Any programmer has done this one a thousand times. But this one is more fun than I remember this being before.
]]>After that, now that Apple has opened the developer floodgates, it's time to put in some time with my Cocoa for MacOSX book, iphone dev docs, etc, and do some iphone work. I enjoy my own iphone way too much to not develop something for it. Yay open platform! I did a small app for PalmOS ages ago, never even distributed it, but just had to to do it because I loved my palm and there was a decent gcc-based toolchain.
I am planning to upgrade to 3g, despite battery concerns. If necessary, I will disable the 3g except when I expect to be using lots of data. I never had an issue with call quality, and don't talk enough (<100m a month on average) to care. Maybe I can figure out a way to make that hotkeyed in some way. (I'd like to have a handful of settings toggles available when you double-click home when locked, like the ipod controls)
I grabbed a mybat external battery for the iphone. We'll see how that works, but tucked in my laptop bag, hopefully that will be serviceable in the clutch when battery is low and a recharge opportunity is not coming.
]]>Enter Voxel, who offer a $199/mo dedicated server that includes:
That last one is a serious nod to their foresight and a judo chop to other providers. Layered Tech overs a KVM solution as a $30 or $35/day rental. Voxel automatically includes it.
Anyhow, with this beefy box, we set about setting up Xen. Voxel's support was admirable when my initial xen install broke the serial console access. It turned out my /etc/grub.conf needed a change:
title CentOS (2.6.18-53.1.21.el5xen) root (hd0,0) kernel /xen.gz-2.6.18-53.1.21.el5 com1=9600,8n1 module /vmlinuz-2.6.18-53.1.21.el5xen ro root=LABEL=/ console=tty0 console=ttyS0,9600 panic=100 module /initrd-2.6.18-53.1.21.el5xen.img
(Change in bold)
Without the com1= line, it defaulted to 38400.
Anyhow, with that done, I got to work actually setting up Xen virtual server instances. The host box (aka the Dom0) is CentOS, and so the "easy" install should be another instance of virtualized CentOS, although any variant should be usable. I tried to use virt-install, but it failed miserably.
First, I had issues with networking. Even when I resolved those, halfway through anaconda installing packages, the system crashed.
Ultimately, I settled on doing it manually using this guide to installing CentOS DomUs on a CentOS Dom0.
Caveats for me included the fact that my bridge was virbr0 instead of xenbr0. I have a xenbr0, it just wasn't the correct bridge for RFC1918 going out...
Anyhow, aside from the networking problems, that went fairly smoothly. (Although the top of the guide has you selecting from i386 or x86_64, and the kickstart config just says i386, so I had to restart to correct that, since I was doing the x86_64 install.
Still on the agenda: getting a real IP address. Voxel offered a reasonable extra 8 IPs for $4/mo, and we'd like to ensure each VPS has its own IP address, not 192.168 addresses that translate.
Still, this has been a pretty fun thing so far. I've heard that Xen is what Amazon is using to provide AWS, and I've been learning a lot of new linux tools (like brctl; I'd never had a reason to do linux bridging prior to now, even though I've done it plenty with networking devices).
]]>jQuery is the write-once, run-anywhere a new type of javascript library.
It's incredibly full of win. Favorite things in 1.2.6:
I'm working on a brief introductions to jQuery I will post to go over a bunch of basic techniques; things that go a tiny bit beyond the jquery.com documentation usage.
]]>function isajax() { return ((!empty($_SERVER['HTTP_X_REQUESTED_WITH'])) && $_SERVER['HTTP_X_REQUESTED_WITH'] == 'XMLHttpRequest'); }
But what happens when you're using the jQuery Form plugin? Normally, things work fine. Below the cut for a serious caveat!
]]> The jQuery form plugin supports posting uploads. However, when an upload is posted, the form plugin instantiates an iframe and submits that form, since xmlhttprequest can't be encoded for file uploads.Therein lies the problem: that xmlhttprequest header will not be set.
I handled it with a hidden field:
<form method='POST' action='/something.php'> <input type='hidden' name='isajaxrequest' id='isajaxrequest' value='0' /> [...] </form>
Now you have a magic variable to check. Then, in your jquery:
$("#myform").ajaxForm() { [...] beforeSubmit: function (formData, jqForm, options) { $("#isajaxrequest").attr("value", 1); }) [...] }
This way, if your form is submitted via iframe, $_REQUEST['isajaxrequest'] (in php parlance) will be non-zero.
WARNING: the isajaxrequest field will only work as presented here in the iframe; so you still have to test for the server header AND the isajaxrequest variable. Why? Because by the time the form plugin calls beforeSubmit, it has already copied the form into an object which will be used to serialize and submit it, and changes to the form do not propagate. What's interesting is, if you apply ajaxForm to a form with an input type='file', it will only use the iframe if that field is selected. So on the same form, clicking submit with the file selected will use an iframe, but clicking submit when the file field is empty will let it submit over xmlhttprequest.
You *can* still use beforeSubmit to set the field regardless, but you'll have to navigate the formData array, which is an array of js objects, like: [ { "name": "isajaxrequest", "value": "1"}, {"name": "someotherfield", "value": "someothervalue" } ]
Not particularly something you want to iterate through if you can avoid it, although if you're concerned about a proxy stripping the xmlhttprequest header, you may want to do it anyhow.
]]>If you are making a dynamic document, you know that CSS settings are applied as entries are inserted. If you dynamically create a div with class="foo", and you have a ".foo" style defined in your stylesheet(s), then it will inherit it automatically.
If you bind to every class="foo" element on a page at some point (say, with $(".foo").bind() with jquery), then append more elements with that class, they do NOT automatically inherit the event binding.
To get around this shortcoming, you can bind your event handler to a higher level event. I'm going to describe it with jquery. For example, let's assume you want to check for clicks on all divs with a class "foo", and make the background color red.
Here's the 'old' way with jquery:
$(".foo").bind("click", function(e) { $(this).css({'backgroundColor': 'red'}); });
The problem is, if you add a new div into the DOM, it will not have that event binding.
Here's the 'new' way:
$(document.body).bind("click", function(e) { var $target = $(e.target); if ($target.is(".foo")) { $target.css({'backgroundColor': 'red'}); } });
Pretty simple, right? Actually, it is. And it's less code and less of a pain than all the code required to bind new elements coming in most likely. Here's the code at work. Elements with class foo are bound to change bgcolor to red when clicked:
The major problem is events that don't bubble up. The wikipedia entry on DOM events has a nice list of events with their Bubble property - among those that don't bubble up: load, unload, focus (which was the one that prompted me to investigate), blur, DOMNode(RemovedFrom|InsertedInto)Document, rowexit, and others.
Still, this is an awesome technique. The more you make your page dynamic, the more useful it becomes.
]]>
Any programmer has done this one a thousand times. But this one is more fun than I remember this being before.
]]>mysql> create database test;
Query OK, 1 row affected (0.01 sec)mysql> use test;
Database changed
mysql> create table foo (
-> x int,
-> y int
-> );
Query OK, 0 rows affected (0.00 sec)mysql> insert into foo values (1, 2);
Query OK, 1 row affected (0.00 sec)mysql> select * from foo;
+------+------+
| x | y |
+------+------+
| 1 | 2 |
+------+------+
1 row in set (0.00 sec)mysql> update foo set x=5,y=10,x=x+y;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0mysql> select * from foo;
+------+------+
| x | y |
+------+------+
| 15 | 10 |
+------+------+
1 row in set (0.00 sec)mysql>
I bolded the part that bothers me. No warnings. Double-updating the same value in the same row in the same statement throws no warnings (never mind errors!). I haven't checked the ANSI standard to see if this is mentioned, but it sure is worth noting.
]]>But you know what? I want to put up a photo I just blogged. But transferring a photo via anything but email is a pain. Enter perl. I whipped up a perl script to receive iphone photo email, piped via procmail, and save the photo attachment to a path, then email back the phone address with the filename it used. Just make sure you set the path in the script to somewhere down from your DocumentRoot, and then you can immediately reference the photo with an img tag.
Now I can photoblog directly from the phone, which is pretty fun.
Requires
sendmail (for the outbound msg, but I bet you could adapt any other mail program)
perl
MIME::Parser
procmail
Here's the relevent part of my procmail entry (note that photoblog is an alias that goes to my user account via /etc/aliases):
:0H * ^TO.*photoblog@ender.com |/home/matt/iphotoparse.pl
And the code, which you can get here: iphotoparse.pl
Happy photoblogging from the phone.
It's true. I'm one of the converted. (Fallen?)
I definitely like it so far, although I was unimpressed with battery the first day. It really should be engineered to survive one day of hard use. I was charging it until late last night. I watched youtube from it in bed for about 30 minutes, had a total of 14 hrs of standby, and then about 6 or so hours of use (mostly as an ipod, small bit of phone). It died while I was talking to my wife en route home.
Rumor has it that bluetooth, and the "prompt" wlan networks features both suck up a lot of bandwidth, so I may try to keep those off when possible. (I'm going to turn bluetooth off while driving, damnit, but I don't really need it otherwise).
]]>Let's say you have some code. Sloppy, but demonstrative:
<html>
<head>
<script lanugage='Javascript' src='dojo/dojo.js'></script>
<script>
dojo.require("dojo.lang.*");
</script>
</head>
<body>
<div id='output' name='output'></div>
<script language='Javascript'>
function foo() {
var x;
var y;
this.go = function() {document.getElementById('output').innerHTML += 'this.x is ' + this.x + '<br />';}
}
var fooz = new foo;
fooz.x = 5;
document.getElementById('output').innerHTML += 'fooz.x is ' + fooz.x + '<br />';
setTimeout(fooz.go, 300);
</script>
</body>
</html>
What happens when you run it?
fooz.x is 5 this.x is undefined
Javascript objects do not stay instantiated when passed into setTimeout. setTimeout() is unavoidable, but I often find that when implementing behaviors which need objects, you're forced into one of two nasty choices:
Not pretty choices.
But dojo.hang.hitch() solves that problem, gloriously. dojo.lang.hitch lets you attach a function to run IN THE SCOPE of an object.
Let's change the code above:
<html>
<head>
<script lanugage='Javascript' src='dojo/dojo.js'></script>
<script>
dojo.require("dojo.lang.*");
</script>
</head>
<body>
<div id='output' name='output'></div>
<script language='Javascript'>
function foo() {
var x;
var y;
this.go = function() {document.getElementById('output').innerHTML += 'this.x is ' + this.x + '<br />';}
}
var fooz = new foo;
fooz.x = 5;
document.getElementById('output').innerHTML += 'fooz.x is ' + fooz.x + '<br />';
setTimeout(dojo.lang.hitch(fooz, fooz.go), 300);
</script>
</body>
</html>
Output now:
fooz.x is 5
this.x is 5
Beautiful.
What's great is that this lets you run events on things without IDs. I dynamically instantiate a lot of elements in the DOM with document.createElement, and there's often no NEED to assign an id except for issues like this; handling events. Now, with DOJO's hitching, you can deal with your objects while preserving context through setTimeout calls.
Dojo is filled with gems.
Check out the Dojo Homepage and this little into to dojo isn't bad either.
]]>(1) Automated invoicing for monthly payees
(2) UPS automatic price acquisition through their api
Longer term I'm tempted to fiddle with some sort of turbo scaffolding system. I've played a few, like cakephp, but was left wanting. I also want to dig into dojo a bit more, and possibly see what 0.9 has been adding; I like 0.4, but some things I've seen (e.g., drag n drop) are lacking (like with dnd, it uses a nasty black bar for the drop targeting rather than dynamic element repositioning).
]]>You are in a dark, outdoor map.
> GO NORTH
You have been pwned by a grue.
Jeff Bezos
Such an alpha nerd. He's rumored to be a crazed idea guy who can brainstorm up innovation the way most people decide what to have for lunch. The Taco Bell commercials, the bizarre business branches of Amazon, they all just add to the mystique. I just wish he'd fight harder for patent reform.
Mark Cuban
You just have to love Mark Cuban. Fired for closing a sale, relentless entrepreneuer, funds the EFF, looking for disruptive tech all the time... he's awesome. And his irreverent personality is the clincher. More fines than anyone in NBA history? Check. Anything he can't do? I'll leave that box blank.
Richard Branson
You just gotta love it. Self made mania, with little tentacles in so many diverse industries, you have to wonder if his prowess just comes from a deal with the devil. Music, transportation, cell phones, health clubs... this guy is awesome.
Janus Friis, Niklas Zennstrom
First, you make Kazaa. Then, because you can't buy the particular small country you wanted, you make Skype. After pocketing 2.4B from that, you're still thinking: what next? So you start making a P2P TV app. THYS? Bad. Ass. They're like a more commercialized version of Justin Frankel, on crack.
]]>