What are appropriate markup languages for users with disabilities? - accessibility

Suppose you're developing a web site and blind users will be a significant chunk of your target market. If the web site includes document editing functionality, what would be appropriate WYSIWYM tools? Are languages like Markdown, Textile and Wiki Formatting really accessible or are they inconvenient to blind users?

I'm a blind programmer and while I haven't used most of the languages you mention I've found that any markdown language is fairly easy to use if you have the desire to learn it. I've had no problem using either HTML or several markup languages for wiki's. Part of it will depend on how invested the users are in your site. If it's a site that will be visited infrequently or for short periods of time, it's much less likely that a user will take the time to learn the required markup whether they are blind or not. Unfortunately, I have not found an accessible JavaScript WYSIWYG editor but I find it easier to manually enter the markup so haven't looked very hard.

the first question is: how important is semantic structure? could you get away with plain text. You could do simple parsing like treating blank lines as paragraph markers, treating a series of lines which begin with * as a bulleted list, identify URLs and make them into links, etc.
As a blind developer myself, I have no problem in understanding languages like Markdown. But if it's a syntax I'm unfamiliar with, I'll only learn it if I expect to use the site very often, or care deeply about the content.
Two final thoughts come to mind: while I certainly experience some accessibility challenges using TinyMCE, you could develop something much simpler - provide less than 10 formatting options, like inserting hyperlinks, making lists, centering text, setting the style (such as heading) etc.
And lastly, when I talk to non-technical blind people, they often just write their content in Word and paste into a wiki or blog post. This sounded strange when I first heard it, but it does make sense. So an ideal solution would accept pasted in content.
In closing - it depends how important this is, and how much effort you want to expend. Maybe a Markdown editor with a live preview (like on this site), buttons for inserting simple formatting like URLs, and the ability to paste in rich text would tick all boxes :-)

On a web page, the most accessible embedded text editor for blind users is one that uses standard HTML, such as a <textarea> element, with a corresponding <label> element:
<label for="editor">Enter your text here using wiki markup:</label>
<textarea id="editor"></textarea>
If a WYSIWYM tool is built using standard accessible HTML, then blind users can easily enter text into it, with full confidence that they're entering text in the right place. Then the question becomes: Which is the better markup language? They all require memorization, but some may be more intuitive than others. One way to find out which is best would be to do some usability testing with a wide variety of target users. Also be sure to providing easy, accessible access to syntax help.

Picture yourself working in pure text 80x4 display (just open a console and resize appropriately), then use vi/emacs/ed and you'll soon realize what markup will get in the way.
Try to do as much work as possible to understand plain text, else use light markup like POD, finally things like AsciiDoc are very powerful but needs training.

I don't know about WYSIWYG/WYSIWYM tools, but I do know that complying with W3C standards (especially their HTML5 en CSS3 drafts) while writing your own editor code will help a lot.
In CSS you can specify speed and intonation of speech. In HTML you can specify alternative text (alt attribute in many elements) that screen readers are compatible with. Be sure to know when to use the abbr and the acronym elements. Use the former when you want the screen reader to read the meaning of an abbreviation and the latter when the acronym should be read as a word (e.g. ASAP, NATO and OS).
For the editor itself, I recommend creating a WYSIWYG editor that uses divs and spans. Screen readers will understand easily the structure of a document. For the current line, use a text box; for every other line that's not being edited, convert the contents immediately to valid HTML.
If you find a good tool, be sure to post it here. I'm looking for one too. :-)

Related

How to style content coming from a Headless CMS?

Last month I read about Headless CMS for the first time, and I just felt in loved with that approach.
But just right after, I wondered how could I format and/or add style to the content if some day I worked with this technology.
By styling the content, I mean words within a title, paragraph and so on; not a whole paragraph, which is quite obvious it can be done.
It seems to me that it is impossible, since you only get a JSON with no HTML whatsoever; just raw texts. So it looks like this is the major downside of consuming content through a Headless CMS from a Front End perspective.
Formatting text is just fundamental, specially when dealing with large content. And I am sure I cannot be the first one concerned about not being able to add some bold and/or italics to a text to emphasize the important parts of it.
But I can't find any website discussing this topic, just "how to model the content" and whatnot.
Does really no one care about it?
I would appreciate if anyone could shed some light about this question.
Diving into the Headless CMS #RicoHancock has pointed out, I've learnt that it is completely feasible to store rich text and strucuted content within a JSON that can be converted to HTML following some specifications I wasn't aware of.
In the particular case of DatoCMS, they use a specification called dast.
To learn more about it, visit their docs (the following link contains very illustrative code examples):
https://www.datocms.com/docs/structured-text/dast
Paraphrasing their own words:
Structured Text format adheres to the Unified collective, which offers a big ecosystem of utilities to parse, transform, manipulate, convert and serialize content of any kind.
The "Unified collective" is a collective of free and open source packages to work with content as structured data with plugins. In order to create the syntax trees, Unified uses UNIST nodes.
UNIST is a specification, and stands for "UNiversal Syntax Tree".
More info about the UNIST spec and the Unified ecosystem:
https://github.com/syntax-tree/unist
https://unifiedjs.com/learn/guide/introduction-to-unified/
https://unifiedjs.com/learn/guide/using-unified/
TLDR: Markdown.
The company I work for uses DatoCMS. We have a blog, and each blog post is created in our CMS by our copywriting team. DatoCMS allows us (the developers) to create "blocks" that make up the blog post. We have image blocks and content blocks that are rendered by a template file on our frontend. The content blocks support Markdown, so italics, bold, and links work. When our copywriting/marketing team want to make a new blog post, they go to the CMS, create a new post, add a title, slug, and blocks, and then save.
I don't have much experience with other Headless CMS', so not sure if Markdown will work there, but I don't know why it wouldn't, Markdown is all over the internet. (In fact, this answer is Markdown XD)

Accessibility with Google Slides Embed on a webpage

Got a site with powerpoint presentations that the client wants embedded, the embedding is being done via google docs embed. I have been doing some accessibility testing, albeit not particularly in-depth but even with OS X screen reader it is not having any luck reading the slides. (I am aware slides are probably terrible for accessibility anyway). I can get the text content of the slides stripped out via the Google API, but I don't know if thats the best thing, to include it on the page below/above the iframe embed with one of the CSS tricks for hiding it from normal view?
I am aware of iframe title and aria-label but those seem to imply they are only to describe the contents of the iframe, which I am doing, but I need somewhere that can contain more text.
Has anyone got any good tips for the best way to deal with such things? Thanks!!
Embedding rich 3rd-party content in web pages poses many challenges.
When we put something like this in a web page, we typically think we're adding a bit of "content", but it often amounts to embedding a complex application; and the user interface, semantics, and presentation are outside of our control. In your case it's a presentation slide deck, but it could also be a Flash/Silverlight/Java applet, a slippy map, interactive SVG infographic, a 3D-panorama, virtual tour, zoomable image, chemical molecule viewer, or who-knows-what. (Note: I'm not familiar with the Google docs embed/API specifically, so most parts of my answer will address these rich content cases in general.)
Even if the embedded rich 3rd-party content/application is accessible today, there's no guarantee it will remain so after the 3rd-party system gets an update.
So what can you do? The safest thing might be to assume it's inaccessible, and consider the best way to provide an accessible alternative. The Web Content Accessibility Guidelines (WCAG) calls this a "conforming alternate version", and it sounds like you're already thinking along these lines.
An important caveat to all of this, is that the use of "conforming alternate versions" isn't considered ideal by many accessibility specialists. It's greatly preferred to make your main content accessible as you can.
Some relevant parts of WCAG:
Understanding conformance, especially the section about "Understanding Conforming Alternate Versions".
Technique G190: Providing a link adjacent to or associated with a non-conforming object that links to a conforming alternate version.
F19: Failure of Conformance Requirement 1 due to not providing a method for the user to find the alternative conforming version of a non-conforming Web page.
It's worth mentioning the 3rd-party content in your website's accessibility statement. Statement of Partial Conformance - Third Party Content offers guidance about that.
The crucial thing about conforming alternate versions, is that it's no use at all if the user isn't made aware of it, or isn't able to reach it.
Implementation-wise, there are a variety of approaches you might take. In many ways, providing an alternative for embedded rich content is similar to providing a long description of a complex image, or a transcript of a video. Have a look at these WAI tutorials for some ideas.
Web Accessibility Tutorials: Complex Images
Making Audio and Video Media Accessible: Where to Put Transcripts
I can get the text content of the slides stripped out via the Google API
It sounds like you're trying to automate the process. That's fine, but it might not give satisfactory results. Some things you should consider:
Is the text content alone going to be enough? Presentations often have images too. Did the author provide text alternatives for these images, and are they present in the text extracted via the API? If the author hasn't provided text alternatives for images in the slide deck, the text you get from the API won't be telling the whole story.
Not all text in slides carries the same weight. Some slides serve to introduce sections, some slides have headings. Does the text obtained from the API convey these relationships?
Lists are very commonly found in presentation. Does the text obtained from the API preserve this structure?
Slides sometimes contain links. Are these included in the text obtained from the API, so the links are available to everybody using the alternative version?
Slides sometimes contain tables and charts. How will the information in these be conveyed in your alterative version? Is the information included in the text obtained from the API?
Sometimes, presentation decks also contain rich 3rd-party embedded content themselves! A slide containing a video, or an animated GIF are examples of this. If so, you can find yourself with a much more complex challenge.
... and many other meaningful info and relationships. Quotations, code samples, etc.
If any of the above points give cause for concern, you will need to consider managing your alternative version manually.
The "conforming alternative version" has to conform to WCAG; if you just offer a choice of two non-conforming version, that doesn't satisfy WCAG.
include it on the page below/above the iframe embed with one of the CSS tricks for hiding it from normal view?
No, I wouldn't recommend that. I assume you're refering to visually-hidden text, using CSS utility classes such as .visually-hidden or .sr-only. It sounds like you're only thinking about screen reader users.
You need to offer the alternative version available to everybody, not just one group of users who you think will need it.
Many groups of users may experience difficulty using the rich 3rd-party embedded content. This includes people using the keyboard only, screen readers, magnifiers, speech control, switch access, or other tools. The conforming alternative version can be navigated like a normal web page though.
The 3rd-party content likely has a different visual style, and it may not be adaptable in the same way as the page it is embedded in. That can frustrate people who make use of browser zooming, text resizing, font preferences, reader mode, Windows high-contrast themes, viewport resizing, and other user-applied presentation changes. The conforming alternate version should be as adaptable as the rest of your site.
Rather than hiding the alternative version in a visually-hidden container, here are some other ways to present it. The first two are the simplest and most reliable.
Put it on the same page, just after the original content, visible to everybody.
Put it in a collapsible disclosure element just after the embedded content. A <details> element is an easy way to achieve this. This is useful if the alternative version is quite long.
Put it elsewhere on the same page, and tell users where to find it. An internal link can help here.
Put it on a separate page, with a link next to the embedded content. I'm less keen on this approach. Only use it if you can commit to maintaining both pages.
Provide a way for users to switch between the two versions. For example some buttons, or a tabbed UI. However, you must also ensure that the switching mechanism is accessible. That might mean a full-blown ARIA tabs implementation.
I am aware of iframe title and aria-label but those seem to imply they are only to describe the contents of the iframe
Giving the iFrame a useful name is important. It's also a useful mechanism to inform screen reader users that an alternative version is available. The WAI Complex Images tutorial linked above has some similar approaches. Example: <iframe title="Google Slides Presentation of FOO BAR BAZ. Link to text version follows this frame.">. This only helps screen reader users though; you still need to make the availability of the alternative version clear to everyone.
How committed are you to using Google Docs for displaying these slides?
Any accessibility enhancements that you'll be able to implement on Google Slides won't be very good.
One way around this whole thing is to offer PDF versions of the slides that have been fully-remediated for accessibility instead of using Google Slides. That would potentially be a single solution that could be accessible to all visitors. Going this route means that you wouldn't have multiple copies of the same slides to update, which could lead to a split in content if one gets updated and the other is forgotten.
If you're really set on having the slides embedded in the page, then you could offer both formats by applying aria-hidden to the embedded iframe and then hiding the PDF links from sighted users using CSS clip, or by positioning content off-screen.

What is the benefit of writing meaningful css .class and #id names?

What is the benefit of writing meaningful css .class and #id names? Do screen readers speak to help the user understand the meaning and purpose of content inside the tags?
Generally-speaking, it's beneficial for the developer/designer only.
Again, as all your recent questions on semantics, the answer stays the same:
It all depends on the data-context of the entity in question.
If your element holds a meaningful field, it is useful to assign it a class (even if you do not want to apply CSS to it) just to easily define that particular field:
<span class="username">Andrew Moore</span>
Doing so has the following advantages:
It easily identifies the field's content in your code.
It increases maintainability.
It helps parsers and third-party applications to fetch this field's value.
Microformats are just a larger example of this. Simply put, they are a set of pre-defined elements and attributes that hold a particular set of data, meant to ease parsing by third-party tools.
Other answers are good, but I will focus on the scraping/third party tools aspect here.
Case 1 is spiders and crawling like search engines. If they parse your page and see something like id="username", they will be more likely to figure out some meaning in that than id="div-style-32". Granted, I'm not sure Google is doing this sort of thing now, but it could be if more people were better about it.
Case 2 is people writing scripts to pull down the HTML and process it in order to extract its content as data. Pretty much anyone who wants to do this can with any markup, its just a matter of how annoying it is. Cleaner and more well described markup allows the scraper script to more easily find the information it needs due to it's increased semantics.
This also includes things like browser extensions or Greasemonkey scripts that allow users to alter the behavior of the site. It will be easier to create these modifications with cleaner markup.
But if you don't want people scraping or modifying your site with client side extension, there is little you can do about from a technical standpoint. You can't stop it, you can only make it more of a pain in the ass. And the benefits of maintainability for the site developers are huge. So really, why not?
In short it makes all the different things you or others could do with your site easier to do.
You don't do it for the machines but for the humans.
If we only cared about machines we'd still be coding in assembly :)

What are the best-practices for making a website accessibility-friendly?

I'm looking for best-practices for designing a site that with accessibility in mind. The site is going to have a lot of older and less-abled individuals visiting it, and I want to make it as friendly for them as possible. Is there a resource that describes all the right tags, and attributes to use?
There are many many resources depending on your goals.
Strongly suggest you start with:
Section 508 (US legislation, obviously US centric though)
W3C's Web Accessibility Initiative and Web Content Accessibility Guidelines
edit:
Forgot to mention that WCAG has come in for some considerable criticism which makes this guy's efforts very helpful.
Also wanted to add, from personal experience, to remember that WA doesn't mean "blind people with screen readers". There are all manner of access limitations which you have to think of as well: e.g. dexterity issues related to e.g. muscle control, unusual input devices, and simple screen magnification.
Good luck!
Here's a quick list I tend to follow
Ensure it uses clean XHTML markup ideally to AAA standards,
Try where possible to spilt HTML, CSS, Javascript into respective files,
Create different style sheets for print, screen, etc.,
Ensure you take into consideration colours and fonts for the hard of sight and colour blindness,
Try to only place the main navigation at the top of the code so that the actual content appears near the top of the code, this way people do not have to scroll to far to see the content especially if they are using a screen reader / low res,
If you do have a lot of navigation before the content then place a link near the top allowing users to skip to the content,
Ensure the very first link on the page is to a text-only / low graphics version of the site,
Ensure ALL pages and all Essential functionality will work without JavaScript turned on,
There are lots of plugins for firefox to assist with development including:
Web Developer
No Script
HTML Validator
Firebug
Ensure the page renders across all browsers including old ones even if that means it works though does not match design exactly.
Ensure HTML, CSS, JavaScript is kept to the minimum file size to aid downloading times e.g. Remove white space and blank lines,
Always use LABELS in forms and alt, title tags in links and images,
Only use Tables for tabular data and ensure data appropriately labelled,
Where possible do not use JavaScript to write content to a page but use CSS to hide it, that way is JavaScript is disabled or does not work properly then content will still appear,
Always ensure you use onkeypress as well as onclick events in JavaScript encase the user can not / is not using a mouse.
Finally if you have to use blank images on a page for tracking etc. then don't give them Alt tags. This is my own view and is one which is hotly debated on-line especially when 1x1px images used to be used for spacing. However as far as I see it, if you are using a screen reader then you don't what it reading out stupid comments for images it does not need to see.
Try looking at Wikipedia's article on Web Accessibility. It contains lots of links to various sources of information for different countries, which may be useful depending on your target audience. The W3C was one of the original standards, but has plenty of critics.
Among other things.. provide "alt" and "title" attributes for every "img" tag.
Get a text-only browser like lynx. If your site works in lynx, it's likely to work for people who need screen readers or have other handicaps. It's no substitute for looking up the regulations, but it's a quick and easy check.
For another perspective, see the Dutch Government Web Guidelines.
The government provides a standard called section 508 that lays out what makes a site compatible.
A good resource is found at W3C site: Web Content Accessibility Guidelines.
A few things to keep in mind:
have a CSS link on each page that easily allows the font size to be changed.
Visually try to have appropriate presentation that is easy to read in a backwards S fashion.. left to right, back down.. etc..
ensuring that all the alt tags, etc, as mentioned in the other responses is vital.
see if there are some disability websites out there that specialize in testing your site. no harm in seeing what they list as being important to do.
make sure things are easy to read and find. this alone will make the job much easier.
There are many many resources on this topic. In fact, the danger is of information overload, rather than not enough information.
But an alternative approach is to think about your HTML page in generic terms, rather than the visual output you see in the web browser. If you wrote a piece of software that interpreted the website what would be helpful? This is a round-about way of saying use good semantics. My top tips would be to use standard XHTML for content and CSS for design. Also look up topics such as "progressive enhancement" and "behavioral Javascript".
But for resources:
The W3C's Web Accessibility Initiative: www.w3.org/wai
www.WebAIM.org
www.Accessify.com
www.CSSZenGarden.com for inspiration on how semantic markup can be styled to look very different.
It hasn't been mentioned yet so I figure I would mention it. If you want blind users to be able to use your site avoid flash. At the most 1% of flash I find on the internet is accessible.
A good list of resources about accessibility (colourblind screen-reader,typography etc) is here in design way.
For validation of web site and general documentation I use the W3C.
If you're developing in asp.net the opensource NAAK tool might be useful.
A must read is Jeffery Zeldman's "Designing with Web Standards"
Not sure if you are using Dreamweaver, but he has also just realeased a toolkit to validate your site for accessiblity.

Is there a business reason for striving for pure CSS layout?

It seems like every time I try to create a pure CSS layout it takes me much longer than if I'd use a table or two. Getting three columns to be equal lengths with different amounts of data seems to require particular fancy hacks, especially when dealing with cross-browser issues.
My Question:
Who are these few tables going to hurt?
Tables seem to work particularly well on tabular data — why are they so reviled in this day and age?
Google.com has a table in its source code, so do many other sites (stackoverflow.com does not by the way).
Since this is stackoverflow, I'll give you my programmer's answer
semantics 101
First take a look at this code and think about what's wrong here...
class car {
int wheels = 4;
string engine;
}
car mybike = new car();
mybike.wheels = 2;
mybike.engine = null;
The problem, of course, is that a bike is not a car. The car class is an inappropriate class for the bike instance. The code is error-free, but is semantically incorrect. It reflects poorly on the programmer.
semantics 102
Now apply this to document markup. If your document needs to present tabular data, then the appropriate tag would be <table>. If you place navigation into a table however, then you're misusing the intended purpose of the <table> element. In the second case, you're not presenting tabular data -- you're (mis)using the <table> element to achieve a presentational goal.
conclusion
Whom does this hurt? No one. Who benefits if you use semantic markup? You -- and your professional reputation. Now go and do the right thing.
Like a lot of things, it's a good idea that often gets carried too far. I like a div+css driven layout because it's usually quite easy to change the appearance, even drastically, just through the stylesheet. It's also nice to be friendly to lower-level browsers, screen readers, etc. But like most decisions in programming, the purpose of the site and the cost of development should be considered in making a decision. Neither side is the right way to go 100% of the time.
BTW, I think everyone agrees that tables should be used for tabular data.
In the real world, your chances of taking one design and totally reskinning it without touching the markup are pretty remote. It's fine for blogs and concocted demos like the csszengarden, but it's a bogus benefit on any site with a moderately complex design, really. Using a CMS is far more important.
DIVs plus CSS != semantic, either. Good HTML is well worthwhile for SEO and accessibility always, whether tables or CSS are used for layout. You get really efficient, fast web designs by combining really simple tables with some good CSS.
Table layouts can be more accessible than CSS layouts, and the reverse is also true - it depends TOTALLY on the source order of the content, and just because you avoided tables does not mean users with screen readers will automatically have a good time on your site. Layout tables are irrelevant to screen reader access provided the content makes sense when linearised, exactly the same as if you do CSS layout. Data tables are different; they are really hard to mark up properly and even then the users of screen reader software generally don't know the commands they need to use to understand the data.
Rather than agonising over using a few layout tables, you should worry that heading tags and alt text are used properly, and that form labels are properly assigned. Then you'll have a pretty good stab at real world accessibility.
This from several years experience running user testing for web accessibility, specialising in accessible site design, and from consulting for Cahoot, an online bank, on this topic for a year.
So my answer to the poster is no, there is no business reason to prefer CSS over tables. It's more elegant, more satisfying and more correct, but you as the person building it and the person that has to maintain it after you are the only two people in the world who give a rat's ass whether it's CSS or tables.
Using semantic HTML design is one of those things where you don't know what you're missing unless you make a practice of it. I've worked on several sites where the site was restyled after the fact with little or no impact to the server-side code.
Restyling sites is a very common request, something that I've noticed more now that I'm able to say "yes" to instead of try to talk my way out of.
And, once you've learned to work with the page layout system, it's usually no harder than table based layout.
I'm of the thought that CSS layout with as few tables as possible is cleaner and better, but I agree that sometimes you just gotta use a table.
Business-wise, it's generally "what's going to get it done the fastest and most reliable way." In my experience, using a few tables generally falls into that category.
I have found that a very effective way to mitigate cross-browser differences in CSS rendering is to use the "strict" doctype at the top of your page:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
Also, for the dreaded IE6 CSS issues, you can use this hack:
.someClass {
background-color:black; /*this is for most browsers*/
_background-color:white; /*this is for IE6 only - all others will ignore it*/
}
The main reason why we changed our web pages to DIV/CSS based layout was the delay in rendering table based pages.
We have a public web site, with most of its users base is in countries like India, where the internet bandwidth is still an issue (its getting improved day by day, but still not on par). In such circumstances, when we used table based layout, users had to stare at a blank page for considerably long time. Then the entire page will get displayed as a whole in a tick. By converting our pages to DIV, we managed to bring some contents to the browser almost instantly as users entered to our web site, and those contents where enough to get the users engaged till browser downloads entire contents of the page.
The major flaw with table based implementation is that, the browser we will show the content of the table only after it downloads the entire html for that table. The issue will blow out when we have a main table which wraps the entire content of the page, and when we have lots of nested tables. For the 'flexible tables' (those without any fixed width), after downloading entire table tag, browser has to parse till the last row of the table to find out the width of each columns, then has to parse it again for displaying the content. Till all these happens users has to stare at a blank screen, then everything will come to screen in a tick.
If you have a public facing website, the real business case is SEO.
Accessibility is important and maintaining semantic (X)HTML is much easier than maintaining table layouts, but that #1 spot on Google will bring home the bacon.
For example: Monthly web report: 127 million page views for July
Monthly web report: 127 million page views for July
...
Latimes.com keeps getting better at SEO (search engine optimization), which means our stories are ranking higher in Google and other search engines. We are also performing better on sites like Digg.com. All that adds up to more exposure and more readership than ever before.
If you look at their site, they've got a pretty decent CSS layout going.
Generally, you find relatively few table layouts performing well in the SERPs these days.
Keep your layout and your content separate allows you to redesign or make tweaks and changes to your site easily. It may take a bit longer up front, but the longest phase of software development is maintenance. A css friendly site with clear separation between content and design is best over the course of maintenance.
One other thing I just remembered, you can assign a different stylesheet to a page for printing vs. display.
In addition to your normal stylesheet definition, you can add the following tag
<link rel="stylesheet" type="text/css" media="print" href="PrintStyle.css" />
Which will render the document according to that style when you send it to the printer. This allows you to strip out the background images, additional header/footer information and just print the raw information without creating a separate module.
doing a complete revamp of a 15 page web site just by updating 1 file is heaven.
This is true. Unfortunately, having one CSS file used by 15,000 complex and widely differing pages is your worst nightmare come true. Change something - did it break a thousand pages? Who knows?
CSS is a double-edged sword on big sites like ours.
In my experience, the only time this really adds business value is when there is a need for 100% support for accessibility. When you have users who are visually impaired and/or use screenreaders to view your site, you need to make sure that your site is compliant to accessibility standards.
Users that use screenreaders will tend to have their own high-contrast, large-font stylesheet (if your site doesn't supply one itself) which makes it easy for screenreaders to parse the page.
When a screenreader reads a page and sees a table, it'll tell the user it's a table. Hence, if you use a table for layout, it gets very confusing because the user doesn't know that the content of the table is actually the article instead of some other tabular data. A menu should be a list or a collection of divs, not a table with menu items, again that's confusing. You should make sure that you use blockquotes, alt-tags title attributes, etc to make it more readable.
If you make your design CSS-driven, then your entire look and feel can be stripped away and replaced with a raw view which is very readable to those users. If you have inline styles, table-based layouts, etc, then you're making it harder for those users to parse your content.
While I do feel that maintenance is made easier for some things when your site is purely laid out with CSS, I don't think it's the case for all kinds of maintenance -- especially when you're dealing with cross-browser CSS, which can obviously be a nightmare.
In short, your page should describe its make-up in a standards compliant way if you want it to be accessible to said users. If you have no need/requirement and likely won't need it in the future, then don't bother wasting too much time attempting to be a CSS purist :) Use the mixture of style and layout techniques that suits you and makes your job easier.
Cheers!
[EDIT - added strikethrough to wrong or misleading parts of this answer - see comments]
The idea is that Designers can Design and Web Developers can implement. This is especially the case in dynamic web applications where you do not want your Designers to mess around in your Source Code.
Now, while there are templating engines, Designers apparantly just love to go crazy and CSS allows to pull a lot more stunts than tables.
That being said: As a developer, i abandoned CSS Layout mostly because my Design sucks anyway, so at least it can suck properly :-) But if I would ever hire a Designer, I would let him use whatever his WYSIWYG Editor spits out.
Business reason for CSS layout: You can blow away the customers by saying "our portal is totally customizable/skinnable without writing code!"
Then again, I don't see any evil in designing block elements with tables. By block elements I mean where it doesn't make any sense to break apart the said element in different designs.
So, tabular data would best be presented with tables, of course. Designing major building blocks (such as a menu bar, news ticker, etc.) within their own tables should be OK as well. Just don't rely on tables for the overall page layout and you'll be fine, methinks.
*I would let him use whatever his WYSIWYG Editor spits out
I just threw-up a little...
*ahh hello? You don't think the graphic designer is writing the CSS by hand do you?
Funnily enough I have worked with a few designers and the best among them do hand-tweak their css. The guy I am thinking of actually does all of his design work as an XHTML file with a couple of CSS files and creates graphical elements on the fly as he needs them. He uses Dreamweaver but only really as a navigation tool. (I learned a lot from that guy)
Once you've made an investment to learn purely CSS-based design and have had a little experience (found out where IE sucks [to be fair it's getting better]) it ends up being faster I've found. I worked on Content Management Systems and the application rarely had to change for the designers to come up with a radically different look.
Besides being easily updatable and compliant...
I use to design all table based web sites and I was resistant at first, but little by little I moved to CSS. It did not happen overnight, but it happened and it is something you should do as well.
There have been some nights I wanted to toss my computer out the window because the style I was applying to a div was not doing what I want, but you learn from those obstacles.
As for a business, once you get to designing web sites by CSS down to a science, you can develop processes for each site and even use past web sites and just add a different header graphic, color, etc.
Also, be sure to embed/include all reusable parts of your website: header, sub-header, footer.
Once you get over the hump, it will be all down hill from there. Good luck!
:: nods at palmsey and Jon Galloway ::
I agree with the maintainability factor. It does take me a bit longer to get my initial layouts done (since I'm still a jedi apprentice in the CSS arts) but doing a complete revamp of a 15 page web site just by updating 1 file is heaven.
Some additional reasons why this is good practice:
Accessibility - the web should ideally be
accessible by all
Performance - save
bandwidth and load faster on mobile
devices (these lack bandwidth to some
degree and cannot layout complex
tables quickly). Besides loading fast is always a good thing...
When a screenreader reads a page and sees a table, it'll tell the user it's a table. Hence, if you use a table for layout, it gets very confusing because the user doesn't know that the content of the table is actually the article instead of some other tabular data
This is actually not true; screen readers like JAWS, Window Eyes and HAL ignore layout tables. They work really well at dealing with the real web.
I don't think there is a business reason at all. Technical reason, maybe, even so, barely - it is a huge timesuck the world over, and then you look at it in IE and break down and weep.
i actually can see Tables in Stack Overflow on the user page.
It even has heaps of inline styles...
There definitely is. If you are still striving for it, you are not getting it right.
DIV+CSS layout is actually much easier than table layout in terms of maintainability and productivity. Just keep practicing it before it's too early to say that.
Table layout is good too it's just not meant for layouts and have exceptional drawbacks when it comes to minor tuning.

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