Configuring Apache to return CORS headers for Drupal Services

Here's what I did to configure Apache to return the proper CORS headers for my webapp consumption which is written in AngularJS:

Header always set Access-Control-Allow-Origin "*"
Header always set Access-Control-Allow-Methods "GET, POST, OPTIONS"
Header always set Access-Control-Allow-Headers "accept, content-type"
Header always set Access-Control-Allow-Credentials "true"

That can be set in the VirtualHost tags for your server instance. Please note that Access-Control-Allow-Origin value shouldn't be set to * in a production environment. This should only be done for testing environments. The mod_headers module must be enabled in Apache for this configuration to work.

Having these options should be sufficient. But since I'm using Drupal 7 Services, it doesn't play well with pre-flight call which uses HTTP OPTIONS method. Drupal services will return a 404 even if the correct endpoint is specified when OPTIONS method is used.

Here's the additional config using mod_rewrite to return HTTP 200 for all OPTIONS requests:

RewriteEngine On
RewriteCond %{REQUEST_METHOD} OPTIONS
RewriteRule ^(.*)$ $1 [R=200,L,E=HTTP_ORIGIN:%{HTTP:ORIGIN}]]

Resizing images in batch using mogrify

Here's a quick way to resize images via shell using mogrify. It's part of ImageMagick package.

mogrify -resize 60% *.jpg

This will resize all files ending with .jpg extension to 60% of their original size.

We're only scratching the surface of what mogrify can do. Have fun exploring :)

Default Parameter Values in PHP Functions

Here's a neat way to set some default parameter values in a PHP function. This only works if a function param is passed in as associative array.

function create_profile($values) {
  if (!is_array($values)) {
    $values = array();
  }
  
  // Default key/values
  $values += array(
      'uid' => NULL,
      'username' => '',
      'mobile' => '99999999',
      'location' => 'POINT(0 0)',
      'fb_id' => ''
  );
}

The most important line is at line 7; where both arrays are merged. If the key/value pair is in the $values array, it will be ignored; else the default values will be used.

Setting "placeholder" attribute in Drupal 7 form elements

Here's a quick way on how to use HTML5 placeholder attribute in Drupal forms. Example below is altering the login form in a custom theme:

function mytheme_form_alter(&$form, &$form_state, $form_id) {
  if ($form_id == 'user_login') {
    $form['name']['#attributes'] = array('placeholder' => $form['name']['#title']);
    
    $form['pass']['#attributes'] = array('placeholder' => $form['pass']['#title']);
  }
}