Cake’s Pagination component gives us – almost – everything we need to paginate some Model data: query management, sort functions, number links, etc, everything perfectly tied together.

One thing that I needed and it did miss was the possibility to sort by a custom field (generated via SQL SELECT … AS …). It only allows, at first glance, to sort by table columns and virtual fields.

Take this code as a very basic example:

$this->paginate = array(
 'fields' => array('User.name', 'COUNT(Post.id) as posts_count'),
 'joins' => array(array('table' => 'posts', 'alias' => 'Post', 'type' => 'LEFT', 'conditions' => array('User.id = Post.user_id')))
 );
 $users = $this->paginate('User');

If you wanted to sort by posts_count you have to do a little hack: set posts_count as a virtual field, pointing to itself. Put the following code before the call to paginate():

$this->User->virtualFields = array(
 'posts_count' => 'posts_count',
 );

That’s all!

Here is a command that will save you some time if you have a lot of text files and need to delete all those that contain a particular string:

find . -type f -exec grep -q string {} \; -exec rm {} \;

Just replace “string” with the string you are looking for.

This problem should be pretty rare, but I’m going to share in case someone else is having the same problem:

• the homepage of your wordpress sites returns “Error establishing a database connection”
• it only happens when not logged in (try visiting /wp-login.php)
• you are using W3 Total Cache

In my case, the root cause of the problem was a server migration without copying files I thought were not needed (caches and temp files). I rsynced the whole site excluding “tmp” and “cache” paths, since those are usually regenerated on need. You may experience this problem because of other reasons, but the fix is pretty simple: login to wp-admin and clear all W3 Total Cache caches!

Downloading http auth protected websites using wget is pretty easy, you just add –user and –password parameters to the command:

wget --user=foo --password=bar http://www.protectedwebsite.com

But most of the websites do protect content using a more user friendly html login page, which does not use http authentication, but server side code to check the user credentials against a database or auth server. Continue…

This is probably not a very common issue, but here’s a nice trick to keep the background image of the body element aligned with the page content (instead of window border). You may want to obtain this effect, for example, when using a particular background image which you prefer to show near the border of your main wrapper. Being based on Javascript you should not use this method to provide core functionality to a web page. Continue…

Calculating directory size of directories with plenty of files can be a very long process without the right tools. Some FTP clients perform this job by recursively getting a list of all the files and doing the sum client side. Continue…

Ever wanted to perform a word search inside all the files of a web site or web application ? Maybe to find out which file is calling a particular function or where in the whole project you have hardcoded a domain name. Continue…

Nothing is more frustrating than a PHP’s blank-page-of-death. You don’t know what’s happening and nothing can help you more than the output of a error message!

Here is how to enable output of PHP errors on the page using .htaccess on Apache. Simply create a file called .htaccess in your website directory (if it doesn’t exists) with the following content:

php_flag display_startup_errors on
php_flag display_errors on
php_flag html_errors on

Protecting a directory via HTTP authentication is a simple and fast way to restrict access to a whole directory or a website. If you do not have a control panel like Plesk or Cpanel, but have SSH access to your server, you can enable HTTP authentication using command line. Continue…

As a sequel to the post about multistep forms with CakePHP, I’d like to add a little bit of complexity to that sample. This time we’ll add some dynamically generated fields and, in general, serialized data.

Dynamically generated fields can be used, for example, when the name and type of the fields is not known in advance, and therefore cannot be hardcoded in the script. Another situation where serialized data is a good solution is when you have a form with lots of fields for whose you don’t want/need to create the relative database field. Continue…

In most cases writing less code gives the developer a series of advantages: it’s easier to maintain and extend, easier to read and easier to debug! In this post I’m going to suggest a little CakePHP tip that in the long run will save you a lot of coding.

Some develepers already implement this method, but I think it deserves much wider usage: I’m talking about merging model save and edit in a single controller method. Continue…

One of the features I really love about PHP frameworks is form management. Coding forms in plain PHP can easily become a pain if not well planned out. Multistep forms take this complexity even further, especially when you care about user experience.

In this tutorial you’ll be amazed by how much little code can manage a whole full featured multistep form when taking advantage of CakePHP powerful classes. We’ll build the form in only 60 lines of controller code. Continue…