How to Learn HTML5

I received this email:

Hi Kroc,

I stumbled on your website today and was quite impressed with quite a few different things about it (the design, the tone of your writing, &c.).

The one thing in particular, and something I wanted to question you on, was your reference to HTML5. Something I know nothing about. In the post I came across you talked about a guy named Sam Ruby and how he referred to it as minimalist code. Anyway that’s beside the point. I’m really interested in using no IDs and/or classes, but know nothing about HTML5.

So here’s my question, ... do you recommend any other resources or tutorials for someone like me? I rely very heavily on classes and my stuff is sloppy for the most part. I’d love to convert my site but have no idea where to start.

Any advice or words of wisdom would be greatly appreciated. Thanks in advance.

Joe Holst

Hello Sir,

You only require one thing, and then to do three things in order to succeed in your goals here.

Firstly, you need to get some willpower. You already seem to have that, as you’ve taken interest to email me to ask about where to start. Without the want to write better code, no learning in the world can help!

It should be noted that absolutely nothing I’m doing is undocumented; in that fact none of the code on my website is even special—all it is, is the representation of my personal drive for quality, as I measure it.

I don’t think willpower is going to be a problem for you if you already twig that HTML5 and cleaner code is the direction you might want to go. Some people don’t ever progress beyond writing IE-only junk, and that’s not down to skill level, it’s a willpower problem.

Secondly, you need to do three things:

1. revise,
2. revise,
3. revise.

I proof-read and break my code over and over again, to chip away what niggles me here and there. Getting rid of classes is a one-by-one process, because each class has a use that may be totally unrelated to the other classes in the document. Each class is it’s own problem, some big, some small—some requiring a complete rewrite even.

I’m quite happy to break my entire codebase for a week—rewriting and reorganising everything—just to get one tiny annoyance out of sight and out of mind.

If you proof read your codebase you’ll spot various things that could be better, all of varying difficulty levels, some maybe without a clear solution. Start by picking something that annoys you, that you know could be done better, and fix it… even if it’s just tidying up a comment so that it looks nicer. Polish your code.

That is how I work. I scan through my code and look at it objectively. I think about where I can make it cleaner, tidier, less complicated, better documented, easier for others to understand; anything that catches my eye.

I pick something that I personally feel motivated toward (I have no boss on my personal site, so I only have to fix what I care about; and in that, the quality, through passion, is maintained) and I set about fixing it. Sometimes that’s a big problem—like what I’m working on right now: a Markdown clone, so as to reduce the amount of HTML I’m writing for minor things like abbreviations, links and citations—or sometimes it’s a small thing like shaving a few lines off here and there. I do whatever my heart feels capable of doing that day. I try never strain myself by doing work I’m not interested in—that’s for secular work.

Once I’ve made my fix, I go through the whole process again. Often whilst I’m implementing one fix it unearths other annoyances that I want to solve and I’ll either get distracted and go off and fix those, or wait until I’ve finished the thing I started on and be well set with another task to do afterwards—with a much stronger understanding of the problem to drive me forward with the design issues.

O, the design issues.

I am a slave to my code sometimes. I will not accept a sloppy solution. I pace around a lot. I wrestle with the architectural design of the code in my mind for days. I spend 100 hours writing 29 lines of code. Because to me, good code is not about how l33t your programming knowledge is, good code is about how much you rethink what you’re trying to do. What cohesive statement are you trying to make with your code?

Sometimes your code is not just about trying to solve a problem,
it’s trying to solve a problem using your personality.

But getting back to HTML5…

Before you learn HTML5, first learn HTML4. I know that sounds stupid, you may very well think you already know HTML4. In learning HTML5, I first referred to this list. Apart from the depreciated ones, do you know how to use all of them? I found that there were a number of HTML4 tags that I rarely used, that could easily replace sloppy <div>s and classes.

I see this often, and it really annoys me.

<div id="header">
	<h1>Title</h1>
</div>

Elements that are not <div>s can be styled just the same as a <div>. A <h1> is not somehow magically unable to have borders or backgrounds or margins or padding or anything a <div> can.

People seem to get this mindset that only <div>s can be used as boxes.
Here’s a list of elements you can use instead of <div>s.

P, BLOCKQUOTE (with P inside), H1/H2/H3…, ADDRESS, DL/DT/DD, UL/OL/LI, HR

All of these can be styled with any effect—meaning that you can get rid of a <div> and/or class, by just referring to the element directly, or by it’s parent.

For example:

<h1>Website Title</h1>
<ol id="menu">
	<li>menu 1</li>
	<li>menu 2</li>
</ol>
<h2>Article Title</h2>

Is better than

<div id="title">Website Title</div>
<div id="menu">
	<div class="menuitem">menu 1</div>
	<div class="menuitem">menu 2</div>
</div>
<div class="title2">Article title</div>

And for that matter, why would have a class for a menu item, when the menu is perfectly identifiable? Even in this bad example, you could still get rid of the menuitem class, and just refer to them with #menu div {...}.

An <ol> makes a perfect menu. It is after all, an Ordered List. Get to know what each of the element names means, how you would think of that in a standard word processor document, and then how that can be applied to your site, imagining your site as a word processor document without any CSS. Your menu would be a table of contents of sorts, and therefore would obviously be an Ordered List.

Here’s a different example I helped someone with:

<div id="leftcol">
	<h2 class="Blue">Recent Project</h2>
	…
</div>
<div id="rightcol">
	<h2 class="Green">News Updates</h2>
	…
</div>

He wanted the headings on the left blue, and the headings on the right, green. Which is fair enough.
However, could you not just select the column, and do away with the need for the classes?

/* as a rough example */
#leftcol h2	{color: blue;}
#rightcol h2	{color: green;}

Knowing, and using more elements, instead of resorting to <div>s all the time, allows you to use CSS to select those elements more widely as well as specifically. Here, both of these are <h2> s. Now if they were <div>s, we would have to use classes, because there would likely be yet more <div>s in the columns and you couldn’t say #leftcol div without turning many things blue or green instead of just what you wanted.

Getting rid of <span>s with classes requires knowing the meaning of the many inline elements. Google them.

ABBR, ACRONYM, BIG, CITE, CODE, DEL, DFN, EM, INS, KBD, Q, SAMP, SMALL, STRONG, SUB, SUP, VAR

Think of these elements outside of the browser, on a printed piece of paper. You can then bombard them with CSS to make them look like anything—even if they don’t look anything like what they’re supposed represent—but their use will be semantically sound, having the right meaning in your website.

Learn the selectors.

If you know the selectors and the the tags well enough, then you only need a class (or ID) when you cannot differentiate two elements from each other with the browser you are supporting. Since I’m using CSS3 and not supporting IE at all, I don’t need any classes because I’ve made the right choice of tags, and can differentiate all of them with the right CSS selectors.

If you want clean code using few, if any, classes then right away ditch IE6. Stop supporting it, tell people to upgrade. Without + and > selectors, IE6 is too frightened to go anywhere that isn’t within sight of a class or ID.

IE7 does support + and >, and whilst it lacks in many other areas, it has the necessary basics to write good HTML/CSS. Check what your targeted browsers support.

Once you have made a decent HTML4 site, then you will look at the HTML5 specification, and it will make sense—you will know what to do with it.


Kind regards,

Improved Title Case Function for PHP

John Gruber originally made available his script to Title Case text, working around the fringe-cases.

From this, a number of ports were made of the script of which particularly noteworthy David Gouch’s Javascript port that was smaller, simpler and handled more fringe cases.

I’ve ported this to PHP and put it to use on this site. My version is based on David Gouch’s Javascript port, unlike the WordPress port which is, frankly, crap.

Code below.

//original Title Case script © John Gruber <daringfireball.net>
//javascript port © David Gouch <individed.com>
//PHP port of the above by Kroc Camen <camendesign.com>

//this is required for PHP to not break unicode characters in your titles when using `strtolower`/`strtoupper`
//you can place this near the top of your script, or within the function itself
mb_internal_encoding ("UTF-8");

function titleCase ($s_title) {
	//remove HTML, storing it for later
	//         html elements to ignore  | tags  | entities
	$regex = '/<(code|var)[^>]*>.*?<\/\1>|<[^>]+>|&[^\w]+;/';
	preg_match_all ($regex, $s_title, $html, PREG_OFFSET_CAPTURE);
	$result = preg_replace ($regex, '', $s_title);
	
	//break by punctuation, find the start of words
	preg_match_all ('/[\w&`\'‘’"“\.@:\/\{\(\[<>_]+-? */', $result, $matches, PREG_OFFSET_CAPTURE);
	foreach ($matches[0] as &$m) {
		//find words that should be lowercase
		if ($m[1]>0 && mb_substr ($result, $m[1]-2, 1) !== ':' && preg_match (
			'/^(a(nd?|s|t)?|b(ut|y)|en|for|i[fn]|o[fnr]|t(he|o)|vs?\.?|via)[ \-]/i', $m[0]
		)) {
			$m[0] = mb_strtolower ($m[0]);
			
		//brackets and other wrappers
		} elseif (preg_match ('/[\'"_{(\[]/', mb_substr ($result, $m[1], 3))) {
			$m[0] = mb_substr ($m[0], 0, 1).mb_strtoupper (mb_substr ($m[0], 1, 1)).
				mb_substr ($m[0], 2)
			;
			
		//both of these cases are no change, thus if not matched fall back to capitalisation
		} elseif (!(
			preg_match ('/[A-Z]+|&|[\w]+[._][\w]+/', mb_substr ($m[0], 1)) ||
			preg_match ('/[\])}]/', mb_substr ($result, $m[1]-1, 3))
		)) {
			$m[0] = mb_strtoupper (mb_substr ($m[0], 0, 1)).mb_substr ($m[0], 1);
		}
		//substitute the change into the title
		$result = substr_replace ($result, $m[0], $m[1], strlen ($m[0]));
	}
	//restore the HTML
	foreach ($html[0] as $tag) $result = substr_replace ($result, $tag[0], $tag[1], 0);
	return $result;
}

Anything broken, please let me know.
Kind regards,

How to Use <abbr> in HTML5, and in General

Before I begin, I should profess that I am completely accountable for having never followed any of these rules in the past. However, the whole reason for writing this article was to solve that problem. Since moving to my new website back-end, I decided to go through the entire site’s contents with a fine brush and polish all of the code.

In doing that, I discovered how vague I was on the semantics of the abbr element, and working through all the test-cases that have sprung up in the wealth of HTML I've written for this site, I’ve documented here my new understanding of the often-abused abbr element.

Ⅰ. Abbreviations Are Not Dictionary Definitions

Let’s first define abbreviation clearly:

An abbreviation is where you have shortened one or more words into:
either one word, or an alternative phrase or acronym

The problem with the use of <abbr> so far, has been that developers have assumed that every abbreviation and acronym has had to be defined in full. This is incorrect.

BAD:	I made some <abbr title="American Standard Code for Information Interchange">ASCII</abbr> art.

An abbr element expands its contents into the desired spoken form. When you read a document, you naturally expand the abbreviations as appropriate in your mind.

GOOD:	Red <abbr title="versus">vs.</abbr> Blue

You would not read out aloud the abbreviated “et cetera” in “Granny went to the market and bought apples, bread & milk etc.” as “eee-tee-see”? So as it should be with HTML abbreviations. Here are some examples:

BAD:	My <abbr title="Cascading Style Sheets">CSS</abbr> is tweaked almost daily.
GOOD:	My <abbr title="style sheet">CSS</abbr> is tweaked almost daily.

Here we’ve used the abbr element to span over an abbreviation and provide an alternative, natural way of reading the abbreviation.

GOOD:	price <abbr title="does not equal">!=</abbr> <abbr title="total cost of ownership">TCO</abbr>

We have adapted something unpronounceable as letters into something perfectly readable.

In general, abbreviations should maintain the grammar. Whilst not necessary, this example demonstrates how grammatical flow can be improved, whilst also expanding a Latin abbreviation:

Along the way, open-source has forgotten what it really means (<abbr title="that is,">i.e.</abbr> in real life) to give.

Try and communicate your intentions. If you would personally read something one-way, define the abbreviation how you intend it to be read:

Switch to using the <abbr title="“wizzy-wig”">WYSIWYG</abbr> editor, instead.

In the example below however, there’s an abbreviation CDs inside the abbreviation title:

<abbr title="recordable CDs">CD-Rs</abbr> and <abbr title="recordable DVDs">DVD±Rs</abbr> are susceptible to literal bit-rot.

Isn’t this wrong? No, because remember that the point of abbreviations are to expand one phrase into another. The user is assumed to already know what a CD is, it doesn’t have to be spelt out for them.

This follows neatly into the next point: when and where to expand abbreviations at all…

Ⅱ. the title Attribute Is Optional

Oh man, this is so important. The misuse of the abbr element is because almost everybody is under the assumption that abbr elements must have a title attribute, in fact— it’d seem pointless otherwise!

Your users do not need to know the definition of every single acronym and abbreviated technical term. In fact, they don’t care. They don’t have to know what the V in DVD stands for if they know a DVD when they see one.

Only title abbreviations that you expect people to read as the expanded form in their mind, or out aloud.

An abbr element without a title attribute should be used on any abbreviation / acronym that is written in all-capitals (unless you are providing a spoken alternative, like the WYSIWYG example from earlier), to communicate that the abbreviation is either unpronounceable as a word, or that it is capitalised—not for emphasis—but because each letter has an individual meaning. E.g.

The <abbr>FBI</abbr> are like the British <abbr>MI5</abbr>.

Ⅲ. Citations Are Not Abbreviations

This one is very sneaky and can easily catch you out.

BAD:	The site will be built using <abbr title="Hypertext Pre-Processor">PHP</abbr>.

Firstly, this reads wrong; the abbreviation breaks the grammar. Secondly, remember that abbreviations are to communicate how things should be read, not to define terms.

But thirdly, it is not an abbreviation. It is not a section of the document that has been shortened or re-phrased by the author to fit their chosen grammar. It is not a personal rendering of words. The sentence is referring to a software product. This is a citation.

GOOD:	The site will be built using <cite>PHP</cite>.

Even though a cited name can be an abbreviation of something else, the name seals that abbreviation and turns that name into a real word of sorts (a brand). Names that are already made from an abbreviation, can then even be abbreviated! (since they behave as normal words) For example “Mac OS X” is already an abbreviation of “Macintosh Operating System version Ten”, and people then often abbreviate further, calling it “OS X” or by referring to the version number / name “10.5 / Leopard”.

What Counts as a Citation?

A citation represents the title of a work, where you are referring to it in the context of your sentence, or in passing. A work is defined as an intellectual human creation.

A work can be a book, a poem, a published piece of writing, a piece of art, a website, a song, a film, a TV show, a game &c. and also software.

However this does not include the following: people’s names, the name of a ship or real products in general; such as a packet of crisps, a stereo or computer hardware.

There Are Exceptions

I won’t go into details, but there are exceptions here and there, that mostly lie around the context; whereby you are either referring to the citation itself, or the use of that work in a specific case - particularly with broadly used technologies like HTML, CSS and PHP.

I am referring directly to the <cite>PHP</cite> language/technology.
My website’s <abbr>PHP</abbr> is small.

That said, details like this will boil down to personal taste, and it’ll never really hurt to just stick to using one element or the other for all such instances, regardless.

Ⅳ. Abbreviations Should Be Meek

An abbreviation is merely anything that is read different from how it is written and vice-versa. It does not need to be in your face, Javascript-powered, “intelli-text”.

What if the Reader Does Not Know What a Technical Abbreviation / Acronym Means?

Isn’t the point of an abbr element so that these technical terms can be defined by hovering the mouse over the term?

There’s two valid answers to this:

1. That’s what the <dfn> element is for, and …
2. It is not your responsibility to be an encyclopædia.
   Being paranoid about your reader’s abilities is just going to make your life difficult

You, the author, only have to take the responsibility to know your audience and define those terms which you think they won’t know, or that you may be newly introducing to them.

If a user does not know a term, your website is not the only resource in existence where they can then find the definition! The user can easily google the term. In many browsers they can just right-click the word and choose to search the web for it. On a Mac, there’s a system-wide integrated dictionary you can access in a number of ways. There is no end to the ways a user can find out what a term means if they need to.

How to Style Your Abbreviations

The traditional way to style abbreviations is a grey dotted line, like so:

abbr	{border-bottom: 1px solid #666;}

However, this was under the previous model of using abbr as some kind of inline dictionary. Abbreviations are for the benefit of screen readers, search engines and enthusiasts like me. Generally, abbreviations shouldn’t be styled at all.

That said, abbreviations still do provide a useful service by allowing readers to uncover how something should be read. We need a subtle approach that doesn’t fill the user’s screen with grey dotted lines, but at the same time does allow them to discover where you’ve provided reading “hints”.

The method I’m using is to only show the grey-dotted underline when the user’s mouse is within the paragraph containing the abbreviations, so that when the user moves their mouse into the surrounding text, the abbreviations (with titles) will be marked, and the user can hover over them to then see the tooltip.

*:hover>abbr[title]	{border-bottom: 1px dotted #666; cursor: help;}

/* first, the immediate descendants of the content area are set to highlight abbreviations on hover, but avoiding lists; as I don’t want *all* abbreviations highlighted when you hover on a root list… */
section>*:not(ol):not(ul):not(dl):hover abbr[title],
/* …only when hovering on each list-item */
 p:hover abbr[title], li:hover abbr[title], dl>*:hover abbr[title] {
	border-bottom: 1px dotted #666; cursor: help;
}

I hope this article provides with some practical guidance and enthusiasm.

If you spot any flaws in the HTML of my articles, please do contact me and let me know, I’ve got so many thousands of lines I’m sure to have made mistakes everywhere. Also you’re free to e-mail me if you’ve any questions about this article and using abbr, cite and HTML5 in general.

Special thanks goes to Adam of firsttube.com for reviewing the article whilst it was being prepared and spotting a number of flaws.

Under the Hood #5:
New Website-Ish

Welcome to Camen Design v0.2-ish. I've replaced the publishing code in the site, leaving the HTML5 & CSS intact. They will be replaced in the next update. I plan to target Firefox 3.1 (and hopefully Safari 4 may be out by then too), allowing me to make use of CSS animation/transitions and border-image.

In fact, because my site has its PHP / HTML / CSS entirely separated, any one can be replaced without touching a line of the other.

On the subject of future-proof CSS, I noted:

A CSS file is such that you can throw it away easily and start again. I could design my website any way I wanted without ever changing the HTML.

Clean and separated HTML/CSS means that parts can be replaced. That’s what future-proof is about – the ability to adapt to changes.

Being bit-rot proof is an entirely different matter!

That’s a different topic for another day though. This article is about the new back-end:

Clean URLs

In the previous version of the site, a PHP script handled the database, spitting out the data as requested. v0.2 is now all static XHTML5 files, ensuring faster load speed and better caching. The publishing script generates pre-gzipped “.xhtml” files for each of the articles, as well as each of the index pages. The home page is “1.xhtml”, the second page “2.xhtml” and so on. Each content-type is a folder, containing another set of numbered files for the pages. e.g. “blog/1.xhtml” and so on.

Mod_Rewrite is used to mask the “.xhtml” extension, so it isn’t required, giving nice looking URLs with no querystring as before. “/?blog&page=2” now becomes “/blog/2”.

The ‘.htaccess’ file I wrote now handles everything dynamic, applying the ‘application/xhtml+xml’ mime-type to the HTML, but falling back to ‘text/html’ for browsers that can’t deal with that.

I've opened up my ‘.htaccess’ file so you can view it fully, but a detailed break-down is covered below.

Serving Compressed XHTML5

A big problem with the old code was that a single PHP page was not being cached very well, relying on me manually setting all the HTTP-Headers for the various pages requested. In this new version each page is a separate file, and so Apache and your browser can handle things fine.

FileETag MTime Size
AddDefaultCharset utf-8

This declaration tells Apache to send ETags in HTTP-Headers. The ETag is a unique hash of the file, so that the browser knows when the file has actually changed. Apache sends ETags automatically anyway, but uses the default “MTime INode Size”, which ties the ETag to the file’s storage cluster on the disk. If you were to upload the same file again, despite it’s contents not changing, Apache would send a different ETag in that case.

# .xhtml files are gzipped html5 documents ready to serve
AddType application/xhtml+xml .xhtml
AddEncoding gzip .xhtml

This creates a new file-type “.xhtml”, and serves it as ‘application/xhtml+xml’ by default. Though it is possible to serve HTML5 as ‘text/html’ in Firefox 3 & Safari, the <legend> tag will not work correctly when used inside a <figure> element. This is due to the all-round broken-ness of the <legend> tag in all browsers (caused by pandering to IE’s even more broken implementation).

The publishing script uses the gzencode PHP function when saving the files to zip the contents for bandwidth-savings and fast delivery. The “AddEncoding” declaration applies this to Apache, adding the necessary “Content-Encoding: gzip;” HTTP-Header automatically.

# load page 1 by deafult
DirectoryIndex 1.xhtml index.php index.html

The home page is just page 1 of however many pages of the full archive of the site. Therefore “1.xhtml” is set as the default page to go to in a folder so that “/art/” returns “/art/1.xhtml”.

# if the url contains the ".xhtml", show the source code
RewriteCond %{THE_REQUEST} \b([^\.]*[^/])\.xhtml\b
RewriteRule ^ - [T=text/plain,L]

Viewing the HTML source of the pages on this site is an integral part of it’s design, so I wanted to make it very easy to do so. Just click the “html” link at the top of any page. The code above checks if the URL typed into the browser had the “.xhtml” included and if so, keeps the URL as is, but serves it as “text/plain” instead, preventing the browser from rendering the HTML.

# leave the ".xhtml" off (clean urls)
RewriteRule ^([^\.]*[^/])$ /$1.xhtml [L]

This finds any URL that has zero or one subfolder, and no dot in the filename. It then rewrites the URL to append “.xhtml” as the actual file to return. This is so “/blog/hello”, secretly returns the file “/blog/hello.xhtml”.

# although I don't support IE, I do have to fall back to text/html,
# otherwise it will try and download the page instead of rendering it
RewriteCond %{HTTP_ACCEPT} !application/xhtml\+xml
RewriteCond %{REQUEST_FILENAME} .*\.xhtml
RewriteRule ^ - [T=text/html,L]

As described, this will check the browser capabilities to see if it does not accept ‘application/xhtml+xml’ and revert to ‘text/html’. If this is not done, IE will try and download the file instead of showing it. In 2008.

Compressed CSS

# "csz" compressed CSS filetype
AddType text/css .csz
AddEncoding gzip .csz

As with the “.xhtml” definition, this creates a “.csz” filetype of mime-type “text/css”, and default gzip (compressed) encoding. The publishing script takes the normal ‘design.css’ file and spins off a compressed copy ‘design.csz’.

# on my localhost, don't use a cached CSS file
RewriteCond %{DOCUMENT_ROOT} "^/Users/kroc/Sites/Camen Design/upload"
RewriteRule ^design/$ /design/design.css [L]
RewriteRule ^design/$ /design/design.csz [L]

When I’m editing the website on my computer, I’m refreshing constantly to see new CSS changes. This code checks if the webroot is that of my Mac’s localhost and passes the standard ‘.css’ file and stops processing. The next line passes the compressed CSS file in the case the document root match was not made (live server).

Compressed RSS

The publishing script creates a compressed ‘rss.rsz’ file in each folder and on root.

AddType application/rss+xml .rsz
AddEncoding gzip .rsz

RewriteRule ^([a-z0-9-]+/)?rss$ /$1.rsz [L]

This redirects URLs ending in “rss” to the compressed “rsz” file. e.g. “/tweet/rss” becomes “/tweet/rss.rsz”.

Static Publishing

When I mentioned my plans for v0.2, I noted one particular fallacy:

A simple text field is never going to replicate the editing power I have with TextMate. I’ve got no search and replace, no syntax highlighting, no keyboard shortcuts.

Trying to add these things is just re-implementing the wheel, and thus breaks my very own design principle №3, Let Everybody Else Do Their Job

Therefore, I removed the administration interface, in favour of a Laguna 2 (sadly offline now) style system.

The publish script is available to view online, but is not much use out of context. You can download a stub copy of this website with everything necessary to roll your own using the enclosure in your RSS reader, or the attachment at the bottom of this article.

Content on Disk

The source content of this website is just a folder, with a sub folder for each of the “content-types” (blog | tweet | photo &c.). In each folder is a file containing a JSON meta-data header and the raw HTML of the article. This layout directly maps to the new clean URLs too.

Creating a new blog post is nothing more than creating a new file. Because content is now disk files, instead of database entries, I can use my text-editor’s global search and replace and HTML editing capabilities and I can use my O.S. to manage the files instead of having to implement more and more server-side administration pages to do the same thing.

Now I can blog the same way I create the stuff I blog about.

Inside a Content Entry

A content file looks like this inside: (this one is for this article)

{	"date"		:	200807101232,
	"updated"	:	200807101232,
	"title"		:	"Under The Hood #3: <br />Using A Quick &amp; Easy SQLite Database",
	"licence"	:	"cc-by",
	"tags"		:	["code-is-art", "web-dev"],
	"enclosure"	:	"sqlite.php"
}

HTML content goes here...

Pretty self-explanatory. When creating a new article, the “date” and “updated” fields are left out, and the publishing script then adds them in automatically. If I want to mark an article as updated, and thus push it to the top of the RSS regardless of it’s original publishing date, I just delete the “updated” line and the publishing script puts in a new timestamp.

The attached zip file is updated every time I publish, so it always contains the most up to date code.

Under the Hood #4:
Getting a File’s Mime-Type From Apache

There is no sane way to get a file’s mime-type in PHP.
The mime_content_type command is depreciated and not installed by default in PHP5.
The FileInfo PECL extension is not installed by default and can be insanely difficult to install.

Thirdly, you can use a Unix call:

$mime_type = exec ("file -i -b '$file_path'");

But that only works on Linux / BSD / Mac systems and not for Windows users, and it also requires that if you’re on a shared webhost that they allow you to use the exec command. This method also doesn’t always give accurate results.

Lastly of course, you could write a simple function to look up a file-extension and return the appropriate mime-type:

function mimeType ($extension) {
	switch ($extension) {
		case 'gif':	return 'image/gif';			break;
		case 'jpg':	return 'image/jpeg';			break;
		case 'png':	return 'image/png';			break;
		case 'pdf':	return 'application/pdf';		break;
		case 'zip':	return 'application/zip';		break;
		case 'exe':	return 'application/octet-stream';	break;
	}
}

But this is hardly automatic, requires constant maintenance when you comes across new types that enter your system and looks plain ugly in your code. It lacks elegance.

I found a cute solution to this problem through looking at the headers returned by Apache. For every file you access, Apache sets various HTTP Headers, here’s an example from a photo.

Date: Sat, 12 Jul 2008 11:24:33 GMT
Server:	Apache/2
Last-Modified: Tue, 17 Jun 2008 13:34:34 GMT
Etag: "2678b24-5edfe-cdfaae80"
Accept-Ranges: bytes
Content-Length: 388606
Content-Type: image/jpeg

And lo, Apache is returning the mime-type automatically for any file-type. Since PHP has the ability to access remote URLs with many of its functions, we could theoretically ask PHP to ping the local file we want to know the mime-type of and retrieve the relevant information from the HTTP headers.

This is indeed possible, the get_headers function will give the HTTP Headers returned from a URL request as an array (if the second parameter is “1”). This function does not work without a full URL (“http://”), and therefore in order to get the mime-type of a local file, it needs to be in a publicly available location (even if only temporarily). You just prepend your domain name to the file path.

Here’s the final example:

$domain = 'http://camendesign.com';
$file_path = 'data/content-media/photo/DSC00013.jpg';

$url_headers = get_headers ("$domain/$file_path", 1);
$mime_type = reset (explode (';', $url_headers['Content-Type']));

echo ($mime_type);

Which correctly outputs:

image/jpeg

Apache sometimes returns a Content-Type value with the character set appended, e.g. “text/html;charset=UTF-8”, so “explode (';', …)” is used to break this apart, and reset returns the first array element.

Limitations

There are a lot of issues with this practice, which is why it is not used on this site:

• On some web hosts, the firewall will prevent the loop-back call of the sever requesting a file on itself via an external route (the full domain URL). This will always work okay on your localhost and may work fine in many environments, but it’s not guaranteed, so always test first. I had to fall back to the stupid look-up function :/
• This introduces lag! Remember that the server is loading an external URL, even if the URL ends up on the same machine. There is inherit lag due to the DNS lookup. Use an IP address if possible, and always cache the result.
  Do not run this code every time a user views a page! Use it once and once only for a file and then save the result somewhere!

Update: Using the ‘mime.types’ File

Hiếu Hoàng writes:

Debian’s default lighttpd.conf executes a
“/usr/share/lighttpd/create-mime.assign.pl” file to get mime-type assignments.
The “/etc/mime.types” which it uses is from the package mime-support.

This would alleviate writing the look-up function.

Sample output:

$ /usr/share/lighttpd/create-mime.assign.pl
mimetype.assign = (
	".ez" => "application/andrew-inset",
	".anx" => "application/annodex",
	".atom" => "application/atom+xml",
	".atomcat" => "application/atomcat+xml",
	".atomsrv" => "application/atomserv+xml",
	[....]
	".avi" => "video/x-msvideo",
	".movie" => "video/x-sgi-movie",
	".mpv" => "video/x-matroska",
	".ice" => "x-conference/x-cooltalk",
	".sisx" => "x-epoc/x-sisx-app",
	".vrm" => "x-world/x-vrml",
)

This file isn’t included in the Mac OS X PHP distribution, but I’ve copied it below with some small modifications (Output a PHP array, and Mac OS X’s ‘mime.types’ file is in ‘/etc/apache2/’ instead of ‘/etc/’).

#!/usr/bin/perl -w
# (I don't know Perl, and how to colour this right)
use strict;
open MIMETYPES, "/etc/apache2/mime.types" or exit;
print "\$mime_types = array (\n";
my %extensions;
while(<MIMETYPES>) {
	chomp;
	s/\#.*//;
	next if /^\w*$/;
	if(/^([a-z0-9\/+-.]+)\s+((?:[a-z0-9.+-]+[ ]?)+)$/) {
		foreach(split / /, $2) {
			# mime.types can have same extension for different
			# mime types
			next if $extensions{$_};
			$extensions{$_} = 1;
			print "\".$_\" => \"$1\",\n";
		}
	}
}
print ");\n";

This could then be used to quickly put together a comprehensive (though massive) look-up function. I’ve saved a copy of the output of this script, enclosed at at the bottom of this article.

The ‘mime.types’ file is interesting as there may be a way to write a real small function (probably regex) to pull out a mime-type on request, which would be a far more elegant (and practical) than my own solution. I’ll have to give that some thought.