The widely unused and powerful setAction()

It has been quite a while since I last developed in Cake, but earlier today I spent a good 5+ hours working on some new controller internals for one of my apps. While working on this app, I thought I would give the not so used method, setAction() a spin. If you are unfamiliar with setAction(), it's a method that will internally forward one action to another. This is incredibly useful as it allows you to switch actions without having to do another HTTP request, nor having to reload all the controller and related objects; could be a huge saver on overhead.

Here's a quick example of a regular action:

public function profile($id) {
	$user = $this->User->findById($id);
	if (empty($user)) {
		$this->redirect(array('action' => 'listing'));
	}
	$this->set('user', $user);
}

What the action is doing is relatively simple. First it grabs a user based on an ID, checks to see if the result is empty, if so redirects to the users listing page, else sets the data. You could either redirect the action like I have, or you can simply throw an error message in the view saying something like "No user was found with that ID". I personally prefer redirecting in most cases, but it's a matter of preference. Lets move forward and try setAction() now.

public function profile($id) {
	$user = $this->User->findById($id);
	if (empty($user)) {
		return $this->setAction('listing');
	}
	$this->set('user', $user);
}

As you can see, I simply switched the redirect() with setAction(). Now if we visit a profile with an non-existent user, the listing action will be rendered without having to do another HTTP request. Also, do notice the use of return; this is extremely important because if you do not use return, all the logic after the setAction() will be ran and processed, causing unneeded overhead and unexpected results.

One downside that I have ran into with this approach is that the URL in the address bar does not change. But 99% of the time it won't matter as the page you render in its place will contain links to the correct pages or the user won't be copy and pasting the URL anyways.

Setting up cron jobs with Cake shells

This post will primarily be about the process I had to go through to get cron jobs and shells working on Dreamhost. The main problem I kept running into was that the shells would simply not work at all through a cron job; yet they worked when I manually did it through SSH. The weird thing was the source of the console/cake file was being printed in my logs, instead of executed. Below is a quick checklist of things to look out for:

TERM environment variable not set

This isn't really an error, but the TERM variable is used by the server environment and does not affect the shell, even if the error is thrown. Now I may not know much about server maintenance and configuration, but adding the following code to console/cake seemed to do the trick (Hats off to Matt Curry for the tip). And of course, you should change linux to whatever your server is.

TERM=linux
export TERM
Cron environment not PHP 5

This was a weird problem I ran into. It seemed the environment in which my crons ran was PHP 4, so I was receiving unexpected results and would receive this error (it mainly depends where the php folder is located and if its loaded correctly).

console/cake: line 30: exec: php: not found

To fix this, I had to rewrite the cake console file and update it with the path to the PHP folder (path should represent your servers structure). You should only need to do this if you can't upgrade PHP to 5 for some reason.

exec php -q ${LIB}cake.php -working "${APP}" "$@"
# change to
exec /usr/local/php5/bin/php -q ${LIB}cake.php -working "${APP}" "$@"
Making sure your cron has ownership

A simple problem with a simple fix. Since the user that uploaded the console files was different than the user running the cron, I would receive this error:

sh: cake/console/cake: Permission denied

All I had to do was switch the cron user to the user that owns the file, and it fixed the permissions problem.

Making sure the cake file uses unix line endings

This was another pain in the ass that took me forever to get working. My cron environment would throw this error once I fixed the things above (this applies to my Dreamhost server and may not apply to all).

sh: cake/console/cake: /bin/bash^M: bad interpreter: No such file or directory

It required me contacting my host and asking for help on this one. I tried saving all my files as unix and made sure my FTP was not converting them in any way. Still nothing. So my host told me about this SSH command called dos2unix which would convert the file to unix line endings, and wallah, magic! Everything seemed to be working now.

dos2unix cake/console/cake

These are just a few of the minor setbacks I had to deal with when setting up my cron jobs. Most of this really applies to my Dreamhost server, as my Media Temple server worked right away with no configuration. Furthermore, here are some more Dreamhost articles that I used for this problem, that might be of aid:

Editing Your Environment Profile
Make PHP5 the Default in the Shell