Web Devout tidings

The latest alpha version of Firefox has been labeled “feature complete,” meaning no significant changes are planned for the webpage layout engine. In response, I have added the Firefox 2.0 information to the Web browser standards support resource. According to my information so far, there have been no significant changes to the areas currently covered in the standards support resource. However, since there were changes to SVG support and I hope to add SVG information to the tables eventually, I have decided to list Firefox 2.0 separately from Firefox 1.5.

Opera 9 information will be added when the public builds are labeled “feature complete” or an equivalent. Opera is known to make significant changes even in the final beta versions, so it’s possible that I will be unable to begin thorough testing until the final version of Opera 9 is released.

I have finished the DOM and ECMAScript support information for Internet Explorer 7.

There isn’t much to say. As far as I could see, only three things have been changed:

• Element.style.maxHeight is now supported.
• Element.style.maxWidth is now supported.
• Element.style.minWidth is now supported.

It’s surely a disappointment for those who were hoping for more of a move toward the DOM standards. There were also some changes regarding XMLHttpRequest, but that’s proprietary and thus beyond the scope of my tables.

And sadly, this is not an April Fool’s joke. Sorry.

I have now finished testing the CSS 2.1 and CSS 3 support in Internet Explorer 7. The results are more significant than the previously reported HTML support improvements. CSS was the primary area of layout engine development in Internet Explorer 7, so this is where most of the layout engine changes reside.

Here are the major changes in Internet Explorer 7 as far as CSS 2.1 and CSS 3 support:

• !important is now properly supported.
• Much better support for selectors, including universal selectors, child selectors, adjacent sibling selectors, CSS 3 indirect adjacent sibling selectors, and all attribute selectors in CSS 2.1 and CSS 3. This is better support than Opera 8.5, although still behind Firefox 1.5 in some areas.
• More correct pseudo-class and pseudo-element grammar implementation.
• :first-child is now supported.
• :hover is now supported for all elements, although not perfectly.
• Backgrounds now correctly include border region.
• dotted border style is now properly supported for one-pixel-wide borders.
• bottom and right can now be used to stretch the box’s dimensions.
• Some float bugs were fixed.
• Box sizes are now properly constrained by the height and width properties.
• Several margin bugs have been fixed.
• max-height, max-width, min-height, and min-width are now mostly supported.
• overflow is now correctly supported.
• position:fixed is now supported.
• z-index property now behaves correctly with select elements.

Here are some things I was disappointed about:

• It still doesn’t support combined class selectors like p.foo.bar{} and still has other bugs with class and ID selectors.
• :hover has some bugs that cause the hover state to sometimes remain even after the mouse has moved away.
• :before and :after still aren’t supported, meaning counters, content, and quotes also aren’t supported.
• inherit (one of the fundamental features of CSS) still isn’t supported.
• Borders still aren’t supported for table row groups.
• border-spacing, caption-side, and empty-cells still aren’t supported.
• There was a nasty regression regarding the clear property that prevents elements from clearing floats under certain conditions.
• clip still isn’t supported.
• There were no improvements to the display property, meaning CSS table displays still aren’t supported.
• Some margin bugs remain.
• outline still isn’t supported.
• There are still a lot of problems with the vertical-align property.
• There were no improvements to the print properties.
• Alternate stylesheets still aren’t supported (a requirement for CSS conformance).
• There is still no option to disable author stylesheets (another requirement for CSS conformance).
• Other than basic selectors, there were no improvements to CSS 3 support. There is still no support for any CSS 3 pseudo-classes or pseudo-elements.

A lot of painful problems were fixed, but Internet Explorer is still miles behind the competition in CSS support. According to the Web Devout tables, Internet Explorer 7’s CSS 2.1 support has risen from 54% to 65%, compared to Firefox 1.5’s 93% and Opera 8.5’s 94%. Due to the added CSS 3 selector support, overall support for CSS 3 changes has risen from 7% to 13%, compared to Firefox 1.5’s 28% and Opera 8.5’s 8%.

The lack of support for inherit, :before and :after pseudo-elements, and table display values will continue to be thorns in the sides of web developers. Hopefully these problems will be fixed in Internet Explorer 8, which is planned for release within one year of the Internet Explorer 7 release.

I will test DOM support improvements next, although I haven’t heard of any changes in that area.

Edit: As a reminder, Microsoft has previously announced that the latest build of Internet Explorer 7 is layout complete, meaning no significant changes will be made to the webpage layout engine until the final release.

Following the announcement that the latest build of Internet Explorer 7 is layout complete, meaning no significant changes will be made to the webpage layout engine until the final release, I have begun testing Internet Explorer 7’s standards support. So far the HTML / XHTML support information is complete, and I will work on the CSS information next.

Here is what was changed in Internet Explorer 7 as far as HTML / XHTML support:

• The abbr element is now supported.
• There are some slight improvements to object support, including some form of fallback mechanism (see below).
• The select, optgroup, and option elements have been improved.

Here are some things I was disappointed about:

• The tabindex attribute still has worthless support
• Important informational attributes like cite, datetime, and longdesc still have no interface for the user to access their values.
• The button element still uses the element contents even if the value attribute is provided.
• The implicit form for label elements still isn’t supported.
• Alternate stylesheets still aren’t supported.
• The object element is still practically unusable for simple things like images, the fallback mechanism doesn’t always seem to work, and sometimes the user is presented with strange messages in the object area instead of the fallback that should be provided in the event of a problem.
• The q element still doesn’t show quotation marks, rendering the element nearly useless unless you’re willing to let user agents without CSS support see two pairs of quotation marks.
• The title attribute is still supported incorrectly.
• There wasn’t a single improvement to XHTML support (other than a change to the layout mode detection algorithm so that XML declarations don’t throw the browser into quirks mode).

All in all, it’s a disappointing outcome in this area. According to the Web Devout tables, overall HTML / XHTML support hasn’t risen by even one percentage point since Internet Explorer 6, and is still sitting at 80%.

The good news is that CSS was the primary focus of Internet Explorer 7 layout engine development (a decision I very much agree with), and I have seen noteable improvement there, particularly in regard to selectors. So far I have found one regression that prevents floats from being cleared under certain circumstances. More information will be available later.