Slashdot Mirror
Developing a Standards-Compliant Web App?
dogas queries: "I work for quite a large company that is creating quite a large web-based enterprise-level application. We've been in development for a long while, and currently our app is only native to IE 5.5. At this point it would take a *lot* of effort to bring our app up to to be Standards-compliant. Now management wants our app to be more flexible, such that if the customer wants to customize the look-and-feel, it won't be a major undertaking that will kill the structure. Naturally, we're switching to a CSS-based layout, ripping out the IE proprietary Javascript in favor of ECMAScript, and bringing the whole app to XHTML 1.0 Transitional compliance while we're at it. Since we started coding the front end at about the time of the browser wars, we didn't have the luxury of planning to use the W3 standards (especially since they were not complete, and browsers weren't honoring them anyways). I'm wondering what type of priority creating a standards-compliant web app is in other companies, and if that priority is being raised given the benefits of creating pages that separate structure from style from behavior."
Separating content and presentation would be a good thing. But the currently supported web standards (HTML, XHTML, JavaScript, DOM, CSS) don't let you do it by themselves. To achieve that kind of separation, you need to use some kind of server-side technology and you need to generate preference-specific HTML anyway.
But even if you manage to do that, it's not clear that it's a good thing: regular folks don't feel all that comfortable authoring abstract markup. They want to write their web pages in something WYSIWYG and they will (trust me) manage to encode lots of assumptions about how the content is ultimately presented.
So, you have to pick some kind of middle ground: not too much user customization but some (maybe light/heavy). Not too much server side separation of content and presentation, but some. Not too much JavaScript and CSS, but a little may help you out quite a bit. Etc.
One of the major advantages of going "standard" is simply the correctness of the XHTML/HTML you'll send to the browser; no missing tags, no misordered, no proprietary tags will do 80% of the job. The W3 validator is your friend.
Most of the trouble with "IE-enhanced" pages is the interpretation of errors by parsers. If I write:
[p][strong]foo[em]bar[/strong]baz[br]
In what tags is the 'baz'? depends on who reads it, mmh?
Except for NN4, unrecognized CSS tags will just go unnoticed for lower-version browsers, so that if your structure is OK, it should be usable for most browsers.
You might want to test with Mac's browsers (IE5 at least) to make sure your ECMAscript works; some core methods are missing.
And, should you need an incentive to go table-less, there is a great presentation that summarizes the advantages.
The css Zen garden is a great example if you want to show colleagues why separating presentation from content is a neat idea.
The W3C WAI resource page has pointers to everything you need to know. A popular tool that helps evaluating web accessibility is Bobby, but unfortunatly it isn't free.
Programming can be fun again. Film at 11.
Do yourself a favour and go for the Strict versions of the (X)HTML markups directly. Don't waste time with Transitional markup, because you'll be creating the same old tag soup that all the browsers (old and new) will happily eat in quirks mode. When the day comes (after your transition?) and you finally set that DTD to Strict, all your pages will be blown to bollocks because the browsers will now render them in strict standards compliance mode.
Why bother? You can't really benefit from Style Sheets in quirks mode anyway? Remember, the rendering is completely different between quirks and strict standards compliance mode, and with good reason! The browser developers finally had a chance to do it right with strict standards compliance mode rendering because their implementations are made from scratch from the same thorough W3C spec. With quirks mode they just use their old layout engines from back during the browser wars.
You'll benefit greatly from the Strict versions of the (X)HTML markup. While taking full advantage of Style Sheets and ridding your old (X)HTML sources of the deprecated presentational tags, you'll end up with more easily maintainable (X)HTML sources. Think about it, most of your pages might already consist of 80% tags related to presentation. When you have removed these from one page and put the presentational information in an external style sheet, it won't be that much of an effort to apply these resulting style sheet rules to the rest of your pages. Why? Because most of the time you'll just be removing deprecated tags. Sure, there's still a bit of structure to deal with, but it's a worthwile task.
I've written "(X)HTML" in this comment a couple of times now. As I see it, the Transitional/Strict issue is infinately more important than the HTML/XHTML issue. When you have Strict HTML markup it's really a no-brainer to convert it to XHTML, because it's pretty much about syntax, well formedness. Try taking a look at W3C's HTML compatibility guidelines for XML. If you do yourself a favor and explicitly use closing tags, etc. you can convert your HTML to XHTML with a couple of regular expression substituions. That's pretty much it. Bottom line: the main difference between the Strict versions og HTML and XHTML is largely syntax. (There are some elements of your DOM that require special attention with respects to applying CSS, but this statement is essentially true.)
If you care about having the same result shown accross browsers (especially IE), then watch out for XHTML.
(Borrowing a bit from a previous comment I made here on /.) IE can be a stick in the wheel, because it
ignores the XML declaration in XHTML documents beginning like this:
<?xml version='1.0' encoding='iso-8859-1'?>
IE expects to encounter the DOCTYPE first, which doesn't make sense - and would be non-valid XHTML markup. When IE encounters the above declaration it throws itself into quirks mode, unconditionally!
Sure, the XML declaration is not strictly required, however if you read the W3C XHTML spec it says:
An XML declaration is not required in all XML documents; however XHTML document authors are strongly encouraged to use XML declarations in all their documents. Such a declaration is required when the character encoding of the document is other than the default UTF-8 or UTF-16 and no encoding was determined by a higher-level protocol.
Another point. XHTML pages should really only be created for the purpose of being served - by your web server - as application/xhtml+xml. See W3C's document on XHTML Media Types. IE doesn't support the application/xhtml+xml media type, and this together with the above mentioned deficiency makes for quite a showstopper with respects to the adoption of XHTML - it's sad, really.
Mozilla and Opera will handle XHTML documents served as application/xhtml+xm
What would an EWOULDBLOCK block, if an EWOULDBLOCK could block would? -- me