Apple's iPhone 5s dock

▼ When the iPhone 5 was released last year, Apple didn't bother with any cases or docks. Third parties certainly addressed the lack of cases, but as far as I can tell, there were never any good docks. But now there's the iPhone 5s dock, which is also compatible with the iPhone 5. So I got on my bicycle and went to the nearest Apple Store to get one. Read on to see if it was worth € 29 and cycling 63 km.

The dock comes in a very small box:

Unlike the iPhone 3G dock I had years ago, there are no holes in the bottom to guide audio in and out. But with the iPhone 5 in place, there's a little bit of room left in front of the iPhone, which is enough to get audio out without issues, and the microphone still picks up enough of my voice for Siri to work.

The dock is fairly small, and not particularly heavy, but sturdy enough to make sure the iPhone stands up relatively securely. The rubbery underside provides a good amount of grip on most surfaces. The lightning connector is looser than the one on the cable that comes with the iPhone 5, so it's easy enough to insert the phone, and not too hard to get it out with one hand.

Speaking of audio, there's a line out port in the back:

What's really nice is that the iPhone detects whether there's a cable inserted in the 3.5 mm jack. If so, it sends most audio (not phone calls, though) out through that port, but if there's nothing connected, it uses the built-in speaker.

There's a lightning receptacle on the back of the dock, which you can use to connect the docked iPhone to a computer for charging and syncing, or to a charger for charging. A charger or cable are not included.

The main reason I got the dock is because I don't want my iPhone to slide around on and fall off of tables and break or even just get scratched for that matter. The dock also allows you to read notifications as they come in, and use a nice clock app, such as Analog Digital Clock or LlamaClock (displayed).

(With power connected, the screen will stay on if an app is running in the foreground.)

The only downside of the dock is that getting at the home button is a bit harder. Or maybe I just have fat fingers. It would be great to have a dock that also works in landscape, though, for things like watching video.

Note that in addition to the iPhone 5s dock, which is compatible with the iPhone 5, there's also an iPhone 5c dock.

Permalink - posted 2013-09-22

Caching PHP-generated pages

▼ For years, I always used to include an If-Modified-Since header in my PHP scripts in order to allow their output to be cached by web brow­sers. Turns out, it takes a bit more work.

The idea is that the HTTP server tells browsers when the page was last modified when browsers request a page. Then, when they request the same page again later, the browser can say "only send me the page if it's been modified since <date>". If the page has been changed since <date> the server sends over the page. If the page is still the same, it just sends a 304 response code, "Not Modified". The browser then displays the page from its cache.

(If the browser doesn't supply an If-Modified-Since date, the page is always sent.)

The Apache HTTP server can handle all of this for HTML and other static files. But PHP scripts generate output on the fly, so the concept of a last modified date doesn't really apply, so PHP-generated pages are always sent, even if they are the same as during an earlier visit.

Of course many PHP scripts generate output based on what's in a database, and as long as the contents of that database don't change, there's really no need to run the script again. But the script itself has to be smart enough to handle this. I had a look at this page and then came up with the following.

First, we determine what the last modified date should be: the last time the script itself was changed, or the last time the database was changed, whichever was more recent:

<? $mtime = getlastmod(); $result = mysql("mydb", "select max(unix_timestamp(createts)) as uts from mydb") if ($row = mysql_fetch_array($result) && $row[uts] > $mtime) $mtime = $row[uts];

Then, we check against the If-Modified-Since header supplied by the browser. If the our last modified date is older or the same as the browser's, we send the Not Modified response and call it a day.

$htime = strtotime($HTTP_IF_MODIFIED_SINCE); if ($htime && $mtime <= $htime) { header("HTTP/1.0 304 Not Modified"); exit(); }

(Of course there's some more error checking here and there.)

If the script is still running, the browser had an old version of the page so we're going to send over the latest version. Before we do that, we generate a Last-Modified date so the browser knows what to say in its If-Modified-Since header the next time.

header("Last-Modified: " . date("r", $mtime));

In Safari, it looks like entering a URL in the URL/search bar doesn't use If-Modified-Since, but clicking on a link does. This is now a good deal faster for me. It should help even more for people on slow links or far away from the server.

Permalink - posted 2013-07-18