Craig Koster » Development

Solving Large Scale Web Operations

admin — Wed, 07 Jul 2010 14:12:13 +0000

What is DevOps? – Blog – dev2ops – Solving Large Scale Web Operations and DevOps Problems

DevOps is, in many ways, an umbrella concept that refers to anything that smoothes out the interaction between development and operations. However, the ideas behind DevOps run much deeper than that.

A Beginner’s Guide to Design Patterns

admin — Wed, 07 Jul 2010 14:08:39 +0000

A Beginner’s Guide to Design Patterns | Nettuts+

Design patterns are optimized, reusable solutions to the programming problems that we encounter every day. A design pattern is not a class or a library that we can simply plug into our system; it’s much more than that. It is a template that has to be implemented in the correct situation.

Pretty good article for beginner’s on using design patterns in PHP and how they can make your life easier.

Classic Dilbert

admin — Wed, 01 Jul 2009 22:07:44 +0000

Hilarious Dilbert today. They’re always pretty funny but this one hits home.

Build Your Own Captcha and Contact Form

admin — Wed, 24 Jun 2009 18:30:12 +0000

Build Your Own Captcha and Contact Form

Ever get hit with spam through the contact form on your personal site? Well, here is a short tutorial on how to build a custom captcha to keep the bad guys out.

Nice tutorial on building a contact for with a captcha in PHP.

PHP Authentication / Authorization

admin — Fri, 12 Jun 2009 20:41:33 +0000

One of the big things I needed to do when switching from ASP.NET to PHP was to figure out how to do authentication and authorization. ASP.NET is pretty strong in this area as it’s very easy to set up forms authentication and authorization rules for a site. I found that things weren’t so straightforward with PHP so I took it upon myself to put together a simple example to show how to accomplish this.

The example has a basic premise: we have a log in page and a secured page. The user cannot view the secured page until he authenticates via the log in page. Conversely, the user cannot view the log in page if he has already been authenticated. If he logs out then he will be taken back to the login page.

A working example of this can be found right here. You can also download the code for this example right here. You’ll need a local web server that will run PHP 5 and MySQL.

The example will try to authenticate a user against the database. If the authentication is successful a session key is written and the user is redirected to the secured page. Most of the code is self explanatory but I wanted to highlight the following:

< ?php
 
session_start();
 
//check if person is already logged in and if so redirect to index page
if(isset($_SESSION['email']))
{
	header('Location: login-example-index.php'); 
}
?>

This code is on our log in page. It’s basically checking to see if the person has already authenticated. If so we want to forward them to the secured page.

A similar snippet is on the secured page and it checks to make sure the user has been authenticated. If not it’ll send them back to the login page.

Hope this simple example will help anyone trying to put together some basic authentication. Please note that this is a very simple example and something a little more secure and robust should be used in a production setting that has sensitive data.

Six Useful Tips for Web Designers and Developers

admin — Wed, 10 Jun 2009 14:37:26 +0000

Six Useful Tips for Web Designers and Developers

We’ve compiled six useful tips for all you web designers and developers out there. They cover various topics including: accessibility, SQL, web developer plugins for Firefox, HTML emails, design and jQuery.

Nice compilation of tips here from Think Vitamin. I’m going to check out FirePHP for FireFox PHP debugging. Wish they made the same thing for Safari.

Also a good tip on creating boxes with nice lighting effects via gradients. Going to put this into practice today.

A Showcase of HTML 5 Sites

admin — Mon, 08 Jun 2009 12:47:00 +0000

html5 Gallery

A showcase of sites using html5 markup

Nice compilation of sites that have adopted HTML 5. I haven’t looked at the spec yet but certainly will sometime in the near future. From what I’ve read there are a lot of great new features.

(via www.zeldman.com)

Using AJAX & JSON With PHP

admin — Tue, 02 Jun 2009 19:37:30 +0000

I’ve used AJAX plenty of times before but it’s always been in an ASP.NET setting. I’m starting to do more and more with PHP and one of the first things I tried to figure out was how to incorporate AJAX into my PHP sites. After a quick search, it seemed that the Prototype Javascript framework would be a good candidate to work with. It proved to be a great choice as it was easy to use and well documented.

I’ve created a simple example that shows how to make an AJAX request to a PHP page and return results using the Prototype library. The first step is to download the latest version of Prototype (for this example it’s 1.6.0.3). It should be a single file that you can drop into a directory to use for this tutorial.

Next, create a file named get-person.php in the same directory as the Prototype file you downloaded. Open up your favorite editor and paste the following into the file:

<html>
 
<head>
 
  	<title>PHP / AJAX / JSON / PROTOTYPE</title>
 
  	<script language="javascript" type="text/javascript" src="prototype-1.6.0.3.js"></script>
 
  	<script language="javascript" type="text/javascript">
 
		function getPerson(id, target)
		{
			//create new ajax request from prototype library
			new Ajax.Request("get-person-handler.php", 
			{
				//inline function to handle success
				onSuccess: function(transport) 
				{
					//get json object from transport
					var person = transport.responseJSON;
 
					//use object properties to populate element
					$(target).innerHTML = person.name;
				},
				parameters: { personId: id }
			});
		}
	</script>
 
</head>
 
<body>
 
 	<input type="text" id="id" name="id" style="width:35px;" />
 
 	<input type="button" value="Get Person" onclick="getPerson($('id').value, 'personDisplay');" />
 
	<div id="personDisplay"></div>
 
</body>
 
</html>

This is a simple file that has one Javascript method we’ll use to invoke Prototype’s Ajax object. The Ajax.Request method will send a POST containing an ID to our PHP file and it will handle the request and return a response formatted in JSON.

Create another file in the same directory called get-person-handler.php and drop the following code into it:

< ?php
#this needs to be first!
header('Content-type: application/json');
 
#create array of person objects
$people[1] = 'John Doe';
$people[2] = 'Jane Smith';
$people[3] = 'Steve Johnson';
 
#get the id from the post
$id = $_POST['personId'];
 
//create return array and populate with id and name
$return['id'] = $id;
$return['name'] = $people[$id];
 
#return json string
echo json_encode($return); 
?>

As you can see, this file handles the POST request, get’s the ID from the posted data, looks up the person in the array we’ve created, and returns the data formatted in JSON.

You should be able to load the get-person.php file into your browser, enter an ID (either 1, 2, or 3) into the text box, and click ‘Get Person’ to populate the screen with the person’s name. Note that since these are PHP files, you’ll need a local web server running on your machine.

It’s a pretty simple setup, but I’ve found that you need to start simple when working with new languages and frameworks. The next step might be to create a Person class in PHP and return person objects to the client via JSON. We could also put in some database code to fetch the data from MySQL instead of using our static array.

You can download an archive with the three files in the example by clicking here.

A working example of this tutorial is right here.

Locking Your Desktop

admin — Mon, 01 Jun 2009 22:24:11 +0000

One of the first things I looked for when I switched to Mac was a way to quickly lock my desktop when I stepped away from my desk. Unfortunately I had a hard time finding a solid solution. Through reading various blogs and trying my own things I came up with the following that works pretty well.

The first step is to enable fast user switching in your System Preferences | Accounts panel.

Next, fire up script editor and create the following script:

do shell script "/System/Library/CoreServices/Menu\\ Extras/User.menu/Contents/Resources/CGSession -suspend"

Once you have this entered, save the script to your Applications directory with the name ‘Lock Desktop’ or something similar. Make sure that in the save dialog you select a File Format of ‘Application’ as we’ll be running this script as an app.

Now, just double click this file to lock your desktop. I use LaunchBar on my Mac to launch things and whenever I want to lock my desktop all I have to do is hit the appropriate hot keys and I’m set.

Code Formatter

admin — Mon, 01 Jun 2009 20:14:01 +0000

I’ve been wanting to be able to post code snippets here and have been looking for a good code formatter/highlighter that integrates with Wordpress. I found this plugin that looks like it’ll do the trick nicely.

Here is an example of some PHP

< ?php
/**
 * Front to the WordPress application.
 * wp-blog-header.php which does
 *
 * @package WordPress
 */
 
/**
 * Tells WordPress to load the WordPress
 *
 * @var bool
 */
define('WP_USE_THEMES', true);
 
/** Loads the WordPress Environment and Template */
require('wp-blog-header.php');
?>

Here is some C#

public static SqlConnection GetConnection()
{
    //create connection
    SqlConnection connection = new SqlConnection(DataAccess.ConnectionString);
 
    //open it
    connection.Open();
 
    //send back
    return connection;
}

So far I’ve been pretty pleased with the output that I’ve seen from this plugin. Hopefully this’ll light a fire under me to post more coding examples here.

Update: If you try this plugin stick with version 0.95 as the latest version (0.96) sometimes throws a preg_match() error when you try to format PHP code.