actly support SSL connections… directly.

Have no fear! If you are willing to give up a little bit of your own bandwidth, you can work around this problem. We are going to do this using a simple PHP script and if you want to get really fancy, Memcached to keep the redundant API calls to a minimum.

Let’s get started.

First, let’s make sure we understand why it is a problem to include a non-secure Google Charts API into your otherwise secure page. When your users are browsing to your page using an address starting with https://, their browser is going to negotiate an TLS/SSL connection which will encrypt all the data flowing between your client and the server. If any element on the page (image, external CSS or JavaScript, etc.) is not being called from a secured connection as well, then the browser will throw up a warning. Each browser is different, but most will alert the user with a broken lock and/or a popup message. The user can usually accept this warning and proceed at their own risk, but this is not acceptable for a production website or application.

The obvious answer to this problem is to make sure that all external elements on the page are loaded over a secure connection. So – how do we do that with Google Charts? Google does not allow you to just take a traditional API call and slap a “https://” in front of it in lieu of the expected http://. Your request will be denied.

Basic Implementation

Here’s what we do:

1. Create a simple PHP script that will fetch a chart from Google Charts API
2. Change your web page to call the new PHP “fetcher” instead of Google Charts directly.
3. Make sure the PHP script is being called by your page over your https:// connection

It is pretty much that simple.

Here is the before example:

<!-- HTML snippet -->
<img src='http://chart.apis.google.com/chart?cht=p&chd=s:Uf9a&chs=200x100&chl=January|February|March|April' alt='Pie Chart'/>

Here is the after example:

<!-- HTML snippet -->
<img src='https://mywebsite.com/gchart.php?api_url=http%3A%2F%2Fchart.apis.google.com%2Fchart%3Fcht%3Dp%26chd%3Ds%3AUf9a%26chs%3D200x100%26chl%3DJanuary%7CFebruary%7CMarch%7CApril' alt='Pie Chart'/>

Notice, the same API URI is used in the “after” example, but it is URL Encoded. This just makes it safer to pass along to the PHP script.

Here is the PHP script that makes this work:

<?php

$url = urldecode($_GET['api_url']);

$image_contents = file_get_contents($url);
echo $image_contents;
exit;

A quick note about this: you may be saying – where is your closing PHP tag!?! Well, PHP doesn’t require that you have a closing PHP tag, as the PHP interpreter will automatically close any open tags. I do this on just about every file that will be used as an include of some sorts – particularly in something like this where any extra, inadvertent white space at the end of the file can alter the output adversely and cause errors in the page.

Advanced Implementation w/ Caching

The script as it is above, is fine and dandy, but terribly inefficient. You see, every time the user requests the page, your script is going out and using your bandwidth to make the request to the Google Charts API instead of the client. You are becoming the proxy for all requests to and from Google Charts. This will not fly – especially if you are in a high volume environment.

So what is the solution? I chose Memcache to store a copy of the image contents for a certain period of time before having to re-query the Charts API and re-fetch the data again.

It looks something like this:

<?php

$url = urldecode($_GET['api_url']);
$cache_key = md5($url);
$item_cache_expire = 3600;
$mc_host = '127.0.0.1';
$mc_port = 11211;

# Connect to Memcache
$memcache = new Memcache;
$memcache->connect($mc_host, $mc_port) or die ("Could not connect");

if ( $get_result = $memcache->get($cache_key) ) {
    $image_contents = $get_result->chart_image;
}
else {
    $image_contents = file_get_contents($url);

    $tmp_object = new stdClass;
    $tmp_object->chart_image = $image_contents;

    $memcache->set($cache_key, $tmp_object, false, $item_cache_expire) or die ("Failed to save data at the server");

}
echo $image_contents;
exit;

Here’s what is happening.

<?php

$url = urldecode($_GET['api_url']);
$cache_key = md5($url);
$item_cache_expire = 3600;
$mc_host = '127.0.0.1';
$mc_port = 11211;

Setup some variables we’ll need in the script. Grab the api_url value from the GET array, create an MD5 hash of the request URL (we’ll use this as our memcache item key), set the expiration time of the cached item to 3600 seconds (a.k.a. 1 hour) and finally provide the connection information to your memecached server.

# Connect to Memcache
$memcache = new Memcache;
$memcache->connect($mc_host, $mc_port) or die ("Could not connect");

Instantiate a new Memcache object using the connection info provided above.

if ( $get_result = $memcache->get($cache_key) ) {
    $image_contents = $get_result->chart_image;
}
else {
    $image_contents = file_get_contents($url);

    $tmp_object = new stdClass;
    $tmp_object->chart_image = $image_contents;

    $memcache->set($cache_key, $tmp_object, false, $item_cache_expire) or die ("Failed to save data at the server");
}

Using the MD5 hash that we created above, check to see if there is a valid cached object on the memcache server for us to retrieve. If not, go out and grab a fresh version from Google Charts API and stick it into memcache. Either way, we end up with a variable $image_contents which contains the desired chart image.

echo $image_contents;
exit;

All that is left to do now is print out the image contents and exit the script. Again, I do not use a closing PHP tag on purpose to avoid extra whitespace.

All ye, all ye, now hear this…

This is a very basic example. It should probably be categorized more as a proof of concept. It does NOT, I repeat – DOES NOT – take into account a variety of security concerns such as SQL injection or CSRF (cross-site request forgeries), etc. Notice that I didn’t even validate the user input from the GET variable. Who does that!?! So, in other words, don’t just copy and paste and then come back and blame me for getting your site hacked. Be smart about employing something like this.

BTW, if you want to know more about how to make your PHP scripts more secure, go see Chris Shifflet’s excellent blog at http://shiflett.org/.

I recently found myself creating more and more objects to store data within apps. I’m not going to get into all the ins and outs of why this is good practice, but it lead me to whipping up this simple script. I had seen a few other similar tools on the inter-webs but none of them worked quite like I needed.

If you’e not familiar with the OO approach for storing data within a script (is there a better way to describe this?) here the gist.

Say you are storing user profile information in your favorite RDBMS. You have a user profile page and will pull data for a specific profile to use in that page. Well, instead of just doing a fetch and grabbing data – creating a bunch of variables, etc., you can take the OO approach. Load all those vars into an object, with nice features like getters and setters – which may manipulate the data, etc. Then you have a clean interface to the data.

My IDE doesn’t have any wizards for this stuff (I think Eclipse can – or has plugins that can) and it can be a bit time consuming to do. Also – its very repetitive to get your basic class structure together. SO – why not write a little script to do this! Like I said, I have seen some others out there that were apparently written for PHP4 or just didn’t format the methods like I prefer.

Check it out and let me know what you think.
http://webguru.org/getset

The resulting class allows you to do stuff like this:

<?php

// create an array of basic user data
$data = array();
$data["user_id"] = 3;
$data["name"] = "Brian Bell";
$data["email"] = "brian@example.com";

$user = new UserDataObj( $data );
echo "User {$user->get_name()} has an id of {$user->get_id()} and an email address of {$user->get_email()}. ";

/*
  You can also instantiate the object with no argument,
  and set things manually
*/
$user = new UserDataObj();
$user->set_name("Brian Bell");
$user->set_email("brian@example.com");

// also comes in handy to pass the data object to your CrUD methods
$new = new Users();
/*
  pass in the data object from above so
  the create_user() method has everything it needs.
*/
$new->create_user( $user );

?>

Let me know if you have any comments or suggestions. I don’t have a lot of time to contribute to it – but I can easily see how it could be extended to give the user some options on formatting, etc.

This site has popped up with an easy way to search and drill-down into the entire text of the House Stimulus bill. Just take a few minutes and browse through this pork-packet. Unbelievable!!

http://code.google.com/p/phpmultithreadeddaemon/

Here’s their example of how to implement it. Everything needed to run the daemon is in the single included file “class.MTDaemon.php” – cool!

<?php

error_reporting(E_ALL);

require_once(include/class.MTDaemon.php);

class MTTest extends MTDaemon {

public function getNext($slot)
{
$this->lock();
$num = $this->getVar("num");
if ($num == null) $num = 1;
if ($num > 100) {
$this->unlock();
return null;
}
$this->unlock();

$rand = rand(0, 5);
echo "Next for slot " . $slot . " : " . $rand . "\n";
if ($rand == 0) return null;
else return $rand;
}

public function run($next, $slot)
{
$rand = rand(3, 10);
$this->lock();
$num = $this->getVar("num");
$this->setVar("num", $this->getVar("num") + 1);
$this->unlock();
echo "## Iteration #" . number_format($num) . " in " . $rand . "sec" . "\n";

sleep($rand);
return 0;
}

}

$mttest = new MTTest(2);
$mttest->handle();

?>

Bottom line is that nobody is really using Silverlight – besides MS’s attempts to force it down your throat on their own website and through some strategic marketing moves (ie. with NBC Olympics online coverage).  Plus, the sites that do offer streaming media via Silverlight were thankfully not stupid enough to make that your only option.  I haven’t been to a site yet that doesn’t offer me the same feature with Flash Video for example.

Anyway – there is a newer version of Silverlight out -  so when I visit a page that is trying to stream content via the Silverlight plugin, I get this error:

How awesome is that?  Did MS really think I could click the link and get to the update page? No – maybe I was expected remember that URL or write it down so that I could quickly download the newer version and get to my content.

How classic is that?!?!

And so, last Friday, in stumbled Sens. Lindsey Graham, John Thune, Saxby Chambliss, Bob Corker and Johnny Isakson — alongside five Senate Democrats. This “Gang of 10″ announced a “sweeping” and “bipartisan” energy plan to break Washington’s energy “stalemate.” What they did was throw every vulnerable Democrat, and Mr. Obama, a life preserver.

Here are the dirty details from the WSJ.

Way to go Lindz, you really know what the people want.

An example in a MySQL query would be this.

<?php
// build our sql string.
$sql = "SELECT * FROM table WHERE field=%d";
$sqlf = sprintf( $sql, $somevalue );
$db->query($sqlf);
?>

As you can see, you can designate where the substitution will take place in the $sql string. That’s easy. But what happens if you need to use MySQL’s DATE_FORMAT() function? It requires that you pass in arguments to define its output (ie. Day as a word, day as a date, month as a number, etc).

<?php
// build our sql string.
$sql = "SELECT DATE_FORMAT( %b %M %d %Y, some_date_field ) as myDate FROM table WHERE field=%d";
$sqlf = sprintf( $sql, $somevalue );
$db->query($sqlf);
?>

This will fail. sprintf() will complain because you haven’t passed in enough arguments. It is expecting 5 values as part of the call, instead of just the one that you are trying to replace (in the SQL WHERE clause).

So what’s the solution? You have to “comment-out” the % that aren’t part of your sprintf() substitution. You can do this by putting another % in front of the ‘%’ symbols in the DATE_FORMAT() function. This deems them as a literal percent-sign instead of the start of another sprintf() “variable”.

<?php
// build our sql string.
$sql = "SELECT DATE_FORMAT( %%b %%M %%d %%Y, some_date_field ) as myDate FROM table WHERE field=%d";
$sqlf = sprintf( $sql, $somevalue );
$db->query($sqlf);

Hope that helps!

Oh – and it would be helpful for you to know that affectedRows is a method in a database class.

A method, that’s right.  Unfortunately for me, method is not spelled, v-a-r-i-a-b-l-e.

Amazing what two little ( ) can do to your stress level.
if ($this->dbi->affectedRows()>0) {

There are many places on the ‘net that you can find “comparable” batteries for your APC (and other) backup units.  Knowing that my friend Jason replaces battery backups with some frequency, I asked for his opinion.  He led me to Gruber Power Services.  What a find!

The prices are extremely reasonable (e.g. $15.99 for a “RBC2″ comparable battery which is $40 through APC and other sites). You obviously have to pay for shipping these heavy lead-acid batteries, but that is the case with any site from which you order.  Shipping for the entire order ended up being about $100 bucks (ugh!).

All told, I estimate that I saved about $350 (incl. shipping) by ordering from Gruber.  Assuming the rest of my experience matches those of my friend, I highly recommend them.

UPDATE (7/23/08): Got a personal email this morning from “Dawn” thanking me for my order and providing to me the UPS tracking numbers for my shipment.  Pretty cool.

UPDATE (7/30/08): The batteries were delivered Monday, as projected.  I have installed one of them so far and it fit well, connected easily and seems to be a great product.

I’m very interested in where I-540/NC540 will be built (assuming NC comes up with the money, and by that I mean raises taxes, builds toll booths and/or Gov. Mike Easley stops robbing the Highway Trust Fund).  The Southern Wake Expressway and the Eastern Wake Expressway will be a great boon to the area and will make it so much easier to get around the triangle if you live in the increasingly popular corridor between Cary and Fuquay-Varina.  So, I did some searching and found the projected routes on the NC DOT Projects website.

I’ve transferred what I found there on various maps into Google Maps.  The route should be pretty close to what is shown on the planning maps from DOT.  I used the satellite view from Google Maps and my own common sense to determine where certain road and property crossing would take place.  For example, I made the assumption that they would snake the road in and around established neighborhoods.  I could be wrong, but I think it is a pretty close approximation of the anticipated route.

Google Maps allows you to export a custom map into a KMZ file, suitable for viewing in Google Earth.  I am making that file available here as well.