I mean, XML is better if you have more text and fewer tags. And JSON is better if you have more tags and less text. Argh! I mean, come on, it’s that easy. But you know, there’s a big debate about it. [Steve Yegge, via Simon Wilison]

I’ve been asking that question in interviews, and I don’t think there’s still a big debate about when to use XML and when to use JSON. It’s now settled.

And Yegge’s answer is not quite right. I think the difference is between structural markup and key/value pairs.

However, there are also cases when you should prefer text/plain over JSON. A hint: every object in a Second Life sim might have an HTTP engine running in it.

• Now uses device-width constant instead of a value in pixels.
• Test for both iphone and ipod in user agent string.
• Switch from semi-colon to comma as separator, per ADC documentation.

James Craig has been great with pointing out bugs and changes to the viewport format, so I’m now listing him as a co-author. Thanks, James.

The Institute for the Future of the Book released CommentPress, a WordPress Theme, that breaks out block-level elements of a blog post into linearly linked nodes. Comments are made on, and displayed with each node.

For example: McKenzie Wark’s Gamer Theory 2.0 serialized as a weblog, each chapter is a long post, broken down into a stack of nodes, with node-level comments at the side.

There’s another WordPress extension, I think it was done by someone at Yahoo!, that allowed comments at the paragraph level. Anyone remember that one?

Update: It’s Jack Slocum’s work I was thinking of. Thanks to Jeppe Kabell in the comments.

[via O'Reilly Radar]

[1] Cited previously in: From Paper Towels to Hypercard?

Update 4: Plugin now hosted at wordpress.org.

Update 3: New version with support for viewport constants, and iPod Touch.

Update 2: James Craig points out that the ID attribute is not allowed in the META element, so I’ve updated the plugin.

Update: I should add what my aim is. Rather than creating a separate template for mobile, I want to have a theme that ‘does the right thing’ for iPhone and desktop browsers.

Some documentation:

1. Plugin tests user agent string.
   • If it contains ‘iPhone’ then it adds <meta content="width=480; maximum-scale=0.6667" name="viewport"/> to the document’s head.
   • It also adds iPhone specific CSS rules. For that reason, you should call wp_head() in your theme file after you declare your default CSS files.
   • These rules were written with Sandbox in mind. You will want to edit the CSS rules to suit your theme.
   • You can force the viewport and CSS rules by adding forceiphone=y to the query string portion of a URL.
2. Adds a boolean function: weh_is_iPhone().
   • Returns true if user agent string contains ‘iPhone’.
   • You can call this function from your theme to add or turn off generation of markup.
   • Most likely you’ll use it to turn off generation of sidebars.

Update: If you use two fingers, you can scroll within the overflowed div.

/* asides rules */

body.home div.category-linklist * {
	display:inline;
}

body.home div.category-linklist h2.entry-title {
	font-size: 12pt;
	display:inline;
}

body.home div.category-linklist h2.entry-title:after {
	content: ": ";
}

body.home div.category-linklist div.entry-meta,
body.home div.category-linklist div.entry-date {
	display: none;
}

body.home div.category-linklist {
padding: 0pt 10pt 10pt 10pt;
}

/* Asides Single Entry Display Rules */

body.single.s-category-linklist h2.entry-title {
	font-size: 200%;
}

body.single.s-category-linklist div.hentry div.entry-content {
	font-size: 175%;
}

Again, I use ‘linklist’ as my ‘asides’ category, so edit appropriately.

What I’d like to see is an option to convert the post in MarsEdit to and from Markdown, so I can publish XHTML, and convert back to Markdown if I edit it later.

Last week, Netscape temporarily removed the DTD for RSS 0.91 from their site, and things promptly went south.

In response to that mess, Henri Sivonen points out that if you’re sending XML (not HTML) over the wire, there’s no reason to attach a Doctype declaration, and consuming applications should use internal Catalogs if they want to validate what they get over the wire.

I echo Sivonen’s reminder that you should declare a DTD when sending HTML, since browsers know to either ignore it or use a local version of the DTD.

Sivonen also mentions, in passing, the Billion Laughs attack. Which, to my shame, I’d missed.

Here’s my CSS rules for asides. You’ll need to use the Sandbox theme, and I advise adding a link in the head of the main template file for your custom CSS.

NB: my ‘asides’ category is ‘linklist’ so edit appropriately.

The first two rules are from Andy’s post.

body.home div.category-linklist * { display:inline; }

The first rule makes all the children of a post in the linklist category (what I use instead of asides) display as inline rather than blocks.

The next hides the display of elements we don’t want to show in an aside.

body.home div.category-linklist div.entry-date,
body.home div.category-linklist span.entry-author,
body.home div.category-linklist span.entry-category,
body.home div.category-linklist span.metasep {
display:none;
}

Then my tweaks follow:

body.home div.category-linklist h2.entry-title {
font-size: 12pt;
display:inline;
}

Now have the post's title, an H2, display inline, and set the font size to the same as the body of the post.

body.home div.category-linklist h2.entry-title:after { content: ": "; }

This puts a ': ' after the post title, before the body of the aside.

Update: the following section on IE conditional comments isn't behaving right for me.

Unfortunately, IE6 does not implement the :after pseudo-element (even though it's part of CSS 2). So on IE6, the aside title will run into the aside body. The alternative is to hide the H2 for IE using a conditional comment.

<!--[if IE 6]>
body.home div.category-linklist h2.entry-title { display: none; }
<![endif]-->

And now set the padding on the entry so it doesn't run-up against other posts and asides.

body.home div.category-linklist {
padding: 0pt 10pt 10pt 10pt;
}

In order to use that with PHP 4, apply Niklas’ patch.

Finally, if you don’t want to syndicate your feed’s content as escaped HTML, apply my patch that combines my changes and Niklas’ to James’ code. However, you’re now responsible for making sure your entries are valid XHTML.

Note: after applying the patch, you’ll need to modify the format string passed to the_time to account for your offset from GMT. There’s probably another way to do this.

While providing a purpose-built (ahem, Atom) feed remains the best answer, hAtom offers two things we didn’t have three years ago:

1. A consistent content model: you don’t have to analyze the markup and write a custom XSLT transform (such as in my example using The Nation, or the feed for The Infinite Matrix.)
2. A widely deployed model: It appears that Sandbox, a theme with hAtom support, will become the default template for WordPress.