Simon Willison's Weblog: charles-miller

Quoting Charles Miller

2009-09-23T15:08:18+00:00

Ask browser users, and they'll tell you the overwhelming reason why they can't upgrade to a more modern, standards-compliant browser is because their work won't let them. Ask IT departments why this is the case and they'll point to the six- to seven-figure costs of upgrading turn-of-the-century Intranets written to work in, and only in, Internet Explorer 6. Google have provided a way for websites to opt out of IE6 (and even IE7) support without requiring enterprise-wide, Intranet-breaking browser upgrades.

— Charles Miller

Tags: charles-miller, chrome, chromeframe, google, ie6, internet-explorer

And so it goes, around again

2009-09-03T09:46:33+00:00

And so it goes, around again

Charles Miller on Java, pointing out that if you don’t have closures and first-class functions you end up having to add band-aid solutions and special case syntactic sugar. Python’s lack of multi-line lambdas leads to a similar (though less pronounced) effect.

Tags: charles-miller, closures, java, programming-languages, python

Cluetrainwreck

2008-04-19T08:00:16+00:00

Cluetrainwreck

Comcast’s official Twitter account is pretty creepy... “I hope we can change your perception of Comcast!”.

Tags: charles-miller, cluetrain, comcast, pr, twitter

Heavier than Air

2008-01-22T01:32:59+00:00

Heavier than Air

Charles Miller points out that every time Apple breaks the mold with a new product (the iPod, the iPod Mini, the iMac and now the MacBook Air) they lose in feature matrix comparisons but win in the marketplace.

Tags: apple, charles-miller, imac, ipod, ipodmini, macbookair

Maven: Broken By Design

2007-12-20T20:24:25+00:00

Maven: Broken By Design

Charles Miller: “If you check out a particular version of your code and build it with particular versions of your tools, you should get a product that is binary-identical each time.”

Tags: buildtools, charles-miller, java, maven

Understanding Engineers: Feasibility

2007-07-17T10:24:09+00:00

Understanding Engineers: Feasibility

Charles Miller provides smart definitions of what programmers mean when they say “impossible”, “trivial”, “unfeasible”, “non-trivial”, “hard” and “very hard”.

Tags: charles-miller, hard, language, nontrivial, programmers, programming, trivial, unfeasible, veryhard

Quoting Charles Miller

2007-07-12T17:18:42+00:00

... if you're in an email conversation with one other person and you're both using Gmail, don't bother quoting at all.

— Charles Miller

Tags: charles-miller, email

Avoiding protracted debates

2004-03-21T04:48:25+00:00

I love Charles Miller's Fishbowl. His latest entry introduces his rules for argument. Read them, follow them and save a truck-load of time avoiding protracted debates in the future. Heck, if everyone stuck to them the overall productivity of the internet would probably increase by a factor of ten.

Tags: charles-miller

Un-happened

2003-11-27T16:21:12+00:00

Charles Miller, in Google, Microsoft and Tall Poppies.:

Bill Gates' original goal in forming Microsoft was famously to have (emphasis mine) "A computer on every desk and in every home, running Microsoft software". You'll not find the last three words of that sentence in any official Microsoft history (or at least I couldn't, and I searched hard). They've been carefully un-happened: the dream of a nascent monopolist truncated into a facade of altruism.

Google:

"desk and in every home" site:microsoft.com -"every home running" - 167 results
"desk and in every home running" site:microsoft.com - 3 results, all from a Bill Gates speech at Stanford in 2002.

Fascinating.

Tags: charles-miller, computer-history, microsoft

Supporting Conditional GET in PHP

2003-04-23T17:22:50+00:00

This site's RSS feeds now support Conditional GET. Since the feeds are dynamically generated on every request, adding support took a bit of hacking around with PHP. Here's the function I came up with (based on the excellent description provided by Charles Miller in the article linked above):

function doConditionalGet($timestamp) {
    // A PHP implementation of conditional get, see 
    //   https://fishbowl.pastiche.org/2002/10/21/http_conditional_get_for_rss_hackers
    $last_modified = substr(date('r', $timestamp), 0, -5).'GMT';
    $etag = '"'.md5($last_modified).'"';
    // Send the headers
    header("Last-Modified: $last_modified");
    header("ETag: $etag");
    // See if the client has provided the required headers
    $if_modified_since = isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) ?
        stripslashes($_SERVER['HTTP_IF_MODIFIED_SINCE']) :
        false;
    $if_none_match = isset($_SERVER['HTTP_IF_NONE_MATCH']) ?
        stripslashes($_SERVER['HTTP_IF_NONE_MATCH']) : 
        false;
    if (!$if_modified_since && !$if_none_match) {
        return;
    }
    // At least one of the headers is there - check them
    if ($if_none_match && $if_none_match != $etag) {
        return; // etag is there but doesn't match
    }
    if ($if_modified_since && $if_modified_since != $last_modified) {
        return; // if-modified-since is there but doesn't match
    }
    // Nothing has changed since their last request - serve a 304 and exit
    header('HTTP/1.0 304 Not Modified');
    exit;
}

Usage is simple: Work out the timestamp that the page content was last modified and call doConditionalGet($timestamp);. It will send the 304 header for you and exit if the client claims to have seen the content already - otherwise control will return to your main script and you can serve content as normal. Slightly inelegant, but it does the job.

Unfortunately I don't have a Conditional-GET supporting RSS aggregator to hand so I have no idea if it works or not (so far I've only tested it by watching the headers sent with LiveHTTPHeaders). I'd be grateful if someone could confirm that this has had the desired effect.

Update: I've changed the above code sample (and my implementation) to send the ETag header as ETag rather than etag.

Tags: charles-miller, etags, php, rss