsers make different assumptions. Therefore:
Declare a valid doctype
Your doctype tells the browser what rules you'll be using in your code. If you don't specify, the browser has to guess, and different browsers will guess differently.
In my experience, a "strict" doctype makes IE behave better (enables things like CSS :hover selectors on divs in IE7).
This article gives good background on doctypes.
Use Web standards
Avoid browser-specific markup, or only use it when its failure in other browsers won't be significant to the site experience.
Validate your HTML and CSS
You don't have to get everything perfect, but validation is good feedback. As Jeff said:
Knowing the rules and boundaries helps you define what you're doing, and gives you legitimate ammunition for agreeing or disagreeing. You can make an informed choice, instead of a random "I just do this and it works" one.
Imagine you opened a paragraph tag and never closed it. If you then open a list tag, did you mean it to be inside the paragraph or not? Validating will help you catch that, close the tag, and eliminate ambiguity.
Consider a CSS Reset
Different browsers assume different baseline CSS rules. You can help them all to act the same by explicitly ironing out the differences up front. Eric Meyer, who wrote CSS: The Definitive Guide, uses this reset. Another popular choice is YUI Reset CSS.
Use a Javascript library for DOM interactions
Whenever your Javascript needs to work with elements on your page, it's best to use a library like jQuery, Prototype, or MooTools. These libraries are used by many thousands of developers, and they take most of the inconsistencies between browsers' interpretation of Javascript, deal with those internally, and give you a consistent set of commands that just work. Trying to find and work around all these inconsistencies yourself is a waste of time and likely to create bugs.
Test in multiple browsers, deal with IE last
Test in multiple browsers as you go. Generally, you'll find that non-IE browsers behave similarly and IE is a special case - especially if you follow the advice above. When necessary, you can add IE hacks in a separate stylesheet and only load it for IE users.
Quirksmode.com is a good place for hunting down random browser differences.
Browsershots.org can help show how your page will be displayed in an assortment of browsers and operating systems.
Fail Gracefully
No site will look perfect in every browser that exists. If a user doesn't have Flash, or Javascript, or advanced CSS, etc, you want your site to be usable anyway. Design with that in mind:
Check the bare HTML
Try loading your site with bare HTML - no styles, no scripts. Are menu options available? Does primary content precede secondary content? Is the site usable, even if ugly?
Consider test-driven progressive enhancement
Described in this article, this technique uses javascript to check if a browser has a given capability, such as support for a given CSS property, before using it on the page. It is unlike browser sniffing because it tests for features rather than a specific browser.
Use a library like jQuery abstract away the differences in the DOM, AJAX and JavaScript.
Make sure you're keeping HTML, CSS and Javascript in separate files as much a possible. Mixing structure, presentation and behavior in your HTML file just makes finding and fixing problems harder.
Use Firebug in Firefox for:
Debugging/stepping through your JS.
Seeing how your stylesheets are being interpreted and hacking them up on the fly to see how to fix your problem.
See how many calls you are making for remote resources and how long they take.
Profile your code.
Chrome and IE8 have similar tools built-in that can be used for the same thing.
Opera and Safari (and IE) have Firebug Lite.
Use CSS Reset on start of your stylesheet...
You can get one here...
Validate your code by w3c ...
You can validate your code here by page link or simply copy paste page element
My #1 rule is use a strict doctype. HTML or XHTML is fine, but using the strict doctype removes pretty much every browser quirk there is, especially in IE7+.
Imagine you opened a paragraph tag and never closed it. If you then open a list tag, did you mean it to be inside the paragraph or not?
Actually you can't put any other block tags inside a <p> tag, that's why the spec allows you to omit the closing tag. If you start a list without closing a paragraph, then the paragraph is implicitly closed. And the validator won't complain.
That's not to say you shouldn't close tags, because it generally makes code easier to skim (you don't need to remember the above rules).
Consider programming you web-site's UI using Google Web Toolkit. With GWT you write all code in Java programming language which GWT then cross-compiles into optimized JavaScript that automatically works across all major browsers.
I think using best practice is the way to go, progressive enhancement is designing with the user in mind and needs to be done with all designers. I believe that a lot of testing on browsers is a good way to ensure proper content is being displayed, many developers over look this.