About Chris Morrell

I am a Philadelphia web designer and developer who focuses on PHP development and usable design. I am also the Director of IT for the International Association of Certified Home Inspectors.

Please Note: My site fell victim to a Wordpress security flaw a few weeks ago, and I'm just getting everything back to normal. Please bear with me.

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If you need to get in touch with me, my name is Chris and my domain name is cmorrell.com. Think about it.

Zend Framework Bash Completion Script

Posted by Chris Morrell on March 20th, 2010 in Zend Framework

If you use the Zend Framework CLI interface much you probably find yourself expecting tab-completion to work.  Well, with this bash completion script it will.  Just add the following line to your .bashrc or .bash_profile:

source path/to/zf.bash

Next time you load the terminal, you can type “zf c” and hit TAB twice to see a list of available commands (change, configure and create” or type “zf cr” and hit TAB to have “create” automatically inserted for you.  The script works for both action names and provider names (but not for anything past that).  Eventually I want the script to dynamically load the available commands (so that it works with custom providers and future versions of ZF without updates) but I couldn’t get that working for this version so I just hard coded them.

There’s also a version that completes commands from the Galahad Framework Extension if you’re testing that out…

Zend Framework CLI Bash Completion Script [1.71 KB]

Enjoy!

5 Comments »

Namespacing ACL resources & Galahad_Acl

Posted by Chris Morrell on March 17th, 2010 in Zend Framework (tagged )

In most of my applications I like to handle authorization (querying the ACL) in one (or more) of three ways:

  • Authorize access to a model’s method
  • Authorize access to a controller action
  • Authorize access to an arbitrary “permission”

In general I find it’s best to keep authorization within the domain (querying the ACL within my models when they’re accessed) as this provides the most consistent behavior.  For example, if I eventually add a REST API to my application I don’t have to duplicate all my authorization logic in the new REST controllers.  When the application calls something like Default_Model_Post::save() it either saves or throws an ACL exception, no matter where it was called from.  This is great in that it saves me from having to duplicate code and keeps my system more secure.

On the other hand, there are times when it’s just a lot easier to handle authorization in the controller.  For example, if guests should never access my “Admin” module, it doesn’t make sense to ever let them access /admin/ URLs.  Also, if you’re using Zend_Navigation, having ACL resources that match controller actions lets you utilize its ACL integration.

If you’re ever going to mix these two techniques, you’ll eventually bump into the case where a model and a controller share the same name.  What if you need to set permissions on a “user” controller and different permissions on a “user” model?  This is where namespacing comes into play.  As suggested by the Zend Framework manual, I always name my controller action resources in the format mvc:module.controller.action.  I name my model resources similarly, in the format model:module.modelName.methodName.  In both theses cases, “mvc” and “model” are the namespace, and everything following the colon is the actual resource name.  Now I can refer to my “admin” module as mvc:admin and the models within my admin module as model:admin.

This is where things get interesting.  If you set up your ACL chains correctly, you can set permissions on whole modules or models and have those rules cascade to their child controllers or methods.  For example, say you set up your ACL as follows:

$acl = new Zend_Acl();
$acl->addResource('mvc:');
$acl->addResource('mvc:admin', 'mvc:');
$acl->addResource('mvc:admin.user', 'mvc:admin');
$acl->addResource('mvc:admin.user.create', 'mvc:admin.user');

$acl->addRole('guest');
$acl->addRole('admin', 'guest');

$acl->deny();
$acl->allow('admin', 'mvc:admin');

Now if a user with the role “admin” tries to access the resource “mvc:admin.user.create” (http://basename/admin/user/create) they will be allowed, but a user with the role “guest” will not.  Using this technique gives you as much granularity as you need in your ACL, but at the same time lets you set broad permissions where appropriate.

This is where Galahad_Acl comes into play.  Setting up all these resources can be tedious, as is checking permissions in each controller.  Galahad_Acl in conjunction with Galahad_Model_Entity and Galahad_Controller_Plugin_Acl automate everything but the actual permissions that are specific to your application.

Continue reading “Namespacing ACL resources & Galahad_Acl” »

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Zend Framework URI validator & filter

Posted by Chris Morrell on March 12th, 2010 in Zend Framework

For the last couple of months I’ve been incorporating portions of applications I’m working on into my Galahad Framework Extension project.  Right now it’s not at a point where I’d feel comfortable promoting it (you can check out the project on GitHub if you want), but there are portions that are pretty solid that might be useful to others right now.  Two such portions are Galahad_Validate_Uri and Galahad_Filter_PrependHttp which are both very useful for processing forms with URL fields.

Continue reading “Zend Framework URI validator & filter” »

2 Comments »

More PHP Modeling (w/ video demo)

Posted by Chris Morrell on December 4th, 2009 in Web Development, Zend Framework

[Updated with follow-up video]

About a month ago I posted some ideas about PHP modeling in the Zend Framework and requested feedback. After a month of on-and-off discussions through this website and #zftalk I decided to sit down and implement things a little more.
Continue reading “More PHP Modeling (w/ video demo)” »

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Crazy idea…

Posted by Chris Morrell on November 23rd, 2009 in Web Development

I’ve been toying with the idea of using my cache as a data store for a project where the data doesn’t need to be updated very often.  Basically, I’d write out plain XHTML documents and then parse the data using XPath when needed.  But that’s a different story.  Once I decided to give my idea a try, I started thinking about how to store authentication information.  The application doesn’t store any private information, so authentication is only needed to prove that you are authorized to edit the information.  So why not store the authentication information publicly as well (as an HTML comment at the top of the file)?  Here’s what I was thinking, in pseudo code:

identity = base64(encrypt_rijndael256([
	sha512_hmac(username, appUsernameSecret),
	sha512_hmac(password, appPasswordSecret)
], appSecret))

This would produce an base64 representation of an encrypted array of hashes.  Basically, the system would produce two hashes using HMAC and two separate secret keys (one for the username hash and one for the password hash).  It would store that data in a way that it could later retrieve it (in my case a serialized array) and then encrypt the whole thing with a third key (the base64 is just so it could easily be represented by an ASCII string).  That way there are multiple points of failure.  An attacker would have to know all three keys just to get at the hashes, but then that’s all they’d have.  They’d still need to brute force both the username and password separately.  It seems to me that this would be pretty darn secure.  Clearly not good enough for a bank, but certainly fine for a web app that would have very few negative consequences if it were broken into.

I would love feedback from someone who know’s what they’re talking about :)   Below is some working PHP code to illustrate my point:

Continue reading “Crazy idea…” »

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Calculating the difference in days between two Zend_Date objects

Posted by Chris Morrell on November 18th, 2009 in Web Development, Zend Framework (tagged , , )

This just came up on #zftalk, and it appears that the information out there is either incomplete or incorrect, so I thought I’d just put out a simple solution.  Here’s a simple way to calculate the difference between two Zend_Date objects (in days):

$jan1 = new Zend_Date('1.12.2009', Zend_Date::DATES);
echo "\nJanuary first: ", $jan1->toString();

$christmas = new Zend_Date('25.12.2009', Zend_Date::DATES);
echo "\nChristmas is on: ", $christmas->toString();

$diff = $christmas->sub($jan1);
echo "\nNumber of days: ", $diff / 60 / 60 / 24;

1 Comment »

PHP Modeling (in Zend Framework)

Posted by Chris Morrell on November 5th, 2009 in Web Development, Zend Framework (tagged , , , , )

I’ve been thinking a lot about Modeling in a MVC application, particularly in the Zend Framework. Obviously each application is different, and any Model is going to be fairly unique to your application. That’s why ZF doesn’t provide a base Model class. That said, there are some design patterns that a lot of people are using nowadays, and applications could use some base functionality to facilitate those patterns.

Zend Framework’s project lead, Matthew Weier O’Phinney, has a lot of great thoughts about Modeling that I’ve been trying to stick to. In implementing those ideas, I’ve started thinking out some base classes to build my Models on top of. Obviously these classes won’t work for everyone. But they should work for a lot of “typical” web applications.

Continue reading “PHP Modeling (in Zend Framework)” »

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Better short URLs

Posted by Chris Morrell on September 8th, 2009 in Web Development

Recently a bunch of people have been proposing ways to produce short URLs without relying on 3rd parties (tr.im nearly shutting down definitely hit home the need for this discussion).  One option was the rev=”canonical” attribute.  Others have been various rel values.  I like what PHP.net has done—just combine them all and see which one wins out:

<link rev="canonical" rel="self alternate shorter shorturl shortlink" href="..." />

I haven’t yet implemented my own short URLs, but when I do I think that the way I’ll go.

2 Comments »

Ethical Autoplay?

Posted by Chris Morrell on August 12th, 2009 in Web Development

I’ve been thinking a lot lately about how to most effectively use video as an online sales tool, and it seems to me that auto starting a video can be a power conversion tool. The problem is, it also can be really (really!) annoying to some (or many) of your users. Like most things, I think that your target audience should guide your decision about autoplay, but if you do decide to use it (or at least to test it) how can you avoid some of the pitfalls? I have a few ideas that I’ve been playing with and I shot a real quick video to demo them. Let me know what you think, and also if you see any other potential problems/solutions.

7 Comments »

Zend Framework: Using separate layouts per module

Posted by Chris Morrell on July 10th, 2009 in Zend Framework

Someone was recently asking on ZFTalk about how to use a different layout for each module in your application. Since this is a problem I’ve dealt with in the past and planned on adding to the Galahad FE, I thought I’d quickly write up a tutorial on how to do it:

First, download the Plugin

Put the following class in a library/Galahad/Controller/Plugin/Modularlayout.php file (you’ll probably have to create all those directories and the file).

<?php
/**
* This file is part of the Galahad Framework Extension.
*
* The Galahad Framework Extension is free software: you can redistribute
* it and/or modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* The Galahad Framework Extension is distributed in the hope that it will
* be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
* General Public License for more details.
*
* @category  Galahad
* @package   Galahad
* @copyright Copyright (c) 2009 Chris Morrell <http://cmorrell.com>
* @license   GPL <http://www.gnu.org/licenses/>
* @version   0.2
*/

/**
* Use separate layout per module
*
* @category   Galahad
* @package    Galahad
* @copyright  Copyright (c) 2009 Chris Morrell <http://cmorrell.com>
* @license    GPL <http://www.gnu.org/licenses/>
*/
class Galahad_Controller_Plugin_Modularlayout extends Zend_Controller_Plugin_Abstract
{
     public function routeShutdown(Zend_Controller_Request_Abstract $request)
     {
          Zend_Layout::getMvcInstance()->setLayout($request->getModuleName());
     }
}

Next, add the Galahad namespace

Update your Bootstrap.php file’s autoloader initialization method (if you don’t have one, add one):

protected function _initAutoloaders()
{
	$this->getApplication()->setAutoloaderNamespaces(array('Galahad_'));
	return $this;
}

Please note: You might need to have other namespaces in there, like My_ or App_ or Default_.

Next, add the Plugin

Update your Bootstrap.php file’s plugin initialization method (if you don’t have one, add one):

protected function _initPlugins()
{
	$this->bootstrap('autoloaders');
	$this->bootstrap('frontController');

	$plugin = new Galahad_Controller_Plugin_Modularlayout();
        $this->frontController->registerPlugin($plugin);
}

And you’re set!

Just make sure you have a layout file in your layouts directory for each module (modulename.phtml).

7 Comments »

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